Merge "VR: Move VR HWC DVR API to libdvr" into oc-dev
diff --git a/libs/vr/libpdx/client.cpp b/libs/vr/libpdx/client.cpp
index c318628..bfa2d87 100644
--- a/libs/vr/libpdx/client.cpp
+++ b/libs/vr/libpdx/client.cpp
@@ -4,7 +4,6 @@
 #include <log/log.h>
 
 #include <pdx/trace.h>
-#include "errno_guard.h"
 
 namespace android {
 namespace pdx {
@@ -84,7 +83,6 @@
 
 Status<void> Client::SendImpulse(int opcode) {
   PDX_TRACE_NAME("Client::SendImpulse");
-  ErrnoGuard errno_guard;
 
   auto status = CheckReconnect();
   if (!status)
@@ -98,7 +96,6 @@
 Status<void> Client::SendImpulse(int opcode, const void* buffer,
                                  size_t length) {
   PDX_TRACE_NAME("Client::SendImpulse");
-  ErrnoGuard errno_guard;
 
   auto status = CheckReconnect();
   if (!status)
@@ -110,7 +107,6 @@
 }
 
 void Client::Close(int error) {
-  ErrnoGuard errno_guard;
   channel_.reset();
   // Normalize error codes to negative integer space.
   error_ = error <= 0 ? error : -error;
@@ -228,37 +224,38 @@
   CheckDisconnect(*ret);
 }
 
-FileReference Transaction::PushFileHandle(const LocalHandle& handle) {
-  return client_.CheckReconnect() && EnsureStateAllocated()
-             ? client_.GetChannel()->PushFileHandle(state_, handle)
-             : -1;
+Status<FileReference> Transaction::PushFileHandle(const LocalHandle& handle) {
+  if (client_.CheckReconnect() && EnsureStateAllocated())
+    return client_.GetChannel()->PushFileHandle(state_, handle);
+  return ErrorStatus{ESHUTDOWN};
 }
 
-FileReference Transaction::PushFileHandle(const BorrowedHandle& handle) {
-  return client_.CheckReconnect() && EnsureStateAllocated()
-             ? client_.GetChannel()->PushFileHandle(state_, handle)
-             : -1;
+Status<FileReference> Transaction::PushFileHandle(
+    const BorrowedHandle& handle) {
+  if (client_.CheckReconnect() && EnsureStateAllocated())
+    return client_.GetChannel()->PushFileHandle(state_, handle);
+  return ErrorStatus{ESHUTDOWN};
 }
 
-FileReference Transaction::PushFileHandle(const RemoteHandle& handle) {
+Status<FileReference> Transaction::PushFileHandle(const RemoteHandle& handle) {
   return handle.Get();
 }
 
-ChannelReference Transaction::PushChannelHandle(
+Status<ChannelReference> Transaction::PushChannelHandle(
     const LocalChannelHandle& handle) {
-  return client_.CheckReconnect() && EnsureStateAllocated()
-             ? client_.GetChannel()->PushChannelHandle(state_, handle)
-             : -1;
+  if (client_.CheckReconnect() && EnsureStateAllocated())
+    return client_.GetChannel()->PushChannelHandle(state_, handle);
+  return ErrorStatus{ESHUTDOWN};
 }
 
-ChannelReference Transaction::PushChannelHandle(
+Status<ChannelReference> Transaction::PushChannelHandle(
     const BorrowedChannelHandle& handle) {
-  return client_.CheckReconnect() && EnsureStateAllocated()
-             ? client_.GetChannel()->PushChannelHandle(state_, handle)
-             : -1;
+  if (client_.CheckReconnect() && EnsureStateAllocated())
+    return client_.GetChannel()->PushChannelHandle(state_, handle);
+  return ErrorStatus{ESHUTDOWN};
 }
 
-ChannelReference Transaction::PushChannelHandle(
+Status<ChannelReference> Transaction::PushChannelHandle(
     const RemoteChannelHandle& handle) {
   return handle.value();
 }
diff --git a/libs/vr/libpdx/client_tests.cpp b/libs/vr/libpdx/client_tests.cpp
index f1fb6d1..99ccc69 100644
--- a/libs/vr/libpdx/client_tests.cpp
+++ b/libs/vr/libpdx/client_tests.cpp
@@ -518,28 +518,29 @@
   EXPECT_CALL(*mock_channel(),
               PushFileHandle(kTransactionState, A<const LocalHandle&>()))
       .WillOnce(Return(1));
-  EXPECT_EQ(1, transaction_.PushFileHandle(LocalHandle{-1}));
+  EXPECT_EQ(1, transaction_.PushFileHandle(LocalHandle{-1}).get());
 
   EXPECT_CALL(*mock_channel(),
               PushFileHandle(kTransactionState, A<const BorrowedHandle&>()))
       .WillOnce(Return(2));
-  EXPECT_EQ(2, transaction_.PushFileHandle(BorrowedHandle{-1}));
+  EXPECT_EQ(2, transaction_.PushFileHandle(BorrowedHandle{-1}).get());
 
-  EXPECT_EQ(3, transaction_.PushFileHandle(RemoteHandle{3}));
+  EXPECT_EQ(3, transaction_.PushFileHandle(RemoteHandle{3}).get());
 
   EXPECT_CALL(
       *mock_channel(),
       PushChannelHandle(kTransactionState, A<const LocalChannelHandle&>()))
       .WillOnce(Return(11));
-  EXPECT_EQ(11, transaction_.PushChannelHandle(LocalChannelHandle{nullptr, 1}));
+  EXPECT_EQ(
+      11, transaction_.PushChannelHandle(LocalChannelHandle{nullptr, 1}).get());
 
   EXPECT_CALL(
       *mock_channel(),
       PushChannelHandle(kTransactionState, A<const BorrowedChannelHandle&>()))
       .WillOnce(Return(12));
-  EXPECT_EQ(12, transaction_.PushChannelHandle(BorrowedChannelHandle{2}));
+  EXPECT_EQ(12, transaction_.PushChannelHandle(BorrowedChannelHandle{2}).get());
 
-  EXPECT_EQ(13, transaction_.PushChannelHandle(RemoteChannelHandle{13}));
+  EXPECT_EQ(13, transaction_.PushChannelHandle(RemoteChannelHandle{13}).get());
 }
 
 TEST_F(ClientTransactionTest, GetHandle) {
diff --git a/libs/vr/libpdx/errno_guard.h b/libs/vr/libpdx/errno_guard.h
deleted file mode 100644
index fc7dfdf..0000000
--- a/libs/vr/libpdx/errno_guard.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#ifndef ANDROID_PDX_ERRNO_GUARD_H_
-#define ANDROID_PDX_ERRNO_GUARD_H_
-
-#include <errno.h>
-
-namespace android {
-namespace pdx {
-
-// Automatically saves and restores the system errno for API implementations to
-// prevent internal use errno from affecting API callers.
-class ErrnoGuard {
- public:
-  ErrnoGuard() : saved_errno_(errno) {}
-  ~ErrnoGuard() { errno = saved_errno_; }
-
-  int saved_errno() const { return saved_errno_; }
-
- private:
-  int saved_errno_;
-
-  ErrnoGuard(const ErrnoGuard&) = delete;
-  void operator=(const ErrnoGuard&) = delete;
-};
-
-// Checks |return_code| and returns either it or the negated system errno based
-// on the return code value.
-inline int ReturnCodeOrError(int return_code) {
-  return return_code < 0 ? -errno : return_code;
-}
-
-}  // namespace pdx
-}  // namespace android
-
-#endif  // ANDROID_PDX_ERRNO_GUARD_H_
diff --git a/libs/vr/libpdx/private/pdx/client.h b/libs/vr/libpdx/private/pdx/client.h
index a590087..656de7e 100644
--- a/libs/vr/libpdx/private/pdx/client.h
+++ b/libs/vr/libpdx/private/pdx/client.h
@@ -253,13 +253,14 @@
   }
 
   // OutputResourceMapper
-  FileReference PushFileHandle(const LocalHandle& handle) override;
-  FileReference PushFileHandle(const BorrowedHandle& handle) override;
-  FileReference PushFileHandle(const RemoteHandle& handle) override;
-  ChannelReference PushChannelHandle(const LocalChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<FileReference> PushFileHandle(const LocalHandle& handle) override;
+  Status<FileReference> PushFileHandle(const BorrowedHandle& handle) override;
+  Status<FileReference> PushFileHandle(const RemoteHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
+      const LocalChannelHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) override;
 
   // InputResourceMapper
diff --git a/libs/vr/libpdx/private/pdx/message_writer.h b/libs/vr/libpdx/private/pdx/message_writer.h
index 0cb6e40..4a101d6 100644
--- a/libs/vr/libpdx/private/pdx/message_writer.h
+++ b/libs/vr/libpdx/private/pdx/message_writer.h
@@ -3,20 +3,22 @@
 
 #include <pdx/channel_handle.h>
 #include <pdx/file_handle.h>
+#include <pdx/status.h>
 
 namespace android {
 namespace pdx {
 
 class OutputResourceMapper {
  public:
-  virtual FileReference PushFileHandle(const LocalHandle& handle) = 0;
-  virtual FileReference PushFileHandle(const BorrowedHandle& handle) = 0;
-  virtual FileReference PushFileHandle(const RemoteHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<FileReference> PushFileHandle(const LocalHandle& handle) = 0;
+  virtual Status<FileReference> PushFileHandle(
+      const BorrowedHandle& handle) = 0;
+  virtual Status<FileReference> PushFileHandle(const RemoteHandle& handle) = 0;
+  virtual Status<ChannelReference> PushChannelHandle(
       const LocalChannelHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) = 0;
 
  protected:
diff --git a/libs/vr/libpdx/private/pdx/mock_message_writer.h b/libs/vr/libpdx/private/pdx/mock_message_writer.h
index 3c513d7..e06e5bb 100644
--- a/libs/vr/libpdx/private/pdx/mock_message_writer.h
+++ b/libs/vr/libpdx/private/pdx/mock_message_writer.h
@@ -9,15 +9,18 @@
 
 class MockOutputResourceMapper : public OutputResourceMapper {
  public:
-  MOCK_METHOD1(PushFileHandle, FileReference(const LocalHandle& handle));
-  MOCK_METHOD1(PushFileHandle, FileReference(const BorrowedHandle& handle));
-  MOCK_METHOD1(PushFileHandle, FileReference(const RemoteHandle& handle));
+  MOCK_METHOD1(PushFileHandle,
+               Status<FileReference>(const LocalHandle& handle));
+  MOCK_METHOD1(PushFileHandle,
+               Status<FileReference>(const BorrowedHandle& handle));
+  MOCK_METHOD1(PushFileHandle,
+               Status<FileReference>(const RemoteHandle& handle));
   MOCK_METHOD1(PushChannelHandle,
-               ChannelReference(const LocalChannelHandle& handle));
+               Status<ChannelReference>(const LocalChannelHandle& handle));
   MOCK_METHOD1(PushChannelHandle,
-               ChannelReference(const BorrowedChannelHandle& handle));
+               Status<ChannelReference>(const BorrowedChannelHandle& handle));
   MOCK_METHOD1(PushChannelHandle,
-               ChannelReference(const RemoteChannelHandle& handle));
+               Status<ChannelReference>(const RemoteChannelHandle& handle));
 };
 
 class MockMessageWriter : public MessageWriter {
diff --git a/libs/vr/libpdx/private/pdx/mock_service_endpoint.h b/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
index ead74d5..e741d4a 100644
--- a/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
+++ b/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
@@ -10,46 +10,54 @@
 class MockEndpoint : public Endpoint {
  public:
   MOCK_CONST_METHOD0(GetIpcTag, uint32_t());
-  MOCK_METHOD1(SetService, int(Service* service));
-  MOCK_METHOD2(SetChannel, int(int channel_id, Channel* channel));
-  MOCK_METHOD1(CloseChannel, int(int channel_id));
+  MOCK_METHOD1(SetService, Status<void>(Service* service));
+  MOCK_METHOD2(SetChannel, Status<void>(int channel_id, Channel* channel));
+  MOCK_METHOD1(CloseChannel, Status<void>(int channel_id));
   MOCK_METHOD3(ModifyChannelEvents,
-               int(int channel_id, int clear_mask, int set_mask));
+               Status<void>(int channel_id, int clear_mask, int set_mask));
   MOCK_METHOD4(PushChannel,
                Status<RemoteChannelHandle>(Message* message, int flags,
                                            Channel* channel, int* channel_id));
   MOCK_METHOD3(CheckChannel,
                Status<int>(const Message* message, ChannelReference ref,
                            Channel** channel));
-  MOCK_METHOD1(DefaultHandleMessage, int(const MessageInfo& info));
-  MOCK_METHOD1(MessageReceive, int(Message* message));
-  MOCK_METHOD2(MessageReply, int(Message* message, int return_code));
-  MOCK_METHOD2(MessageReplyFd, int(Message* message, unsigned int push_fd));
+  MOCK_METHOD1(MessageReceive, Status<void>(Message* message));
+  MOCK_METHOD2(MessageReply, Status<void>(Message* message, int return_code));
+  MOCK_METHOD2(MessageReplyFd,
+               Status<void>(Message* message, unsigned int push_fd));
   MOCK_METHOD2(MessageReplyChannelHandle,
-               int(Message* message, const LocalChannelHandle& handle));
+               Status<void>(Message* message,
+                            const LocalChannelHandle& handle));
   MOCK_METHOD2(MessageReplyChannelHandle,
-               int(Message* message, const BorrowedChannelHandle& handle));
+               Status<void>(Message* message,
+                            const BorrowedChannelHandle& handle));
   MOCK_METHOD2(MessageReplyChannelHandle,
-               int(Message* message, const RemoteChannelHandle& handle));
-  MOCK_METHOD3(ReadMessageData, ssize_t(Message* message, const iovec* vector,
-                                        size_t vector_length));
-  MOCK_METHOD3(WriteMessageData, ssize_t(Message* message, const iovec* vector,
-                                         size_t vector_length));
+               Status<void>(Message* message,
+                            const RemoteChannelHandle& handle));
+  MOCK_METHOD3(ReadMessageData,
+               Status<size_t>(Message* message, const iovec* vector,
+                              size_t vector_length));
+  MOCK_METHOD3(WriteMessageData,
+               Status<size_t>(Message* message, const iovec* vector,
+                              size_t vector_length));
   MOCK_METHOD2(PushFileHandle,
-               FileReference(Message* message, const LocalHandle& handle));
+               Status<FileReference>(Message* message,
+                                     const LocalHandle& handle));
   MOCK_METHOD2(PushFileHandle,
-               FileReference(Message* message, const BorrowedHandle& handle));
+               Status<FileReference>(Message* message,
+                                     const BorrowedHandle& handle));
   MOCK_METHOD2(PushFileHandle,
-               FileReference(Message* message, const RemoteHandle& handle));
+               Status<FileReference>(Message* message,
+                                     const RemoteHandle& handle));
   MOCK_METHOD2(PushChannelHandle,
-               ChannelReference(Message* message,
-                                const LocalChannelHandle& handle));
+               Status<ChannelReference>(Message* message,
+                                        const LocalChannelHandle& handle));
   MOCK_METHOD2(PushChannelHandle,
-               ChannelReference(Message* message,
-                                const BorrowedChannelHandle& handle));
+               Status<ChannelReference>(Message* message,
+                                        const BorrowedChannelHandle& handle));
   MOCK_METHOD2(PushChannelHandle,
-               ChannelReference(Message* message,
-                                const RemoteChannelHandle& handle));
+               Status<ChannelReference>(Message* message,
+                                        const RemoteChannelHandle& handle));
   MOCK_CONST_METHOD2(GetFileHandle,
                      LocalHandle(Message* message, FileReference ref));
   MOCK_CONST_METHOD2(GetChannelHandle,
@@ -57,7 +65,7 @@
                                         ChannelReference ref));
   MOCK_METHOD0(AllocateMessageState, void*());
   MOCK_METHOD1(FreeMessageState, void(void* state));
-  MOCK_METHOD0(Cancel, int());
+  MOCK_METHOD0(Cancel, Status<void>());
 };
 
 }  // namespace pdx
diff --git a/libs/vr/libpdx/private/pdx/rpc/remote_method.h b/libs/vr/libpdx/private/pdx/rpc/remote_method.h
index 3eca9e5..505c63b 100644
--- a/libs/vr/libpdx/private/pdx/rpc/remote_method.h
+++ b/libs/vr/libpdx/private/pdx/rpc/remote_method.h
@@ -121,9 +121,9 @@
 // either during dispatch of the remote method handler or at a later time if the
 // message is moved for delayed response.
 inline void RemoteMethodError(Message& message, int error_code) {
-  const int ret = message.ReplyError(error_code);
-  ALOGE_IF(ret < 0, "RemoteMethodError: Failed to reply to message: %s",
-           strerror(-ret));
+  const auto status = message.ReplyError(error_code);
+  ALOGE_IF(!status, "RemoteMethodError: Failed to reply to message: %s",
+           status.GetErrorMessage().c_str());
 }
 
 // Returns a value from a remote method to the client. The usual method to
@@ -135,9 +135,9 @@
 template <typename RemoteMethodType, typename Return>
 EnableIfDirectReturn<typename RemoteMethodType::Return> RemoteMethodReturn(
     Message& message, const Return& return_value) {
-  const int ret = message.Reply(return_value);
-  ALOGE_IF(ret < 0, "RemoteMethodReturn: Failed to reply to message: %s",
-           strerror(-ret));
+  const auto status = message.Reply(return_value);
+  ALOGE_IF(!status, "RemoteMethodReturn: Failed to reply to message: %s",
+           status.GetErrorMessage().c_str());
 }
 
 // Overload for non-direct return types.
@@ -148,14 +148,10 @@
   rpc::ServicePayload<ReplyBuffer> payload(message);
   MakeArgumentEncoder<Signature>(&payload).EncodeReturn(return_value);
 
-  int ret;
-  auto size = message.Write(payload.Data(), payload.Size());
-  if (size < static_cast<decltype(size)>(payload.Size()))
-    ret = message.ReplyError(EIO);
-  else
-    ret = message.Reply(0);
-  ALOGE_IF(ret < 0, "RemoteMethodReturn: Failed to reply to message: %s",
-           strerror(-ret));
+  auto ret = message.WriteAll(payload.Data(), payload.Size());
+  auto status = message.Reply(ret);
+  ALOGE_IF(!status, "RemoteMethodReturn: Failed to reply to message: %s",
+           status.GetErrorMessage().c_str());
 }
 
 // Overload for Status<void> return types.
@@ -189,13 +185,13 @@
   rpc::ServicePayload<ReceiveBuffer> payload(message);
   payload.Resize(max_capacity);
 
-  auto size = message.Read(payload.Data(), payload.Size());
-  if (size < 0) {
-    RemoteMethodError(message, -size);
+  Status<size_t> read_status = message.Read(payload.Data(), payload.Size());
+  if (!read_status) {
+    RemoteMethodError(message, read_status.error());
     return;
   }
 
-  payload.Resize(size);
+  payload.Resize(read_status.get());
 
   ErrorType error;
   auto decoder = MakeArgumentDecoder<Signature>(&payload);
@@ -225,13 +221,13 @@
   rpc::ServicePayload<ReceiveBuffer> payload(message);
   payload.Resize(max_capacity);
 
-  auto size = message.Read(payload.Data(), payload.Size());
-  if (size < 0) {
-    RemoteMethodError(message, -size);
+  Status<size_t> read_status = message.Read(payload.Data(), payload.Size());
+  if (!read_status) {
+    RemoteMethodError(message, read_status.error());
     return;
   }
 
-  payload.Resize(size);
+  payload.Resize(read_status.get());
 
   ErrorType error;
   auto decoder = MakeArgumentDecoder<Signature>(&payload);
@@ -265,13 +261,13 @@
   rpc::ServicePayload<ReceiveBuffer> payload(message);
   payload.Resize(max_capacity);
 
-  auto size = message.Read(payload.Data(), payload.Size());
-  if (size < 0) {
-    RemoteMethodError(message, -size);
+  Status<size_t> read_status = message.Read(payload.Data(), payload.Size());
+  if (!read_status) {
+    RemoteMethodError(message, read_status.error());
     return;
   }
 
-  payload.Resize(size);
+  payload.Resize(read_status.get());
 
   ErrorType error;
   auto decoder = MakeArgumentDecoder<Signature>(&payload);
diff --git a/libs/vr/libpdx/private/pdx/rpc/serialization.h b/libs/vr/libpdx/private/pdx/rpc/serialization.h
index fccd028..9a012ed 100644
--- a/libs/vr/libpdx/private/pdx/rpc/serialization.h
+++ b/libs/vr/libpdx/private/pdx/rpc/serialization.h
@@ -905,8 +905,9 @@
 inline void SerializeObject(const FileHandle<Mode>& fd, MessageWriter* writer,
                             void*& buffer) {
   SerializeType(fd, buffer);
-  const FileReference value =
+  const Status<FileReference> status =
       writer->GetOutputResourceMapper()->PushFileHandle(fd);
+  FileReference value = status ? status.get() : -status.error();
   SerializeRaw(value, buffer);
 }
 
@@ -915,8 +916,9 @@
 inline void SerializeObject(const ChannelHandle<Mode>& handle,
                             MessageWriter* writer, void*& buffer) {
   SerializeType(handle, buffer);
-  const ChannelReference value =
+  const Status<ChannelReference> status =
       writer->GetOutputResourceMapper()->PushChannelHandle(handle);
+  ChannelReference value = status ? status.get() : -status.error();
   SerializeRaw(value, buffer);
 }
 
diff --git a/libs/vr/libpdx/private/pdx/service.h b/libs/vr/libpdx/private/pdx/service.h
index 175cedf..0d30614 100644
--- a/libs/vr/libpdx/private/pdx/service.h
+++ b/libs/vr/libpdx/private/pdx/service.h
@@ -98,29 +98,62 @@
   /*
    * Read/write payload, in either single buffer or iovec form.
    */
-  ssize_t ReadVector(const iovec* vector, size_t vector_length);
-  ssize_t Read(void* buffer, size_t length);
-  ssize_t WriteVector(const iovec* vector, size_t vector_length);
-  ssize_t Write(const void* buffer, size_t length);
+  Status<size_t> ReadVector(const iovec* vector, size_t vector_length);
+  Status<size_t> Read(void* buffer, size_t length);
+  Status<size_t> WriteVector(const iovec* vector, size_t vector_length);
+  Status<size_t> Write(const void* buffer, size_t length);
 
   template <size_t N>
-  inline ssize_t ReadVector(const iovec (&vector)[N]) {
+  inline Status<size_t> ReadVector(const iovec (&vector)[N]) {
     return ReadVector(vector, N);
   }
 
   template <size_t N>
-  inline ssize_t WriteVector(const iovec (&vector)[N]) {
+  inline Status<size_t> WriteVector(const iovec (&vector)[N]) {
     return WriteVector(vector, N);
   }
 
+  // Helper functions to read/write all requested bytes, and return EIO if not
+  // all were read/written.
+  Status<void> ReadVectorAll(const iovec* vector, size_t vector_length);
+  Status<void> WriteVectorAll(const iovec* vector, size_t vector_length);
+
+  inline Status<void> ReadAll(void* buffer, size_t length) {
+    Status<size_t> status = Read(buffer, length);
+    if (status && status.get() < length)
+      status.SetError(EIO);
+    Status<void> ret;
+    ret.PropagateError(status);
+    return ret;
+  }
+  inline Status<void> WriteAll(const void* buffer, size_t length) {
+    Status<size_t> status = Write(buffer, length);
+    if (status && status.get() < length)
+      status.SetError(EIO);
+    Status<void> ret;
+    ret.PropagateError(status);
+    return ret;
+  }
+
+  template <size_t N>
+  inline Status<void> ReadVectorAll(const iovec (&vector)[N]) {
+    return ReadVectorAll(vector, N);
+  }
+
+  template <size_t N>
+  inline Status<void> WriteVectorAll(const iovec (&vector)[N]) {
+    return WriteVectorAll(vector, N);
+  }
+
   // OutputResourceMapper
-  FileReference PushFileHandle(const LocalHandle& handle) override;
-  FileReference PushFileHandle(const BorrowedHandle& handle) override;
-  FileReference PushFileHandle(const RemoteHandle& handle) override;
-  ChannelReference PushChannelHandle(const LocalChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<FileReference> PushFileHandle(const LocalHandle& handle) override;
+  Status<FileReference> PushFileHandle(const BorrowedHandle& handle) override;
+  Status<FileReference> PushFileHandle(const RemoteHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
+      const LocalChannelHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) override;
 
   // InputResourceMapper
@@ -131,25 +164,29 @@
   /*
    * Various ways to reply to a message.
    */
-  int Reply(int return_code);
-  int ReplyError(unsigned error);
-  int ReplyFileDescriptor(unsigned int fd);
-  int Reply(const LocalHandle& handle);
-  int Reply(const BorrowedHandle& handle);
-  int Reply(const RemoteHandle& handle);
-  int Reply(const LocalChannelHandle& handle);
-  int Reply(const BorrowedChannelHandle& handle);
-  int Reply(const RemoteChannelHandle& handle);
+  Status<void> Reply(int return_code);
+  Status<void> ReplyError(unsigned int error);
+  Status<void> ReplyFileDescriptor(unsigned int fd);
+  Status<void> Reply(const LocalHandle& handle);
+  Status<void> Reply(const BorrowedHandle& handle);
+  Status<void> Reply(const RemoteHandle& handle);
+  Status<void> Reply(const LocalChannelHandle& handle);
+  Status<void> Reply(const BorrowedChannelHandle& handle);
+  Status<void> Reply(const RemoteChannelHandle& handle);
 
   template <typename T>
-  inline int Reply(const Status<T>& status) {
+  inline Status<void> Reply(const Status<T>& status) {
     return status ? Reply(status.get()) : ReplyError(status.error());
   }
 
+  inline Status<void> Reply(const Status<void>& status) {
+    return status ? Reply(0) : ReplyError(status.error());
+  }
+
   /*
    * Update the channel event bits with the given clear and set masks.
    */
-  int ModifyChannelEvents(int clear_mask, int set_mask);
+  Status<void> ModifyChannelEvents(int clear_mask, int set_mask);
 
   /*
    * Create a new channel and push it as a file descriptor to the client. See
@@ -264,7 +301,7 @@
    * these in multi-threaded services.
    */
   std::shared_ptr<Channel> GetChannel() const;
-  void SetChannel(const std::shared_ptr<Channel>& channnel);
+  Status<void> SetChannel(const std::shared_ptr<Channel>& channnel);
 
   /*
    * Get the Channel object for the channel associated with this message,
@@ -355,7 +392,8 @@
    * the Channel object until the channel is closed or another call replaces
    * the current value.
    */
-  int SetChannel(int channel_id, const std::shared_ptr<Channel>& channel);
+  Status<void> SetChannel(int channel_id,
+                          const std::shared_ptr<Channel>& channel);
 
   /*
    * Get the channel context for the given channel id. This method should be
@@ -404,7 +442,7 @@
    *
    * OnChannelClosed is not called in response to this method call.
    */
-  int CloseChannel(int channel_id);
+  Status<void> CloseChannel(int channel_id);
 
   /*
    * Update the event bits for the given channel (given by id), using the
@@ -413,7 +451,8 @@
    * This is useful for asynchronously signaling events that clients may be
    * waiting for using select/poll/epoll.
    */
-  int ModifyChannelEvents(int channel_id, int clear_mask, int set_mask);
+  Status<void> ModifyChannelEvents(int channel_id, int clear_mask,
+                                   int set_mask);
 
   /*
    * Create a new channel and push it as a file descriptor to the process
@@ -478,7 +517,7 @@
    * The default implementation simply calls defaultHandleMessage().
    * Subclasses should call the same for any unrecognized message opcodes.
    */
-  virtual int HandleMessage(Message& message);
+  virtual Status<void> HandleMessage(Message& message);
 
   /*
    * Handle an asynchronous message. Subclasses override this to receive
@@ -496,9 +535,9 @@
    * Provides default handling of CHANNEL_OPEN and CHANNEL_CLOSE, calling
    * OnChannelOpen() and OnChannelClose(), respectively.
    *
-   * For all other message opcodes, this method replies with -ENOTSUP.
+   * For all other message opcodes, this method replies with ENOTSUP.
    */
-  int DefaultHandleMessage(Message& message);
+  Status<void> DefaultHandleMessage(Message& message);
 
   /*
    * Called when system properties have changed. Subclasses should implement
@@ -515,7 +554,7 @@
    * Cancels the endpoint, unblocking any receiver threads waiting in
    * ReceiveAndDispatch().
    */
-  int Cancel();
+  Status<void> Cancel();
 
   /*
    * Iterator type for Channel map iterators.
@@ -564,14 +603,14 @@
    * If the endpoint is in blocking mode this call blocks until a message is
    * received, a signal is delivered to this thread, or the service is canceled.
    * If the endpoint is in non-blocking mode and a message is not pending this
-   * call returns immediately with -ETIMEDOUT.
+   * call returns immediately with ETIMEDOUT.
    */
-  int ReceiveAndDispatch();
+  Status<void> ReceiveAndDispatch();
 
  private:
   friend class Message;
 
-  bool HandleSystemMessage(Message& message);
+  Status<void> HandleSystemMessage(Message& message);
 
   Service(const Service&);
   void operator=(const Service&) = delete;
@@ -639,28 +678,28 @@
 
 #define REPLY_ERROR(message, error, error_label)                              \
   do {                                                                        \
-    int __ret = message.ReplyError(error);                                    \
-    CHECK_ERROR(__ret < 0, error_label,                                       \
+    auto __status = message.ReplyError(error);                                \
+    CHECK_ERROR(!__status, error_label,                                       \
                 PDX_ERROR_PREFIX " Failed to reply to message because: %s\n", \
-                strerror(-__ret));                                            \
+                __status.GetErrorMessage().c_str());                          \
     goto error_label;                                                         \
   } while (0)
 
 #define REPLY_ERROR_RETURN(message, error, ...)                          \
   do {                                                                   \
-    int __ret = message.ReplyError(error);                               \
-    ALOGE_IF(__ret < 0,                                                  \
+    auto __status = message.ReplyError(error);                           \
+    ALOGE_IF(!__status,                                                  \
              PDX_ERROR_PREFIX " Failed to reply to message because: %s", \
-             strerror(-__ret));                                          \
+             __status.GetErrorMessage().c_str());                        \
     return __VA_ARGS__;                                                  \
   } while (0)
 
 #define REPLY_MESSAGE(message, message_return_code, error_label)              \
   do {                                                                        \
-    int __ret = message.Reply(message_return_code);                           \
-    CHECK_ERROR(__ret < 0, error_label,                                       \
+    auto __status = message.Reply(message_return_code);                       \
+    CHECK_ERROR(!__status, error_label,                                       \
                 PDX_ERROR_PREFIX " Failed to reply to message because: %s\n", \
-                strerror(-__ret));                                            \
+                __status.GetErrorMessage().c_str());                          \
     goto error_label;                                                         \
   } while (0)
 
@@ -669,10 +708,10 @@
 
 #define REPLY_MESSAGE_RETURN(message, message_return_code, ...)          \
   do {                                                                   \
-    int __ret = message.Reply(message_return_code);                      \
-    ALOGE_IF(__ret < 0,                                                  \
+    auto __status = message.Reply(message_return_code);                  \
+    ALOGE_IF(!__status,                                                  \
              PDX_ERROR_PREFIX " Failed to reply to message because: %s", \
-             strerror(-__ret));                                          \
+             __status.GetErrorMessage().c_str());                        \
     return __VA_ARGS__;                                                  \
   } while (0)
 
@@ -681,19 +720,19 @@
 
 #define REPLY_FD(message, push_fd, error_label)                               \
   do {                                                                        \
-    int __ret = message.ReplyFileDescriptor(push_fd);                         \
-    CHECK_ERROR(__ret < 0, error_label,                                       \
+    auto __status = message.ReplyFileDescriptor(push_fd);                     \
+    CHECK_ERROR(!__status, error_label,                                       \
                 PDX_ERROR_PREFIX " Failed to reply to message because: %s\n", \
-                strerror(-__ret));                                            \
+                __status.GetErrorMessage().c_str());                          \
     goto error_label;                                                         \
   } while (0)
 
 #define REPLY_FD_RETURN(message, push_fd, ...)                           \
   do {                                                                   \
-    int __ret = message.ReplyFileDescriptor(push_fd);                    \
-    ALOGE_IF(__ret < 0,                                                  \
+    auto __status = message.ReplyFileDescriptor(push_fd);                \
+    ALOGE_IF(__status < 0,                                               \
              PDX_ERROR_PREFIX " Failed to reply to message because: %s", \
-             strerror(-__ret));                                          \
+             __status.GetErrorMessage().c_str());                        \
     return __VA_ARGS__;                                                  \
   } while (0)
 
diff --git a/libs/vr/libpdx/private/pdx/service_endpoint.h b/libs/vr/libpdx/private/pdx/service_endpoint.h
index 613be7c..28bd6bc 100644
--- a/libs/vr/libpdx/private/pdx/service_endpoint.h
+++ b/libs/vr/libpdx/private/pdx/service_endpoint.h
@@ -44,20 +44,20 @@
   // Associates a Service instance with an endpoint by setting the service
   // context pointer to the address of the Service. Only one Service may be
   // associated with a given endpoint.
-  virtual int SetService(Service* service) = 0;
+  virtual Status<void> SetService(Service* service) = 0;
 
   // Set the channel context for the given channel.
-  virtual int SetChannel(int channel_id, Channel* channel) = 0;
+  virtual Status<void> SetChannel(int channel_id, Channel* channel) = 0;
 
   // Close a channel, signaling the client file object and freeing the channel
   // id. Once closed, the client side of the channel always returns the error
   // ESHUTDOWN and signals the poll/epoll events POLLHUP and POLLFREE.
-  virtual int CloseChannel(int channel_id) = 0;
+  virtual Status<void> CloseChannel(int channel_id) = 0;
 
   // Update the event bits for the given channel (given by id), using the
   // given clear and set masks.
-  virtual int ModifyChannelEvents(int channel_id, int clear_mask,
-                                  int set_mask) = 0;
+  virtual Status<void> ModifyChannelEvents(int channel_id, int clear_mask,
+                                           int set_mask) = 0;
 
   // Create a new channel and push it as a file descriptor to the process
   // sending the |message|. |flags| may be set to O_NONBLOCK and/or
@@ -77,54 +77,49 @@
   virtual Status<int> CheckChannel(const Message* message, ChannelReference ref,
                                    Channel** channel) = 0;
 
-  // The default message handler. It is important that all messages
-  // (eventually) get a reply. This method should be called for any unrecognized
-  // opcodes or otherwise unhandled messages to prevent erroneous requests from
-  // blocking indefinitely.
-  virtual int DefaultHandleMessage(const MessageInfo& info) = 0;
-
   // Receives a message on the given endpoint file descriptor.
-  virtual int MessageReceive(Message* message) = 0;
+  virtual Status<void> MessageReceive(Message* message) = 0;
 
   // Replies to the message with a return code.
-  virtual int MessageReply(Message* message, int return_code) = 0;
+  virtual Status<void> MessageReply(Message* message, int return_code) = 0;
 
   // Replies to the message with a file descriptor.
-  virtual int MessageReplyFd(Message* message, unsigned int push_fd) = 0;
+  virtual Status<void> MessageReplyFd(Message* message,
+                                      unsigned int push_fd) = 0;
 
   // Replies to the message with a local channel handle.
-  virtual int MessageReplyChannelHandle(Message* message,
-                                        const LocalChannelHandle& handle) = 0;
+  virtual Status<void> MessageReplyChannelHandle(
+      Message* message, const LocalChannelHandle& handle) = 0;
 
   // Replies to the message with a borrowed local channel handle.
-  virtual int MessageReplyChannelHandle(
+  virtual Status<void> MessageReplyChannelHandle(
       Message* message, const BorrowedChannelHandle& handle) = 0;
 
   // Replies to the message with a remote channel handle.
-  virtual int MessageReplyChannelHandle(Message* message,
-                                        const RemoteChannelHandle& handle) = 0;
+  virtual Status<void> MessageReplyChannelHandle(
+      Message* message, const RemoteChannelHandle& handle) = 0;
 
   // Reads message data into an array of memory buffers.
-  virtual ssize_t ReadMessageData(Message* message, const iovec* vector,
-                                  size_t vector_length) = 0;
+  virtual Status<size_t> ReadMessageData(Message* message, const iovec* vector,
+                                         size_t vector_length) = 0;
 
   // Sends reply data for message.
-  virtual ssize_t WriteMessageData(Message* message, const iovec* vector,
-                                   size_t vector_length) = 0;
+  virtual Status<size_t> WriteMessageData(Message* message, const iovec* vector,
+                                          size_t vector_length) = 0;
 
   // Records a file descriptor into the message buffer and returns the remapped
   // reference to be sent to the remote process.
-  virtual FileReference PushFileHandle(Message* message,
-                                       const LocalHandle& handle) = 0;
-  virtual FileReference PushFileHandle(Message* message,
-                                       const BorrowedHandle& handle) = 0;
-  virtual FileReference PushFileHandle(Message* message,
-                                       const RemoteHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<FileReference> PushFileHandle(Message* message,
+                                               const LocalHandle& handle) = 0;
+  virtual Status<FileReference> PushFileHandle(
+      Message* message, const BorrowedHandle& handle) = 0;
+  virtual Status<FileReference> PushFileHandle(Message* message,
+                                               const RemoteHandle& handle) = 0;
+  virtual Status<ChannelReference> PushChannelHandle(
       Message* message, const LocalChannelHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<ChannelReference> PushChannelHandle(
       Message* message, const BorrowedChannelHandle& handle) = 0;
-  virtual ChannelReference PushChannelHandle(
+  virtual Status<ChannelReference> PushChannelHandle(
       Message* message, const RemoteChannelHandle& handle) = 0;
 
   // Obtains a file descriptor/channel handle from a message for the given
@@ -140,7 +135,7 @@
 
   // Cancels the endpoint, unblocking any receiver threads waiting for a
   // message.
-  virtual int Cancel() = 0;
+  virtual Status<void> Cancel() = 0;
 };
 
 }  // namespace pdx
diff --git a/libs/vr/libpdx/private/pdx/status.h b/libs/vr/libpdx/private/pdx/status.h
index ca2832c..067fe25 100644
--- a/libs/vr/libpdx/private/pdx/status.h
+++ b/libs/vr/libpdx/private/pdx/status.h
@@ -103,6 +103,17 @@
   // is not empty nor containing a valid value).
   int error() const { return std::max(error_, 0); }
 
+  // Returns the error code as ErrorStatus object. This is a helper method
+  // to aid in propagation of error codes between Status<T> of different types
+  // as in the following example:
+  //    Status<int> foo() {
+  //      Status<void> status = bar();
+  //      if(!status)
+  //        return status.error_status();
+  //      return 12;
+  //    }
+  inline ErrorStatus error_status() const { return ErrorStatus{error()}; }
+
   // Returns the error message associated with error code stored in the object.
   // The message is the same as the string returned by strerror(status.error()).
   // Can be called only when an error is actually stored (that is, the object
@@ -142,6 +153,7 @@
   bool empty() const { return false; }
   explicit operator bool() const { return ok(); }
   int error() const { return std::max(error_, 0); }
+  inline ErrorStatus error_status() const { return ErrorStatus{error()}; }
   std::string GetErrorMessage() const {
     std::string message;
     if (error_ > 0)
diff --git a/libs/vr/libpdx/private/pdx/utility.h b/libs/vr/libpdx/private/pdx/utility.h
index c8c717c..305c3b8 100644
--- a/libs/vr/libpdx/private/pdx/utility.h
+++ b/libs/vr/libpdx/private/pdx/utility.h
@@ -150,29 +150,29 @@
 
 class NoOpOutputResourceMapper : public OutputResourceMapper {
  public:
-  FileReference PushFileHandle(const LocalHandle& handle) override {
+  Status<FileReference> PushFileHandle(const LocalHandle& handle) override {
     return handle.Get();
   }
 
-  FileReference PushFileHandle(const BorrowedHandle& handle) override {
+  Status<FileReference> PushFileHandle(const BorrowedHandle& handle) override {
     return handle.Get();
   }
 
-  FileReference PushFileHandle(const RemoteHandle& handle) override {
+  Status<FileReference> PushFileHandle(const RemoteHandle& handle) override {
     return handle.Get();
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const LocalChannelHandle& handle) override {
     return handle.value();
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) override {
     return handle.value();
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) override {
     return handle.value();
   }
@@ -278,7 +278,7 @@
   OutputResourceMapper* GetOutputResourceMapper() override { return this; }
 
   // OutputResourceMapper
-  FileReference PushFileHandle(const LocalHandle& handle) override {
+  Status<FileReference> PushFileHandle(const LocalHandle& handle) override {
     if (handle) {
       const int ref = file_handles_.size();
       file_handles_.push_back(handle.Get());
@@ -288,7 +288,7 @@
     }
   }
 
-  FileReference PushFileHandle(const BorrowedHandle& handle) override {
+  Status<FileReference> PushFileHandle(const BorrowedHandle& handle) override {
     if (handle) {
       const int ref = file_handles_.size();
       file_handles_.push_back(handle.Get());
@@ -298,11 +298,11 @@
     }
   }
 
-  FileReference PushFileHandle(const RemoteHandle& handle) override {
+  Status<FileReference> PushFileHandle(const RemoteHandle& handle) override {
     return handle.Get();
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const LocalChannelHandle& handle) override {
     if (handle) {
       const int ref = file_handles_.size();
@@ -313,7 +313,7 @@
     }
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) override {
     if (handle) {
       const int ref = file_handles_.size();
@@ -324,7 +324,7 @@
     }
   }
 
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) override {
     return handle.value();
   }
diff --git a/libs/vr/libpdx/service.cpp b/libs/vr/libpdx/service.cpp
index daf9af8..fab4770 100644
--- a/libs/vr/libpdx/service.cpp
+++ b/libs/vr/libpdx/service.cpp
@@ -9,7 +9,6 @@
 #include <cstdint>
 
 #include <pdx/trace.h>
-#include "errno_guard.h"
 
 #define TRACE 0
 
@@ -60,7 +59,7 @@
           "ERROR: Service \"%s\" failed to reply to message: op=%d pid=%d "
           "cid=%d\n",
           svc->name_.c_str(), info_.op, info_.pid, info_.cid);
-      svc->endpoint()->DefaultHandleMessage(info_);
+      svc->DefaultHandleMessage(*this);
     }
     svc->endpoint()->FreeMessageState(state_);
   }
@@ -77,112 +76,138 @@
   return ImpulseBegin() + (IsImpulse() ? GetSendLength() : 0);
 }
 
-ssize_t Message::ReadVector(const struct iovec* vector, size_t vector_length) {
+Status<size_t> Message::ReadVector(const struct iovec* vector,
+                                   size_t vector_length) {
   PDX_TRACE_NAME("Message::ReadVector");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    const ssize_t ret =
-        svc->endpoint()->ReadMessageData(this, vector, vector_length);
-    return ReturnCodeOrError(ret);
+    return svc->endpoint()->ReadMessageData(this, vector, vector_length);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ssize_t Message::Read(void* buffer, size_t length) {
+Status<void> Message::ReadVectorAll(const struct iovec* vector,
+                                    size_t vector_length) {
+  PDX_TRACE_NAME("Message::ReadVectorAll");
+  if (auto svc = service_.lock()) {
+    const auto status =
+        svc->endpoint()->ReadMessageData(this, vector, vector_length);
+    if (!status)
+      return status.error_status();
+    size_t size_to_read = 0;
+    for (size_t i = 0; i < vector_length; i++)
+      size_to_read += vector[i].iov_len;
+    if (status.get() < size_to_read)
+      return ErrorStatus{EIO};
+    return {};
+  } else {
+    return ErrorStatus{ESHUTDOWN};
+  }
+}
+
+Status<size_t> Message::Read(void* buffer, size_t length) {
   PDX_TRACE_NAME("Message::Read");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
     const struct iovec vector = {buffer, length};
-    const ssize_t ret = svc->endpoint()->ReadMessageData(this, &vector, 1);
-    return ReturnCodeOrError(ret);
+    return svc->endpoint()->ReadMessageData(this, &vector, 1);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ssize_t Message::WriteVector(const struct iovec* vector, size_t vector_length) {
+Status<size_t> Message::WriteVector(const struct iovec* vector,
+                                    size_t vector_length) {
   PDX_TRACE_NAME("Message::WriteVector");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    const ssize_t ret =
-        svc->endpoint()->WriteMessageData(this, vector, vector_length);
-    return ReturnCodeOrError(ret);
+    return svc->endpoint()->WriteMessageData(this, vector, vector_length);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ssize_t Message::Write(const void* buffer, size_t length) {
+Status<void> Message::WriteVectorAll(const struct iovec* vector,
+                                     size_t vector_length) {
+  PDX_TRACE_NAME("Message::WriteVector");
+  if (auto svc = service_.lock()) {
+    const auto status =
+        svc->endpoint()->WriteMessageData(this, vector, vector_length);
+    if (!status)
+      return status.error_status();
+    size_t size_to_write = 0;
+    for (size_t i = 0; i < vector_length; i++)
+      size_to_write += vector[i].iov_len;
+    if (status.get() < size_to_write)
+      return ErrorStatus{EIO};
+    return {};
+  } else {
+    return ErrorStatus{ESHUTDOWN};
+  }
+}
+
+Status<size_t> Message::Write(const void* buffer, size_t length) {
   PDX_TRACE_NAME("Message::Write");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
     const struct iovec vector = {const_cast<void*>(buffer), length};
-    const ssize_t ret = svc->endpoint()->WriteMessageData(this, &vector, 1);
-    return ReturnCodeOrError(ret);
+    return svc->endpoint()->WriteMessageData(this, &vector, 1);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-FileReference Message::PushFileHandle(const LocalHandle& handle) {
+Status<FileReference> Message::PushFileHandle(const LocalHandle& handle) {
   PDX_TRACE_NAME("Message::PushFileHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushFileHandle(this, handle));
+    return svc->endpoint()->PushFileHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-FileReference Message::PushFileHandle(const BorrowedHandle& handle) {
+Status<FileReference> Message::PushFileHandle(const BorrowedHandle& handle) {
   PDX_TRACE_NAME("Message::PushFileHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushFileHandle(this, handle));
+    return svc->endpoint()->PushFileHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-FileReference Message::PushFileHandle(const RemoteHandle& handle) {
+Status<FileReference> Message::PushFileHandle(const RemoteHandle& handle) {
   PDX_TRACE_NAME("Message::PushFileHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushFileHandle(this, handle));
+    return svc->endpoint()->PushFileHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ChannelReference Message::PushChannelHandle(const LocalChannelHandle& handle) {
+Status<ChannelReference> Message::PushChannelHandle(
+    const LocalChannelHandle& handle) {
   PDX_TRACE_NAME("Message::PushChannelHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushChannelHandle(this, handle));
+    return svc->endpoint()->PushChannelHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ChannelReference Message::PushChannelHandle(
+Status<ChannelReference> Message::PushChannelHandle(
     const BorrowedChannelHandle& handle) {
   PDX_TRACE_NAME("Message::PushChannelHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushChannelHandle(this, handle));
+    return svc->endpoint()->PushChannelHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
-ChannelReference Message::PushChannelHandle(const RemoteChannelHandle& handle) {
+Status<ChannelReference> Message::PushChannelHandle(
+    const RemoteChannelHandle& handle) {
   PDX_TRACE_NAME("Message::PushChannelHandle");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    return ReturnCodeOrError(svc->endpoint()->PushChannelHandle(this, handle));
+    return svc->endpoint()->PushChannelHandle(this, handle);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
@@ -193,7 +218,6 @@
     return false;
 
   if (ref >= 0) {
-    ErrnoGuard errno_guard;
     *handle = svc->endpoint()->GetFileHandle(this, ref);
     if (!handle->IsValid())
       return false;
@@ -211,7 +235,6 @@
     return false;
 
   if (ref >= 0) {
-    ErrnoGuard errno_guard;
     *handle = svc->endpoint()->GetChannelHandle(this, ref);
     if (!handle->valid())
       return false;
@@ -221,141 +244,137 @@
   return true;
 }
 
-int Message::Reply(int return_code) {
+Status<void> Message::Reply(int return_code) {
   PDX_TRACE_NAME("Message::Reply");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReply(this, return_code);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret = svc->endpoint()->MessageReply(this, return_code);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::ReplyFileDescriptor(unsigned int fd) {
+Status<void> Message::ReplyFileDescriptor(unsigned int fd) {
   PDX_TRACE_NAME("Message::ReplyFileDescriptor");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReplyFd(this, fd);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret = svc->endpoint()->MessageReplyFd(this, fd);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::ReplyError(unsigned error) {
+Status<void> Message::ReplyError(unsigned int error) {
   PDX_TRACE_NAME("Message::ReplyError");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReply(this, -error);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret =
+        svc->endpoint()->MessageReply(this, -static_cast<int>(error));
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const LocalHandle& handle) {
+Status<void> Message::Reply(const LocalHandle& handle) {
   PDX_TRACE_NAME("Message::ReplyFileHandle");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    int ret;
+    Status<void> ret;
 
     if (handle)
       ret = svc->endpoint()->MessageReplyFd(this, handle.Get());
     else
       ret = svc->endpoint()->MessageReply(this, handle.Get());
 
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const BorrowedHandle& handle) {
+Status<void> Message::Reply(const BorrowedHandle& handle) {
   PDX_TRACE_NAME("Message::ReplyFileHandle");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    int ret;
+    Status<void> ret;
 
     if (handle)
       ret = svc->endpoint()->MessageReplyFd(this, handle.Get());
     else
       ret = svc->endpoint()->MessageReply(this, handle.Get());
 
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const RemoteHandle& handle) {
+Status<void> Message::Reply(const RemoteHandle& handle) {
   PDX_TRACE_NAME("Message::ReplyFileHandle");
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReply(this, handle.Get());
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    Status<void> ret;
+
+    if (handle)
+      ret = svc->endpoint()->MessageReply(this, handle.Get());
+    else
+      ret = svc->endpoint()->MessageReply(this, handle.Get());
+
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const LocalChannelHandle& handle) {
+Status<void> Message::Reply(const LocalChannelHandle& handle) {
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const BorrowedChannelHandle& handle) {
+Status<void> Message::Reply(const BorrowedChannelHandle& handle) {
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::Reply(const RemoteChannelHandle& handle) {
+Status<void> Message::Reply(const RemoteChannelHandle& handle) {
   auto svc = service_.lock();
   if (!replied_ && svc) {
-    ErrnoGuard errno_guard;
-    const int ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
-    replied_ = ret == 0;
-    return ReturnCodeOrError(ret);
+    const auto ret = svc->endpoint()->MessageReplyChannelHandle(this, handle);
+    replied_ = ret.ok();
+    return ret;
   } else {
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 }
 
-int Message::ModifyChannelEvents(int clear_mask, int set_mask) {
+Status<void> Message::ModifyChannelEvents(int clear_mask, int set_mask) {
   PDX_TRACE_NAME("Message::ModifyChannelEvents");
   if (auto svc = service_.lock()) {
-    ErrnoGuard errno_guard;
-    const int ret =
-        svc->endpoint()->ModifyChannelEvents(info_.cid, clear_mask, set_mask);
-    return ReturnCodeOrError(ret);
+    return svc->endpoint()->ModifyChannelEvents(info_.cid, clear_mask,
+                                                set_mask);
   } else {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 }
 
@@ -416,11 +435,12 @@
 
 std::shared_ptr<Channel> Message::GetChannel() const { return channel_.lock(); }
 
-void Message::SetChannel(const std::shared_ptr<Channel>& chan) {
+Status<void> Message::SetChannel(const std::shared_ptr<Channel>& chan) {
   channel_ = chan;
-
+  Status<void> status;
   if (auto svc = service_.lock())
-    svc->SetChannel(info_.cid, chan);
+    status = svc->SetChannel(info_.cid, chan);
+  return status;
 }
 
 std::shared_ptr<Service> Message::GetService() const { return service_.lock(); }
@@ -432,16 +452,16 @@
   if (!endpoint_)
     return;
 
-  const int ret = endpoint_->SetService(this);
-  ALOGE_IF(ret < 0, "Failed to set service context because: %s",
-           strerror(-ret));
+  const auto status = endpoint_->SetService(this);
+  ALOGE_IF(!status, "Failed to set service context because: %s",
+           status.GetErrorMessage().c_str());
 }
 
 Service::~Service() {
   if (endpoint_) {
-    const int ret = endpoint_->SetService(nullptr);
-    ALOGE_IF(ret < 0, "Failed to clear service context because: %s",
-             strerror(-ret));
+    const auto status = endpoint_->SetService(nullptr);
+    ALOGE_IF(!status, "Failed to clear service context because: %s",
+             status.GetErrorMessage().c_str());
   }
 }
 
@@ -459,32 +479,28 @@
 void Service::OnChannelClose(Message& /*message*/,
                              const std::shared_ptr<Channel>& /*channel*/) {}
 
-int Service::SetChannel(int channel_id,
-                        const std::shared_ptr<Channel>& channel) {
+Status<void> Service::SetChannel(int channel_id,
+                                 const std::shared_ptr<Channel>& channel) {
   PDX_TRACE_NAME("Service::SetChannel");
-  ErrnoGuard errno_guard;
   std::lock_guard<std::mutex> autolock(channels_mutex_);
 
-  const int ret = endpoint_->SetChannel(channel_id, channel.get());
-  if (ret == -1) {
+  const auto status = endpoint_->SetChannel(channel_id, channel.get());
+  if (!status) {
     ALOGE("%s::SetChannel: Failed to set channel context: %s\n", name_.c_str(),
-          strerror(errno));
+          status.GetErrorMessage().c_str());
 
     // It's possible someone mucked with things behind our back by calling the C
     // API directly. Since we know the channel id isn't valid, make sure we
     // don't have it in the channels map.
-    if (errno == ENOENT)
+    if (status.error() == ENOENT)
       channels_.erase(channel_id);
-
-    return ReturnCodeOrError(ret);
+  } else {
+    if (channel != nullptr)
+      channels_[channel_id] = channel;
+    else
+      channels_.erase(channel_id);
   }
-
-  if (channel != nullptr)
-    channels_[channel_id] = channel;
-  else
-    channels_.erase(channel_id);
-
-  return ret;
+  return status;
 }
 
 std::shared_ptr<Channel> Service::GetChannel(int channel_id) const {
@@ -498,21 +514,21 @@
     return nullptr;
 }
 
-int Service::CloseChannel(int channel_id) {
+Status<void> Service::CloseChannel(int channel_id) {
   PDX_TRACE_NAME("Service::CloseChannel");
-  ErrnoGuard errno_guard;
   std::lock_guard<std::mutex> autolock(channels_mutex_);
 
-  const int ret = endpoint_->CloseChannel(channel_id);
+  const auto status = endpoint_->CloseChannel(channel_id);
 
   // Always erase the map entry, in case someone mucked with things behind our
   // back using the C API directly.
   channels_.erase(channel_id);
 
-  return ReturnCodeOrError(ret);
+  return status;
 }
 
-int Service::ModifyChannelEvents(int channel_id, int clear_mask, int set_mask) {
+Status<void> Service::ModifyChannelEvents(int channel_id, int clear_mask,
+                                          int set_mask) {
   PDX_TRACE_NAME("Service::ModifyChannelEvents");
   return endpoint_->ModifyChannelEvents(channel_id, clear_mask, set_mask);
 }
@@ -521,7 +537,6 @@
     Message* message, int flags, const std::shared_ptr<Channel>& channel,
     int* channel_id) {
   PDX_TRACE_NAME("Service::PushChannel");
-  ErrnoGuard errno_guard;
 
   std::lock_guard<std::mutex> autolock(channels_mutex_);
 
@@ -542,7 +557,6 @@
 Status<int> Service::CheckChannel(const Message* message, ChannelReference ref,
                                   std::shared_ptr<Channel>* channel) const {
   PDX_TRACE_NAME("Service::CheckChannel");
-  ErrnoGuard errno_guard;
 
   // Synchronization to maintain consistency between the kernel's channel
   // context pointer and the userspace channels_ map. Other threads may attempt
@@ -565,13 +579,13 @@
 
 std::string Service::DumpState(size_t /*max_length*/) { return ""; }
 
-int Service::HandleMessage(Message& message) {
+Status<void> Service::HandleMessage(Message& message) {
   return DefaultHandleMessage(message);
 }
 
 void Service::HandleImpulse(Message& /*impulse*/) {}
 
-bool Service::HandleSystemMessage(Message& message) {
+Status<void> Service::HandleSystemMessage(Message& message) {
   const MessageInfo& info = message.GetInfo();
 
   switch (info.op) {
@@ -579,8 +593,7 @@
       ALOGD("%s::OnChannelOpen: pid=%d cid=%d\n", name_.c_str(), info.pid,
             info.cid);
       message.SetChannel(OnChannelOpen(message));
-      message.Reply(0);
-      return true;
+      return message.Reply(0);
     }
 
     case opcodes::CHANNEL_CLOSE: {
@@ -588,8 +601,7 @@
             info.cid);
       OnChannelClose(message, Channel::GetFromMessageInfo(info));
       message.SetChannel(nullptr);
-      message.Reply(0);
-      return true;
+      return message.Reply(0);
     }
 
     case opcodes::REPORT_SYSPROP_CHANGE:
@@ -597,8 +609,7 @@
             info.pid, info.cid);
       OnSysPropChange();
       android::report_sysprop_change();
-      message.Reply(0);
-      return true;
+      return message.Reply(0);
 
     case opcodes::DUMP_STATE: {
       ALOGD("%s:DUMP_STATE: pid=%d cid=%d\n", name_.c_str(), info.pid,
@@ -607,21 +618,20 @@
       const size_t response_size = response.size() < message.GetReceiveLength()
                                        ? response.size()
                                        : message.GetReceiveLength();
-      const ssize_t bytes_written =
+      const Status<size_t> status =
           message.Write(response.data(), response_size);
-      if (bytes_written < static_cast<ssize_t>(response_size))
-        message.ReplyError(EIO);
+      if (status && status.get() < response_size)
+        return message.ReplyError(EIO);
       else
-        message.Reply(bytes_written);
-      return true;
+        return message.Reply(status);
     }
 
     default:
-      return false;
+      return ErrorStatus{EOPNOTSUPP};
   }
 }
 
-int Service::DefaultHandleMessage(Message& message) {
+Status<void> Service::DefaultHandleMessage(Message& message) {
   const MessageInfo& info = message.GetInfo();
 
   ALOGD_IF(TRACE, "Service::DefaultHandleMessage: pid=%d cid=%d op=%d\n",
@@ -632,23 +642,21 @@
     case opcodes::CHANNEL_CLOSE:
     case opcodes::REPORT_SYSPROP_CHANGE:
     case opcodes::DUMP_STATE:
-      HandleSystemMessage(message);
-      return 0;
+      return HandleSystemMessage(message);
 
     default:
-      return message.ReplyError(ENOTSUP);
+      return message.ReplyError(EOPNOTSUPP);
   }
 }
 
 void Service::OnSysPropChange() {}
 
-int Service::ReceiveAndDispatch() {
-  ErrnoGuard errno_guard;
+Status<void> Service::ReceiveAndDispatch() {
   Message message;
-  const int ret = endpoint_->MessageReceive(&message);
-  if (ret < 0) {
-    ALOGE("Failed to receive message: %s\n", strerror(errno));
-    return ReturnCodeOrError(ret);
+  const auto status = endpoint_->MessageReceive(&message);
+  if (!status) {
+    ALOGE("Failed to receive message: %s\n", status.GetErrorMessage().c_str());
+    return status;
   }
 
   std::shared_ptr<Service> service = message.GetService();
@@ -657,24 +665,20 @@
     ALOGE("Service::ReceiveAndDispatch: service context is NULL!!!\n");
     // Don't block the sender indefinitely in this error case.
     endpoint_->MessageReply(&message, -EINVAL);
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   }
 
   if (message.IsImpulse()) {
     service->HandleImpulse(message);
-    return 0;
+    return {};
   } else if (service->HandleSystemMessage(message)) {
-    return 0;
+    return {};
   } else {
     return service->HandleMessage(message);
   }
 }
 
-int Service::Cancel() {
-  ErrnoGuard errno_guard;
-  const int ret = endpoint_->Cancel();
-  return ReturnCodeOrError(ret);
-}
+Status<void> Service::Cancel() { return endpoint_->Cancel(); }
 
 }  // namespace pdx
 }  // namespace android
diff --git a/libs/vr/libpdx/service_tests.cpp b/libs/vr/libpdx/service_tests.cpp
index fc0c8db..c7412b7 100644
--- a/libs/vr/libpdx/service_tests.cpp
+++ b/libs/vr/libpdx/service_tests.cpp
@@ -30,7 +30,6 @@
 using testing::Ref;
 using testing::Return;
 using testing::SetArgPointee;
-using testing::SetErrnoAndReturn;
 using testing::WithArg;
 using testing::WithoutArgs;
 using testing::_;
@@ -91,7 +90,7 @@
   MOCK_METHOD1(OnChannelOpen, std::shared_ptr<Channel>(Message& message));
   MOCK_METHOD2(OnChannelClose,
                void(Message& message, const std::shared_ptr<Channel>& channel));
-  MOCK_METHOD1(HandleMessage, int(Message& message));
+  MOCK_METHOD1(HandleMessage, Status<void>(Message& message));
   MOCK_METHOD1(HandleImpulse, void(Message& impulse));
   MOCK_METHOD0(OnSysPropChange, void());
   MOCK_METHOD1(DumpState, std::string(size_t max_length));
@@ -101,7 +100,9 @@
  public:
   ServiceTest() {
     auto endpoint = std::make_unique<testing::StrictMock<MockEndpoint>>();
-    EXPECT_CALL(*endpoint, SetService(_)).Times(2).WillRepeatedly(Return(0));
+    EXPECT_CALL(*endpoint, SetService(_))
+        .Times(2)
+        .WillRepeatedly(Return(Status<void>{}));
     service_ = std::make_shared<MockService>("MockSvc", std::move(endpoint));
   }
 
@@ -134,7 +135,8 @@
   }
 
   void ExpectDefaultHandleMessage() {
-    EXPECT_CALL(*endpoint(), DefaultHandleMessage(_));
+    EXPECT_CALL(*endpoint(), MessageReply(_, -EOPNOTSUPP))
+        .WillOnce(Return(Status<void>{}));
   }
 
   std::shared_ptr<MockService> service_;
@@ -222,10 +224,11 @@
   auto channel = std::make_shared<Channel>();
   EXPECT_CALL(*service_, OnChannelOpen(Ref(message))).WillOnce(Return(channel));
   EXPECT_CALL(*endpoint(), SetChannel(kTestCid, channel.get()))
-      .WillOnce(Return(0));
-  EXPECT_CALL(*endpoint(), MessageReply(&message, 0)).WillOnce(Return(0));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_CALL(*endpoint(), MessageReply(&message, 0))
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageChannelClose) {
@@ -237,10 +240,12 @@
   Message message{info};
 
   EXPECT_CALL(*service_, OnChannelClose(Ref(message), channel));
-  EXPECT_CALL(*endpoint(), SetChannel(kTestCid, nullptr)).WillOnce(Return(0));
-  EXPECT_CALL(*endpoint(), MessageReply(&message, 0)).WillOnce(Return(0));
+  EXPECT_CALL(*endpoint(), SetChannel(kTestCid, nullptr))
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_CALL(*endpoint(), MessageReply(&message, 0))
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageOnSysPropChange) {
@@ -250,9 +255,10 @@
   Message message{info};
 
   EXPECT_CALL(*service_, OnSysPropChange());
-  EXPECT_CALL(*endpoint(), MessageReply(&message, 0)).WillOnce(Return(0));
+  EXPECT_CALL(*endpoint(), MessageReply(&message, 0))
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageOnDumpState) {
@@ -270,9 +276,9 @@
       WriteMessageData(&message, IoVecDataMatcher(IoVecData{kReply}), 1))
       .WillOnce(Return(kReply.size()));
   EXPECT_CALL(*endpoint(), MessageReply(&message, kReply.size()))
-      .WillOnce(Return(0));
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageOnDumpStateTooLarge) {
@@ -291,9 +297,9 @@
       WriteMessageData(&message, IoVecDataMatcher(IoVecData{kActualReply}), 1))
       .WillOnce(Return(kActualReply.size()));
   EXPECT_CALL(*endpoint(), MessageReply(&message, kActualReply.size()))
-      .WillOnce(Return(0));
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageOnDumpStateFail) {
@@ -310,9 +316,10 @@
       *endpoint(),
       WriteMessageData(&message, IoVecDataMatcher(IoVecData{kReply}), 1))
       .WillOnce(Return(1));
-  EXPECT_CALL(*endpoint(), MessageReply(&message, -EIO)).WillOnce(Return(0));
+  EXPECT_CALL(*endpoint(), MessageReply(&message, -EIO))
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, HandleMessageCustom) {
@@ -320,10 +327,10 @@
   SetupMessageInfoAndDefaultExpectations(&info, kTestOp);
   Message message{info};
 
-  EXPECT_CALL(*endpoint(), MessageReply(&message, -ENOTSUP))
-      .WillOnce(Return(0));
+  EXPECT_CALL(*endpoint(), MessageReply(&message, -EOPNOTSUPP))
+      .WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->Service::HandleMessage(message));
+  EXPECT_TRUE(service_->Service::HandleMessage(message));
 }
 
 TEST_F(ServiceTest, ReplyMessageWithoutService) {
@@ -337,7 +344,7 @@
   service_.reset();
   EXPECT_TRUE(message.IsServiceExpired());
 
-  EXPECT_EQ(-EINVAL, message.Reply(12));
+  EXPECT_EQ(EINVAL, message.Reply(12).error());
 }
 
 TEST_F(ServiceTest, ReceiveAndDispatchMessage) {
@@ -345,33 +352,33 @@
   SetupMessageInfoAndDefaultExpectations(&info, kTestOp);
   ExpectDefaultHandleMessage();
 
-  auto on_receive = [&info](Message* message) {
+  auto on_receive = [&info](Message* message) -> Status<void> {
     *message = Message{info};
-    return 0;
+    return {};
   };
   EXPECT_CALL(*endpoint(), MessageReceive(_)).WillOnce(Invoke(on_receive));
-  EXPECT_CALL(*service_, HandleMessage(_)).WillOnce(Return(0));
+  EXPECT_CALL(*service_, HandleMessage(_)).WillOnce(Return(Status<void>{}));
 
-  EXPECT_EQ(0, service_->ReceiveAndDispatch());
+  EXPECT_TRUE(service_->ReceiveAndDispatch());
 }
 
 TEST_F(ServiceTest, ReceiveAndDispatchImpulse) {
   MessageInfo info;
   SetupMessageInfoAndDefaultExpectations(&info, kTestOp, true);
 
-  auto on_receive = [&info](Message* message) {
+  auto on_receive = [&info](Message* message) -> Status<void> {
     *message = Message{info};
-    return 0;
+    return {};
   };
   EXPECT_CALL(*endpoint(), MessageReceive(_)).WillOnce(Invoke(on_receive));
   EXPECT_CALL(*service_, HandleImpulse(_));
 
-  EXPECT_EQ(0, service_->ReceiveAndDispatch());
+  EXPECT_TRUE(service_->ReceiveAndDispatch());
 }
 
 TEST_F(ServiceTest, Cancel) {
-  EXPECT_CALL(*endpoint(), Cancel()).WillOnce(Return(0));
-  EXPECT_EQ(0, service_->Cancel());
+  EXPECT_CALL(*endpoint(), Cancel()).WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(service_->Cancel());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -380,85 +387,85 @@
 
 TEST_F(ServiceMessageTest, Reply) {
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), 12))
-      .WillOnce(Return(0));
+      .WillOnce(Return(Status<void>{}));
   EXPECT_FALSE(message_->replied());
-  EXPECT_EQ(0, message_->Reply(12));
+  EXPECT_TRUE(message_->Reply(12));
   EXPECT_TRUE(message_->replied());
 
-  EXPECT_EQ(-EINVAL, message_->Reply(12));  // Already replied.
+  EXPECT_EQ(EINVAL, message_->Reply(12).error());  // Already replied.
 }
 
 TEST_F(ServiceMessageTest, ReplyFail) {
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), 12))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(-EIO, message_->Reply(12));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(EIO, message_->Reply(12).error());
 
   ExpectDefaultHandleMessage();
 }
 
 TEST_F(ServiceMessageTest, ReplyError) {
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), -12))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->ReplyError(12));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->ReplyError(12));
 }
 
 TEST_F(ServiceMessageTest, ReplyFileDescriptor) {
   EXPECT_CALL(*endpoint(), MessageReplyFd(message_.get(), 5))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->ReplyFileDescriptor(5));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->ReplyFileDescriptor(5));
 }
 
 TEST_F(ServiceMessageTest, ReplyLocalFileHandle) {
   const int kFakeFd = 12345;
   LocalHandle handle{kFakeFd};
   EXPECT_CALL(*endpoint(), MessageReplyFd(message_.get(), kFakeFd))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
   handle.Release();  // Make sure we do not close the fake file descriptor.
 }
 
 TEST_F(ServiceMessageTest, ReplyLocalFileHandleError) {
   LocalHandle handle{-EINVAL};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), -EINVAL))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyBorrowedFileHandle) {
   const int kFakeFd = 12345;
   BorrowedHandle handle{kFakeFd};
   EXPECT_CALL(*endpoint(), MessageReplyFd(message_.get(), kFakeFd))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyBorrowedFileHandleError) {
   BorrowedHandle handle{-EACCES};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), -EACCES))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyRemoteFileHandle) {
   RemoteHandle handle{123};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), handle.Get()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyRemoteFileHandleError) {
   RemoteHandle handle{-EIO};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), -EIO))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyLocalChannelHandle) {
   LocalChannelHandle handle{nullptr, 12345};
   EXPECT_CALL(*endpoint(), MessageReplyChannelHandle(
                                message_.get(), A<const LocalChannelHandle&>()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyBorrowedChannelHandle) {
@@ -466,30 +473,30 @@
   EXPECT_CALL(*endpoint(),
               MessageReplyChannelHandle(message_.get(),
                                         A<const BorrowedChannelHandle&>()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyRemoteChannelHandle) {
   RemoteChannelHandle handle{12345};
   EXPECT_CALL(*endpoint(), MessageReplyChannelHandle(
                                message_.get(), A<const RemoteChannelHandle&>()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(handle));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(handle));
 }
 
 TEST_F(ServiceMessageTest, ReplyStatusInt) {
   Status<int> status{123};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), status.get()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(status));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(status));
 }
 
 TEST_F(ServiceMessageTest, ReplyStatusError) {
   Status<int> status{ErrorStatus{EIO}};
   EXPECT_CALL(*endpoint(), MessageReply(message_.get(), -status.error()))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->Reply(status));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->Reply(status));
 }
 
 TEST_F(ServiceMessageTest, Read) {
@@ -500,9 +507,9 @@
       *endpoint(),
       ReadMessageData(message_.get(), IoVecMatcher(kDataBuffer, kDataSize), 1))
       .WillOnce(Return(50))
-      .WillOnce(SetErrnoAndReturn(EACCES, -1));
-  EXPECT_EQ(50, message_->Read(kDataBuffer, kDataSize));
-  EXPECT_EQ(-EACCES, message_->Read(kDataBuffer, kDataSize));
+      .WillOnce(Return(ErrorStatus{EACCES}));
+  EXPECT_EQ(50u, message_->Read(kDataBuffer, kDataSize).get());
+  EXPECT_EQ(EACCES, message_->Read(kDataBuffer, kDataSize).error());
 }
 
 TEST_F(ServiceMessageTest, ReadVector) {
@@ -516,10 +523,10 @@
                   IoVecMatcher(IoVecArray{std::begin(vec), std::end(vec)}), 2))
       .WillOnce(Return(30))
       .WillOnce(Return(15))
-      .WillOnce(SetErrnoAndReturn(EBADF, -1));
-  EXPECT_EQ(30, message_->ReadVector(vec, 2));
-  EXPECT_EQ(15, message_->ReadVector(vec));
-  EXPECT_EQ(-EBADF, message_->ReadVector(vec));
+      .WillOnce(Return(ErrorStatus{EBADF}));
+  EXPECT_EQ(30u, message_->ReadVector(vec, 2).get());
+  EXPECT_EQ(15u, message_->ReadVector(vec).get());
+  EXPECT_EQ(EBADF, message_->ReadVector(vec).error());
 }
 
 TEST_F(ServiceMessageTest, Write) {
@@ -530,9 +537,9 @@
       *endpoint(),
       WriteMessageData(message_.get(), IoVecMatcher(kDataBuffer, kDataSize), 1))
       .WillOnce(Return(50))
-      .WillOnce(SetErrnoAndReturn(EBADMSG, -1));
-  EXPECT_EQ(50, message_->Write(kDataBuffer, kDataSize));
-  EXPECT_EQ(-EBADMSG, message_->Write(kDataBuffer, kDataSize));
+      .WillOnce(Return(ErrorStatus{EBADMSG}));
+  EXPECT_EQ(50u, message_->Write(kDataBuffer, kDataSize).get());
+  EXPECT_EQ(EBADMSG, message_->Write(kDataBuffer, kDataSize).error());
 }
 
 TEST_F(ServiceMessageTest, WriteVector) {
@@ -546,10 +553,10 @@
                   IoVecMatcher(IoVecArray{std::begin(vec), std::end(vec)}), 2))
       .WillOnce(Return(30))
       .WillOnce(Return(15))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(30, message_->WriteVector(vec, 2));
-  EXPECT_EQ(15, message_->WriteVector(vec));
-  EXPECT_EQ(-EIO, message_->WriteVector(vec, 2));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(30u, message_->WriteVector(vec, 2).get());
+  EXPECT_EQ(15u, message_->WriteVector(vec).get());
+  EXPECT_EQ(EIO, message_->WriteVector(vec, 2).error());
 }
 
 TEST_F(ServiceMessageTest, PushLocalFileHandle) {
@@ -560,9 +567,9 @@
               PushFileHandle(message_.get(), Matcher<const LocalHandle&>(
                                                  FileHandleMatcher(kFakeFd))))
       .WillOnce(Return(12))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(12, message_->PushFileHandle(handle));
-  EXPECT_EQ(-EIO, message_->PushFileHandle(handle));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(12, message_->PushFileHandle(handle).get());
+  EXPECT_EQ(EIO, message_->PushFileHandle(handle).error());
   handle.Release();  // Make sure we do not close the fake file descriptor.
 }
 
@@ -574,9 +581,9 @@
               PushFileHandle(message_.get(), Matcher<const BorrowedHandle&>(
                                                  FileHandleMatcher(kFakeFd))))
       .WillOnce(Return(13))
-      .WillOnce(SetErrnoAndReturn(EACCES, -1));
-  EXPECT_EQ(13, message_->PushFileHandle(handle));
-  EXPECT_EQ(-EACCES, message_->PushFileHandle(handle));
+      .WillOnce(Return(ErrorStatus{EACCES}));
+  EXPECT_EQ(13, message_->PushFileHandle(handle).get());
+  EXPECT_EQ(EACCES, message_->PushFileHandle(handle).error());
 }
 
 TEST_F(ServiceMessageTest, PushRemoteFileHandle) {
@@ -587,9 +594,9 @@
               PushFileHandle(message_.get(), Matcher<const RemoteHandle&>(
                                                  FileHandleMatcher(kFakeFd))))
       .WillOnce(Return(kFakeFd))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(kFakeFd, message_->PushFileHandle(handle));
-  EXPECT_EQ(-EIO, message_->PushFileHandle(handle));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(kFakeFd, message_->PushFileHandle(handle).get());
+  EXPECT_EQ(EIO, message_->PushFileHandle(handle).error());
 }
 
 TEST_F(ServiceMessageTest, PushLocalChannelHandle) {
@@ -600,9 +607,9 @@
                                              Matcher<const LocalChannelHandle&>(
                                                  ChannelHandleMatcher(kValue))))
       .WillOnce(Return(7))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(7, message_->PushChannelHandle(handle));
-  EXPECT_EQ(-EIO, message_->PushChannelHandle(handle));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(7, message_->PushChannelHandle(handle).get());
+  EXPECT_EQ(EIO, message_->PushChannelHandle(handle).error());
 }
 
 TEST_F(ServiceMessageTest, PushBorrowedChannelHandle) {
@@ -614,9 +621,9 @@
       PushChannelHandle(message_.get(), Matcher<const BorrowedChannelHandle&>(
                                             ChannelHandleMatcher(kValue))))
       .WillOnce(Return(8))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(8, message_->PushChannelHandle(handle));
-  EXPECT_EQ(-EIO, message_->PushChannelHandle(handle));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(8, message_->PushChannelHandle(handle).get());
+  EXPECT_EQ(EIO, message_->PushChannelHandle(handle).error());
 }
 
 TEST_F(ServiceMessageTest, PushRemoteChannelHandle) {
@@ -628,9 +635,9 @@
       PushChannelHandle(message_.get(), Matcher<const RemoteChannelHandle&>(
                                             ChannelHandleMatcher(kValue))))
       .WillOnce(Return(kValue))
-      .WillOnce(SetErrnoAndReturn(EIO, -1));
-  EXPECT_EQ(kValue, message_->PushChannelHandle(handle));
-  EXPECT_EQ(-EIO, message_->PushChannelHandle(handle));
+      .WillOnce(Return(ErrorStatus{EIO}));
+  EXPECT_EQ(kValue, message_->PushChannelHandle(handle).get());
+  EXPECT_EQ(EIO, message_->PushChannelHandle(handle).error());
 }
 
 TEST_F(ServiceMessageTest, GetFileHandle) {
@@ -701,8 +708,8 @@
   int kClearMask = 1;
   int kSetMask = 2;
   EXPECT_CALL(*endpoint(), ModifyChannelEvents(kTestCid, kClearMask, kSetMask))
-      .WillOnce(Return(0));
-  EXPECT_EQ(0, message_->ModifyChannelEvents(kClearMask, kSetMask));
+      .WillOnce(Return(Status<void>{}));
+  EXPECT_TRUE(message_->ModifyChannelEvents(kClearMask, kSetMask));
 }
 
 TEST_F(ServiceMessageTest, PushChannelSameService) {
@@ -733,7 +740,9 @@
 TEST_F(ServiceMessageTest, PushChannelDifferentService) {
   ExpectDefaultHandleMessage();
   auto endpoint2 = std::make_unique<testing::StrictMock<MockEndpoint>>();
-  EXPECT_CALL(*endpoint2, SetService(_)).Times(2).WillRepeatedly(Return(0));
+  EXPECT_CALL(*endpoint2, SetService(_))
+      .Times(2)
+      .WillRepeatedly(Return(Status<void>{}));
   auto service2 =
       std::make_shared<MockService>("MockSvc2", std::move(endpoint2));
 
@@ -779,7 +788,9 @@
 TEST_F(ServiceMessageTest, CheckChannelDifferentService) {
   ExpectDefaultHandleMessage();
   auto endpoint2 = std::make_unique<testing::StrictMock<MockEndpoint>>();
-  EXPECT_CALL(*endpoint2, SetService(_)).Times(2).WillRepeatedly(Return(0));
+  EXPECT_CALL(*endpoint2, SetService(_))
+      .Times(2)
+      .WillRepeatedly(Return(Status<void>{}));
   auto service2 =
       std::make_shared<MockService>("MockSvc2", std::move(endpoint2));
 
diff --git a/libs/vr/libpdx_default_transport/pdx_benchmarks.cpp b/libs/vr/libpdx_default_transport/pdx_benchmarks.cpp
index de02401..0b658fb 100644
--- a/libs/vr/libpdx_default_transport/pdx_benchmarks.cpp
+++ b/libs/vr/libpdx_default_transport/pdx_benchmarks.cpp
@@ -38,6 +38,7 @@
 using android::pdx::Channel;
 using android::pdx::ClientBase;
 using android::pdx::Endpoint;
+using android::pdx::ErrorStatus;
 using android::pdx::Message;
 using android::pdx::Service;
 using android::pdx::ServiceBase;
@@ -246,7 +247,7 @@
             << message.GetChannelId();
   }
 
-  int HandleMessage(Message& message) override {
+  Status<void> HandleMessage(Message& message) override {
     ATRACE_NAME("BenchmarkService::HandleMessage");
 
     switch (message.GetOp()) {
@@ -254,30 +255,27 @@
         VLOG(1) << "BenchmarkService::HandleMessage: op=nop";
         {
           ATRACE_NAME("Reply");
-          CHECK(message.Reply(0) == 0);
+          CHECK(message.Reply(0));
         }
-        return 0;
+        return {};
 
       case BenchmarkOps::Write: {
         VLOG(1) << "BenchmarkService::HandleMessage: op=write send_length="
                 << message.GetSendLength()
                 << " receive_length=" << message.GetReceiveLength();
 
-        const ssize_t expected_length =
-            static_cast<ssize_t>(message.GetSendLength());
-        const ssize_t actual_length =
-            expected_length > 0
-                ? message.Read(send_buffer.data(), message.GetSendLength())
-                : 0;
+        Status<void> status;
+        if (message.GetSendLength())
+          status = message.ReadAll(send_buffer.data(), message.GetSendLength());
 
         {
           ATRACE_NAME("Reply");
-          if (actual_length < expected_length)
-            CHECK(message.ReplyError(EIO) == 0);
+          if (!status)
+            CHECK(message.ReplyError(status.error()));
           else
-            CHECK(message.Reply(actual_length) == 0);
+            CHECK(message.Reply(message.GetSendLength()));
         }
-        return 0;
+        return {};
       }
 
       case BenchmarkOps::Read: {
@@ -285,22 +283,20 @@
                 << message.GetSendLength()
                 << " receive_length=" << message.GetReceiveLength();
 
-        const ssize_t expected_length =
-            static_cast<ssize_t>(message.GetReceiveLength());
-        const ssize_t actual_length =
-            expected_length > 0
-                ? message.Write(receive_buffer.data(),
-                                message.GetReceiveLength())
-                : 0;
+        Status<void> status;
+        if (message.GetReceiveLength()) {
+          status = message.WriteAll(receive_buffer.data(),
+                                    message.GetReceiveLength());
+        }
 
         {
           ATRACE_NAME("Reply");
-          if (actual_length < expected_length)
-            CHECK(message.ReplyError(EIO) == 0);
+          if (!status)
+            CHECK(message.ReplyError(status.error()));
           else
-            CHECK(message.Reply(actual_length) == 0);
+            CHECK(message.Reply(message.GetReceiveLength()));
         }
-        return 0;
+        return {};
       }
 
       case BenchmarkOps::Echo: {
@@ -308,31 +304,28 @@
                 << message.GetSendLength()
                 << " receive_length=" << message.GetReceiveLength();
 
-        const ssize_t expected_length =
-            static_cast<ssize_t>(message.GetSendLength());
-        ssize_t actual_length =
-            expected_length > 0
-                ? message.Read(send_buffer.data(), message.GetSendLength())
-                : 0;
+        Status<void> status;
+        if (message.GetSendLength())
+          status = message.ReadAll(send_buffer.data(), message.GetSendLength());
 
-        if (actual_length < expected_length) {
-          CHECK(message.ReplyError(EIO) == 0);
-          return 0;
+        if (!status) {
+          CHECK(message.ReplyError(status.error()));
+          return {};
         }
 
-        actual_length =
-            expected_length > 0
-                ? message.Write(send_buffer.data(), message.GetSendLength())
-                : 0;
+        if (message.GetSendLength()) {
+          status =
+              message.WriteAll(send_buffer.data(), message.GetSendLength());
+        }
 
         {
           ATRACE_NAME("Reply");
-          if (actual_length < expected_length)
-            CHECK(message.ReplyError(EIO) == 0);
+          if (!status)
+            CHECK(message.ReplyError(status.error()));
           else
-            CHECK(message.Reply(actual_length) == 0);
+            CHECK(message.Reply(message.GetSendLength()));
         }
-        return 0;
+        return {};
       }
 
       case BenchmarkOps::Stats: {
@@ -348,7 +341,7 @@
         RemoteMethodReturn<BenchmarkRPC::Stats>(
             message, BenchmarkRPC::Stats::Return{receive_time_ns, GetClockNs(),
                                                  sched_stats_});
-        return 0;
+        return {};
       }
 
       case BenchmarkOps::WriteVector:
@@ -358,7 +351,7 @@
 
         DispatchRemoteMethod<BenchmarkRPC::WriteVector>(
             *this, &BenchmarkService::OnWriteVector, message, kMaxMessageSize);
-        return 0;
+        return {};
 
       case BenchmarkOps::EchoVector:
         VLOG(1) << "BenchmarkService::HandleMessage: op=echovec send_length="
@@ -367,11 +360,11 @@
 
         DispatchRemoteMethod<BenchmarkRPC::EchoVector>(
             *this, &BenchmarkService::OnEchoVector, message, kMaxMessageSize);
-        return 0;
+        return {};
 
       case BenchmarkOps::Quit:
         Cancel();
-        return -ESHUTDOWN;
+        return ErrorStatus{ESHUTDOWN};
 
       default:
         VLOG(1) << "BenchmarkService::HandleMessage: default case; op="
@@ -543,17 +536,17 @@
               const std::shared_ptr<BenchmarkService>& local_service) {
             SetThreadName("service" + std::to_string(service_id));
 
-            // Read the inital schedstats for this thread from procfs.
+            // Read the initial schedstats for this thread from procfs.
             local_service->UpdateSchedStats();
 
             ATRACE_NAME("BenchmarkService::Dispatch");
             while (!done) {
-              const int ret = local_service->ReceiveAndDispatch();
-              if (ret < 0) {
-                if (ret != -ESHUTDOWN) {
+              auto ret = local_service->ReceiveAndDispatch();
+              if (!ret) {
+                if (ret.error() != ESHUTDOWN) {
                   std::cerr << "Error while dispatching message on thread "
                             << thread_id << " service " << service_id << ": "
-                            << strerror(-ret) << std::endl;
+                            << ret.GetErrorMessage() << std::endl;
                 } else {
                   std::cerr << "Quitting thread " << thread_id << " service "
                             << service_id << std::endl;
diff --git a/libs/vr/libpdx_uds/Android.bp b/libs/vr/libpdx_uds/Android.bp
index 09eeaa0..9f308ec 100644
--- a/libs/vr/libpdx_uds/Android.bp
+++ b/libs/vr/libpdx_uds/Android.bp
@@ -41,6 +41,8 @@
         "libpdx",
     ],
     shared_libs: [
+        "libbase",
+        "libcutils",
         "liblog",
         "libutils",
     ],
diff --git a/libs/vr/libpdx_uds/ipc_helper.cpp b/libs/vr/libpdx_uds/ipc_helper.cpp
index ee7299e..fe5c986 100644
--- a/libs/vr/libpdx_uds/ipc_helper.cpp
+++ b/libs/vr/libpdx_uds/ipc_helper.cpp
@@ -87,7 +87,7 @@
 OutputResourceMapper* SendPayload::GetOutputResourceMapper() { return this; }
 
 // OutputResourceMapper
-FileReference SendPayload::PushFileHandle(const LocalHandle& handle) {
+Status<FileReference> SendPayload::PushFileHandle(const LocalHandle& handle) {
   if (handle) {
     const int ref = file_handles_.size();
     file_handles_.push_back(handle.Get());
@@ -97,7 +97,8 @@
   }
 }
 
-FileReference SendPayload::PushFileHandle(const BorrowedHandle& handle) {
+Status<FileReference> SendPayload::PushFileHandle(
+    const BorrowedHandle& handle) {
   if (handle) {
     const int ref = file_handles_.size();
     file_handles_.push_back(handle.Get());
@@ -107,21 +108,21 @@
   }
 }
 
-FileReference SendPayload::PushFileHandle(const RemoteHandle& handle) {
+Status<FileReference> SendPayload::PushFileHandle(const RemoteHandle& handle) {
   return handle.Get();
 }
 
-ChannelReference SendPayload::PushChannelHandle(
+Status<ChannelReference> SendPayload::PushChannelHandle(
     const LocalChannelHandle& /*handle*/) {
-  return -1;
+  return ErrorStatus{EOPNOTSUPP};
 }
-ChannelReference SendPayload::PushChannelHandle(
+Status<ChannelReference> SendPayload::PushChannelHandle(
     const BorrowedChannelHandle& /*handle*/) {
-  return -1;
+  return ErrorStatus{EOPNOTSUPP};
 }
-ChannelReference SendPayload::PushChannelHandle(
+Status<ChannelReference> SendPayload::PushChannelHandle(
     const RemoteChannelHandle& /*handle*/) {
-  return -1;
+  return ErrorStatus{EOPNOTSUPP};
 }
 
 Status<void> ReceivePayload::Receive(int socket_fd) {
diff --git a/libs/vr/libpdx_uds/private/uds/ipc_helper.h b/libs/vr/libpdx_uds/private/uds/ipc_helper.h
index 00f3490..80530bf 100644
--- a/libs/vr/libpdx_uds/private/uds/ipc_helper.h
+++ b/libs/vr/libpdx_uds/private/uds/ipc_helper.h
@@ -33,13 +33,14 @@
   OutputResourceMapper* GetOutputResourceMapper() override;
 
   // OutputResourceMapper
-  FileReference PushFileHandle(const LocalHandle& handle) override;
-  FileReference PushFileHandle(const BorrowedHandle& handle) override;
-  FileReference PushFileHandle(const RemoteHandle& handle) override;
-  ChannelReference PushChannelHandle(const LocalChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<FileReference> PushFileHandle(const LocalHandle& handle) override;
+  Status<FileReference> PushFileHandle(const BorrowedHandle& handle) override;
+  Status<FileReference> PushFileHandle(const RemoteHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
+      const LocalChannelHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
       const BorrowedChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<ChannelReference> PushChannelHandle(
       const RemoteChannelHandle& handle) override;
 
  private:
diff --git a/libs/vr/libpdx_uds/private/uds/service_endpoint.h b/libs/vr/libpdx_uds/private/uds/service_endpoint.h
index 3ec8519..9d038cb 100644
--- a/libs/vr/libpdx_uds/private/uds/service_endpoint.h
+++ b/libs/vr/libpdx_uds/private/uds/service_endpoint.h
@@ -39,41 +39,40 @@
   ~Endpoint() override = default;
 
   uint32_t GetIpcTag() const override { return kIpcTag; }
-  int SetService(Service* service) override;
-  int SetChannel(int channel_id, Channel* channel) override;
-  int CloseChannel(int channel_id) override;
-  int ModifyChannelEvents(int channel_id, int clear_mask,
-                          int set_mask) override;
+  Status<void> SetService(Service* service) override;
+  Status<void> SetChannel(int channel_id, Channel* channel) override;
+  Status<void> CloseChannel(int channel_id) override;
+  Status<void> ModifyChannelEvents(int channel_id, int clear_mask,
+                                   int set_mask) override;
   Status<RemoteChannelHandle> PushChannel(Message* message, int flags,
                                           Channel* channel,
                                           int* channel_id) override;
   Status<int> CheckChannel(const Message* message, ChannelReference ref,
                            Channel** channel) override;
-  int DefaultHandleMessage(const MessageInfo& info) override;
-  int MessageReceive(Message* message) override;
-  int MessageReply(Message* message, int return_code) override;
-  int MessageReplyFd(Message* message, unsigned int push_fd) override;
-  int MessageReplyChannelHandle(Message* message,
-                                const LocalChannelHandle& handle) override;
-  int MessageReplyChannelHandle(Message* message,
-                                const BorrowedChannelHandle& handle) override;
-  int MessageReplyChannelHandle(Message* message,
-                                const RemoteChannelHandle& handle) override;
-  ssize_t ReadMessageData(Message* message, const iovec* vector,
-                          size_t vector_length) override;
-  ssize_t WriteMessageData(Message* message, const iovec* vector,
-                           size_t vector_length) override;
-  FileReference PushFileHandle(Message* message,
-                               const LocalHandle& handle) override;
-  FileReference PushFileHandle(Message* message,
-                               const BorrowedHandle& handle) override;
-  FileReference PushFileHandle(Message* message,
-                               const RemoteHandle& handle) override;
-  ChannelReference PushChannelHandle(Message* message,
-                                     const LocalChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<void> MessageReceive(Message* message) override;
+  Status<void> MessageReply(Message* message, int return_code) override;
+  Status<void> MessageReplyFd(Message* message, unsigned int push_fd) override;
+  Status<void> MessageReplyChannelHandle(
+      Message* message, const LocalChannelHandle& handle) override;
+  Status<void> MessageReplyChannelHandle(
       Message* message, const BorrowedChannelHandle& handle) override;
-  ChannelReference PushChannelHandle(
+  Status<void> MessageReplyChannelHandle(
+      Message* message, const RemoteChannelHandle& handle) override;
+  Status<size_t> ReadMessageData(Message* message, const iovec* vector,
+                                 size_t vector_length) override;
+  Status<size_t> WriteMessageData(Message* message, const iovec* vector,
+                                  size_t vector_length) override;
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const LocalHandle& handle) override;
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const BorrowedHandle& handle) override;
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const RemoteHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
+      Message* message, const LocalChannelHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
+      Message* message, const BorrowedChannelHandle& handle) override;
+  Status<ChannelReference> PushChannelHandle(
       Message* message, const RemoteChannelHandle& handle) override;
   LocalHandle GetFileHandle(Message* message, FileReference ref) const override;
   LocalChannelHandle GetChannelHandle(Message* message,
@@ -82,15 +81,22 @@
   void* AllocateMessageState() override;
   void FreeMessageState(void* state) override;
 
-  int Cancel() override;
+  Status<void> Cancel() override;
 
   // Open an endpoint at the given path.
   // Second parameter is unused for UDS, but we have it here for compatibility
   // in signature with servicefs::Endpoint::Create().
+  // This method uses |endpoint_path| as a relative path to endpoint socket
+  // created by init process.
   static std::unique_ptr<Endpoint> Create(const std::string& endpoint_path,
                                           mode_t /*unused_mode*/ = kDefaultMode,
                                           bool blocking = kDefaultBlocking);
 
+  // Helper method to create an endpoint at the given UDS socket path. This
+  // method physically creates and binds a socket at that path.
+  static std::unique_ptr<Endpoint> CreateAndBindSocket(
+      const std::string& endpoint_path, bool blocking = kDefaultBlocking);
+
   int epoll_fd() const { return epoll_fd_.Get(); }
 
  private:
@@ -117,7 +123,7 @@
   Status<void> OnNewChannel(LocalHandle channel_fd);
   Status<ChannelData*> OnNewChannelLocked(LocalHandle channel_fd,
                                           Channel* channel_state);
-  int CloseChannelLocked(int channel_id);
+  Status<void> CloseChannelLocked(int channel_id);
   Status<void> ReenableEpollEvent(int fd);
   Channel* GetChannelState(int channel_id);
   int GetChannelSocketFd(int channel_id);
diff --git a/libs/vr/libpdx_uds/remote_method_tests.cpp b/libs/vr/libpdx_uds/remote_method_tests.cpp
index 9050500..3109753 100644
--- a/libs/vr/libpdx_uds/remote_method_tests.cpp
+++ b/libs/vr/libpdx_uds/remote_method_tests.cpp
@@ -342,87 +342,87 @@
 // Test service that encodes/decodes messages from clients.
 class TestService : public ServiceBase<TestService> {
  public:
-  int HandleMessage(Message& message) override {
+  Status<void> HandleMessage(Message& message) override {
     switch (message.GetOp()) {
       case TestInterface::Add::Opcode:
         DispatchRemoteMethod<TestInterface::Add>(*this, &TestService::OnAdd,
                                                  message);
-        return 0;
+        return {};
 
       case TestInterface::Foo::Opcode:
         DispatchRemoteMethod<TestInterface::Foo>(*this, &TestService::OnFoo,
                                                  message);
-        return 0;
+        return {};
 
       case TestInterface::Concatenate::Opcode:
         DispatchRemoteMethod<TestInterface::Concatenate>(
             *this, &TestService::OnConcatenate, message);
-        return 0;
+        return {};
 
       case TestInterface::SumVector::Opcode:
         DispatchRemoteMethod<TestInterface::SumVector>(
             *this, &TestService::OnSumVector, message);
-        return 0;
+        return {};
 
       case TestInterface::StringLength::Opcode:
         DispatchRemoteMethod<TestInterface::StringLength>(
             *this, &TestService::OnStringLength, message);
-        return 0;
+        return {};
 
       case TestInterface::SendTestType::Opcode:
         DispatchRemoteMethod<TestInterface::SendTestType>(
             *this, &TestService::OnSendTestType, message);
-        return 0;
+        return {};
 
       case TestInterface::SendVector::Opcode:
         DispatchRemoteMethod<TestInterface::SendVector>(
             *this, &TestService::OnSendVector, message);
-        return 0;
+        return {};
 
       case TestInterface::Rot13::Opcode:
         DispatchRemoteMethod<TestInterface::Rot13>(*this, &TestService::OnRot13,
                                                    message);
-        return 0;
+        return {};
 
       case TestInterface::NoArgs::Opcode:
         DispatchRemoteMethod<TestInterface::NoArgs>(
             *this, &TestService::OnNoArgs, message);
-        return 0;
+        return {};
 
       case TestInterface::SendFile::Opcode:
         DispatchRemoteMethod<TestInterface::SendFile>(
             *this, &TestService::OnSendFile, message);
-        return 0;
+        return {};
 
       case TestInterface::GetFile::Opcode:
         DispatchRemoteMethod<TestInterface::GetFile>(
             *this, &TestService::OnGetFile, message);
-        return 0;
+        return {};
 
       case TestInterface::GetTestFdType::Opcode:
         DispatchRemoteMethod<TestInterface::GetTestFdType>(
             *this, &TestService::OnGetTestFdType, message);
-        return 0;
+        return {};
 
       case TestInterface::OpenFiles::Opcode:
         DispatchRemoteMethod<TestInterface::OpenFiles>(
             *this, &TestService::OnOpenFiles, message);
-        return 0;
+        return {};
 
       case TestInterface::ReadFile::Opcode:
         DispatchRemoteMethod<TestInterface::ReadFile>(
             *this, &TestService::OnReadFile, message);
-        return 0;
+        return {};
 
       case TestInterface::PushChannel::Opcode:
         DispatchRemoteMethod<TestInterface::PushChannel>(
             *this, &TestService::OnPushChannel, message);
-        return 0;
+        return {};
 
       case TestInterface::Positive::Opcode:
         DispatchRemoteMethod<TestInterface::Positive>(
             *this, &TestService::OnPositive, message);
-        return 0;
+        return {};
 
       default:
         return Service::DefaultHandleMessage(message);
@@ -433,7 +433,8 @@
   friend BASE;
 
   TestService()
-      : BASE("TestService", Endpoint::Create(TestInterface::kClientPath)) {}
+      : BASE("TestService",
+             Endpoint::CreateAndBindSocket(TestInterface::kClientPath)) {}
 
   int OnAdd(Message&, int a, int b) { return a + b; }
 
diff --git a/libs/vr/libpdx_uds/service_endpoint.cpp b/libs/vr/libpdx_uds/service_endpoint.cpp
index 7bf753d..f89b8a8 100644
--- a/libs/vr/libpdx_uds/service_endpoint.cpp
+++ b/libs/vr/libpdx_uds/service_endpoint.cpp
@@ -19,6 +19,7 @@
 using android::pdx::BorrowedChannelHandle;
 using android::pdx::BorrowedHandle;
 using android::pdx::ChannelReference;
+using android::pdx::ErrorStatus;
 using android::pdx::FileReference;
 using android::pdx::LocalChannelHandle;
 using android::pdx::LocalHandle;
@@ -51,14 +52,14 @@
     return true;
   }
 
-  FileReference PushFileHandle(BorrowedHandle handle) {
+  Status<FileReference> PushFileHandle(BorrowedHandle handle) {
     if (!handle)
       return handle.Get();
     response.file_descriptors.push_back(std::move(handle));
     return response.file_descriptors.size() - 1;
   }
 
-  ChannelReference PushChannelHandle(BorrowedChannelHandle handle) {
+  Status<ChannelReference> PushChannelHandle(BorrowedChannelHandle handle) {
     if (!handle)
       return handle.value();
 
@@ -70,14 +71,14 @@
       response.channels.push_back(std::move(channel_info));
       return response.channels.size() - 1;
     } else {
-      return -1;
+      return ErrorStatus{EINVAL};
     }
   }
 
-  ChannelReference PushChannelHandle(BorrowedHandle data_fd,
-                                     BorrowedHandle event_fd) {
+  Status<ChannelReference> PushChannelHandle(BorrowedHandle data_fd,
+                                             BorrowedHandle event_fd) {
     if (!data_fd || !event_fd)
-      return -1;
+      return ErrorStatus{EINVAL};
     ChannelInfo<BorrowedHandle> channel_info;
     channel_info.data_fd = std::move(data_fd);
     channel_info.event_fd = std::move(event_fd);
@@ -85,8 +86,8 @@
     return response.channels.size() - 1;
   }
 
-  ssize_t WriteData(const iovec* vector, size_t vector_length) {
-    ssize_t size = 0;
+  Status<size_t> WriteData(const iovec* vector, size_t vector_length) {
+    size_t size = 0;
     for (size_t i = 0; i < vector_length; i++) {
       const auto* data = reinterpret_cast<const uint8_t*>(vector[i].iov_base);
       response_data.insert(response_data.end(), data, data + vector[i].iov_len);
@@ -95,9 +96,9 @@
     return size;
   }
 
-  ssize_t ReadData(const iovec* vector, size_t vector_length) {
+  Status<size_t> ReadData(const iovec* vector, size_t vector_length) {
     size_t size_remaining = request_data.size() - request_data_read_pos;
-    ssize_t size = 0;
+    size_t size = 0;
     for (size_t i = 0; i < vector_length && size_remaining > 0; i++) {
       size_t size_to_copy = std::min(size_remaining, vector[i].iov_len);
       memcpy(vector[i].iov_base, request_data.data() + request_data_read_pos,
@@ -214,18 +215,18 @@
   return status;
 }
 
-int Endpoint::SetService(Service* service) {
+Status<void> Endpoint::SetService(Service* service) {
   service_ = service;
-  return 0;
+  return {};
 }
 
-int Endpoint::SetChannel(int channel_id, Channel* channel) {
+Status<void> Endpoint::SetChannel(int channel_id, Channel* channel) {
   std::lock_guard<std::mutex> autolock(channel_mutex_);
   auto channel_data = channels_.find(channel_id);
   if (channel_data == channels_.end())
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
   channel_data->second.channel_state = channel;
-  return 0;
+  return {};
 }
 
 Status<void> Endpoint::OnNewChannel(LocalHandle channel_fd) {
@@ -269,44 +270,46 @@
   return {};
 }
 
-int Endpoint::CloseChannel(int channel_id) {
+Status<void> Endpoint::CloseChannel(int channel_id) {
   std::lock_guard<std::mutex> autolock(channel_mutex_);
   return CloseChannelLocked(channel_id);
 }
 
-int Endpoint::CloseChannelLocked(int channel_id) {
+Status<void> Endpoint::CloseChannelLocked(int channel_id) {
   ALOGD_IF(TRACE, "Endpoint::CloseChannelLocked: channel_id=%d", channel_id);
 
   auto channel_data = channels_.find(channel_id);
   if (channel_data == channels_.end())
-    return -EINVAL;
+    return ErrorStatus{EINVAL};
 
-  int ret = 0;
+  Status<void> status;
   epoll_event dummy;  // See BUGS in man 2 epoll_ctl.
   if (epoll_ctl(epoll_fd_.Get(), EPOLL_CTL_DEL, channel_id, &dummy) < 0) {
-    ret = -errno;
+    status.SetError(errno);
     ALOGE(
         "Endpoint::CloseChannelLocked: Failed to remove channel from endpoint: "
         "%s\n",
         strerror(errno));
+  } else {
+    status.SetValue();
   }
 
   channels_.erase(channel_data);
-  return ret;
+  return status;
 }
 
-int Endpoint::ModifyChannelEvents(int channel_id, int clear_mask,
-                                  int set_mask) {
+Status<void> Endpoint::ModifyChannelEvents(int channel_id, int clear_mask,
+                                           int set_mask) {
   std::lock_guard<std::mutex> autolock(channel_mutex_);
 
   auto search = channels_.find(channel_id);
   if (search != channels_.end()) {
     auto& channel_data = search->second;
     channel_data.event_set.ModifyEvents(clear_mask, set_mask);
-    return 0;
+    return {};
   }
 
-  return -EINVAL;
+  return ErrorStatus{EINVAL};
 }
 
 Status<RemoteChannelHandle> Endpoint::PushChannel(Message* message,
@@ -337,17 +340,19 @@
   *channel_id = local_socket.Get();
   auto channel_data = OnNewChannelLocked(std::move(local_socket), channel);
   if (!channel_data)
-    return ErrorStatus(channel_data.error());
+    return channel_data.error_status();
 
   // Flags are ignored for now.
   // TODO(xiaohuit): Implement those.
 
   auto* state = static_cast<MessageState*>(message->GetState());
-  ChannelReference ref = state->PushChannelHandle(
+  Status<ChannelReference> ref = state->PushChannelHandle(
       remote_socket.Borrow(),
       channel_data.get()->event_set.event_fd().Borrow());
+  if (!ref)
+    return ref.error_status();
   state->sockets_to_close.push_back(std::move(remote_socket));
-  return RemoteChannelHandle{ref};
+  return RemoteChannelHandle{ref.get()};
 }
 
 Status<int> Endpoint::CheckChannel(const Message* /*message*/,
@@ -357,13 +362,6 @@
   return ErrorStatus(EFAULT);
 }
 
-int Endpoint::DefaultHandleMessage(const MessageInfo& /* info */) {
-  ALOGE(
-      "Endpoint::CheckChannel: Not implemented! Endpoint DefaultHandleMessage "
-      "does nothing!");
-  return 0;
-}
-
 Channel* Endpoint::GetChannelState(int channel_id) {
   std::lock_guard<std::mutex> autolock(channel_mutex_);
   auto channel_data = channels_.find(channel_id);
@@ -464,7 +462,7 @@
   *message = Message{info};
 }
 
-int Endpoint::MessageReceive(Message* message) {
+Status<void> Endpoint::MessageReceive(Message* message) {
   // Receive at most one event from the epoll set. This should prevent multiple
   // dispatch threads from attempting to handle messages on the same socket at
   // the same time.
@@ -474,40 +472,36 @@
   if (count < 0) {
     ALOGE("Endpoint::MessageReceive: Failed to wait for epoll events: %s\n",
           strerror(errno));
-    return -errno;
+    return ErrorStatus{errno};
   } else if (count == 0) {
-    return -ETIMEDOUT;
+    return ErrorStatus{ETIMEDOUT};
   }
 
   if (event.data.fd == cancel_event_fd_.Get()) {
-    return -ESHUTDOWN;
+    return ErrorStatus{ESHUTDOWN};
   }
 
   if (event.data.fd == socket_fd_.Get()) {
     auto status = AcceptConnection(message);
     if (!status)
-      return -status.error();
-    status = ReenableEpollEvent(socket_fd_.Get());
-    return status ? 0 : -status.error();
+      return status;
+    return ReenableEpollEvent(socket_fd_.Get());
   }
 
   int channel_id = event.data.fd;
   if (event.events & (EPOLLRDHUP | EPOLLHUP)) {
     BuildCloseMessage(channel_id, message);
-    return 0;
+    return {};
   }
 
-  auto status = ReceiveMessageForChannel(channel_id, message);
-  if (!status)
-    return -status.error();
-  return 0;
+  return ReceiveMessageForChannel(channel_id, message);
 }
 
-int Endpoint::MessageReply(Message* message, int return_code) {
+Status<void> Endpoint::MessageReply(Message* message, int return_code) {
   const int channel_id = message->GetChannelId();
   const int channel_socket = GetChannelSocketFd(channel_id);
   if (channel_socket < 0)
-    return -EBADF;
+    return ErrorStatus{EBADF};
 
   auto* state = static_cast<MessageState*>(message->GetState());
   switch (message->GetOp()) {
@@ -515,12 +509,17 @@
       return CloseChannel(channel_id);
 
     case opcodes::CHANNEL_OPEN:
-      if (return_code < 0)
+      if (return_code < 0) {
         return CloseChannel(channel_id);
-      // Reply with the event fd.
-      return_code = state->PushFileHandle(
-          BorrowedHandle{GetChannelEventFd(channel_socket)});
-      state->response_data.clear();  // Just in case...
+      } else {
+        // Reply with the event fd.
+        auto push_status = state->PushFileHandle(
+            BorrowedHandle{GetChannelEventFd(channel_socket)});
+        state->response_data.clear();  // Just in case...
+        if (!push_status)
+          return push_status.error_status();
+        return_code = push_status.get();
+      }
       break;
   }
 
@@ -535,76 +534,82 @@
   if (status)
     status = ReenableEpollEvent(channel_socket);
 
-  return status ? 0 : -status.error();
+  return status;
 }
 
-int Endpoint::MessageReplyFd(Message* message, unsigned int push_fd) {
+Status<void> Endpoint::MessageReplyFd(Message* message, unsigned int push_fd) {
   auto* state = static_cast<MessageState*>(message->GetState());
   auto ref = state->PushFileHandle(BorrowedHandle{static_cast<int>(push_fd)});
-  return MessageReply(message, ref);
+  if (!ref)
+    return ref.error_status();
+  return MessageReply(message, ref.get());
 }
 
-int Endpoint::MessageReplyChannelHandle(Message* message,
-                                        const LocalChannelHandle& handle) {
+Status<void> Endpoint::MessageReplyChannelHandle(
+    Message* message, const LocalChannelHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   auto ref = state->PushChannelHandle(handle.Borrow());
-  return MessageReply(message, ref);
+  if (!ref)
+    return ref.error_status();
+  return MessageReply(message, ref.get());
 }
 
-int Endpoint::MessageReplyChannelHandle(Message* message,
-                                        const BorrowedChannelHandle& handle) {
+Status<void> Endpoint::MessageReplyChannelHandle(
+    Message* message, const BorrowedChannelHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   auto ref = state->PushChannelHandle(handle.Duplicate());
-  return MessageReply(message, ref);
+  if (!ref)
+    return ref.error_status();
+  return MessageReply(message, ref.get());
 }
 
-int Endpoint::MessageReplyChannelHandle(Message* message,
-                                        const RemoteChannelHandle& handle) {
+Status<void> Endpoint::MessageReplyChannelHandle(
+    Message* message, const RemoteChannelHandle& handle) {
   return MessageReply(message, handle.value());
 }
 
-ssize_t Endpoint::ReadMessageData(Message* message, const iovec* vector,
-                                  size_t vector_length) {
+Status<size_t> Endpoint::ReadMessageData(Message* message, const iovec* vector,
+                                         size_t vector_length) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->ReadData(vector, vector_length);
 }
 
-ssize_t Endpoint::WriteMessageData(Message* message, const iovec* vector,
-                                   size_t vector_length) {
+Status<size_t> Endpoint::WriteMessageData(Message* message, const iovec* vector,
+                                          size_t vector_length) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->WriteData(vector, vector_length);
 }
 
-FileReference Endpoint::PushFileHandle(Message* message,
-                                       const LocalHandle& handle) {
+Status<FileReference> Endpoint::PushFileHandle(Message* message,
+                                               const LocalHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->PushFileHandle(handle.Borrow());
 }
 
-FileReference Endpoint::PushFileHandle(Message* message,
-                                       const BorrowedHandle& handle) {
+Status<FileReference> Endpoint::PushFileHandle(Message* message,
+                                               const BorrowedHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->PushFileHandle(handle.Duplicate());
 }
 
-FileReference Endpoint::PushFileHandle(Message* /*message*/,
-                                       const RemoteHandle& handle) {
+Status<FileReference> Endpoint::PushFileHandle(Message* /*message*/,
+                                               const RemoteHandle& handle) {
   return handle.Get();
 }
 
-ChannelReference Endpoint::PushChannelHandle(Message* message,
-                                             const LocalChannelHandle& handle) {
+Status<ChannelReference> Endpoint::PushChannelHandle(
+    Message* message, const LocalChannelHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->PushChannelHandle(handle.Borrow());
 }
 
-ChannelReference Endpoint::PushChannelHandle(
+Status<ChannelReference> Endpoint::PushChannelHandle(
     Message* message, const BorrowedChannelHandle& handle) {
   auto* state = static_cast<MessageState*>(message->GetState());
   return state->PushChannelHandle(handle.Duplicate());
 }
 
-ChannelReference Endpoint::PushChannelHandle(
+Status<ChannelReference> Endpoint::PushChannelHandle(
     Message* /*message*/, const RemoteChannelHandle& handle) {
   return handle.value();
 }
@@ -624,8 +629,10 @@
   return handle;
 }
 
-int Endpoint::Cancel() {
-  return (eventfd_write(cancel_event_fd_.Get(), 1) < 0) ? -errno : 0;
+Status<void> Endpoint::Cancel() {
+  if (eventfd_write(cancel_event_fd_.Get(), 1) < 0)
+    return ErrorStatus{errno};
+  return {};
 }
 
 std::unique_ptr<Endpoint> Endpoint::Create(const std::string& endpoint_path,
@@ -634,6 +641,14 @@
   return std::unique_ptr<Endpoint>(new Endpoint(endpoint_path, blocking));
 }
 
+std::unique_ptr<Endpoint> Endpoint::CreateAndBindSocket(
+    const std::string& endpoint_path, bool blocking) {
+  // TODO(avakulenko): When Endpoint can differentiate between absolute paths
+  // and relative paths/socket names created by the init process, change this
+  // code to reflect the fact that we want to use absolute paths here.
+  return std::unique_ptr<Endpoint>(new Endpoint(endpoint_path, blocking));
+}
+
 }  // namespace uds
 }  // namespace pdx
 }  // namespace android
diff --git a/libs/vr/libpdx_uds/service_framework_tests.cpp b/libs/vr/libpdx_uds/service_framework_tests.cpp
index 9e31e82..2943239 100644
--- a/libs/vr/libpdx_uds/service_framework_tests.cpp
+++ b/libs/vr/libpdx_uds/service_framework_tests.cpp
@@ -119,106 +119,106 @@
     }
   }
 
-  int HandleMessage(Message& message) override {
+  Status<void> HandleMessage(Message& message) override {
     switch (message.GetOp()) {
       case TEST_OP_GET_SERVICE_ID:
-        REPLY_MESSAGE_RETURN(message, service_id_, 0);
+        REPLY_MESSAGE_RETURN(message, service_id_, {});
 
       // Set the test channel to the TestChannel for the current channel. Other
       // messages can use this to perform tests.
       case TEST_OP_SET_TEST_CHANNEL:
         test_channel_ = message.GetChannel<TestChannel>();
-        REPLY_MESSAGE_RETURN(message, 0, 0);
+        REPLY_MESSAGE_RETURN(message, 0, {});
 
       // Return the channel id for the current channel.
       case TEST_OP_GET_THIS_CHANNEL_ID:
-        REPLY_MESSAGE_RETURN(message, message.GetChannelId(), 0);
+        REPLY_MESSAGE_RETURN(message, message.GetChannelId(), {});
 
       // Return the channel id for the test channel.
       case TEST_OP_GET_TEST_CHANNEL_ID:
         if (test_channel_)
-          REPLY_MESSAGE_RETURN(message, test_channel_->channel_id(), 0);
+          REPLY_MESSAGE_RETURN(message, test_channel_->channel_id(), {});
         else
-          REPLY_ERROR_RETURN(message, ENOENT, 0);
+          REPLY_ERROR_RETURN(message, ENOENT, {});
 
       // Test check channel feature.
       case TEST_OP_CHECK_CHANNEL_ID: {
         ChannelReference ref = 0;
-        if (message.Read(&ref, sizeof(ref)) < static_cast<ssize_t>(sizeof(ref)))
-          REPLY_ERROR_RETURN(message, EIO, 0);
+        if (!message.ReadAll(&ref, sizeof(ref)))
+          REPLY_ERROR_RETURN(message, EIO, {});
 
         const Status<int> ret = message.CheckChannel<TestChannel>(ref, nullptr);
-        REPLY_MESSAGE_RETURN(message, ret, 0);
+        REPLY_MESSAGE_RETURN(message, ret, {});
       }
 
       case TEST_OP_CHECK_CHANNEL_OBJECT: {
         std::shared_ptr<TestChannel> channel;
         ChannelReference ref = 0;
-        if (message.Read(&ref, sizeof(ref)) < static_cast<ssize_t>(sizeof(ref)))
-          REPLY_ERROR_RETURN(message, EIO, 0);
+        if (!message.ReadAll(&ref, sizeof(ref)))
+          REPLY_ERROR_RETURN(message, EIO, {});
 
         const Status<int> ret =
             message.CheckChannel<TestChannel>(ref, &channel);
         if (!ret)
-          REPLY_MESSAGE_RETURN(message, ret, 0);
+          REPLY_MESSAGE_RETURN(message, ret, {});
 
         if (channel != nullptr)
-          REPLY_MESSAGE_RETURN(message, channel->channel_id(), 0);
+          REPLY_MESSAGE_RETURN(message, channel->channel_id(), {});
         else
-          REPLY_ERROR_RETURN(message, ENODATA, 0);
+          REPLY_ERROR_RETURN(message, ENODATA, {});
       }
 
       case TEST_OP_CHECK_CHANNEL_FROM_OTHER_SERVICE: {
         ChannelReference ref = 0;
-        if (message.Read(&ref, sizeof(ref)) < static_cast<ssize_t>(sizeof(ref)))
-          REPLY_ERROR_RETURN(message, EIO, 0);
+        if (!message.ReadAll(&ref, sizeof(ref)))
+          REPLY_ERROR_RETURN(message, EIO, {});
 
         const Status<int> ret = message.CheckChannel<TestChannel>(
             other_service_.get(), ref, nullptr);
-        REPLY_MESSAGE_RETURN(message, ret, 0);
+        REPLY_MESSAGE_RETURN(message, ret, {});
       }
 
       case TEST_OP_GET_NEW_CHANNEL: {
         auto channel = std::make_shared<TestChannel>(-1);
         Status<RemoteChannelHandle> channel_handle =
             message.PushChannel(0, channel, &channel->channel_id_);
-        REPLY_MESSAGE_RETURN(message, channel_handle, 0);
+        REPLY_MESSAGE_RETURN(message, channel_handle, {});
       }
 
       case TEST_OP_GET_NEW_CHANNEL_FROM_OTHER_SERVICE: {
         if (!other_service_)
-          REPLY_ERROR_RETURN(message, EINVAL, 0);
+          REPLY_ERROR_RETURN(message, EINVAL, {});
 
         auto channel = std::make_shared<TestChannel>(-1);
         Status<RemoteChannelHandle> channel_handle = message.PushChannel(
             other_service_.get(), 0, channel, &channel->channel_id_);
-        REPLY_MESSAGE_RETURN(message, channel_handle, 0);
+        REPLY_MESSAGE_RETURN(message, channel_handle, {});
       }
 
       case TEST_OP_GET_THIS_PROCESS_ID:
-        REPLY_MESSAGE_RETURN(message, message.GetProcessId(), 0);
+        REPLY_MESSAGE_RETURN(message, message.GetProcessId(), {});
 
       case TEST_OP_GET_THIS_THREAD_ID:
-        REPLY_MESSAGE_RETURN(message, message.GetThreadId(), 0);
+        REPLY_MESSAGE_RETURN(message, message.GetThreadId(), {});
 
       case TEST_OP_GET_THIS_EUID:
-        REPLY_MESSAGE_RETURN(message, message.GetEffectiveUserId(), 0);
+        REPLY_MESSAGE_RETURN(message, message.GetEffectiveUserId(), {});
 
       case TEST_OP_GET_THIS_EGID:
-        REPLY_MESSAGE_RETURN(message, message.GetEffectiveGroupId(), 0);
+        REPLY_MESSAGE_RETURN(message, message.GetEffectiveGroupId(), {});
 
       case TEST_OP_POLLIN_FROM_SERVICE:
         REPLY_MESSAGE_RETURN(message, message.ModifyChannelEvents(0, EPOLLIN),
-                             0);
+                             {});
 
       case TEST_OP_SEND_LARGE_DATA_RETURN_SUM: {
         std::array<int, kLargeDataSize> data_array;
-        ssize_t size_to_read = data_array.size() * sizeof(int);
-        ssize_t read = message.Read(data_array.data(), size_to_read);
-        if (read < size_to_read)
-          REPLY_ERROR_RETURN(message, EIO, 0);
+        size_t size_to_read = data_array.size() * sizeof(int);
+        if (!message.ReadAll(data_array.data(), size_to_read)) {
+          REPLY_ERROR_RETURN(message, EIO, {});
+        }
         int sum = std::accumulate(data_array.begin(), data_array.end(), 0);
-        REPLY_MESSAGE_RETURN(message, sum, 0);
+        REPLY_MESSAGE_RETURN(message, sum, {});
       }
 
       default:
@@ -245,7 +245,7 @@
   TestService(const std::string& name,
               const std::shared_ptr<TestService>& other_service, bool blocking)
       : BASE(std::string("TestService") + name,
-             Endpoint::Create(kTestServicePath + name, blocking)),
+             Endpoint::CreateAndBindSocket(kTestServicePath + name, blocking)),
         other_service_(other_service),
         service_id_(service_counter_++) {}
 
@@ -300,7 +300,7 @@
   // Returns the channel id of the channel.
   int CheckChannelIdArgument(BorrowedChannelHandle channel) {
     Transaction trans{*this};
-    ChannelReference ref = trans.PushChannelHandle(channel);
+    ChannelReference ref = trans.PushChannelHandle(channel).get();
     return ReturnStatusOrError(trans.Send<int>(TEST_OP_CHECK_CHANNEL_ID, &ref,
                                                sizeof(ref), nullptr, 0));
   }
@@ -309,7 +309,7 @@
   // Returns the channel id of the channel exercising the context pointer.
   int CheckChannelObjectArgument(BorrowedChannelHandle channel) {
     Transaction trans{*this};
-    ChannelReference ref = trans.PushChannelHandle(channel);
+    ChannelReference ref = trans.PushChannelHandle(channel).get();
     return ReturnStatusOrError(trans.Send<int>(TEST_OP_CHECK_CHANNEL_OBJECT,
                                                &ref, sizeof(ref), nullptr, 0));
   }
@@ -318,7 +318,7 @@
   // Returns 0 on success.
   int CheckChannelFromOtherService(BorrowedChannelHandle channel) {
     Transaction trans{*this};
-    ChannelReference ref = trans.PushChannelHandle(channel);
+    ChannelReference ref = trans.PushChannelHandle(channel).get();
     return ReturnStatusOrError(
         trans.Send<int>(TEST_OP_CHECK_CHANNEL_FROM_OTHER_SERVICE, &ref,
                         sizeof(ref), nullptr, 0));
diff --git a/libs/vr/libvrflinger/display_manager_service.cpp b/libs/vr/libvrflinger/display_manager_service.cpp
index e07901d..49b6f09 100644
--- a/libs/vr/libvrflinger/display_manager_service.cpp
+++ b/libs/vr/libvrflinger/display_manager_service.cpp
@@ -32,12 +32,12 @@
 namespace dvr {
 
 void DisplayManager::SetNotificationsPending(bool pending) {
-  int ret = service_->ModifyChannelEvents(channel_id_, pending ? 0 : POLLIN,
-                                          pending ? POLLIN : 0);
-  ALOGE_IF(ret < 0,
+  auto status = service_->ModifyChannelEvents(channel_id_, pending ? 0 : POLLIN,
+                                              pending ? POLLIN : 0);
+  ALOGE_IF(!status,
            "DisplayManager::SetNotificationPending: Failed to modify channel "
            "events: %s",
-           strerror(-ret));
+           status.GetErrorMessage().c_str());
 }
 
 DisplayManagerService::DisplayManagerService(
@@ -68,24 +68,24 @@
     display_manager_ = nullptr;
 }
 
-int DisplayManagerService::HandleMessage(pdx::Message& message) {
+pdx::Status<void> DisplayManagerService::HandleMessage(pdx::Message& message) {
   auto channel = std::static_pointer_cast<DisplayManager>(message.GetChannel());
 
   switch (message.GetOp()) {
     case DisplayManagerRPC::GetSurfaceList::Opcode:
       DispatchRemoteMethod<DisplayManagerRPC::GetSurfaceList>(
           *this, &DisplayManagerService::OnGetSurfaceList, message);
-      return 0;
+      return {};
 
     case DisplayManagerRPC::UpdateSurfaces::Opcode:
       DispatchRemoteMethod<DisplayManagerRPC::UpdateSurfaces>(
           *this, &DisplayManagerService::OnUpdateSurfaces, message);
-      return 0;
+      return {};
 
   case DisplayManagerRPC::SetupPoseBuffer::Opcode:
       DispatchRemoteMethod<DisplayManagerRPC::SetupPoseBuffer>(
           *this, &DisplayManagerService::OnSetupPoseBuffer, message);
-      return 0;
+      return {};
 
     default:
       return Service::DefaultHandleMessage(message);
@@ -189,7 +189,7 @@
 }
 
 pdx::BorrowedChannelHandle DisplayManagerService::OnSetupPoseBuffer(
-    pdx::Message& message, size_t extended_region_size, int usage) {
+    pdx::Message& /*message*/, size_t extended_region_size, int usage) {
   return display_service_->SetupPoseBuffer(extended_region_size, usage);
 }
 
diff --git a/libs/vr/libvrflinger/display_manager_service.h b/libs/vr/libvrflinger/display_manager_service.h
index 19098c2..80324fd 100644
--- a/libs/vr/libvrflinger/display_manager_service.h
+++ b/libs/vr/libvrflinger/display_manager_service.h
@@ -42,7 +42,7 @@
   std::shared_ptr<pdx::Channel> OnChannelOpen(pdx::Message& message) override;
   void OnChannelClose(pdx::Message& message,
                       const std::shared_ptr<pdx::Channel>& channel) override;
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
 
  private:
   friend BASE;
diff --git a/libs/vr/libvrflinger/display_service.cpp b/libs/vr/libvrflinger/display_service.cpp
index c079187..3750ea3 100644
--- a/libs/vr/libvrflinger/display_service.cpp
+++ b/libs/vr/libvrflinger/display_service.cpp
@@ -65,39 +65,39 @@
 // First-level dispatch for display service messages. Directly handles messages
 // that are independent of the display surface (metrics, creation) and routes
 // surface-specific messages to the per-instance handlers.
-int DisplayService::HandleMessage(pdx::Message& message) {
+pdx::Status<void> DisplayService::HandleMessage(pdx::Message& message) {
   auto channel = message.GetChannel<SurfaceChannel>();
 
   switch (message.GetOp()) {
     case DisplayRPC::GetMetrics::Opcode:
       DispatchRemoteMethod<DisplayRPC::GetMetrics>(
           *this, &DisplayService::OnGetMetrics, message);
-      return 0;
+      return {};
 
     case DisplayRPC::GetEdsCapture::Opcode:
       DispatchRemoteMethod<DisplayRPC::GetEdsCapture>(
           *this, &DisplayService::OnGetEdsCapture, message);
-      return 0;
+      return {};
 
     case DisplayRPC::CreateSurface::Opcode:
       DispatchRemoteMethod<DisplayRPC::CreateSurface>(
           *this, &DisplayService::OnCreateSurface, message);
-      return 0;
+      return {};
 
     case DisplayRPC::SetViewerParams::Opcode:
       DispatchRemoteMethod<DisplayRPC::SetViewerParams>(
           *this, &DisplayService::OnSetViewerParams, message);
-      return 0;
+      return {};
 
     case DisplayRPC::GetPoseBuffer::Opcode:
       DispatchRemoteMethod<DisplayRPC::GetPoseBuffer>(
           *this, &DisplayService::OnGetPoseBuffer, message);
-      return 0;
+      return {};
 
     case DisplayRPC::IsVrAppRunning::Opcode:
       DispatchRemoteMethod<DisplayRPC::IsVrAppRunning>(
           *this, &DisplayService::IsVrAppRunning, message);
-      return 0;
+      return {};
 
     // Direct the surface specific messages to the surface instance.
     case DisplayRPC::CreateBufferQueue::Opcode:
@@ -265,7 +265,7 @@
 
 // Calls the message handler for the DisplaySurface associated with this
 // channel.
-int DisplayService::HandleSurfaceMessage(pdx::Message& message) {
+pdx::Status<void> DisplayService::HandleSurfaceMessage(pdx::Message& message) {
   auto surface = std::static_pointer_cast<SurfaceChannel>(message.GetChannel());
   ALOGW_IF(!surface,
            "DisplayService::HandleSurfaceMessage: surface is nullptr!");
@@ -273,7 +273,7 @@
   if (surface)
     return surface->HandleMessage(message);
   else
-    REPLY_ERROR_RETURN(message, EINVAL, 0);
+    REPLY_ERROR_RETURN(message, EINVAL, {});
 }
 
 std::shared_ptr<DisplaySurface> DisplayService::GetDisplaySurface(
diff --git a/libs/vr/libvrflinger/display_service.h b/libs/vr/libvrflinger/display_service.h
index 8e96172..da80a84 100644
--- a/libs/vr/libvrflinger/display_service.h
+++ b/libs/vr/libvrflinger/display_service.h
@@ -27,7 +27,7 @@
 
   void OnChannelClose(pdx::Message& message,
                       const std::shared_ptr<pdx::Channel>& channel) override;
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
 
   std::shared_ptr<DisplaySurface> GetDisplaySurface(int surface_id) const;
   std::vector<std::shared_ptr<DisplaySurface>> GetDisplaySurfaces() const;
@@ -94,7 +94,7 @@
   // the display manager should be notified.
   void NotifyDisplayConfigurationUpdate();
 
-  int HandleSurfaceMessage(pdx::Message& message);
+  pdx::Status<void> HandleSurfaceMessage(pdx::Message& message);
 
   DisplayService(const DisplayService&) = delete;
   void operator=(const DisplayService&) = delete;
diff --git a/libs/vr/libvrflinger/display_surface.cpp b/libs/vr/libvrflinger/display_surface.cpp
index 66e9925..a7220fe 100644
--- a/libs/vr/libvrflinger/display_surface.cpp
+++ b/libs/vr/libvrflinger/display_surface.cpp
@@ -206,7 +206,7 @@
   return !acquired_buffers_.IsEmpty();
 }
 
-int DisplaySurface::HandleMessage(pdx::Message& message) {
+pdx::Status<void> DisplaySurface::HandleMessage(pdx::Message& message) {
   switch (message.GetOp()) {
     case DisplayRPC::SetAttributes::Opcode:
       DispatchRemoteMethod<DisplayRPC::SetAttributes>(
@@ -227,7 +227,7 @@
       return SurfaceChannel::HandleMessage(message);
   }
 
-  return 0;
+  return {};
 }
 
 int DisplaySurface::OnClientSetAttributes(
@@ -301,7 +301,7 @@
     pdx::Message& message) {
   if (flags_ & DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION) {
     ALOGE(
-        "DisplaySurface::OnCreateVideoMeshSurface: system distorion is "
+        "DisplaySurface::OnCreateVideoMeshSurface: system distortion is "
         "disabled on this display surface, cannot create VideoMeshSurface on "
         "top of it.");
     REPLY_ERROR_RETURN(message, EINVAL, {});
@@ -309,22 +309,21 @@
 
   int channel_id;
   auto status = message.PushChannel(0, nullptr, &channel_id);
-
   if (!status) {
     ALOGE(
         "DisplaySurface::OnCreateVideoMeshSurface: failed to push channel: %s",
         status.GetErrorMessage().c_str());
-    REPLY_ERROR_RETURN(message, ENOMEM, {});
+    REPLY_ERROR_RETURN(message, status.error(), {});
   }
 
   auto surface = std::make_shared<VideoMeshSurface>(service(), channel_id);
-  const int ret = service()->SetChannel(channel_id, surface);
-  if (ret < 0) {
+  auto channel_status = service()->SetChannel(channel_id, surface);
+  if (!channel_status) {
     ALOGE(
         "DisplaySurface::OnCreateVideoMeshSurface: failed to set new video "
         "mesh surface channel: %s",
-        strerror(-ret));
-    REPLY_ERROR_RETURN(message, ENOMEM, {});
+        channel_status.GetErrorMessage().c_str());
+    REPLY_ERROR_RETURN(message, channel_status.error(), {});
   }
 
   {
diff --git a/libs/vr/libvrflinger/display_surface.h b/libs/vr/libvrflinger/display_surface.h
index d31a3a9..2e4cf75 100644
--- a/libs/vr/libvrflinger/display_surface.h
+++ b/libs/vr/libvrflinger/display_surface.h
@@ -106,7 +106,7 @@
 
   // Dispatches display surface messages to the appropriate handlers. This
   // handler runs on the displayd message dispatch thread.
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
 
   // Sets display surface's client-controlled attributes.
   int OnClientSetAttributes(pdx::Message& message,
diff --git a/libs/vr/libvrflinger/screenshot_service.cpp b/libs/vr/libvrflinger/screenshot_service.cpp
index fd1c582..d14d588 100644
--- a/libs/vr/libvrflinger/screenshot_service.cpp
+++ b/libs/vr/libvrflinger/screenshot_service.cpp
@@ -19,17 +19,17 @@
 
 ScreenshotService::~ScreenshotService() { instance_ = nullptr; }
 
-int ScreenshotService::HandleMessage(pdx::Message& message) {
+pdx::Status<void> ScreenshotService::HandleMessage(pdx::Message& message) {
   switch (message.GetOp()) {
     case DisplayScreenshotRPC::GetFormat::Opcode:
       DispatchRemoteMethod<DisplayScreenshotRPC::GetFormat>(
           *this, &ScreenshotService::OnGetFormat, message);
-      return 0;
+      return {};
 
     case DisplayScreenshotRPC::TakeScreenshot::Opcode:
       DispatchRemoteMethod<DisplayScreenshotRPC::TakeScreenshot>(
           *this, &ScreenshotService::OnTakeScreenshot, message);
-      return 0;
+      return {};
 
     default:
       return Service::HandleMessage(message);
diff --git a/libs/vr/libvrflinger/screenshot_service.h b/libs/vr/libvrflinger/screenshot_service.h
index ec4c527..f59e872 100644
--- a/libs/vr/libvrflinger/screenshot_service.h
+++ b/libs/vr/libvrflinger/screenshot_service.h
@@ -38,7 +38,7 @@
  public:
   ~ScreenshotService();
 
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
 
   // Returns true if there is a pending screenshot request.
   bool IsScreenshotRequestPending() const {
diff --git a/libs/vr/libvrflinger/surface_channel.cpp b/libs/vr/libvrflinger/surface_channel.cpp
index 8aa220b..263b382 100644
--- a/libs/vr/libvrflinger/surface_channel.cpp
+++ b/libs/vr/libvrflinger/surface_channel.cpp
@@ -7,7 +7,7 @@
 namespace android {
 namespace dvr {
 
-int SurfaceChannel::HandleMessage(Message& message) {
+pdx::Status<void> SurfaceChannel::HandleMessage(Message& message) {
   switch (message.GetOp()) {
     case DisplayRPC::GetMetadataBuffer::Opcode:
       DispatchRemoteMethod<DisplayRPC::GetMetadataBuffer>(
@@ -15,7 +15,7 @@
       break;
   }
 
-  return 0;
+  return {};
 }
 
 BorrowedChannelHandle SurfaceChannel::OnGetMetadataBuffer(Message& message) {
diff --git a/libs/vr/libvrflinger/surface_channel.h b/libs/vr/libvrflinger/surface_channel.h
index 870e1a4..bb6b1c5 100644
--- a/libs/vr/libvrflinger/surface_channel.h
+++ b/libs/vr/libvrflinger/surface_channel.h
@@ -33,7 +33,7 @@
 
   // Dispatches surface channel messages to the appropriate handlers. This
   // handler runs on the displayd message dispatch thread.
-  virtual int HandleMessage(pdx::Message& message);
+  virtual pdx::Status<void> HandleMessage(pdx::Message& message);
 
  protected:
   // Contains the surface metadata.
diff --git a/libs/vr/libvrflinger/video_mesh_surface.cpp b/libs/vr/libvrflinger/video_mesh_surface.cpp
index a961a3d..d915a4a 100644
--- a/libs/vr/libvrflinger/video_mesh_surface.cpp
+++ b/libs/vr/libvrflinger/video_mesh_surface.cpp
@@ -14,7 +14,7 @@
 
 VideoMeshSurface::~VideoMeshSurface() {}
 
-int VideoMeshSurface::HandleMessage(Message& message) {
+pdx::Status<void> VideoMeshSurface::HandleMessage(Message& message) {
   ATRACE_NAME("VideoMeshSurface::HandleMessage");
 
   switch (message.GetOp()) {
@@ -27,7 +27,7 @@
       return SurfaceChannel::HandleMessage(message);
   }
 
-  return 0;
+  return {};
 }
 
 std::shared_ptr<ConsumerQueue> VideoMeshSurface::GetConsumerQueue() {
diff --git a/libs/vr/libvrflinger/video_mesh_surface.h b/libs/vr/libvrflinger/video_mesh_surface.h
index 1370793..2c9f3e8 100644
--- a/libs/vr/libvrflinger/video_mesh_surface.h
+++ b/libs/vr/libvrflinger/video_mesh_surface.h
@@ -12,7 +12,7 @@
 
 // VideoMeshSurface takes three inputs: 1) buffers filled by Android system
 // components (e.g. MediaCodec or camera stack) other than applications' GL
-// context; 2) a 3D mesh choosen by application to define the shape of the
+// context; 2) a 3D mesh chosen by application to define the shape of the
 // surface; 3) a transformation matrix from application to define the rotation,
 // position, and scaling of the video surface.
 class VideoMeshSurface : public SurfaceChannel {
@@ -33,7 +33,7 @@
     }
   }
 
-  int HandleMessage(Message& message) override;
+  pdx::Status<void> HandleMessage(Message& message) override;
 
   std::shared_ptr<ConsumerQueue> GetConsumerQueue();
 
diff --git a/libs/vr/libvrflinger/vsync_service.cpp b/libs/vr/libvrflinger/vsync_service.cpp
index 48fa2c2..612b9b2 100644
--- a/libs/vr/libvrflinger/vsync_service.cpp
+++ b/libs/vr/libvrflinger/vsync_service.cpp
@@ -107,26 +107,26 @@
   }
 }
 
-int VSyncService::HandleMessage(pdx::Message& message) {
+pdx::Status<void> VSyncService::HandleMessage(pdx::Message& message) {
   switch (message.GetOp()) {
     case DisplayVSyncRPC::Wait::Opcode:
       AddWaiter(message);
-      return 0;
+      return {};
 
     case DisplayVSyncRPC::GetLastTimestamp::Opcode:
       DispatchRemoteMethod<DisplayVSyncRPC::GetLastTimestamp>(
           *this, &VSyncService::OnGetLastTimestamp, message);
-      return 0;
+      return {};
 
     case DisplayVSyncRPC::GetSchedInfo::Opcode:
       DispatchRemoteMethod<DisplayVSyncRPC::GetSchedInfo>(
           *this, &VSyncService::OnGetSchedInfo, message);
-      return 0;
+      return {};
 
     case DisplayVSyncRPC::Acknowledge::Opcode:
       DispatchRemoteMethod<DisplayVSyncRPC::Acknowledge>(
           *this, &VSyncService::OnAcknowledge, message);
-      return 0;
+      return {};
 
     default:
       return Service::HandleMessage(message);
diff --git a/libs/vr/libvrflinger/vsync_service.h b/libs/vr/libvrflinger/vsync_service.h
index ba1d4df..1c86d42 100644
--- a/libs/vr/libvrflinger/vsync_service.h
+++ b/libs/vr/libvrflinger/vsync_service.h
@@ -56,7 +56,7 @@
  public:
   ~VSyncService() override;
 
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
 
   std::shared_ptr<pdx::Channel> OnChannelOpen(pdx::Message& message) override;
   void OnChannelClose(pdx::Message& message,
diff --git a/services/vr/bufferhubd/buffer_hub.cpp b/services/vr/bufferhubd/buffer_hub.cpp
index 80efcf8..de4950e 100644
--- a/services/vr/bufferhubd/buffer_hub.cpp
+++ b/services/vr/bufferhubd/buffer_hub.cpp
@@ -189,7 +189,7 @@
     channel->HandleImpulse(message);
 }
 
-int BufferHubService::HandleMessage(Message& message) {
+pdx::Status<void> BufferHubService::HandleMessage(Message& message) {
   ATRACE_NAME("BufferHubService::HandleMessage");
   auto channel = message.GetChannel<BufferHubChannel>();
 
@@ -207,22 +207,22 @@
     case BufferHubRPC::CreateBuffer::Opcode:
       DispatchRemoteMethod<BufferHubRPC::CreateBuffer>(
           *this, &BufferHubService::OnCreateBuffer, message);
-      return 0;
+      return {};
 
     case BufferHubRPC::CreatePersistentBuffer::Opcode:
       DispatchRemoteMethod<BufferHubRPC::CreatePersistentBuffer>(
           *this, &BufferHubService::OnCreatePersistentBuffer, message);
-      return 0;
+      return {};
 
     case BufferHubRPC::GetPersistentBuffer::Opcode:
       DispatchRemoteMethod<BufferHubRPC::GetPersistentBuffer>(
           *this, &BufferHubService::OnGetPersistentBuffer, message);
-      return 0;
+      return {};
 
     case BufferHubRPC::CreateProducerQueue::Opcode:
       DispatchRemoteMethod<BufferHubRPC::CreateProducerQueue>(
           *this, &BufferHubService::OnCreateProducerQueue, message);
-      return 0;
+      return {};
 
     default:
       return DefaultHandleMessage(message);
@@ -438,11 +438,11 @@
            "BufferHubChannel::SignalAvailable: channel_id=%d buffer_id=%d",
            channel_id(), buffer_id());
   if (!IsDetached()) {
-    const int ret = service_->ModifyChannelEvents(channel_id_, 0, POLLIN);
-    ALOGE_IF(ret < 0,
+    const auto status = service_->ModifyChannelEvents(channel_id_, 0, POLLIN);
+    ALOGE_IF(!status,
              "BufferHubChannel::SignalAvailable: failed to signal availability "
              "channel_id=%d: %s",
-             channel_id_, strerror(-ret));
+             channel_id_, status.GetErrorMessage().c_str());
   } else {
     ALOGD_IF(TRACE, "BufferHubChannel::SignalAvailable: detached buffer.");
   }
@@ -454,11 +454,11 @@
            "BufferHubChannel::ClearAvailable: channel_id=%d buffer_id=%d",
            channel_id(), buffer_id());
   if (!IsDetached()) {
-    const int ret = service_->ModifyChannelEvents(channel_id_, POLLIN, 0);
-    ALOGE_IF(ret < 0,
+    const auto status = service_->ModifyChannelEvents(channel_id_, POLLIN, 0);
+    ALOGE_IF(!status,
              "BufferHubChannel::ClearAvailable: failed to clear availability "
              "channel_id=%d: %s",
-             channel_id_, strerror(-ret));
+             channel_id_, status.GetErrorMessage().c_str());
   } else {
     ALOGD_IF(TRACE, "BufferHubChannel::ClearAvailable: detached buffer.");
   }
@@ -469,11 +469,11 @@
   ALOGD_IF(TRACE, "BufferHubChannel::Hangup: channel_id=%d buffer_id=%d",
            channel_id(), buffer_id());
   if (!IsDetached()) {
-    const int ret = service_->ModifyChannelEvents(channel_id_, 0, POLLHUP);
+    const auto status = service_->ModifyChannelEvents(channel_id_, 0, POLLHUP);
     ALOGE_IF(
-        ret < 0,
+        !status,
         "BufferHubChannel::Hangup: failed to signal hangup channel_id=%d: %s",
-        channel_id_, strerror(-ret));
+        channel_id_, status.GetErrorMessage().c_str());
   } else {
     ALOGD_IF(TRACE, "BufferHubChannel::Hangup: detached buffer.");
   }
diff --git a/services/vr/bufferhubd/buffer_hub.h b/services/vr/bufferhubd/buffer_hub.h
index 28cb468..8a7dca8 100644
--- a/services/vr/bufferhubd/buffer_hub.h
+++ b/services/vr/bufferhubd/buffer_hub.h
@@ -141,7 +141,7 @@
   BufferHubService();
   ~BufferHubService() override;
 
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
   void HandleImpulse(pdx::Message& message) override;
 
   void OnChannelClose(pdx::Message& message,
diff --git a/services/vr/bufferhubd/producer_channel.cpp b/services/vr/bufferhubd/producer_channel.cpp
index 43010b0..903d174 100644
--- a/services/vr/bufferhubd/producer_channel.cpp
+++ b/services/vr/bufferhubd/producer_channel.cpp
@@ -161,12 +161,12 @@
 
   auto consumer = std::make_shared<ConsumerChannel>(
       service(), buffer_id(), channel_id, shared_from_this());
-  const int ret = service()->SetChannel(channel_id, consumer);
-  if (ret < 0) {
+  const auto channel_status = service()->SetChannel(channel_id, consumer);
+  if (!channel_status) {
     ALOGE(
         "ProducerChannel::CreateConsumer: failed to set new consumer channel: "
         "%s",
-        strerror(-ret));
+        channel_status.GetErrorMessage().c_str());
     return RemoteChannelHandle();
   }
 
diff --git a/services/vr/bufferhubd/producer_queue_channel.cpp b/services/vr/bufferhubd/producer_queue_channel.cpp
index 08f1e9d..7952642 100644
--- a/services/vr/bufferhubd/producer_queue_channel.cpp
+++ b/services/vr/bufferhubd/producer_queue_channel.cpp
@@ -97,18 +97,18 @@
         "ProducerQueueChannel::OnCreateConsumerQueue: failed to push consumer "
         "channel: %s",
         status.GetErrorMessage().c_str());
-    REPLY_ERROR_RETURN(message, ENOMEM, {});
+    REPLY_ERROR_RETURN(message, status.error(), {});
   }
 
-  const int ret = service()->SetChannel(
+  const auto channel_status = service()->SetChannel(
       channel_id, std::make_shared<ConsumerQueueChannel>(
                       service(), buffer_id(), channel_id, shared_from_this()));
-  if (ret < 0) {
+  if (!channel_status) {
     ALOGE(
         "ProducerQueueChannel::OnCreateConsumerQueue: failed to set new "
         "consumer channel: %s",
-        strerror(-ret));
-    REPLY_ERROR_RETURN(message, ENOMEM, {});
+        channel_status.GetErrorMessage().c_str());
+    REPLY_ERROR_RETURN(message, channel_status.error(), {});
   }
 
   return std::make_pair(status.take(), meta_size_bytes_);
@@ -214,12 +214,13 @@
       "ProducerQueueChannel::AllocateBuffer: buffer_id=%d, buffer_handle=%d",
       buffer_id, buffer_handle.value());
 
-  const int ret = service()->SetChannel(buffer_id, producer_channel);
-  if (ret < 0) {
+  const auto channel_status =
+      service()->SetChannel(buffer_id, producer_channel);
+  if (!channel_status) {
     ALOGE(
-        "ProducerQueueChannel::AllocateBuffer: failed to set prodcuer channel "
+        "ProducerQueueChannel::AllocateBuffer: failed to set producer channel "
         "for new BufferHubBuffer: %s",
-        strerror(-ret));
+        channel_status.GetErrorMessage().c_str());
     return {};
   }
 
@@ -252,7 +253,7 @@
   return {std::move(buffer_handle), slot};
 }
 
-int ProducerQueueChannel::OnProducerQueueDetachBuffer(Message& message,
+int ProducerQueueChannel::OnProducerQueueDetachBuffer(Message& /*message*/,
                                                       size_t slot) {
   if (buffers_[slot].expired()) {
     ALOGE(
diff --git a/services/vr/performanced/performance_service.cpp b/services/vr/performanced/performance_service.cpp
index c99c8d4..955c661 100644
--- a/services/vr/performanced/performance_service.cpp
+++ b/services/vr/performanced/performance_service.cpp
@@ -170,22 +170,22 @@
   return task.GetCpuSetPath();
 }
 
-int PerformanceService::HandleMessage(Message& message) {
+pdx::Status<void> PerformanceService::HandleMessage(Message& message) {
   switch (message.GetOp()) {
     case PerformanceRPC::SetCpuPartition::Opcode:
       DispatchRemoteMethod<PerformanceRPC::SetSchedulerClass>(
           *this, &PerformanceService::OnSetCpuPartition, message);
-      return 0;
+      return {};
 
     case PerformanceRPC::SetSchedulerClass::Opcode:
       DispatchRemoteMethod<PerformanceRPC::SetSchedulerClass>(
           *this, &PerformanceService::OnSetSchedulerClass, message);
-      return 0;
+      return {};
 
     case PerformanceRPC::GetCpuPartition::Opcode:
       DispatchRemoteMethod<PerformanceRPC::GetCpuPartition>(
           *this, &PerformanceService::OnGetCpuPartition, message);
-      return 0;
+      return {};
 
     default:
       return Service::HandleMessage(message);
diff --git a/services/vr/performanced/performance_service.h b/services/vr/performanced/performance_service.h
index e32d834..34abba7 100644
--- a/services/vr/performanced/performance_service.h
+++ b/services/vr/performanced/performance_service.h
@@ -17,7 +17,7 @@
 // achieve system performance goals.
 class PerformanceService : public pdx::ServiceBase<PerformanceService> {
  public:
-  int HandleMessage(pdx::Message& message) override;
+  pdx::Status<void> HandleMessage(pdx::Message& message) override;
   bool IsInitialized() const override;
 
   std::string DumpState(size_t max_length) override;
diff --git a/services/vr/sensord/pose_service.cpp b/services/vr/sensord/pose_service.cpp
index 2c4fc30..3cd5297 100644
--- a/services/vr/sensord/pose_service.cpp
+++ b/services/vr/sensord/pose_service.cpp
@@ -476,8 +476,8 @@
   }
 }
 
-int PoseService::HandleMessage(pdx::Message& msg) {
-  int ret = 0;
+pdx::Status<void> PoseService::HandleMessage(pdx::Message& msg) {
+  pdx::Status<void> ret;
   const pdx::MessageInfo& info = msg.GetInfo();
   switch (info.op) {
     case DVR_POSE_NOTIFY_VSYNC: {
@@ -495,21 +495,13 @@
           {.iov_base = &right_eye_photon_offset_ns_,
            .iov_len = sizeof(right_eye_photon_offset_ns_)},
       };
-      constexpr int expected_size =
-          sizeof(vsync_count_) + sizeof(photon_timestamp_) +
-          sizeof(display_period_ns_) + sizeof(right_eye_photon_offset_ns_);
-      ret = msg.ReadVector(data, sizeof(data) / sizeof(data[0]));
-      if (ret < expected_size) {
-        ALOGI("error: msg.Read read too little (%d < %d)", ret, expected_size);
-        REPLY_ERROR(msg, EIO, error);
-      }
-
-      if (!enable_external_pose_) {
+      ret = msg.ReadVectorAll(data);
+      if (ret && !enable_external_pose_) {
         mapped_pose_buffer_->vsync_count = vsync_count_;
       }
 
       // TODO(jbates, eieio): make this async, no need to reply.
-      REPLY_SUCCESS(msg, 0, error);
+      REPLY_MESSAGE(msg, ret, error);
     }
     case DVR_POSE_POLL: {
       ATRACE_NAME("pose_poll");
@@ -535,61 +527,43 @@
 
       Btrace("Pose polled");
 
-      ret = msg.Write(&client_state, sizeof(client_state));
-      const int expected_size = sizeof(client_state);
-      if (ret < expected_size) {
-        ALOGI("error: msg.Write wrote too little (%d < %d)", ret,
-              expected_size);
-        REPLY_ERROR(msg, EIO, error);
-      }
-      REPLY_SUCCESS(msg, 0, error);
+      ret = msg.WriteAll(&client_state, sizeof(client_state));
+      REPLY_MESSAGE(msg, ret, error);
     }
     case DVR_POSE_FREEZE: {
       {
         std::lock_guard<std::mutex> guard(mutex_);
 
         DvrPoseState frozen_state;
-        const int expected_size = sizeof(frozen_state);
-        ret = msg.Read(&frozen_state, expected_size);
-        if (ret < expected_size) {
-          ALOGI("error: msg.Read read too little (%d < %d)", ret,
-                expected_size);
-          REPLY_ERROR(msg, EIO, error);
+        ret = msg.ReadAll(&frozen_state, sizeof(frozen_state));
+        if (!ret) {
+          REPLY_ERROR(msg, ret.error(), error);
         }
         frozen_state_ = frozen_state;
       }
       SetPoseMode(DVR_POSE_MODE_MOCK_FROZEN);
-      REPLY_SUCCESS(msg, 0, error);
+      REPLY_MESSAGE(msg, ret, error);
     }
     case DVR_POSE_SET_MODE: {
       int mode;
       {
         std::lock_guard<std::mutex> guard(mutex_);
-        const int expected_size = sizeof(mode);
-        ret = msg.Read(&mode, expected_size);
-        if (ret < expected_size) {
-          ALOGI("error: msg.Read read too little (%d < %d)", ret,
-                expected_size);
-          REPLY_ERROR(msg, EIO, error);
+        ret = msg.ReadAll(&mode, sizeof(mode));
+        if (!ret) {
+          REPLY_ERROR(msg, ret.error(), error);
         }
         if (mode < 0 || mode >= DVR_POSE_MODE_COUNT) {
           REPLY_ERROR(msg, EINVAL, error);
         }
       }
       SetPoseMode(DvrPoseMode(mode));
-      REPLY_SUCCESS(msg, 0, error);
+      REPLY_MESSAGE(msg, ret, error);
     }
     case DVR_POSE_GET_MODE: {
       std::lock_guard<std::mutex> guard(mutex_);
       int mode = pose_mode_;
-      ret = msg.Write(&mode, sizeof(mode));
-      const int expected_size = sizeof(mode);
-      if (ret < expected_size) {
-        ALOGI("error: msg.Write wrote too little (%d < %d)", ret,
-              expected_size);
-        REPLY_ERROR(msg, EIO, error);
-      }
-      REPLY_SUCCESS(msg, 0, error);
+      ret = msg.WriteAll(&mode, sizeof(mode));
+      REPLY_MESSAGE(msg, ret, error);
     }
     case DVR_POSE_GET_RING_BUFFER: {
       std::lock_guard<std::mutex> guard(mutex_);
diff --git a/services/vr/sensord/pose_service.h b/services/vr/sensord/pose_service.h
index 4df5036..fdd29b5 100644
--- a/services/vr/sensord/pose_service.h
+++ b/services/vr/sensord/pose_service.h
@@ -27,7 +27,7 @@
   ~PoseService() override;
 
   bool IsInitialized() const override;
-  int HandleMessage(pdx::Message& msg) override;
+  pdx::Status<void> HandleMessage(pdx::Message& msg) override;
   std::string DumpState(size_t max_length) override;
 
   // Handle events from the sensor HAL.
diff --git a/services/vr/sensord/sensor_service.cpp b/services/vr/sensord/sensor_service.cpp
index 1b809b0..a182a26 100644
--- a/services/vr/sensord/sensor_service.cpp
+++ b/services/vr/sensord/sensor_service.cpp
@@ -69,8 +69,8 @@
   client->unset_sensor();
 }
 
-int SensorService::HandleMessage(pdx::Message& msg) {
-  int ret = 0;
+pdx::Status<void> SensorService::HandleMessage(pdx::Message& msg) {
+  pdx::Status<void> ret;
   const pdx::MessageInfo& info = msg.GetInfo();
   switch (info.op) {
     case DVR_SENSOR_START: {
@@ -82,8 +82,7 @@
       if (client->has_sensor())
         REPLY_ERROR(msg, EINVAL, error);
       int sensor_type;
-      if (msg.Read(&sensor_type, sizeof(sensor_type)) <
-          (ssize_t)sizeof(sensor_type))
+      if (!msg.ReadAll(&sensor_type, sizeof(sensor_type)))
         REPLY_ERROR(msg, EIO, error);
 
       // Find the sensor of the requested type.
@@ -120,10 +119,8 @@
           {.iov_base = out_buffer,
            .iov_len = num_events * sizeof(sensors_event_t)},
       };
-      ret = msg.WriteVector(svec, 2);
-      int expected_size = sizeof(int) + num_events * sizeof(sensors_event_t);
-      if (ret < expected_size) {
-        ALOGI("error: msg.WriteVector wrote too little.");
+      ret = msg.WriteVectorAll(svec, 2);
+      if (!ret) {
         REPLY_ERROR(msg, EIO, error);
       }
       REPLY_SUCCESS(msg, 0, error);
diff --git a/services/vr/sensord/sensor_service.h b/services/vr/sensord/sensor_service.h
index c35fada..6ea470b 100644
--- a/services/vr/sensord/sensor_service.h
+++ b/services/vr/sensord/sensor_service.h
@@ -22,7 +22,7 @@
  */
 class SensorService : public pdx::ServiceBase<SensorService> {
  public:
-  int HandleMessage(pdx::Message& msg) override;
+  pdx::Status<void> HandleMessage(pdx::Message& msg) override;
   std::shared_ptr<pdx::Channel> OnChannelOpen(pdx::Message& msg) override;
   void OnChannelClose(pdx::Message& msg,
                       const std::shared_ptr<pdx::Channel>& chan) override;
diff --git a/vulkan/libvulkan/swapchain.cpp b/vulkan/libvulkan/swapchain.cpp
index 2fee8a5..3b785e6 100644
--- a/vulkan/libvulkan/swapchain.cpp
+++ b/vulkan/libvulkan/swapchain.cpp
@@ -981,25 +981,9 @@
     int gralloc_usage = 0;
     if (dispatch.GetSwapchainGrallocUsage2ANDROID) {
         uint64_t consumer_usage, producer_usage;
-        if (GetData(device).driver_version == 256587285) {
-            // HACK workaround for loader/driver mismatch during transition to
-            // vkGetSwapchainGrallocUsage2ANDROID.
-            typedef VkResult(VKAPI_PTR *
-                             PFN_vkGetSwapchainGrallocUsage2ANDROID_HACK)(
-                VkDevice device, VkFormat format, VkImageUsageFlags imageUsage,
-                uint64_t * grallocConsumerUsage,
-                uint64_t * grallocProducerUsage);
-            auto get_swapchain_gralloc_usage =
-                reinterpret_cast<PFN_vkGetSwapchainGrallocUsage2ANDROID_HACK>(
-                    dispatch.GetSwapchainGrallocUsage2ANDROID);
-            result = get_swapchain_gralloc_usage(
-                device, create_info->imageFormat, create_info->imageUsage,
-                &consumer_usage, &producer_usage);
-        } else {
-            result = dispatch.GetSwapchainGrallocUsage2ANDROID(
-                device, create_info->imageFormat, create_info->imageUsage,
-                swapchain_image_usage, &consumer_usage, &producer_usage);
-        }
+        result = dispatch.GetSwapchainGrallocUsage2ANDROID(
+            device, create_info->imageFormat, create_info->imageUsage,
+            swapchain_image_usage, &consumer_usage, &producer_usage);
         if (result != VK_SUCCESS) {
             ALOGE("vkGetSwapchainGrallocUsage2ANDROID failed: %d", result);
             return VK_ERROR_SURFACE_LOST_KHR;