diff --git a/libs/vr/libvrflinger/display_service.cpp b/libs/vr/libvrflinger/display_service.cpp
index 733edc6..f350762 100644
--- a/libs/vr/libvrflinger/display_service.cpp
+++ b/libs/vr/libvrflinger/display_service.cpp
@@ -40,10 +40,8 @@
 DisplayService::DisplayService(Hwc2::Composer* hidl,
                                RequestDisplayCallback request_display_callback)
     : BASE("DisplayService",
-           Endpoint::Create(display::DisplayProtocol::kClientPath)),
-      hardware_composer_(hidl, request_display_callback),
-      request_display_callback_(request_display_callback) {
-  hardware_composer_.Initialize();
+           Endpoint::Create(display::DisplayProtocol::kClientPath)) {
+  hardware_composer_.Initialize(hidl, request_display_callback);
 }
 
 bool DisplayService::IsInitialized() const {
@@ -398,10 +396,6 @@
   return {0};
 }
 
-void DisplayService::OnHardwareComposerRefresh() {
-  hardware_composer_.OnHardwareComposerRefresh();
-}
-
 void DisplayService::SetDisplayConfigurationUpdateNotifier(
     DisplayConfigurationUpdateNotifier update_notifier) {
   update_notifier_ = update_notifier;
diff --git a/libs/vr/libvrflinger/display_service.h b/libs/vr/libvrflinger/display_service.h
index 6efe264..55e33ab 100644
--- a/libs/vr/libvrflinger/display_service.h
+++ b/libs/vr/libvrflinger/display_service.h
@@ -72,8 +72,6 @@
   void GrantDisplayOwnership() { hardware_composer_.Enable(); }
   void SeizeDisplayOwnership() { hardware_composer_.Disable(); }
 
-  void OnHardwareComposerRefresh();
-
  private:
   friend BASE;
   friend DisplaySurface;
@@ -119,7 +117,6 @@
   pdx::Status<void> HandleSurfaceMessage(pdx::Message& message);
 
   HardwareComposer hardware_composer_;
-  RequestDisplayCallback request_display_callback_;
   EpollEventDispatcher dispatcher_;
   DisplayConfigurationUpdateNotifier update_notifier_;
 
diff --git a/libs/vr/libvrflinger/hardware_composer.cpp b/libs/vr/libvrflinger/hardware_composer.cpp
index 11c1370..f9a5dcd 100644
--- a/libs/vr/libvrflinger/hardware_composer.cpp
+++ b/libs/vr/libvrflinger/hardware_composer.cpp
@@ -28,6 +28,8 @@
 #include <private/dvr/clock_ns.h>
 #include <private/dvr/ion_buffer.h>
 
+using android::hardware::Return;
+using android::hardware::Void;
 using android::pdx::LocalHandle;
 using android::pdx::rpc::EmptyVariant;
 using android::pdx::rpc::IfAnyOf;
@@ -42,9 +44,6 @@
 const char kBacklightBrightnessSysFile[] =
     "/sys/class/leds/lcd-backlight/brightness";
 
-const char kPrimaryDisplayVSyncEventFile[] =
-    "/sys/class/graphics/fb0/vsync_event";
-
 const char kPrimaryDisplayWaitPPEventFile[] = "/sys/class/graphics/fb0/wait_pp";
 
 const char kDvrPerformanceProperty[] = "sys.dvr.performance";
@@ -86,22 +85,11 @@
 
 }  // anonymous namespace
 
-// Layer static data.
-Hwc2::Composer* Layer::hwc2_hidl_;
-const HWCDisplayMetrics* Layer::display_metrics_;
-
 // HardwareComposer static data;
 constexpr size_t HardwareComposer::kMaxHardwareLayers;
 
 HardwareComposer::HardwareComposer()
-    : HardwareComposer(nullptr, RequestDisplayCallback()) {}
-
-HardwareComposer::HardwareComposer(
-    Hwc2::Composer* hwc2_hidl, RequestDisplayCallback request_display_callback)
-    : initialized_(false),
-      hwc2_hidl_(hwc2_hidl),
-      request_display_callback_(request_display_callback),
-      callbacks_(new ComposerCallback) {}
+    : initialized_(false), request_display_callback_(nullptr) {}
 
 HardwareComposer::~HardwareComposer(void) {
   UpdatePostThreadState(PostThreadState::Quit, true);
@@ -109,16 +97,19 @@
     post_thread_.join();
 }
 
-bool HardwareComposer::Initialize() {
+bool HardwareComposer::Initialize(
+    Hwc2::Composer* hidl, RequestDisplayCallback request_display_callback) {
   if (initialized_) {
     ALOGE("HardwareComposer::Initialize: already initialized.");
     return false;
   }
 
+  request_display_callback_ = request_display_callback;
+
   HWC::Error error = HWC::Error::None;
 
   Hwc2::Config config;
-  error = hwc2_hidl_->getActiveConfig(HWC_DISPLAY_PRIMARY, &config);
+  error = hidl->getActiveConfig(HWC_DISPLAY_PRIMARY, &config);
 
   if (error != HWC::Error::None) {
     ALOGE("HardwareComposer: Failed to get current display config : %d",
@@ -126,8 +117,8 @@
     return false;
   }
 
-  error =
-      GetDisplayMetrics(HWC_DISPLAY_PRIMARY, config, &native_display_metrics_);
+  error = GetDisplayMetrics(hidl, HWC_DISPLAY_PRIMARY, config,
+                            &native_display_metrics_);
 
   if (error != HWC::Error::None) {
     ALOGE(
@@ -149,9 +140,6 @@
   display_transform_ = HWC_TRANSFORM_NONE;
   display_metrics_ = native_display_metrics_;
 
-  // Pass hwc instance and metrics to setup globals for Layer.
-  Layer::InitializeGlobals(hwc2_hidl_, &native_display_metrics_);
-
   post_thread_event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
   LOG_ALWAYS_FATAL_IF(
       !post_thread_event_fd_,
@@ -210,15 +198,11 @@
 }
 
 void HardwareComposer::OnPostThreadResumed() {
-  hwc2_hidl_->resetCommands();
+  hidl_.reset(new Hwc2::Composer("default"));
+  hidl_callback_ = new ComposerCallback;
+  hidl_->registerCallback(hidl_callback_);
 
-  // HIDL HWC seems to have an internal race condition. If we submit a frame too
-  // soon after turning on VSync we don't get any VSync signals. Give poor HWC
-  // implementations a chance to enable VSync before we continue.
-  EnableVsync(false);
-  std::this_thread::sleep_for(100ms);
   EnableVsync(true);
-  std::this_thread::sleep_for(100ms);
 
   // TODO(skiazyk): We need to do something about accessing this directly,
   // supposedly there is a backlight service on the way.
@@ -240,9 +224,12 @@
   }
   active_layer_count_ = 0;
 
-  EnableVsync(false);
+  if (hidl_) {
+    EnableVsync(false);
+  }
 
-  hwc2_hidl_->resetCommands();
+  hidl_callback_ = nullptr;
+  hidl_.reset(nullptr);
 
   // Trigger target-specific performance mode change.
   property_set(kDvrPerformanceProperty, "idle");
@@ -252,21 +239,21 @@
   uint32_t num_types;
   uint32_t num_requests;
   HWC::Error error =
-      hwc2_hidl_->validateDisplay(display, &num_types, &num_requests);
+      hidl_->validateDisplay(display, &num_types, &num_requests);
 
   if (error == HWC2_ERROR_HAS_CHANGES) {
     // TODO(skiazyk): We might need to inspect the requested changes first, but
     // so far it seems like we shouldn't ever hit a bad state.
     // error = hwc2_funcs_.accept_display_changes_fn_(hardware_composer_device_,
     //                                               display);
-    error = hwc2_hidl_->acceptDisplayChanges(display);
+    error = hidl_->acceptDisplayChanges(display);
   }
 
   return error;
 }
 
-int32_t HardwareComposer::EnableVsync(bool enabled) {
-  return (int32_t)hwc2_hidl_->setVsyncEnabled(
+HWC::Error HardwareComposer::EnableVsync(bool enabled) {
+  return hidl_->setVsyncEnabled(
       HWC_DISPLAY_PRIMARY,
       (Hwc2::IComposerClient::Vsync)(enabled ? HWC2_VSYNC_ENABLE
                                              : HWC2_VSYNC_DISABLE));
@@ -274,7 +261,7 @@
 
 HWC::Error HardwareComposer::Present(hwc2_display_t display) {
   int32_t present_fence;
-  HWC::Error error = hwc2_hidl_->presentDisplay(display, &present_fence);
+  HWC::Error error = hidl_->presentDisplay(display, &present_fence);
 
   // According to the documentation, this fence is signaled at the time of
   // vsync/DMA for physical displays.
@@ -288,20 +275,21 @@
   return error;
 }
 
-HWC::Error HardwareComposer::GetDisplayAttribute(hwc2_display_t display,
+HWC::Error HardwareComposer::GetDisplayAttribute(Hwc2::Composer* hidl,
+                                                 hwc2_display_t display,
                                                  hwc2_config_t config,
                                                  hwc2_attribute_t attribute,
                                                  int32_t* out_value) const {
-  return hwc2_hidl_->getDisplayAttribute(
+  return hidl->getDisplayAttribute(
       display, config, (Hwc2::IComposerClient::Attribute)attribute, out_value);
 }
 
 HWC::Error HardwareComposer::GetDisplayMetrics(
-    hwc2_display_t display, hwc2_config_t config,
+    Hwc2::Composer* hidl, hwc2_display_t display, hwc2_config_t config,
     HWCDisplayMetrics* out_metrics) const {
   HWC::Error error;
 
-  error = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_WIDTH,
+  error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_WIDTH,
                               &out_metrics->width);
   if (error != HWC::Error::None) {
     ALOGE(
@@ -310,7 +298,7 @@
     return error;
   }
 
-  error = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_HEIGHT,
+  error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_HEIGHT,
                               &out_metrics->height);
   if (error != HWC::Error::None) {
     ALOGE(
@@ -319,7 +307,8 @@
     return error;
   }
 
-  error = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_VSYNC_PERIOD,
+  error = GetDisplayAttribute(hidl, display, config,
+                              HWC2_ATTRIBUTE_VSYNC_PERIOD,
                               &out_metrics->vsync_period_ns);
   if (error != HWC::Error::None) {
     ALOGE(
@@ -328,7 +317,7 @@
     return error;
   }
 
-  error = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_DPI_X,
+  error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_DPI_X,
                               &out_metrics->dpi.x);
   if (error != HWC::Error::None) {
     ALOGE(
@@ -337,7 +326,7 @@
     return error;
   }
 
-  error = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_DPI_Y,
+  error = GetDisplayAttribute(hidl, display, config, HWC2_ATTRIBUTE_DPI_Y,
                               &out_metrics->dpi.y);
   if (error != HWC::Error::None) {
     ALOGE(
@@ -374,7 +363,7 @@
 
   if (post_thread_resumed_) {
     stream << "Hardware Composer Debug Info:" << std::endl;
-    stream << hwc2_hidl_->dumpDebugInfo();
+    stream << hidl_->dumpDebugInfo();
   }
 
   return stream.str();
@@ -446,8 +435,8 @@
 
   std::vector<Hwc2::Layer> out_layers;
   std::vector<int> out_fences;
-  error = hwc2_hidl_->getReleaseFences(HWC_DISPLAY_PRIMARY, &out_layers,
-                                       &out_fences);
+  error = hidl_->getReleaseFences(HWC_DISPLAY_PRIMARY, &out_layers,
+                                  &out_fences);
   ALOGE_IF(error != HWC::Error::None,
            "HardwareComposer::PostLayers: Failed to get release fences: %s",
            error.to_string().c_str());
@@ -546,7 +535,7 @@
 }
 
 int HardwareComposer::PostThreadPollInterruptible(
-    const pdx::LocalHandle& event_fd, int requested_events) {
+    const pdx::LocalHandle& event_fd, int requested_events, int timeout_ms) {
   pollfd pfd[2] = {
       {
           .fd = event_fd.Get(),
@@ -561,7 +550,7 @@
   };
   int ret, error;
   do {
-    ret = poll(pfd, 2, -1);
+    ret = poll(pfd, 2, timeout_ms);
     error = errno;
     ALOGW_IF(ret < 0,
              "HardwareComposer::PostThreadPollInterruptible: Error during "
@@ -571,6 +560,8 @@
 
   if (ret < 0) {
     return -error;
+  } else if (ret == 0) {
+    return -ETIMEDOUT;
   } else if (pfd[0].revents != 0) {
     return 0;
   } else if (pfd[1].revents != 0) {
@@ -623,114 +614,17 @@
   }
 }
 
-// Reads the timestamp of the last vsync from the display driver.
-// TODO(eieio): This is pretty driver specific, this should be moved to a
-// separate class eventually.
-int HardwareComposer::ReadVSyncTimestamp(int64_t* timestamp) {
-  const int event_fd = primary_display_vsync_event_fd_.Get();
-  int ret, error;
-
-  // The driver returns data in the form "VSYNC=<timestamp ns>".
-  std::array<char, 32> data;
-  data.fill('\0');
-
-  // Seek back to the beginning of the event file.
-  ret = lseek(event_fd, 0, SEEK_SET);
-  if (ret < 0) {
-    error = errno;
-    ALOGE(
-        "HardwareComposer::ReadVSyncTimestamp: Failed to seek vsync event fd: "
-        "%s",
-        strerror(error));
-    return -error;
-  }
-
-  // Read the vsync event timestamp.
-  ret = read(event_fd, data.data(), data.size());
-  if (ret < 0) {
-    error = errno;
-    ALOGE_IF(
-        error != EAGAIN,
-        "HardwareComposer::ReadVSyncTimestamp: Error while reading timestamp: "
-        "%s",
-        strerror(error));
-    return -error;
-  }
-
-  ret = sscanf(data.data(), "VSYNC=%" PRIu64,
-               reinterpret_cast<uint64_t*>(timestamp));
-  if (ret < 0) {
-    error = errno;
-    ALOGE(
-        "HardwareComposer::ReadVSyncTimestamp: Error while parsing timestamp: "
-        "%s",
-        strerror(error));
-    return -error;
-  }
-
-  return 0;
-}
-
-// Blocks until the next vsync event is signaled by the display driver.
-// TODO(eieio): This is pretty driver specific, this should be moved to a
-// separate class eventually.
-int HardwareComposer::BlockUntilVSync() {
-  // Vsync is signaled by POLLPRI on the fb vsync node.
-  return PostThreadPollInterruptible(primary_display_vsync_event_fd_, POLLPRI);
-}
-
 // Waits for the next vsync and returns the timestamp of the vsync event. If
 // vsync already passed since the last call, returns the latest vsync timestamp
-// instead of blocking. This method updates the last_vsync_timeout_ in the
-// process.
-//
-// TODO(eieio): This is pretty driver specific, this should be moved to a
-// separate class eventually.
+// instead of blocking.
 int HardwareComposer::WaitForVSync(int64_t* timestamp) {
-  int error;
-
-  // Get the current timestamp and decide what to do.
-  while (true) {
-    int64_t current_vsync_timestamp;
-    error = ReadVSyncTimestamp(&current_vsync_timestamp);
-    if (error < 0 && error != -EAGAIN)
-      return error;
-
-    if (error == -EAGAIN) {
-      // Vsync was turned off, wait for the next vsync event.
-      error = BlockUntilVSync();
-      if (error < 0 || error == kPostThreadInterrupted)
-        return error;
-
-      // Try again to get the timestamp for this new vsync interval.
-      continue;
-    }
-
-    // Check that we advanced to a later vsync interval.
-    if (TimestampGT(current_vsync_timestamp, last_vsync_timestamp_)) {
-      *timestamp = last_vsync_timestamp_ = current_vsync_timestamp;
-      return 0;
-    }
-
-    // See how close we are to the next expected vsync. If we're within 1ms,
-    // sleep for 1ms and try again.
-    const int64_t ns_per_frame = display_metrics_.vsync_period_ns;
-    const int64_t threshold_ns = 1000000;  // 1ms
-
-    const int64_t next_vsync_est = last_vsync_timestamp_ + ns_per_frame;
-    const int64_t distance_to_vsync_est = next_vsync_est - GetSystemClockNs();
-
-    if (distance_to_vsync_est > threshold_ns) {
-      // Wait for vsync event notification.
-      error = BlockUntilVSync();
-      if (error < 0 || error == kPostThreadInterrupted)
-        return error;
-    } else {
-      // Sleep for a short time (1 millisecond) before retrying.
-      error = SleepUntil(GetSystemClockNs() + threshold_ns);
-      if (error < 0 || error == kPostThreadInterrupted)
-        return error;
-    }
+  int error = PostThreadPollInterruptible(
+      hidl_callback_->GetVsyncEventFd(), POLLIN, /*timeout_ms*/ 1000);
+  if (error == kPostThreadInterrupted || error < 0) {
+    return error;
+  } else {
+    *timestamp = hidl_callback_->GetVsyncTime();
+    return 0;
   }
 }
 
@@ -749,7 +643,8 @@
     return -error;
   }
 
-  return PostThreadPollInterruptible(vsync_sleep_timer_fd_, POLLIN);
+  return PostThreadPollInterruptible(
+      vsync_sleep_timer_fd_, POLLIN, /*timeout_ms*/ -1);
 }
 
 void HardwareComposer::PostThread() {
@@ -772,15 +667,6 @@
            strerror(errno));
 #endif  // ENABLE_BACKLIGHT_BRIGHTNESS
 
-  // Open the vsync event node for the primary display.
-  // TODO(eieio): Move this into a platform-specific class.
-  primary_display_vsync_event_fd_ =
-      LocalHandle(kPrimaryDisplayVSyncEventFile, O_RDONLY);
-  ALOGE_IF(!primary_display_vsync_event_fd_,
-           "HardwareComposer: Failed to open vsync event node for primary "
-           "display: %s",
-           strerror(errno));
-
   // Open the wait pingpong status node for the primary display.
   // TODO(eieio): Move this into a platform-specific class.
   primary_display_wait_pp_fd_ =
@@ -951,7 +837,8 @@
     // The bottom layer is opaque, other layers blend.
     HWC::BlendMode blending =
         layer_index == 0 ? HWC::BlendMode::None : HWC::BlendMode::Coverage;
-    layers_[layer_index].Setup(surfaces[layer_index], blending,
+    layers_[layer_index].Setup(surfaces[layer_index], native_display_metrics_,
+                               hidl_.get(), blending,
                                display_transform_, HWC::Composition::Device,
                                layer_index);
     display_surfaces_.push_back(surfaces[layer_index]);
@@ -979,30 +866,6 @@
   vsync_callback_ = callback;
 }
 
-void HardwareComposer::HwcRefresh(hwc2_callback_data_t /*data*/,
-                                  hwc2_display_t /*display*/) {
-  // TODO(eieio): implement invalidate callbacks.
-}
-
-void HardwareComposer::HwcVSync(hwc2_callback_data_t /*data*/,
-                                hwc2_display_t /*display*/,
-                                int64_t /*timestamp*/) {
-  ATRACE_NAME(__PRETTY_FUNCTION__);
-  // Intentionally empty. HWC may require a callback to be set to enable vsync
-  // signals. We bypass this callback thread by monitoring the vsync event
-  // directly, but signals still need to be enabled.
-}
-
-void HardwareComposer::HwcHotplug(hwc2_callback_data_t /*callbackData*/,
-                                  hwc2_display_t /*display*/,
-                                  hwc2_connection_t /*connected*/) {
-  // TODO(eieio): implement display hotplug callbacks.
-}
-
-void HardwareComposer::OnHardwareComposerRefresh() {
-  // TODO(steventhomas): Handle refresh.
-}
-
 void HardwareComposer::SetBacklightBrightness(int brightness) {
   if (backlight_brightness_fd_) {
     std::array<char, 32> text;
@@ -1011,18 +874,59 @@
   }
 }
 
-void Layer::InitializeGlobals(Hwc2::Composer* hwc2_hidl,
-                              const HWCDisplayMetrics* metrics) {
-  hwc2_hidl_ = hwc2_hidl;
-  display_metrics_ = metrics;
+HardwareComposer::ComposerCallback::ComposerCallback() {
+  vsync_event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
+  LOG_ALWAYS_FATAL_IF(
+      !vsync_event_fd_,
+      "Failed to create vsync event fd : %s",
+      strerror(errno));
+}
+
+Return<void> HardwareComposer::ComposerCallback::onHotplug(
+    Hwc2::Display /*display*/,
+    IComposerCallback::Connection /*conn*/) {
+  return Void();
+}
+
+Return<void> HardwareComposer::ComposerCallback::onRefresh(
+    Hwc2::Display /*display*/) {
+  return hardware::Void();
+}
+
+Return<void> HardwareComposer::ComposerCallback::onVsync(
+    Hwc2::Display display, int64_t timestamp) {
+  if (display == HWC_DISPLAY_PRIMARY) {
+    std::lock_guard<std::mutex> lock(vsync_mutex_);
+    vsync_time_ = timestamp;
+    int error = eventfd_write(vsync_event_fd_.Get(), 1);
+    LOG_ALWAYS_FATAL_IF(error != 0, "Failed writing to vsync event fd");
+  }
+  return Void();
+}
+
+const pdx::LocalHandle&
+HardwareComposer::ComposerCallback::GetVsyncEventFd() const {
+  return vsync_event_fd_;
+}
+
+int64_t HardwareComposer::ComposerCallback::GetVsyncTime() {
+  std::lock_guard<std::mutex> lock(vsync_mutex_);
+  eventfd_t event;
+  eventfd_read(vsync_event_fd_.Get(), &event);
+  LOG_ALWAYS_FATAL_IF(vsync_time_ < 0,
+                      "Attempt to read vsync time before vsync event");
+  int64_t return_val = vsync_time_;
+  vsync_time_ = -1;
+  return return_val;
 }
 
 void Layer::Reset() {
-  if (hwc2_hidl_ != nullptr && hardware_composer_layer_) {
-    hwc2_hidl_->destroyLayer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_);
+  if (hidl_ != nullptr && hardware_composer_layer_) {
+    hidl_->destroyLayer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_);
     hardware_composer_layer_ = 0;
   }
 
+  hidl_ = nullptr;
   z_order_ = 0;
   blending_ = HWC::BlendMode::None;
   transform_ = HWC::Transform::None;
@@ -1034,29 +938,35 @@
 }
 
 void Layer::Setup(const std::shared_ptr<DirectDisplaySurface>& surface,
-                  HWC::BlendMode blending, HWC::Transform transform,
-                  HWC::Composition composition_type, size_t z_order) {
+                  const HWCDisplayMetrics& display_metrics,
+                  Hwc2::Composer* hidl, HWC::BlendMode blending,
+                  HWC::Transform transform, HWC::Composition composition_type,
+                  size_t z_order) {
   Reset();
+  hidl_ = hidl;
   z_order_ = z_order;
   blending_ = blending;
   transform_ = transform;
   composition_type_ = HWC::Composition::Invalid;
   target_composition_type_ = composition_type;
   source_ = SourceSurface{surface};
-  CommonLayerSetup();
+  CommonLayerSetup(display_metrics);
 }
 
 void Layer::Setup(const std::shared_ptr<IonBuffer>& buffer,
-                  HWC::BlendMode blending, HWC::Transform transform,
-                  HWC::Composition composition_type, size_t z_order) {
+                  const HWCDisplayMetrics& display_metrics,
+                  Hwc2::Composer* hidl, HWC::BlendMode blending,
+                  HWC::Transform transform, HWC::Composition composition_type,
+                  size_t z_order) {
   Reset();
+  hidl_ = hidl;
   z_order_ = z_order;
   blending_ = blending;
   transform_ = transform;
   composition_type_ = HWC::Composition::Invalid;
   target_composition_type_ = composition_type;
   source_ = SourceBuffer{buffer};
-  CommonLayerSetup();
+  CommonLayerSetup(display_metrics);
 }
 
 void Layer::UpdateBuffer(const std::shared_ptr<IonBuffer>& buffer) {
@@ -1076,7 +986,7 @@
   return source_.Visit(Visitor{});
 }
 
-void Layer::UpdateLayerSettings() {
+void Layer::UpdateLayerSettings(const HWCDisplayMetrics& display_metrics) {
   if (!IsLayerSetup()) {
     ALOGE(
         "HardwareComposer::Layer::UpdateLayerSettings: Attempt to update "
@@ -1087,7 +997,7 @@
   HWC::Error error;
   hwc2_display_t display = HWC_DISPLAY_PRIMARY;
 
-  error = hwc2_hidl_->setLayerCompositionType(
+  error = hidl_->setLayerCompositionType(
       display, hardware_composer_layer_,
       composition_type_.cast<Hwc2::IComposerClient::Composition>());
   ALOGE_IF(
@@ -1095,7 +1005,7 @@
       "Layer::UpdateLayerSettings: Error setting layer composition type: %s",
       error.to_string().c_str());
 
-  error = hwc2_hidl_->setLayerBlendMode(
+  error = hidl_->setLayerBlendMode(
       display, hardware_composer_layer_,
       blending_.cast<Hwc2::IComposerClient::BlendMode>());
   ALOGE_IF(error != HWC::Error::None,
@@ -1104,41 +1014,39 @@
 
   // TODO(eieio): Use surface attributes or some other mechanism to control
   // the layer display frame.
-  error = hwc2_hidl_->setLayerDisplayFrame(
+  error = hidl_->setLayerDisplayFrame(
       display, hardware_composer_layer_,
-      {0, 0, display_metrics_->width, display_metrics_->height});
+      {0, 0, display_metrics.width, display_metrics.height});
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer display frame: %s",
            error.to_string().c_str());
 
-  error = hwc2_hidl_->setLayerVisibleRegion(
+  error = hidl_->setLayerVisibleRegion(
       display, hardware_composer_layer_,
-      {{0, 0, display_metrics_->width, display_metrics_->height}});
+      {{0, 0, display_metrics.width, display_metrics.height}});
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer visible region: %s",
            error.to_string().c_str());
 
-  error =
-      hwc2_hidl_->setLayerPlaneAlpha(display, hardware_composer_layer_, 1.0f);
+  error = hidl_->setLayerPlaneAlpha(display, hardware_composer_layer_, 1.0f);
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer plane alpha: %s",
            error.to_string().c_str());
 
-  error =
-      hwc2_hidl_->setLayerZOrder(display, hardware_composer_layer_, z_order_);
+  error = hidl_->setLayerZOrder(display, hardware_composer_layer_, z_order_);
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting z_ order: %s",
            error.to_string().c_str());
 }
 
-void Layer::CommonLayerSetup() {
+void Layer::CommonLayerSetup(const HWCDisplayMetrics& display_metrics) {
   HWC::Error error =
-      hwc2_hidl_->createLayer(HWC_DISPLAY_PRIMARY, &hardware_composer_layer_);
+      hidl_->createLayer(HWC_DISPLAY_PRIMARY, &hardware_composer_layer_);
   ALOGE_IF(
       error != HWC::Error::None,
       "Layer::CommonLayerSetup: Failed to create layer on primary display: %s",
       error.to_string().c_str());
-  UpdateLayerSettings();
+  UpdateLayerSettings(display_metrics);
 }
 
 void Layer::Prepare() {
@@ -1157,12 +1065,12 @@
   if (!handle.get()) {
     if (composition_type_ == HWC::Composition::Invalid) {
       composition_type_ = HWC::Composition::SolidColor;
-      hwc2_hidl_->setLayerCompositionType(
+      hidl_->setLayerCompositionType(
           HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
           composition_type_.cast<Hwc2::IComposerClient::Composition>());
       Hwc2::IComposerClient::Color layer_color = {0, 0, 0, 0};
-      hwc2_hidl_->setLayerColor(HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
-                                layer_color);
+      hidl_->setLayerColor(HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+                           layer_color);
     } else {
       // The composition type is already set. Nothing else to do until a
       // buffer arrives.
@@ -1170,15 +1078,15 @@
   } else {
     if (composition_type_ != target_composition_type_) {
       composition_type_ = target_composition_type_;
-      hwc2_hidl_->setLayerCompositionType(
+      hidl_->setLayerCompositionType(
           HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
           composition_type_.cast<Hwc2::IComposerClient::Composition>());
     }
 
     HWC::Error error{HWC::Error::None};
-    error = hwc2_hidl_->setLayerBuffer(HWC_DISPLAY_PRIMARY,
-                                       hardware_composer_layer_, 0, handle,
-                                       acquire_fence_.Get());
+    error = hidl_->setLayerBuffer(HWC_DISPLAY_PRIMARY,
+                                  hardware_composer_layer_, 0, handle,
+                                  acquire_fence_.Get());
 
     ALOGE_IF(error != HWC::Error::None,
              "Layer::Prepare: Error setting layer buffer: %s",
@@ -1187,9 +1095,9 @@
     if (!surface_rect_functions_applied_) {
       const float float_right = right;
       const float float_bottom = bottom;
-      error = hwc2_hidl_->setLayerSourceCrop(HWC_DISPLAY_PRIMARY,
-                                             hardware_composer_layer_,
-                                             {0, 0, float_right, float_bottom});
+      error = hidl_->setLayerSourceCrop(HWC_DISPLAY_PRIMARY,
+                                        hardware_composer_layer_,
+                                        {0, 0, float_right, float_bottom});
 
       ALOGE_IF(error != HWC::Error::None,
                "Layer::Prepare: Error setting layer source crop: %s",
diff --git a/libs/vr/libvrflinger/hardware_composer.h b/libs/vr/libvrflinger/hardware_composer.h
index a0c50e1..fc0efee 100644
--- a/libs/vr/libvrflinger/hardware_composer.h
+++ b/libs/vr/libvrflinger/hardware_composer.h
@@ -54,11 +54,6 @@
  public:
   Layer() {}
 
-  // Sets up the global state used by all Layer instances. This must be called
-  // before using any Layer methods.
-  static void InitializeGlobals(Hwc2::Composer* hwc2_hidl,
-                                const HWCDisplayMetrics* metrics);
-
   // Releases any shared pointers and fence handles held by this instance.
   void Reset();
 
@@ -72,6 +67,7 @@
   // HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
   // |index| is the index of this surface in the DirectDisplaySurface array.
   void Setup(const std::shared_ptr<DirectDisplaySurface>& surface,
+             const HWCDisplayMetrics& display_metrics, Hwc2::Composer* hidl,
              HWC::BlendMode blending, HWC::Transform transform,
              HWC::Composition composition_type, size_t z_roder);
 
@@ -83,9 +79,10 @@
   // |transform| receives HWC_TRANSFORM_* values.
   // |composition_type| receives either HWC_FRAMEBUFFER for most layers or
   // HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
-  void Setup(const std::shared_ptr<IonBuffer>& buffer, HWC::BlendMode blending,
-             HWC::Transform transform, HWC::Composition composition_type,
-             size_t z_order);
+  void Setup(const std::shared_ptr<IonBuffer>& buffer,
+             const HWCDisplayMetrics& display_metrics, Hwc2::Composer* hidl,
+             HWC::BlendMode blending, HWC::Transform transform,
+             HWC::Composition composition_type, size_t z_order);
 
   // Layers that use a direct IonBuffer should call this each frame to update
   // which buffer will be used for the next PostLayers.
@@ -121,7 +118,7 @@
   bool IsLayerSetup() const { return !source_.empty(); }
 
   // Applies all of the settings to this layer using the hwc functions
-  void UpdateLayerSettings();
+  void UpdateLayerSettings(const HWCDisplayMetrics& display_metrics);
 
   int GetSurfaceId() const {
     int surface_id = -1;
@@ -142,10 +139,9 @@
   }
 
  private:
-  void CommonLayerSetup();
+  void CommonLayerSetup(const HWCDisplayMetrics& display_metrics);
 
-  static Hwc2::Composer* hwc2_hidl_;
-  static const HWCDisplayMetrics* display_metrics_;
+  Hwc2::Composer* hidl_ = nullptr;
 
   // The hardware composer layer and metrics to use during the prepare cycle.
   hwc2_layer_t hardware_composer_layer_ = 0;
@@ -263,11 +259,10 @@
   static constexpr size_t kMaxHardwareLayers = 4;
 
   HardwareComposer();
-  HardwareComposer(Hwc2::Composer* hidl,
-                   RequestDisplayCallback request_display_callback);
   ~HardwareComposer();
 
-  bool Initialize();
+  bool Initialize(Hwc2::Composer* hidl,
+                  RequestDisplayCallback request_display_callback);
 
   bool IsInitialized() const { return initialized_; }
 
@@ -281,11 +276,6 @@
   // Get the HMD display metrics for the current display.
   display::Metrics GetHmdDisplayMetrics() const;
 
-  HWC::Error GetDisplayAttribute(hwc2_display_t display, hwc2_config_t config,
-                                 hwc2_attribute_t attributes,
-                                 int32_t* out_value) const;
-  HWC::Error GetDisplayMetrics(hwc2_display_t display, hwc2_config_t config,
-                               HWCDisplayMetrics* out_metrics) const;
   std::string Dump();
 
   void SetVSyncCallback(VSyncCallback callback);
@@ -308,34 +298,31 @@
   int OnNewGlobalBuffer(DvrGlobalBufferKey key, IonBuffer& ion_buffer);
   void OnDeletedGlobalBuffer(DvrGlobalBufferKey key);
 
-  void OnHardwareComposerRefresh();
-
  private:
-  int32_t EnableVsync(bool enabled);
+  HWC::Error GetDisplayAttribute(Hwc2::Composer* hidl, hwc2_display_t display,
+                                 hwc2_config_t config,
+                                 hwc2_attribute_t attributes,
+                                 int32_t* out_value) const;
+  HWC::Error GetDisplayMetrics(Hwc2::Composer* hidl, hwc2_display_t display,
+                               hwc2_config_t config,
+                               HWCDisplayMetrics* out_metrics) const;
+
+  HWC::Error EnableVsync(bool enabled);
 
   class ComposerCallback : public Hwc2::IComposerCallback {
    public:
-    ComposerCallback() {}
-
-    hardware::Return<void> onHotplug(Hwc2::Display /*display*/,
-                                     Connection /*connected*/) override {
-      // TODO(skiazyk): depending on how the server is implemented, we might
-      // have to set it up to synchronize with receiving this event, as it can
-      // potentially be a critical event for setting up state within the
-      // hwc2 module. That is, we (technically) should not call any other hwc
-      // methods until this method has been called after registering the
-      // callbacks.
-      return hardware::Void();
-    }
-
-    hardware::Return<void> onRefresh(Hwc2::Display /*display*/) override {
-      return hardware::Void();
-    }
-
-    hardware::Return<void> onVsync(Hwc2::Display /*display*/,
-                                   int64_t /*timestamp*/) override {
-      return hardware::Void();
-    }
+    ComposerCallback();
+    hardware::Return<void> onHotplug(Hwc2::Display display,
+                                     Connection conn) override;
+    hardware::Return<void> onRefresh(Hwc2::Display display) override;
+    hardware::Return<void> onVsync(Hwc2::Display display,
+                                   int64_t timestamp) override;
+    const pdx::LocalHandle& GetVsyncEventFd() const;
+    int64_t GetVsyncTime();
+   private:
+    std::mutex vsync_mutex_;
+    pdx::LocalHandle vsync_event_fd_;
+    int64_t vsync_time_ = -1;
   };
 
   HWC::Error Validate(hwc2_display_t display);
@@ -364,17 +351,18 @@
   void UpdatePostThreadState(uint32_t state, bool suspend);
 
   // Blocks until either event_fd becomes readable, or we're interrupted by a
-  // control thread. Any errors are returned as negative errno values. If we're
-  // interrupted, kPostThreadInterrupted will be returned.
+  // control thread, or timeout_ms is reached before any events occur. Any
+  // errors are returned as negative errno values, with -ETIMEDOUT returned in
+  // the case of a timeout. If we're interrupted, kPostThreadInterrupted will be
+  // returned.
   int PostThreadPollInterruptible(const pdx::LocalHandle& event_fd,
-                                  int requested_events);
+                                  int requested_events,
+                                  int timeout_ms);
 
-  // BlockUntilVSync, WaitForVSync, and SleepUntil are all blocking calls made
-  // on the post thread that can be interrupted by a control thread. If
-  // interrupted, these calls return kPostThreadInterrupted.
+  // WaitForVSync and SleepUntil are blocking calls made on the post thread that
+  // can be interrupted by a control thread. If interrupted, these calls return
+  // kPostThreadInterrupted.
   int ReadWaitPPState();
-  int BlockUntilVSync();
-  int ReadVSyncTimestamp(int64_t* timestamp);
   int WaitForVSync(int64_t* timestamp);
   int SleepUntil(int64_t wakeup_timestamp);
 
@@ -398,11 +386,9 @@
 
   bool initialized_;
 
-  // Hardware composer HAL device from SurfaceFlinger. VrFlinger does not own
-  // this pointer.
-  Hwc2::Composer* hwc2_hidl_;
+  std::unique_ptr<Hwc2::Composer> hidl_;
+  sp<ComposerCallback> hidl_callback_;
   RequestDisplayCallback request_display_callback_;
-  sp<ComposerCallback> callbacks_;
 
   // Display metrics of the physical display.
   HWCDisplayMetrics native_display_metrics_;
@@ -433,7 +419,8 @@
   std::thread post_thread_;
 
   // Post thread state machine and synchronization primitives.
-  PostThreadStateType post_thread_state_{PostThreadState::Idle};
+  PostThreadStateType post_thread_state_{
+      PostThreadState::Idle | PostThreadState::Suspended};
   std::atomic<bool> post_thread_quiescent_{true};
   bool post_thread_resumed_{false};
   pdx::LocalHandle post_thread_event_fd_;
@@ -444,9 +431,6 @@
   // Backlight LED brightness sysfs node.
   pdx::LocalHandle backlight_brightness_fd_;
 
-  // Primary display vsync event sysfs node.
-  pdx::LocalHandle primary_display_vsync_event_fd_;
-
   // Primary display wait_pingpong state sysfs node.
   pdx::LocalHandle primary_display_wait_pp_fd_;
 
@@ -478,12 +462,6 @@
 
   static constexpr int kPostThreadInterrupted = 1;
 
-  static void HwcRefresh(hwc2_callback_data_t data, hwc2_display_t display);
-  static void HwcVSync(hwc2_callback_data_t data, hwc2_display_t display,
-                       int64_t timestamp);
-  static void HwcHotplug(hwc2_callback_data_t callbackData,
-                         hwc2_display_t display, hwc2_connection_t connected);
-
   HardwareComposer(const HardwareComposer&) = delete;
   void operator=(const HardwareComposer&) = delete;
 };
diff --git a/libs/vr/libvrflinger/include/dvr/vr_flinger.h b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
index e7f41a7..33cbc84 100644
--- a/libs/vr/libvrflinger/include/dvr/vr_flinger.h
+++ b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
@@ -29,9 +29,6 @@
   void GrantDisplayOwnership();
   void SeizeDisplayOwnership();
 
-  // Called on a binder thread.
-  void OnHardwareComposerRefresh();
-
   // dump all vr flinger state.
   std::string Dump();
 
diff --git a/libs/vr/libvrflinger/vr_flinger.cpp b/libs/vr/libvrflinger/vr_flinger.cpp
index 56405de..fcf94f0 100644
--- a/libs/vr/libvrflinger/vr_flinger.cpp
+++ b/libs/vr/libvrflinger/vr_flinger.cpp
@@ -133,10 +133,6 @@
   display_service_->SeizeDisplayOwnership();
 }
 
-void VrFlinger::OnHardwareComposerRefresh() {
-  display_service_->OnHardwareComposerRefresh();
-}
-
 std::string VrFlinger::Dump() {
   // TODO(karthikrs): Add more state information here.
   return display_service_->DumpState(0/*unused*/);
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index 744dd50..248ef53 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -134,9 +134,11 @@
     EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
     if (config == EGL_NO_CONFIG) {
 #ifdef USE_HWC2
-        config = RenderEngine::chooseEglConfig(display, PIXEL_FORMAT_RGBA_8888);
+        config = RenderEngine::chooseEglConfig(display, PIXEL_FORMAT_RGBA_8888,
+                                               /*logConfig*/ false);
 #else
-        config = RenderEngine::chooseEglConfig(display, format);
+        config = RenderEngine::chooseEglConfig(display, format,
+                                               /*logConfig*/ false);
 #endif
     }
     eglSurface = eglCreateWindowSurface(display, config, window, NULL);
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.cpp b/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
index 704b17e..433a224 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
@@ -215,6 +215,10 @@
     }
 }
 
+bool Composer::isRemote() {
+    return mClient->isRemote();
+}
+
 void Composer::resetCommands() {
     mWriter.reset();
 }
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.h b/services/surfaceflinger/DisplayHardware/ComposerHal.h
index 40d2a4c..31a3c1d 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.h
@@ -143,6 +143,11 @@
 
     void registerCallback(const sp<IComposerCallback>& callback);
 
+    // Returns true if the connected composer service is running in a remote
+    // process, false otherwise. This will return false if the service is
+    // configured in passthrough mode, for example.
+    bool isRemote();
+
     // Reset all pending commands in the command buffer. Useful if you want to
     // skip a frame but have already queued some commands.
     void resetCommands();
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index b749ce6..78c0c85 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -33,45 +33,6 @@
 #include <algorithm>
 #include <inttypes.h>
 
-extern "C" {
-    static void hotplug_hook(hwc2_callback_data_t callbackData,
-            hwc2_display_t displayId, int32_t intConnected) {
-        auto device = static_cast<HWC2::Device*>(callbackData);
-        auto display = device->getDisplayById(displayId);
-        if (display) {
-            auto connected = static_cast<HWC2::Connection>(intConnected);
-            device->callHotplug(std::move(display), connected);
-        } else {
-            ALOGE("Hotplug callback called with unknown display %" PRIu64,
-                    displayId);
-        }
-    }
-
-    static void refresh_hook(hwc2_callback_data_t callbackData,
-            hwc2_display_t displayId) {
-        auto device = static_cast<HWC2::Device*>(callbackData);
-        auto display = device->getDisplayById(displayId);
-        if (display) {
-            device->callRefresh(std::move(display));
-        } else {
-            ALOGE("Refresh callback called with unknown display %" PRIu64,
-                    displayId);
-        }
-    }
-
-    static void vsync_hook(hwc2_callback_data_t callbackData,
-            hwc2_display_t displayId, int64_t timestamp) {
-        auto device = static_cast<HWC2::Device*>(callbackData);
-        auto display = device->getDisplayById(displayId);
-        if (display) {
-            device->callVsync(std::move(display), timestamp);
-        } else {
-            ALOGE("Vsync callback called with unknown display %" PRIu64,
-                    displayId);
-        }
-    }
-}
-
 using android::Fence;
 using android::FloatRect;
 using android::GraphicBuffer;
@@ -86,51 +47,78 @@
 
 namespace Hwc2 = android::Hwc2;
 
+namespace {
+
+class ComposerCallbackBridge : public Hwc2::IComposerCallback {
+public:
+    ComposerCallbackBridge(ComposerCallback* callback, int32_t sequenceId)
+            : mCallback(callback), mSequenceId(sequenceId),
+              mHasPrimaryDisplay(false) {}
+
+    Return<void> onHotplug(Hwc2::Display display,
+                           IComposerCallback::Connection conn) override
+    {
+        HWC2::Connection connection = static_cast<HWC2::Connection>(conn);
+        if (!mHasPrimaryDisplay) {
+            LOG_ALWAYS_FATAL_IF(connection != HWC2::Connection::Connected,
+                    "Initial onHotplug callback should be "
+                    "primary display connected");
+            mHasPrimaryDisplay = true;
+            mCallback->onHotplugReceived(mSequenceId, display,
+                                         connection, true);
+        } else {
+            mCallback->onHotplugReceived(mSequenceId, display,
+                                         connection, false);
+        }
+        return Void();
+    }
+
+    Return<void> onRefresh(Hwc2::Display display) override
+    {
+        mCallback->onRefreshReceived(mSequenceId, display);
+        return Void();
+    }
+
+    Return<void> onVsync(Hwc2::Display display, int64_t timestamp) override
+    {
+        mCallback->onVsyncReceived(mSequenceId, display, timestamp);
+        return Void();
+    }
+
+    bool HasPrimaryDisplay() { return mHasPrimaryDisplay; }
+
+private:
+    ComposerCallback* mCallback;
+    int32_t mSequenceId;
+    bool mHasPrimaryDisplay;
+};
+
+} // namespace anonymous
+
+
 // Device methods
 
 Device::Device(const std::string& serviceName)
   : mComposer(std::make_unique<Hwc2::Composer>(serviceName)),
     mCapabilities(),
     mDisplays(),
-    mHotplug(),
-    mPendingHotplugs(),
-    mRefresh(),
-    mPendingRefreshes(),
-    mVsync(),
-    mPendingVsyncs()
+    mRegisteredCallback(false)
 {
     loadCapabilities();
-    registerCallbacks();
 }
 
-Device::~Device()
-{
-    for (auto element : mDisplays) {
-        auto display = element.second.lock();
-        if (!display) {
-            ALOGE("~Device: Found a display (%" PRId64 " that has already been"
-                    " destroyed", element.first);
-            continue;
-        }
-
-        DisplayType displayType = HWC2::DisplayType::Invalid;
-        auto error = display->getType(&displayType);
-        if (error != Error::None) {
-            ALOGE("~Device: Failed to determine type of display %" PRIu64
-                    ": %s (%d)", display->getId(), to_string(error).c_str(),
-                    static_cast<int32_t>(error));
-            continue;
-        }
-
-        if (displayType == HWC2::DisplayType::Physical) {
-            error = display->setVsyncEnabled(HWC2::Vsync::Disable);
-            if (error != Error::None) {
-                ALOGE("~Device: Failed to disable vsync for display %" PRIu64
-                        ": %s (%d)", display->getId(), to_string(error).c_str(),
-                        static_cast<int32_t>(error));
-            }
-        }
+void Device::registerCallback(ComposerCallback* callback, int32_t sequenceId) {
+    if (mRegisteredCallback) {
+        ALOGW("Callback already registered. Ignored extra registration "
+                "attempt.");
+        return;
     }
+    mRegisteredCallback = true;
+    sp<ComposerCallbackBridge> callbackBridge(
+            new ComposerCallbackBridge(callback, sequenceId));
+    mComposer->registerCallback(callbackBridge);
+    LOG_ALWAYS_FATAL_IF(!callbackBridge->HasPrimaryDisplay(),
+            "Registered composer callback but didn't get primary display");
 }
 
 // Required by HWC2 device
@@ -146,7 +134,7 @@
 }
 
 Error Device::createVirtualDisplay(uint32_t width, uint32_t height,
-        android_pixel_format_t* format, std::shared_ptr<Display>* outDisplay)
+        android_pixel_format_t* format, Display** outDisplay)
 {
     ALOGI("Creating virtual display");
 
@@ -159,104 +147,66 @@
         return error;
     }
 
-    ALOGI("Created virtual display");
+    auto display = std::make_unique<Display>(
+            *mComposer.get(), mCapabilities, displayId, DisplayType::Virtual);
+    *outDisplay = display.get();
     *format = static_cast<android_pixel_format_t>(intFormat);
-    *outDisplay = getDisplayById(displayId);
-    if (!*outDisplay) {
-        ALOGE("Failed to get display by id");
-        return Error::BadDisplay;
-    }
-    (*outDisplay)->setConnected(true);
+    mDisplays.emplace(displayId, std::move(display));
+    ALOGI("Created virtual display");
     return Error::None;
 }
 
-void Device::registerHotplugCallback(HotplugCallback hotplug)
+void Device::destroyDisplay(hwc2_display_t displayId)
 {
-    ALOGV("registerHotplugCallback");
-    mHotplug = hotplug;
-    for (auto& pending : mPendingHotplugs) {
-        auto& display = pending.first;
-        auto connected = pending.second;
-        ALOGV("Sending pending hotplug(%" PRIu64 ", %s)", display->getId(),
-                to_string(connected).c_str());
-        mHotplug(std::move(display), connected);
-    }
+    ALOGI("Destroying display %" PRIu64, displayId);
+    mDisplays.erase(displayId);
 }
 
-void Device::registerRefreshCallback(RefreshCallback refresh)
-{
-    mRefresh = refresh;
-    for (auto& pending : mPendingRefreshes) {
-        mRefresh(std::move(pending));
-    }
-}
+void Device::onHotplug(hwc2_display_t displayId, Connection connection) {
+    if (connection == Connection::Connected) {
+        auto display = getDisplayById(displayId);
+        if (display) {
+            if (display->isConnected()) {
+                ALOGW("Attempt to hotplug connect display %" PRIu64
+                        " , which is already connected.", displayId);
+            } else {
+                display->setConnected(true);
+            }
+        } else {
+            DisplayType displayType;
+            auto intError = mComposer->getDisplayType(displayId,
+                    reinterpret_cast<Hwc2::IComposerClient::DisplayType *>(
+                            &displayType));
+            auto error = static_cast<Error>(intError);
+            if (error != Error::None) {
+                ALOGE("getDisplayType(%" PRIu64 ") failed: %s (%d). "
+                        "Aborting hotplug attempt.",
+                        displayId, to_string(error).c_str(), intError);
+                return;
+            }
 
-void Device::registerVsyncCallback(VsyncCallback vsync)
-{
-    mVsync = vsync;
-    for (auto& pending : mPendingVsyncs) {
-        auto& display = pending.first;
-        auto timestamp = pending.second;
-        mVsync(std::move(display), timestamp);
-    }
-}
-
-// For use by Device callbacks
-
-void Device::callHotplug(std::shared_ptr<Display> display, Connection connected)
-{
-    if (connected == Connection::Connected) {
-        if (!display->isConnected()) {
-            mComposer->setClientTargetSlotCount(display->getId());
-            display->loadConfigs();
-            display->setConnected(true);
+            auto newDisplay = std::make_unique<Display>(
+                    *mComposer.get(), mCapabilities, displayId, displayType);
+            mDisplays.emplace(displayId, std::move(newDisplay));
         }
-    } else {
-        display->setConnected(false);
-        mDisplays.erase(display->getId());
-    }
-
-    if (mHotplug) {
-        mHotplug(std::move(display), connected);
-    } else {
-        ALOGV("callHotplug called, but no valid callback registered, storing");
-        mPendingHotplugs.emplace_back(std::move(display), connected);
-    }
-}
-
-void Device::callRefresh(std::shared_ptr<Display> display)
-{
-    if (mRefresh) {
-        mRefresh(std::move(display));
-    } else {
-        ALOGV("callRefresh called, but no valid callback registered, storing");
-        mPendingRefreshes.emplace_back(std::move(display));
-    }
-}
-
-void Device::callVsync(std::shared_ptr<Display> display, nsecs_t timestamp)
-{
-    if (mVsync) {
-        mVsync(std::move(display), timestamp);
-    } else {
-        ALOGV("callVsync called, but no valid callback registered, storing");
-        mPendingVsyncs.emplace_back(std::move(display), timestamp);
+    } else if (connection == Connection::Disconnected) {
+        // The display will later be destroyed by a call to
+        // destroyDisplay(). For now we just mark it disconnected.
+        auto display = getDisplayById(displayId);
+        if (display) {
+            display->setConnected(false);
+        } else {
+            ALOGW("Attempted to disconnect unknown display %" PRIu64,
+                  displayId);
+        }
     }
 }
 
 // Other Device methods
 
-std::shared_ptr<Display> Device::getDisplayById(hwc2_display_t id) {
-    if (mDisplays.count(id) != 0) {
-        auto strongDisplay = mDisplays[id].lock();
-        ALOGE_IF(!strongDisplay, "Display %" PRId64 " is in mDisplays but is no"
-                " longer alive", id);
-        return strongDisplay;
-    }
-
-    auto display = std::make_shared<Display>(*this, id);
-    mDisplays.emplace(id, display);
-    return display;
+Display* Device::getDisplayById(hwc2_display_t id) {
+    auto iter = mDisplays.find(id);
+    return iter == mDisplays.end() ? nullptr : iter->second.get();
 }
 
 // Device initialization methods
@@ -271,84 +221,37 @@
     }
 }
 
-bool Device::hasCapability(HWC2::Capability capability) const
-{
-    return std::find(mCapabilities.cbegin(), mCapabilities.cend(),
-            capability) != mCapabilities.cend();
-}
-
-namespace {
-class ComposerCallback : public Hwc2::IComposerCallback {
-public:
-    ComposerCallback(Device* device) : mDevice(device) {}
-
-    Return<void> onHotplug(Hwc2::Display display,
-            Connection connected) override
-    {
-        hotplug_hook(mDevice, display, static_cast<int32_t>(connected));
-        return Void();
-    }
-
-    Return<void> onRefresh(Hwc2::Display display) override
-    {
-        refresh_hook(mDevice, display);
-        return Void();
-    }
-
-    Return<void> onVsync(Hwc2::Display display, int64_t timestamp) override
-    {
-        vsync_hook(mDevice, display, timestamp);
-        return Void();
-    }
-
-private:
-    Device* mDevice;
-};
-} // namespace anonymous
-
-void Device::registerCallbacks()
-{
-    sp<ComposerCallback> callback = new ComposerCallback(this);
-    mComposer->registerCallback(callback);
-}
-
-
-// For use by Display
-
-void Device::destroyVirtualDisplay(hwc2_display_t display)
-{
-    ALOGI("Destroying virtual display");
-    auto intError = mComposer->destroyVirtualDisplay(display);
-    auto error = static_cast<Error>(intError);
-    ALOGE_IF(error != Error::None, "destroyVirtualDisplay(%" PRIu64 ") failed:"
-            " %s (%d)", display, to_string(error).c_str(), intError);
-    mDisplays.erase(display);
-}
-
 // Display methods
 
-Display::Display(Device& device, hwc2_display_t id)
-  : mDevice(device),
+Display::Display(android::Hwc2::Composer& composer,
+                 const std::unordered_set<Capability>& capabilities,
+                 hwc2_display_t id, DisplayType type)
+  : mComposer(composer),
+    mCapabilities(capabilities),
     mId(id),
     mIsConnected(false),
-    mType(DisplayType::Invalid)
+    mType(type)
 {
     ALOGV("Created display %" PRIu64, id);
-
-    auto intError = mDevice.mComposer->getDisplayType(mId,
-            reinterpret_cast<Hwc2::IComposerClient::DisplayType *>(&mType));
-    auto error = static_cast<Error>(intError);
-    if (error != Error::None) {
-        ALOGE("getDisplayType(%" PRIu64 ") failed: %s (%d)",
-              id, to_string(error).c_str(), intError);
-    }
+    setConnected(true);
 }
 
-Display::~Display()
-{
-    ALOGV("Destroyed display %" PRIu64, mId);
+Display::~Display() {
+    mLayers.clear();
+
     if (mType == DisplayType::Virtual) {
-        mDevice.destroyVirtualDisplay(mId);
+        ALOGV("Destroying virtual display");
+        auto intError = mComposer.destroyVirtualDisplay(mId);
+        auto error = static_cast<Error>(intError);
+        ALOGE_IF(error != Error::None, "destroyVirtualDisplay(%" PRIu64
+                ") failed: %s (%d)", mId, to_string(error).c_str(), intError);
+    } else if (mType == DisplayType::Physical) {
+        auto error = setVsyncEnabled(HWC2::Vsync::Disable);
+        if (error != Error::None) {
+            ALOGE("~Display: Failed to disable vsync for display %" PRIu64
+                    ": %s (%d)", mId, to_string(error).c_str(),
+                    static_cast<int32_t>(error));
+        }
     }
 }
 
@@ -383,22 +286,35 @@
 
 Error Display::acceptChanges()
 {
-    auto intError = mDevice.mComposer->acceptDisplayChanges(mId);
+    auto intError = mComposer.acceptDisplayChanges(mId);
     return static_cast<Error>(intError);
 }
 
-Error Display::createLayer(std::shared_ptr<Layer>* outLayer)
+Error Display::createLayer(Layer** outLayer)
 {
+    if (!outLayer) {
+        return Error::BadParameter;
+    }
     hwc2_layer_t layerId = 0;
-    auto intError = mDevice.mComposer->createLayer(mId, &layerId);
+    auto intError = mComposer.createLayer(mId, &layerId);
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
         return error;
     }
 
-    auto layer = std::make_shared<Layer>(shared_from_this(), layerId);
-    mLayers.emplace(layerId, layer);
-    *outLayer = std::move(layer);
+    auto layer = std::make_unique<Layer>(
+            mComposer, mCapabilities, mId, layerId);
+    *outLayer = layer.get();
+    mLayers.emplace(layerId, std::move(layer));
+    return Error::None;
+}
+
+Error Display::destroyLayer(Layer* layer)
+{
+    if (!layer) {
+        return Error::BadParameter;
+    }
+    mLayers.erase(layer->getId());
     return Error::None;
 }
 
@@ -407,7 +323,7 @@
 {
     ALOGV("[%" PRIu64 "] getActiveConfig", mId);
     hwc2_config_t configId = 0;
-    auto intError = mDevice.mComposer->getActiveConfig(mId, &configId);
+    auto intError = mComposer.getActiveConfig(mId, &configId);
     auto error = static_cast<Error>(intError);
 
     if (error != Error::None) {
@@ -430,12 +346,12 @@
 }
 
 Error Display::getChangedCompositionTypes(
-        std::unordered_map<std::shared_ptr<Layer>, Composition>* outTypes)
+        std::unordered_map<Layer*, Composition>* outTypes)
 {
     std::vector<Hwc2::Layer> layerIds;
     std::vector<Hwc2::IComposerClient::Composition> types;
-    auto intError = mDevice.mComposer->getChangedCompositionTypes(mId,
-            &layerIds, &types);
+    auto intError = mComposer.getChangedCompositionTypes(
+            mId, &layerIds, &types);
     uint32_t numElements = layerIds.size();
     auto error = static_cast<Error>(intError);
     error = static_cast<Error>(intError);
@@ -464,7 +380,7 @@
 Error Display::getColorModes(std::vector<android_color_mode_t>* outModes) const
 {
     std::vector<Hwc2::ColorMode> modes;
-    auto intError = mDevice.mComposer->getColorModes(mId, &modes);
+    auto intError = mComposer.getColorModes(mId, &modes);
     uint32_t numModes = modes.size();
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
@@ -489,19 +405,18 @@
 
 Error Display::getName(std::string* outName) const
 {
-    auto intError = mDevice.mComposer->getDisplayName(mId, outName);
+    auto intError = mComposer.getDisplayName(mId, outName);
     return static_cast<Error>(intError);
 }
 
 Error Display::getRequests(HWC2::DisplayRequest* outDisplayRequests,
-        std::unordered_map<std::shared_ptr<Layer>, LayerRequest>*
-                outLayerRequests)
+        std::unordered_map<Layer*, LayerRequest>* outLayerRequests)
 {
     uint32_t intDisplayRequests;
     std::vector<Hwc2::Layer> layerIds;
     std::vector<uint32_t> layerRequests;
-    auto intError = mDevice.mComposer->getDisplayRequests(mId,
-            &intDisplayRequests, &layerIds, &layerRequests);
+    auto intError = mComposer.getDisplayRequests(
+            mId, &intDisplayRequests, &layerIds, &layerRequests);
     uint32_t numElements = layerIds.size();
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
@@ -535,7 +450,7 @@
 Error Display::supportsDoze(bool* outSupport) const
 {
     bool intSupport = false;
-    auto intError = mDevice.mComposer->getDozeSupport(mId, &intSupport);
+    auto intError = mComposer.getDozeSupport(mId, &intSupport);
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
         return error;
@@ -552,7 +467,7 @@
     float maxAverageLuminance = -1.0f;
     float minLuminance = -1.0f;
     std::vector<Hwc2::Hdr> intTypes;
-    auto intError = mDevice.mComposer->getHdrCapabilities(mId, &intTypes,
+    auto intError = mComposer.getHdrCapabilities(mId, &intTypes,
             &maxLuminance, &maxAverageLuminance, &minLuminance);
     auto error = static_cast<HWC2::Error>(intError);
 
@@ -571,25 +486,24 @@
 }
 
 Error Display::getReleaseFences(
-        std::unordered_map<std::shared_ptr<Layer>, sp<Fence>>* outFences) const
+        std::unordered_map<Layer*, sp<Fence>>* outFences) const
 {
     std::vector<Hwc2::Layer> layerIds;
     std::vector<int> fenceFds;
-    auto intError = mDevice.mComposer->getReleaseFences(mId,
-            &layerIds, &fenceFds);
+    auto intError = mComposer.getReleaseFences(mId, &layerIds, &fenceFds);
     auto error = static_cast<Error>(intError);
     uint32_t numElements = layerIds.size();
     if (error != Error::None) {
         return error;
     }
 
-    std::unordered_map<std::shared_ptr<Layer>, sp<Fence>> releaseFences;
+    std::unordered_map<Layer*, sp<Fence>> releaseFences;
     releaseFences.reserve(numElements);
     for (uint32_t element = 0; element < numElements; ++element) {
         auto layer = getLayerById(layerIds[element]);
         if (layer) {
             sp<Fence> fence(new Fence(fenceFds[element]));
-            releaseFences.emplace(std::move(layer), fence);
+            releaseFences.emplace(layer, fence);
         } else {
             ALOGE("getReleaseFences: invalid layer %" PRIu64
                     " found on display %" PRIu64, layerIds[element], mId);
@@ -607,7 +521,7 @@
 Error Display::present(sp<Fence>* outPresentFence)
 {
     int32_t presentFenceFd = -1;
-    auto intError = mDevice.mComposer->presentDisplay(mId, &presentFenceFd);
+    auto intError = mComposer.presentDisplay(mId, &presentFenceFd);
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
         return error;
@@ -625,7 +539,7 @@
                 config->getDisplayId(), mId);
         return Error::BadConfig;
     }
-    auto intError = mDevice.mComposer->setActiveConfig(mId, config->getId());
+    auto intError = mComposer.setActiveConfig(mId, config->getId());
     return static_cast<Error>(intError);
 }
 
@@ -634,7 +548,7 @@
 {
     // TODO: Properly encode client target surface damage
     int32_t fenceFd = acquireFence->dup();
-    auto intError = mDevice.mComposer->setClientTarget(mId, slot, target,
+    auto intError = mComposer.setClientTarget(mId, slot, target,
             fenceFd, static_cast<Hwc2::Dataspace>(dataspace),
             std::vector<Hwc2::IComposerClient::Rect>());
     return static_cast<Error>(intError);
@@ -642,15 +556,15 @@
 
 Error Display::setColorMode(android_color_mode_t mode)
 {
-    auto intError = mDevice.mComposer->setColorMode(mId,
-            static_cast<Hwc2::ColorMode>(mode));
+    auto intError = mComposer.setColorMode(
+            mId, static_cast<Hwc2::ColorMode>(mode));
     return static_cast<Error>(intError);
 }
 
 Error Display::setColorTransform(const android::mat4& matrix,
         android_color_transform_t hint)
 {
-    auto intError = mDevice.mComposer->setColorTransform(mId,
+    auto intError = mComposer.setColorTransform(mId,
             matrix.asArray(), static_cast<Hwc2::ColorTransform>(hint));
     return static_cast<Error>(intError);
 }
@@ -660,7 +574,7 @@
 {
     int32_t fenceFd = releaseFence->dup();
     auto handle = buffer->getNativeBuffer()->handle;
-    auto intError = mDevice.mComposer->setOutputBuffer(mId, handle, fenceFd);
+    auto intError = mComposer.setOutputBuffer(mId, handle, fenceFd);
     close(fenceFd);
     return static_cast<Error>(intError);
 }
@@ -668,14 +582,14 @@
 Error Display::setPowerMode(PowerMode mode)
 {
     auto intMode = static_cast<Hwc2::IComposerClient::PowerMode>(mode);
-    auto intError = mDevice.mComposer->setPowerMode(mId, intMode);
+    auto intError = mComposer.setPowerMode(mId, intMode);
     return static_cast<Error>(intError);
 }
 
 Error Display::setVsyncEnabled(Vsync enabled)
 {
     auto intEnabled = static_cast<Hwc2::IComposerClient::Vsync>(enabled);
-    auto intError = mDevice.mComposer->setVsyncEnabled(mId, intEnabled);
+    auto intError = mComposer.setVsyncEnabled(mId, intEnabled);
     return static_cast<Error>(intError);
 }
 
@@ -683,8 +597,7 @@
 {
     uint32_t numTypes = 0;
     uint32_t numRequests = 0;
-    auto intError = mDevice.mComposer->validateDisplay(mId,
-            &numTypes, &numRequests);
+    auto intError = mComposer.validateDisplay(mId, &numTypes, &numRequests);
     auto error = static_cast<Error>(intError);
     if (error != Error::None && error != Error::HasChanges) {
         return error;
@@ -701,7 +614,8 @@
     uint32_t numTypes = 0;
     uint32_t numRequests = 0;
     int32_t presentFenceFd = -1;
-    auto intError = mDevice.mComposer->presentOrValidateDisplay(mId, &numTypes, &numRequests, &presentFenceFd, state);
+    auto intError = mComposer.presentOrValidateDisplay(
+            mId, &numTypes, &numRequests, &presentFenceFd, state);
     auto error = static_cast<Error>(intError);
     if (error != Error::None && error != Error::HasChanges) {
         return error;
@@ -720,15 +634,23 @@
 
 void Display::discardCommands()
 {
-    mDevice.mComposer->resetCommands();
+    mComposer.resetCommands();
 }
 
 // For use by Device
 
+void Display::setConnected(bool connected) {
+    if (!mIsConnected && connected && mType == DisplayType::Physical) {
+        mComposer.setClientTargetSlotCount(mId);
+        loadConfigs();
+    }
+    mIsConnected = connected;
+}
+
 int32_t Display::getAttribute(hwc2_config_t configId, Attribute attribute)
 {
     int32_t value = 0;
-    auto intError = mDevice.mComposer->getDisplayAttribute(mId, configId,
+    auto intError = mComposer.getDisplayAttribute(mId, configId,
             static_cast<Hwc2::IComposerClient::Attribute>(attribute),
             &value);
     auto error = static_cast<Error>(intError);
@@ -760,7 +682,7 @@
     ALOGV("[%" PRIu64 "] loadConfigs", mId);
 
     std::vector<Hwc2::Config> configIds;
-    auto intError = mDevice.mComposer->getDisplayConfigs(mId, &configIds);
+    auto intError = mComposer.getDisplayConfigs(mId, &configIds);
     auto error = static_cast<Error>(intError);
     if (error != Error::None) {
         ALOGE("[%" PRIu64 "] getDisplayConfigs [2] failed: %s (%d)", mId,
@@ -773,54 +695,51 @@
     }
 }
 
-// For use by Layer
-
-void Display::destroyLayer(hwc2_layer_t layerId)
-{
-    auto intError =mDevice.mComposer->destroyLayer(mId, layerId);
-    auto error = static_cast<Error>(intError);
-    ALOGE_IF(error != Error::None, "destroyLayer(%" PRIu64 ", %" PRIu64 ")"
-            " failed: %s (%d)", mId, layerId, to_string(error).c_str(),
-            intError);
-    mLayers.erase(layerId);
-}
-
 // Other Display methods
 
-std::shared_ptr<Layer> Display::getLayerById(hwc2_layer_t id) const
+Layer* Display::getLayerById(hwc2_layer_t id) const
 {
     if (mLayers.count(id) == 0) {
         return nullptr;
     }
 
-    auto layer = mLayers.at(id).lock();
-    return layer;
+    return mLayers.at(id).get();
 }
 
 // Layer methods
 
-Layer::Layer(const std::shared_ptr<Display>& display, hwc2_layer_t id)
-  : mDisplay(display),
-    mDisplayId(display->getId()),
-    mDevice(display->getDevice()),
-    mId(id)
+Layer::Layer(android::Hwc2::Composer& composer,
+             const std::unordered_set<Capability>& capabilities,
+             hwc2_display_t displayId, hwc2_layer_t layerId)
+  : mComposer(composer),
+    mCapabilities(capabilities),
+    mDisplayId(displayId),
+    mId(layerId)
 {
-    ALOGV("Created layer %" PRIu64 " on display %" PRIu64, id,
-            display->getId());
+    ALOGV("Created layer %" PRIu64 " on display %" PRIu64, layerId, displayId);
 }
 
 Layer::~Layer()
 {
-    auto display = mDisplay.lock();
-    if (display) {
-        display->destroyLayer(mId);
+    auto intError = mComposer.destroyLayer(mDisplayId, mId);
+    auto error = static_cast<Error>(intError);
+    ALOGE_IF(error != Error::None, "destroyLayer(%" PRIu64 ", %" PRIu64 ")"
+            " failed: %s (%d)", mDisplayId, mId, to_string(error).c_str(),
+            intError);
+    if (mLayerDestroyedListener) {
+        mLayerDestroyedListener(this);
     }
 }
 
+void Layer::setLayerDestroyedListener(std::function<void(Layer*)> listener) {
+    LOG_ALWAYS_FATAL_IF(mLayerDestroyedListener && listener,
+            "Attempt to set layer destroyed listener multiple times");
+    mLayerDestroyedListener = listener;
+}
+
 Error Layer::setCursorPosition(int32_t x, int32_t y)
 {
-    auto intError = mDevice.mComposer->setCursorPosition(mDisplayId,
-            mId, x, y);
+    auto intError = mComposer.setCursorPosition(mDisplayId, mId, x, y);
     return static_cast<Error>(intError);
 }
 
@@ -828,8 +747,8 @@
         const sp<Fence>& acquireFence)
 {
     int32_t fenceFd = acquireFence->dup();
-    auto intError = mDevice.mComposer->setLayerBuffer(mDisplayId,
-            mId, slot, buffer, fenceFd);
+    auto intError = mComposer.setLayerBuffer(mDisplayId, mId, slot, buffer,
+                                             fenceFd);
     return static_cast<Error>(intError);
 }
 
@@ -839,7 +758,7 @@
     // rects for HWC
     Hwc2::Error intError = Hwc2::Error::NONE;
     if (damage.isRect() && damage.getBounds() == Rect::INVALID_RECT) {
-        intError = mDevice.mComposer->setLayerSurfaceDamage(mDisplayId,
+        intError = mComposer.setLayerSurfaceDamage(mDisplayId,
                 mId, std::vector<Hwc2::IComposerClient::Rect>());
     } else {
         size_t rectCount = 0;
@@ -851,8 +770,7 @@
                     rectArray[rect].right, rectArray[rect].bottom});
         }
 
-        intError = mDevice.mComposer->setLayerSurfaceDamage(mDisplayId,
-                mId, hwcRects);
+        intError = mComposer.setLayerSurfaceDamage(mDisplayId, mId, hwcRects);
     }
 
     return static_cast<Error>(intError);
@@ -861,24 +779,22 @@
 Error Layer::setBlendMode(BlendMode mode)
 {
     auto intMode = static_cast<Hwc2::IComposerClient::BlendMode>(mode);
-    auto intError = mDevice.mComposer->setLayerBlendMode(mDisplayId,
-            mId, intMode);
+    auto intError = mComposer.setLayerBlendMode(mDisplayId, mId, intMode);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setColor(hwc_color_t color)
 {
     Hwc2::IComposerClient::Color hwcColor{color.r, color.g, color.b, color.a};
-    auto intError = mDevice.mComposer->setLayerColor(mDisplayId,
-            mId, hwcColor);
+    auto intError = mComposer.setLayerColor(mDisplayId, mId, hwcColor);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setCompositionType(Composition type)
 {
     auto intType = static_cast<Hwc2::IComposerClient::Composition>(type);
-    auto intError = mDevice.mComposer->setLayerCompositionType(mDisplayId,
-            mId, intType);
+    auto intError = mComposer.setLayerCompositionType(
+            mDisplayId, mId, intType);
     return static_cast<Error>(intError);
 }
 
@@ -889,8 +805,7 @@
     }
     mDataSpace = dataspace;
     auto intDataspace = static_cast<Hwc2::Dataspace>(dataspace);
-    auto intError = mDevice.mComposer->setLayerDataspace(mDisplayId,
-            mId, intDataspace);
+    auto intError = mComposer.setLayerDataspace(mDisplayId, mId, intDataspace);
     return static_cast<Error>(intError);
 }
 
@@ -898,27 +813,24 @@
 {
     Hwc2::IComposerClient::Rect hwcRect{frame.left, frame.top,
         frame.right, frame.bottom};
-    auto intError = mDevice.mComposer->setLayerDisplayFrame(mDisplayId,
-            mId, hwcRect);
+    auto intError = mComposer.setLayerDisplayFrame(mDisplayId, mId, hwcRect);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setPlaneAlpha(float alpha)
 {
-    auto intError = mDevice.mComposer->setLayerPlaneAlpha(mDisplayId,
-            mId, alpha);
+    auto intError = mComposer.setLayerPlaneAlpha(mDisplayId, mId, alpha);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setSidebandStream(const native_handle_t* stream)
 {
-    if (!mDevice.hasCapability(Capability::SidebandStream)) {
+    if (mCapabilities.count(Capability::SidebandStream) == 0) {
         ALOGE("Attempted to call setSidebandStream without checking that the "
                 "device supports sideband streams");
         return Error::Unsupported;
     }
-    auto intError = mDevice.mComposer->setLayerSidebandStream(mDisplayId,
-            mId, stream);
+    auto intError = mComposer.setLayerSidebandStream(mDisplayId, mId, stream);
     return static_cast<Error>(intError);
 }
 
@@ -926,16 +838,14 @@
 {
     Hwc2::IComposerClient::FRect hwcRect{
         crop.left, crop.top, crop.right, crop.bottom};
-    auto intError = mDevice.mComposer->setLayerSourceCrop(mDisplayId,
-            mId, hwcRect);
+    auto intError = mComposer.setLayerSourceCrop(mDisplayId, mId, hwcRect);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setTransform(Transform transform)
 {
     auto intTransform = static_cast<Hwc2::Transform>(transform);
-    auto intError = mDevice.mComposer->setLayerTransform(mDisplayId,
-            mId, intTransform);
+    auto intError = mComposer.setLayerTransform(mDisplayId, mId, intTransform);
     return static_cast<Error>(intError);
 }
 
@@ -950,20 +860,19 @@
                 rectArray[rect].right, rectArray[rect].bottom});
     }
 
-    auto intError = mDevice.mComposer->setLayerVisibleRegion(mDisplayId,
-            mId, hwcRects);
+    auto intError = mComposer.setLayerVisibleRegion(mDisplayId, mId, hwcRects);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setZOrder(uint32_t z)
 {
-    auto intError = mDevice.mComposer->setLayerZOrder(mDisplayId, mId, z);
+    auto intError = mComposer.setLayerZOrder(mDisplayId, mId, z);
     return static_cast<Error>(intError);
 }
 
 Error Layer::setInfo(uint32_t type, uint32_t appId)
 {
-  auto intError = mDevice.mComposer->setLayerInfo(mDisplayId, mId, type, appId);
+  auto intError = mComposer.setLayerInfo(mDisplayId, mId, type, appId);
   return static_cast<Error>(intError);
 }
 
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index 9bcda1e..fbe4c7e 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -53,10 +53,26 @@
 class Display;
 class Layer;
 
-typedef std::function<void(std::shared_ptr<Display>, Connection)>
-        HotplugCallback;
-typedef std::function<void(std::shared_ptr<Display>)> RefreshCallback;
-typedef std::function<void(std::shared_ptr<Display>, nsecs_t)> VsyncCallback;
+// Implement this interface to receive hardware composer events.
+//
+// These callback functions will generally be called on a hwbinder thread, but
+// when first registering the callback the onHotplugReceived() function will
+// immediately be called on the thread calling registerCallback().
+//
+// All calls receive a sequenceId, which will be the value that was supplied to
+// HWC2::Device::registerCallback(). It's used to help differentiate callbacks
+// from different hardware composer instances.
+class ComposerCallback {
+ public:
+    virtual void onHotplugReceived(int32_t sequenceId, hwc2_display_t display,
+                                   Connection connection,
+                                   bool primaryDisplay) = 0;
+    virtual void onRefreshReceived(int32_t sequenceId,
+                                   hwc2_display_t display) = 0;
+    virtual void onVsyncReceived(int32_t sequenceId, hwc2_display_t display,
+                                 int64_t timestamp) = 0;
+    virtual ~ComposerCallback() = default;
+};
 
 // C++ Wrapper around hwc2_device_t. Load all functions pointers
 // and handle callback registration.
@@ -66,10 +82,8 @@
     // Service name is expected to be 'default' or 'vr' for normal use.
     // 'vr' will slightly modify the behavior of the mComposer.
     Device(const std::string& serviceName);
-    ~Device();
 
-    friend class HWC2::Display;
-    friend class HWC2::Layer;
+    void registerCallback(ComposerCallback* callback, int32_t sequenceId);
 
     // Required by HWC2
 
@@ -81,27 +95,14 @@
 
     uint32_t getMaxVirtualDisplayCount() const;
     Error createVirtualDisplay(uint32_t width, uint32_t height,
-            android_pixel_format_t* format,
-            std::shared_ptr<Display>* outDisplay);
+            android_pixel_format_t* format, Display** outDisplay);
+    void destroyDisplay(hwc2_display_t displayId);
 
-    void registerHotplugCallback(HotplugCallback hotplug);
-    void registerRefreshCallback(RefreshCallback refresh);
-    void registerVsyncCallback(VsyncCallback vsync);
-
-    // For use by callbacks
-
-    void callHotplug(std::shared_ptr<Display> display, Connection connected);
-    void callRefresh(std::shared_ptr<Display> display);
-    void callVsync(std::shared_ptr<Display> display, nsecs_t timestamp);
+    void onHotplug(hwc2_display_t displayId, Connection connection);
 
     // Other Device methods
 
-    // This will create a Display if one is not found, but it will not be marked
-    // as connected. This Display may be null if the display has been torn down
-    // but has not been removed from the map yet.
-    std::shared_ptr<Display> getDisplayById(hwc2_display_t id);
-
-    bool hasCapability(HWC2::Capability capability) const;
+    Display* getDisplayById(hwc2_display_t id);
 
     android::Hwc2::Composer* getComposer() { return mComposer.get(); }
 
@@ -109,37 +110,23 @@
     // Initialization methods
 
     void loadCapabilities();
-    void registerCallbacks();
-
-    // For use by Display
-
-    void destroyVirtualDisplay(hwc2_display_t display);
 
     // Member variables
     std::unique_ptr<android::Hwc2::Composer> mComposer;
-
     std::unordered_set<Capability> mCapabilities;
-    std::unordered_map<hwc2_display_t, std::weak_ptr<Display>> mDisplays;
-
-    HotplugCallback mHotplug;
-    std::vector<std::pair<std::shared_ptr<Display>, Connection>>
-            mPendingHotplugs;
-    RefreshCallback mRefresh;
-    std::vector<std::shared_ptr<Display>> mPendingRefreshes;
-    VsyncCallback mVsync;
-    std::vector<std::pair<std::shared_ptr<Display>, nsecs_t>> mPendingVsyncs;
+    std::unordered_map<hwc2_display_t, std::unique_ptr<Display>> mDisplays;
+    bool mRegisteredCallback;
 };
 
 // Convenience C++ class to access hwc2_device_t Display functions directly.
-class Display : public std::enable_shared_from_this<Display>
+class Display
 {
 public:
-    Display(Device& device, hwc2_display_t id);
+    Display(android::Hwc2::Composer& composer,
+            const std::unordered_set<Capability>& capabilities,
+            hwc2_display_t id, DisplayType type);
     ~Display();
 
-    friend class HWC2::Device;
-    friend class HWC2::Layer;
-
     class Config
     {
     public:
@@ -212,12 +199,12 @@
     // Required by HWC2
 
     [[clang::warn_unused_result]] Error acceptChanges();
-    [[clang::warn_unused_result]] Error createLayer(
-            std::shared_ptr<Layer>* outLayer);
+    [[clang::warn_unused_result]] Error createLayer(Layer** outLayer);
+    [[clang::warn_unused_result]] Error destroyLayer(Layer* layer);
     [[clang::warn_unused_result]] Error getActiveConfig(
             std::shared_ptr<const Config>* outConfig) const;
     [[clang::warn_unused_result]] Error getChangedCompositionTypes(
-            std::unordered_map<std::shared_ptr<Layer>, Composition>* outTypes);
+            std::unordered_map<Layer*, Composition>* outTypes);
     [[clang::warn_unused_result]] Error getColorModes(
             std::vector<android_color_mode_t>* outModes) const;
 
@@ -227,14 +214,13 @@
     [[clang::warn_unused_result]] Error getName(std::string* outName) const;
     [[clang::warn_unused_result]] Error getRequests(
             DisplayRequest* outDisplayRequests,
-            std::unordered_map<std::shared_ptr<Layer>, LayerRequest>*
-                    outLayerRequests);
+            std::unordered_map<Layer*, LayerRequest>* outLayerRequests);
     [[clang::warn_unused_result]] Error getType(DisplayType* outType) const;
     [[clang::warn_unused_result]] Error supportsDoze(bool* outSupport) const;
     [[clang::warn_unused_result]] Error getHdrCapabilities(
             std::unique_ptr<android::HdrCapabilities>* outCapabilities) const;
     [[clang::warn_unused_result]] Error getReleaseFences(
-            std::unordered_map<std::shared_ptr<Layer>,
+            std::unordered_map<Layer*,
                     android::sp<android::Fence>>* outFences) const;
     [[clang::warn_unused_result]] Error present(
             android::sp<android::Fence>* outPresentFence);
@@ -266,32 +252,31 @@
 
     // Other Display methods
 
-    Device& getDevice() const { return mDevice; }
     hwc2_display_t getId() const { return mId; }
     bool isConnected() const { return mIsConnected; }
+    void setConnected(bool connected);  // For use by Device only
 
 private:
-    // For use by Device
-
-    void setConnected(bool connected) { mIsConnected = connected; }
     int32_t getAttribute(hwc2_config_t configId, Attribute attribute);
     void loadConfig(hwc2_config_t configId);
     void loadConfigs();
 
-    // For use by Layer
-    void destroyLayer(hwc2_layer_t layerId);
-
     // This may fail (and return a null pointer) if no layer with this ID exists
     // on this display
-    std::shared_ptr<Layer> getLayerById(hwc2_layer_t id) const;
+    Layer* getLayerById(hwc2_layer_t id) const;
 
     // Member variables
 
-    Device& mDevice;
+    // These are references to data owned by HWC2::Device, which will outlive
+    // this HWC2::Display, so these references are guaranteed to be valid for
+    // the lifetime of this object.
+    android::Hwc2::Composer& mComposer;
+    const std::unordered_set<Capability>& mCapabilities;
+
     hwc2_display_t mId;
     bool mIsConnected;
     DisplayType mType;
-    std::unordered_map<hwc2_layer_t, std::weak_ptr<Layer>> mLayers;
+    std::unordered_map<hwc2_layer_t, std::unique_ptr<Layer>> mLayers;
     // The ordering in this map matters, for getConfigs(), when it is
     // converted to a vector
     std::map<hwc2_config_t, std::shared_ptr<const Config>> mConfigs;
@@ -301,12 +286,18 @@
 class Layer
 {
 public:
-    Layer(const std::shared_ptr<Display>& display, hwc2_layer_t id);
+    Layer(android::Hwc2::Composer& composer,
+          const std::unordered_set<Capability>& capabilities,
+          hwc2_display_t displayId, hwc2_layer_t layerId);
     ~Layer();
 
-    bool isAbandoned() const { return mDisplay.expired(); }
     hwc2_layer_t getId() const { return mId; }
 
+    // Register a listener to be notified when the layer is destroyed. When the
+    // listener function is called, the Layer will be in the process of being
+    // destroyed, so it's not safe to call methods on it.
+    void setLayerDestroyedListener(std::function<void(Layer*)> listener);
+
     [[clang::warn_unused_result]] Error setCursorPosition(int32_t x, int32_t y);
     [[clang::warn_unused_result]] Error setBuffer(uint32_t slot,
             const android::sp<android::GraphicBuffer>& buffer,
@@ -333,11 +324,16 @@
     [[clang::warn_unused_result]] Error setInfo(uint32_t type, uint32_t appId);
 
 private:
-    std::weak_ptr<Display> mDisplay;
+    // These are references to data owned by HWC2::Device, which will outlive
+    // this HWC2::Layer, so these references are guaranteed to be valid for
+    // the lifetime of this object.
+    android::Hwc2::Composer& mComposer;
+    const std::unordered_set<Capability>& mCapabilities;
+
     hwc2_display_t mDisplayId;
-    Device& mDevice;
     hwc2_layer_t mId;
     android_dataspace mDataSpace = HAL_DATASPACE_UNKNOWN;
+    std::function<void(Layer*)> mLayerDestroyedListener;
 };
 
 } // namespace HWC2
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index abf7dd1..b096a3a 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -65,7 +65,6 @@
       mFreeDisplaySlots(),
       mHwcDisplaySlots(),
       mCBContext(),
-      mEventHandler(nullptr),
       mVSyncCounts(),
       mRemainingHwcVirtualDisplays(0)
 {
@@ -74,41 +73,15 @@
         mVSyncCounts[i] = 0;
     }
 
-    loadHwcModule(serviceName);
+    mHwcDevice = std::make_unique<HWC2::Device>(serviceName);
+    mRemainingHwcVirtualDisplays = mHwcDevice->getMaxVirtualDisplayCount();
 }
 
 HWComposer::~HWComposer() {}
 
-void HWComposer::setEventHandler(EventHandler* handler)
-{
-    if (handler == nullptr) {
-        ALOGE("setEventHandler: Rejected attempt to clear handler");
-        return;
-    }
-
-    bool wasNull = (mEventHandler == nullptr);
-    mEventHandler = handler;
-
-    if (wasNull) {
-        auto hotplugHook = std::bind(&HWComposer::hotplug, this,
-                std::placeholders::_1, std::placeholders::_2);
-        mHwcDevice->registerHotplugCallback(hotplugHook);
-        auto invalidateHook = std::bind(&HWComposer::invalidate, this,
-                std::placeholders::_1);
-        mHwcDevice->registerRefreshCallback(invalidateHook);
-        auto vsyncHook = std::bind(&HWComposer::vsync, this,
-                std::placeholders::_1, std::placeholders::_2);
-        mHwcDevice->registerVsyncCallback(vsyncHook);
-    }
-}
-
-// Load and prepare the hardware composer module.  Sets mHwc.
-void HWComposer::loadHwcModule(const std::string& serviceName)
-{
-    ALOGV("loadHwcModule");
-    mHwcDevice = std::make_unique<HWC2::Device>(serviceName);
-
-    mRemainingHwcVirtualDisplays = mHwcDevice->getMaxVirtualDisplayCount();
+void HWComposer::registerCallback(HWC2::ComposerCallback* callback,
+                                  int32_t sequenceId) {
+    mHwcDevice->registerCallback(callback, sequenceId);
 }
 
 bool HWComposer::hasCapability(HWC2::Capability capability) const
@@ -146,54 +119,51 @@
     }
 }
 
-void HWComposer::hotplug(const std::shared_ptr<HWC2::Display>& display,
-        HWC2::Connection connected) {
-    ALOGV("hotplug: %" PRIu64 ", %s", display->getId(),
-            to_string(connected).c_str());
-    int32_t disp = 0;
+void HWComposer::onHotplug(hwc2_display_t displayId,
+                           HWC2::Connection connection) {
+    ALOGV("hotplug: %" PRIu64 ", %s", displayId,
+            to_string(connection).c_str());
+    mHwcDevice->onHotplug(displayId, connection);
     if (!mDisplayData[0].hwcDisplay) {
-        ALOGE_IF(connected != HWC2::Connection::Connected, "Assumed primary"
+        ALOGE_IF(connection != HWC2::Connection::Connected, "Assumed primary"
                 " display would be connected");
-        mDisplayData[0].hwcDisplay = display;
-        mHwcDisplaySlots[display->getId()] = 0;
-        disp = DisplayDevice::DISPLAY_PRIMARY;
+        mDisplayData[0].hwcDisplay = mHwcDevice->getDisplayById(displayId);
+        mHwcDisplaySlots[displayId] = 0;
     } else {
         // Disconnect is handled through HWComposer::disconnectDisplay via
         // SurfaceFlinger's onHotplugReceived callback handling
-        if (connected == HWC2::Connection::Connected) {
-            mDisplayData[1].hwcDisplay = display;
-            mHwcDisplaySlots[display->getId()] = 1;
+        if (connection == HWC2::Connection::Connected) {
+            mDisplayData[1].hwcDisplay = mHwcDevice->getDisplayById(displayId);
+            mHwcDisplaySlots[displayId] = 1;
         }
-        disp = DisplayDevice::DISPLAY_EXTERNAL;
     }
-    mEventHandler->onHotplugReceived(this, disp,
-            connected == HWC2::Connection::Connected);
 }
 
-void HWComposer::invalidate(const std::shared_ptr<HWC2::Display>& /*display*/) {
-    mEventHandler->onInvalidateReceived(this);
-}
-
-void HWComposer::vsync(const std::shared_ptr<HWC2::Display>& display,
-        int64_t timestamp) {
+bool HWComposer::onVsync(hwc2_display_t displayId, int64_t timestamp,
+                         int32_t* outDisplay) {
+    auto display = mHwcDevice->getDisplayById(displayId);
+    if (!display) {
+        ALOGE("onVsync Failed to find display %" PRIu64, displayId);
+        return false;
+    }
     auto displayType = HWC2::DisplayType::Invalid;
     auto error = display->getType(&displayType);
     if (error != HWC2::Error::None) {
-        ALOGE("vsync: Failed to determine type of display %" PRIu64,
+        ALOGE("onVsync: Failed to determine type of display %" PRIu64,
                 display->getId());
-        return;
+        return false;
     }
 
     if (displayType == HWC2::DisplayType::Virtual) {
         ALOGE("Virtual display %" PRIu64 " passed to vsync callback",
                 display->getId());
-        return;
+        return false;
     }
 
     if (mHwcDisplaySlots.count(display->getId()) == 0) {
         ALOGE("Unknown physical display %" PRIu64 " passed to vsync callback",
                 display->getId());
-        return;
+        return false;
     }
 
     int32_t disp = mHwcDisplaySlots[display->getId()];
@@ -207,17 +177,21 @@
         if (timestamp == mLastHwVSync[disp]) {
             ALOGW("Ignoring duplicate VSYNC event from HWC (t=%" PRId64 ")",
                     timestamp);
-            return;
+            return false;
         }
 
         mLastHwVSync[disp] = timestamp;
     }
 
+    if (outDisplay) {
+        *outDisplay = disp;
+    }
+
     char tag[16];
     snprintf(tag, sizeof(tag), "HW_VSYNC_%1u", disp);
     ATRACE_INT(tag, ++mVSyncCounts[disp] & 1);
 
-    mEventHandler->onVSyncReceived(this, disp, timestamp);
+    return true;
 }
 
 status_t HWComposer::allocateVirtualDisplay(uint32_t width, uint32_t height,
@@ -236,7 +210,7 @@
         return INVALID_OPERATION;
     }
 
-    std::shared_ptr<HWC2::Display> display;
+    HWC2::Display* display;
     auto error = mHwcDevice->createVirtualDisplay(width, height, format,
             &display);
     if (error != HWC2::Error::None) {
@@ -265,13 +239,13 @@
     return NO_ERROR;
 }
 
-std::shared_ptr<HWC2::Layer> HWComposer::createLayer(int32_t displayId) {
+HWC2::Layer* HWComposer::createLayer(int32_t displayId) {
     if (!isValidDisplay(displayId)) {
         ALOGE("Failed to create layer on invalid display %d", displayId);
         return nullptr;
     }
     auto display = mDisplayData[displayId].hwcDisplay;
-    std::shared_ptr<HWC2::Layer> layer;
+    HWC2::Layer* layer;
     auto error = display->createLayer(&layer);
     if (error != HWC2::Error::None) {
         ALOGE("Failed to create layer on display %d: %s (%d)", displayId,
@@ -281,6 +255,19 @@
     return layer;
 }
 
+void HWComposer::destroyLayer(int32_t displayId, HWC2::Layer* layer) {
+    if (!isValidDisplay(displayId)) {
+        ALOGE("Failed to destroy layer on invalid display %d", displayId);
+        return;
+    }
+    auto display = mDisplayData[displayId].hwcDisplay;
+    auto error = display->destroyLayer(layer);
+    if (error != HWC2::Error::None) {
+        ALOGE("Failed to destroy layer on display %d: %s (%d)", displayId,
+                to_string(error).c_str(), static_cast<int32_t>(error));
+    }
+}
+
 nsecs_t HWComposer::getRefreshTimestamp(int32_t displayId) const {
     // this returns the last refresh timestamp.
     // if the last one is not available, we estimate it based on
@@ -348,10 +335,8 @@
                 displayId);
         return modes;
     }
-    const std::shared_ptr<HWC2::Display>& hwcDisplay =
-            mDisplayData[displayId].hwcDisplay;
 
-    auto error = hwcDisplay->getColorModes(&modes);
+    auto error = mDisplayData[displayId].hwcDisplay->getColorModes(&modes);
     if (error != HWC2::Error::None) {
         ALOGE("getColorModes failed for display %d: %s (%d)", displayId,
                 to_string(error).c_str(), static_cast<int32_t>(error));
@@ -471,7 +456,7 @@
             return UNKNOWN_ERROR;
         }
         if (state == 1) { //Present Succeeded.
-            std::unordered_map<std::shared_ptr<HWC2::Layer>, sp<Fence>> releaseFences;
+            std::unordered_map<HWC2::Layer*, sp<Fence>> releaseFences;
             error = hwcDisplay->getReleaseFences(&releaseFences);
             displayData.releaseFences = std::move(releaseFences);
             displayData.lastPresentFence = outPresentFence;
@@ -490,8 +475,7 @@
         return BAD_INDEX;
     }
 
-    std::unordered_map<std::shared_ptr<HWC2::Layer>, HWC2::Composition>
-        changedTypes;
+    std::unordered_map<HWC2::Layer*, HWC2::Composition> changedTypes;
     changedTypes.reserve(numTypes);
     error = hwcDisplay->getChangedCompositionTypes(&changedTypes);
     if (error != HWC2::Error::None) {
@@ -503,8 +487,7 @@
 
 
     displayData.displayRequests = static_cast<HWC2::DisplayRequest>(0);
-    std::unordered_map<std::shared_ptr<HWC2::Layer>, HWC2::LayerRequest>
-        layerRequests;
+    std::unordered_map<HWC2::Layer*, HWC2::LayerRequest> layerRequests;
     layerRequests.reserve(numRequests);
     error = hwcDisplay->getRequests(&displayData.displayRequests,
             &layerRequests);
@@ -598,7 +581,7 @@
 }
 
 sp<Fence> HWComposer::getLayerReleaseFence(int32_t displayId,
-        const std::shared_ptr<HWC2::Layer>& layer) const {
+        HWC2::Layer* layer) const {
     if (!isValidDisplay(displayId)) {
         ALOGE("getLayerReleaseFence: Invalid display");
         return Fence::NO_FENCE;
@@ -639,7 +622,7 @@
         return UNKNOWN_ERROR;
     }
 
-    std::unordered_map<std::shared_ptr<HWC2::Layer>, sp<Fence>> releaseFences;
+    std::unordered_map<HWC2::Layer*, sp<Fence>> releaseFences;
     error = hwcDisplay->getReleaseFences(&releaseFences);
     if (error != HWC2::Error::None) {
         ALOGE("presentAndGetReleaseFences: Failed to get release fences "
@@ -787,6 +770,8 @@
     auto hwcId = displayData.hwcDisplay->getId();
     mHwcDisplaySlots.erase(hwcId);
     displayData.reset();
+
+    mHwcDevice->destroyDisplay(hwcId);
 }
 
 status_t HWComposer::setOutputBuffer(int32_t displayId,
@@ -885,7 +870,7 @@
 HWComposer::DisplayData::DisplayData()
   : hasClientComposition(false),
     hasDeviceComposition(false),
-    hwcDisplay(),
+    hwcDisplay(nullptr),
     lastPresentFence(Fence::NO_FENCE),
     outbufHandle(nullptr),
     outbufAcquireFence(Fence::NO_FENCE),
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 3dfb65b..3640bb5 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -65,23 +65,14 @@
 class HWComposer
 {
 public:
-    class EventHandler {
-        friend class HWComposer;
-        virtual void onVSyncReceived(
-            HWComposer* composer, int32_t disp, nsecs_t timestamp) = 0;
-        virtual void onHotplugReceived(HWComposer* composer, int32_t disp, bool connected) = 0;
-        virtual void onInvalidateReceived(HWComposer* composer) = 0;
-    protected:
-        virtual ~EventHandler() {}
-    };
-
     // Uses the named composer service. Valid choices for normal use
     // are 'default' and 'vr'.
     HWComposer(const std::string& serviceName);
 
     ~HWComposer();
 
-    void setEventHandler(EventHandler* handler);
+    void registerCallback(HWC2::ComposerCallback* callback,
+                          int32_t sequenceId);
 
     bool hasCapability(HWC2::Capability capability) const;
 
@@ -91,7 +82,9 @@
             android_pixel_format_t* format, int32_t* outId);
 
     // Attempts to create a new layer on this display
-    std::shared_ptr<HWC2::Layer> createLayer(int32_t displayId);
+    HWC2::Layer* createLayer(int32_t displayId);
+    // Destroy a previously created layer
+    void destroyLayer(int32_t displayId, HWC2::Layer* layer);
 
     // Asks the HAL what it can do
     status_t prepare(DisplayDevice& displayDevice);
@@ -126,7 +119,7 @@
 
     // Get last release fence for the given layer
     sp<Fence> getLayerReleaseFence(int32_t displayId,
-            const std::shared_ptr<HWC2::Layer>& layer) const;
+            HWC2::Layer* layer) const;
 
     // Set the output buffer and acquire fence for a virtual display.
     // Returns INVALID_OPERATION if displayId is not a virtual display.
@@ -142,6 +135,12 @@
 
     // Events handling ---------------------------------------------------------
 
+    // Returns true if successful, false otherwise. The
+    // DisplayDevice::DisplayType of the display is returned as an output param.
+    bool onVsync(hwc2_display_t displayId, int64_t timestamp,
+                 int32_t* outDisplay);
+    void onHotplug(hwc2_display_t displayId, HWC2::Connection connection);
+
     void setVsyncEnabled(int32_t displayId, HWC2::Vsync enabled);
 
     // Query display parameters.  Pass in a display index (e.g.
@@ -169,19 +168,11 @@
 private:
     static const int32_t VIRTUAL_DISPLAY_ID_BASE = 2;
 
-    void loadHwcModule(const std::string& serviceName);
-
     bool isValidDisplay(int32_t displayId) const;
     static void validateChange(HWC2::Composition from, HWC2::Composition to);
 
     struct cb_context;
 
-    void invalidate(const std::shared_ptr<HWC2::Display>& display);
-    void vsync(const std::shared_ptr<HWC2::Display>& display,
-            int64_t timestamp);
-    void hotplug(const std::shared_ptr<HWC2::Display>& display,
-            HWC2::Connection connected);
-
     struct DisplayData {
         DisplayData();
         ~DisplayData();
@@ -189,11 +180,10 @@
 
         bool hasClientComposition;
         bool hasDeviceComposition;
-        std::shared_ptr<HWC2::Display> hwcDisplay;
+        HWC2::Display* hwcDisplay;
         HWC2::DisplayRequest displayRequests;
         sp<Fence> lastPresentFence;  // signals when the last set op retires
-        std::unordered_map<std::shared_ptr<HWC2::Layer>, sp<Fence>>
-                releaseFences;
+        std::unordered_map<HWC2::Layer*, sp<Fence>> releaseFences;
         buffer_handle_t outbufHandle;
         sp<Fence> outbufAcquireFence;
         mutable std::unordered_map<int32_t,
@@ -214,7 +204,6 @@
     mutable Mutex mDisplayLock;
 
     cb_context*                     mCBContext;
-    EventHandler*                   mEventHandler;
     size_t                          mVSyncCounts[HWC_NUM_PHYSICAL_DISPLAY_TYPES];
     uint32_t                        mRemainingHwcVirtualDisplays;
 
diff --git a/services/surfaceflinger/EventControlThread.cpp b/services/surfaceflinger/EventControlThread.cpp
index ee6e886..052a959 100644
--- a/services/surfaceflinger/EventControlThread.cpp
+++ b/services/surfaceflinger/EventControlThread.cpp
@@ -31,34 +31,35 @@
 }
 
 bool EventControlThread::threadLoop() {
-    Mutex::Autolock lock(mMutex);
-
-    bool vsyncEnabled = mVsyncEnabled;
-
-#ifdef USE_HWC2
-    mFlinger->setVsyncEnabled(HWC_DISPLAY_PRIMARY, mVsyncEnabled);
-#else
-    mFlinger->eventControl(HWC_DISPLAY_PRIMARY, SurfaceFlinger::EVENT_VSYNC,
-            mVsyncEnabled);
-#endif
+    enum class VsyncState {Unset, On, Off};
+    auto currentVsyncState = VsyncState::Unset;
 
     while (true) {
-        status_t err = mCond.wait(mMutex);
-        if (err != NO_ERROR) {
-            ALOGE("error waiting for new events: %s (%d)",
-                strerror(-err), err);
-            return false;
+        auto requestedVsyncState = VsyncState::On;
+        {
+            Mutex::Autolock lock(mMutex);
+            requestedVsyncState =
+                    mVsyncEnabled ? VsyncState::On : VsyncState::Off;
+            while (currentVsyncState == requestedVsyncState) {
+                status_t err = mCond.wait(mMutex);
+                if (err != NO_ERROR) {
+                    ALOGE("error waiting for new events: %s (%d)",
+                          strerror(-err), err);
+                    return false;
+                }
+                requestedVsyncState =
+                        mVsyncEnabled ? VsyncState::On : VsyncState::Off;
+            }
         }
 
-        if (vsyncEnabled != mVsyncEnabled) {
+        bool enable = requestedVsyncState == VsyncState::On;
 #ifdef USE_HWC2
-            mFlinger->setVsyncEnabled(HWC_DISPLAY_PRIMARY, mVsyncEnabled);
+        mFlinger->setVsyncEnabled(HWC_DISPLAY_PRIMARY, enable);
 #else
-            mFlinger->eventControl(HWC_DISPLAY_PRIMARY,
-                    SurfaceFlinger::EVENT_VSYNC, mVsyncEnabled);
+        mFlinger->eventControl(HWC_DISPLAY_PRIMARY,
+                SurfaceFlinger::EVENT_VSYNC, enable);
 #endif
-            vsyncEnabled = mVsyncEnabled;
-        }
+        currentVsyncState = requestedVsyncState;
     }
 
     return false;
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 3903a55..54d4cbd 100755
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -201,6 +201,12 @@
     }
     mFlinger->deleteTextureAsync(mTextureName);
     mFrameTracker.logAndResetStats(mName);
+
+#ifdef USE_HWC2
+    ALOGE_IF(!mHwcLayers.empty(),
+            "Found stale hardware composer layers when destroying "
+            "surface flinger layer");
+#endif
 }
 
 // ---------------------------------------------------------------------------
@@ -303,7 +309,7 @@
     mSurfaceFlingerConsumer->abandon();
 
 #ifdef USE_HWC2
-    clearHwcLayers();
+    destroyAllHwcLayers();
 #endif
 
     for (const auto& child : mCurrentChildren) {
@@ -364,6 +370,48 @@
 // h/w composer set-up
 // ---------------------------------------------------------------------------
 
+#ifdef USE_HWC2
+bool Layer::createHwcLayer(HWComposer* hwc, int32_t hwcId) {
+    LOG_ALWAYS_FATAL_IF(mHwcLayers.count(hwcId) != 0,
+                "Already have a layer for hwcId %d", hwcId);
+    HWC2::Layer* layer = hwc->createLayer(hwcId);
+    if (!layer) {
+        return false;
+    }
+    HWCInfo& hwcInfo = mHwcLayers[hwcId];
+    hwcInfo.hwc = hwc;
+    hwcInfo.layer = layer;
+    layer->setLayerDestroyedListener(
+            [this, hwcId] (HWC2::Layer* /*layer*/){mHwcLayers.erase(hwcId);});
+    return true;
+}
+
+void Layer::destroyHwcLayer(int32_t hwcId) {
+    if (mHwcLayers.count(hwcId) == 0) {
+        return;
+    }
+    auto& hwcInfo = mHwcLayers[hwcId];
+    LOG_ALWAYS_FATAL_IF(hwcInfo.layer == nullptr,
+            "Attempt to destroy null layer");
+    LOG_ALWAYS_FATAL_IF(hwcInfo.hwc == nullptr, "Missing HWComposer");
+    hwcInfo.hwc->destroyLayer(hwcId, hwcInfo.layer);
+    // The layer destroyed listener should have cleared the entry from
+    // mHwcLayers. Verify that.
+    LOG_ALWAYS_FATAL_IF(mHwcLayers.count(hwcId) != 0,
+            "Stale layer entry in mHwcLayers");
+}
+
+void Layer::destroyAllHwcLayers() {
+    size_t numLayers = mHwcLayers.size();
+    for (size_t i = 0; i < numLayers; ++i) {
+        LOG_ALWAYS_FATAL_IF(mHwcLayers.empty(), "destroyAllHwcLayers failed");
+        destroyHwcLayer(mHwcLayers.begin()->first);
+    }
+    LOG_ALWAYS_FATAL_IF(!mHwcLayers.empty(),
+            "All hardware composer layers should have been destroyed");
+}
+#endif
+
 Rect Layer::getContentCrop() const {
     // this is the crop rectangle that applies to the buffer
     // itself (as opposed to the window)
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 8df8c49..1b7d075 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -447,37 +447,21 @@
 #ifdef USE_HWC2
     // -----------------------------------------------------------------------
 
+    bool createHwcLayer(HWComposer* hwc, int32_t hwcId);
+    void destroyHwcLayer(int32_t hwcId);
+    void destroyAllHwcLayers();
+
     bool hasHwcLayer(int32_t hwcId) {
-        if (mHwcLayers.count(hwcId) == 0) {
-            return false;
-        }
-        if (mHwcLayers[hwcId].layer->isAbandoned()) {
-            ALOGI("Erasing abandoned layer %s on %d", mName.string(), hwcId);
-            mHwcLayers.erase(hwcId);
-            return false;
-        }
-        return true;
+        return mHwcLayers.count(hwcId) > 0;
     }
 
-    std::shared_ptr<HWC2::Layer> getHwcLayer(int32_t hwcId) {
+    HWC2::Layer* getHwcLayer(int32_t hwcId) {
         if (mHwcLayers.count(hwcId) == 0) {
             return nullptr;
         }
         return mHwcLayers[hwcId].layer;
     }
 
-    void setHwcLayer(int32_t hwcId, std::shared_ptr<HWC2::Layer>&& layer) {
-        if (layer) {
-            mHwcLayers[hwcId].layer = layer;
-        } else {
-            mHwcLayers.erase(hwcId);
-        }
-    }
-
-    void clearHwcLayers() {
-        mHwcLayers.clear();
-    }
-
 #endif
     // -----------------------------------------------------------------------
 
@@ -766,12 +750,14 @@
     // HWC items, accessed from the main thread
     struct HWCInfo {
         HWCInfo()
-          : layer(),
+          : hwc(nullptr),
+            layer(nullptr),
             forceClientComposition(false),
             compositionType(HWC2::Composition::Invalid),
             clearClientTarget(false) {}
 
-        std::shared_ptr<HWC2::Layer> layer;
+        HWComposer* hwc;
+        HWC2::Layer* layer;
         bool forceClientComposition;
         HWC2::Composition compositionType;
         bool clearClientTarget;
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index ac2d8b2..57f468d 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -64,7 +64,7 @@
                        "EGL_ANDROIDX_no_config_context") &&
         !findExtension(eglQueryStringImplementationANDROID(display, EGL_EXTENSIONS),
                        "EGL_KHR_no_config_context")) {
-        config = chooseEglConfig(display, hwcFormat);
+        config = chooseEglConfig(display, hwcFormat, /*logConfig*/ true);
     }
 
     EGLint renderableType = 0;
@@ -108,7 +108,7 @@
 
     EGLConfig dummyConfig = config;
     if (dummyConfig == EGL_NO_CONFIG) {
-        dummyConfig = chooseEglConfig(display, hwcFormat);
+        dummyConfig = chooseEglConfig(display, hwcFormat, /*logConfig*/ true);
     }
     EGLint attribs[] = { EGL_WIDTH, 1, EGL_HEIGHT, 1, EGL_NONE, EGL_NONE };
     EGLSurface dummy = eglCreatePbufferSurface(display, dummyConfig, attribs);
@@ -406,7 +406,8 @@
     return err;
 }
 
-EGLConfig RenderEngine::chooseEglConfig(EGLDisplay display, int format) {
+EGLConfig RenderEngine::chooseEglConfig(EGLDisplay display, int format,
+                                        bool logConfig) {
     status_t err;
     EGLConfig config;
 
@@ -427,18 +428,20 @@
         }
     }
 
-    // print some debugging info
-    EGLint r,g,b,a;
-    eglGetConfigAttrib(display, config, EGL_RED_SIZE,   &r);
-    eglGetConfigAttrib(display, config, EGL_GREEN_SIZE, &g);
-    eglGetConfigAttrib(display, config, EGL_BLUE_SIZE,  &b);
-    eglGetConfigAttrib(display, config, EGL_ALPHA_SIZE, &a);
-    ALOGI("EGL information:");
-    ALOGI("vendor    : %s", eglQueryString(display, EGL_VENDOR));
-    ALOGI("version   : %s", eglQueryString(display, EGL_VERSION));
-    ALOGI("extensions: %s", eglQueryString(display, EGL_EXTENSIONS));
-    ALOGI("Client API: %s", eglQueryString(display, EGL_CLIENT_APIS)?:"Not Supported");
-    ALOGI("EGLSurface: %d-%d-%d-%d, config=%p", r, g, b, a, config);
+    if (logConfig) {
+        // print some debugging info
+        EGLint r,g,b,a;
+        eglGetConfigAttrib(display, config, EGL_RED_SIZE,   &r);
+        eglGetConfigAttrib(display, config, EGL_GREEN_SIZE, &g);
+        eglGetConfigAttrib(display, config, EGL_BLUE_SIZE,  &b);
+        eglGetConfigAttrib(display, config, EGL_ALPHA_SIZE, &a);
+        ALOGI("EGL information:");
+        ALOGI("vendor    : %s", eglQueryString(display, EGL_VENDOR));
+        ALOGI("version   : %s", eglQueryString(display, EGL_VERSION));
+        ALOGI("extensions: %s", eglQueryString(display, EGL_EXTENSIONS));
+        ALOGI("Client API: %s", eglQueryString(display, EGL_CLIENT_APIS)?:"Not Supported");
+        ALOGI("EGLSurface: %d-%d-%d-%d, config=%p", r, g, b, a, config);
+    }
 
     return config;
 }
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index 56f5827..9544579 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -64,7 +64,7 @@
     };
     static RenderEngine* create(EGLDisplay display, int hwcFormat, uint32_t featureFlags);
 
-    static EGLConfig chooseEglConfig(EGLDisplay display, int format);
+    static EGLConfig chooseEglConfig(EGLDisplay display, int format, bool logConfig);
 
     void primeCache() const;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 609b15b..0d93467 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -77,6 +77,7 @@
 #include "MonitoredProducer.h"
 #include "SurfaceFlinger.h"
 
+#include "DisplayHardware/ComposerHal.h"
 #include "DisplayHardware/FramebufferSurface.h"
 #include "DisplayHardware/HWComposer.h"
 #include "DisplayHardware/VirtualDisplaySurface.h"
@@ -101,10 +102,24 @@
 
 namespace android {
 
-
 using namespace android::hardware::configstore;
 using namespace android::hardware::configstore::V1_0;
 
+namespace {
+class ConditionalLock {
+public:
+    ConditionalLock(Mutex& mutex, bool lock) : mMutex(mutex), mLocked(lock) {
+        if (lock) {
+            mMutex.lock();
+        }
+    }
+    ~ConditionalLock() { if (mLocked) mMutex.unlock(); }
+private:
+    Mutex& mMutex;
+    bool mLocked;
+};
+}  // namespace anonymous
+
 // ---------------------------------------------------------------------------
 
 const String16 sHardwareTest("android.permission.HARDWARE_TEST");
@@ -147,9 +162,6 @@
         mLayersRemoved(false),
         mLayersAdded(false),
         mRepaintEverything(0),
-        mHwc(nullptr),
-        mRealHwc(nullptr),
-        mVrHwc(nullptr),
         mHwcServiceName(getHwcServiceName()),
         mRenderEngine(nullptr),
         mBootTime(systemTime()),
@@ -177,7 +189,9 @@
         mTotalTime(0),
         mLastSwapTime(0),
         mNumLayers(0),
-        mVrFlingerRequestsDisplay(false)
+        mVrFlingerRequestsDisplay(false),
+        mMainThreadId(std::this_thread::get_id()),
+        mComposerSequenceId(0)
 {
     ALOGI("SurfaceFlinger is starting");
 
@@ -583,48 +597,46 @@
 
     ALOGI("Phase offset NS: %" PRId64 "", vsyncPhaseOffsetNs);
 
-    { // Autolock scope
-        Mutex::Autolock _l(mStateLock);
+    Mutex::Autolock _l(mStateLock);
 
-        // initialize EGL for the default display
-        mEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-        eglInitialize(mEGLDisplay, NULL, NULL);
+    // initialize EGL for the default display
+    mEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+    eglInitialize(mEGLDisplay, NULL, NULL);
 
-        // start the EventThread
-        sp<VSyncSource> vsyncSrc = new DispSyncSource(&mPrimaryDispSync,
-                vsyncPhaseOffsetNs, true, "app");
-        mEventThread = new EventThread(vsyncSrc, *this, false);
-        sp<VSyncSource> sfVsyncSrc = new DispSyncSource(&mPrimaryDispSync,
-                sfVsyncPhaseOffsetNs, true, "sf");
-        mSFEventThread = new EventThread(sfVsyncSrc, *this, true);
-        mEventQueue.setEventThread(mSFEventThread);
+    // start the EventThread
+    sp<VSyncSource> vsyncSrc = new DispSyncSource(&mPrimaryDispSync,
+            vsyncPhaseOffsetNs, true, "app");
+    mEventThread = new EventThread(vsyncSrc, *this, false);
+    sp<VSyncSource> sfVsyncSrc = new DispSyncSource(&mPrimaryDispSync,
+            sfVsyncPhaseOffsetNs, true, "sf");
+    mSFEventThread = new EventThread(sfVsyncSrc, *this, true);
+    mEventQueue.setEventThread(mSFEventThread);
 
-        // set EventThread and SFEventThread to SCHED_FIFO to minimize jitter
-        struct sched_param param = {0};
-        param.sched_priority = 2;
-        if (sched_setscheduler(mSFEventThread->getTid(), SCHED_FIFO, &param) != 0) {
-            ALOGE("Couldn't set SCHED_FIFO for SFEventThread");
-        }
-        if (sched_setscheduler(mEventThread->getTid(), SCHED_FIFO, &param) != 0) {
-            ALOGE("Couldn't set SCHED_FIFO for EventThread");
-        }
-
-        // Get a RenderEngine for the given display / config (can't fail)
-        mRenderEngine = RenderEngine::create(mEGLDisplay,
-                HAL_PIXEL_FORMAT_RGBA_8888,
-                hasWideColorDisplay ? RenderEngine::WIDE_COLOR_SUPPORT : 0);
+    // set EventThread and SFEventThread to SCHED_FIFO to minimize jitter
+    struct sched_param param = {0};
+    param.sched_priority = 2;
+    if (sched_setscheduler(mSFEventThread->getTid(), SCHED_FIFO, &param) != 0) {
+        ALOGE("Couldn't set SCHED_FIFO for SFEventThread");
+    }
+    if (sched_setscheduler(mEventThread->getTid(), SCHED_FIFO, &param) != 0) {
+        ALOGE("Couldn't set SCHED_FIFO for EventThread");
     }
 
-    // Drop the state lock while we initialize the hardware composer. We drop
-    // the lock because on creation, it will call back into SurfaceFlinger to
-    // initialize the primary display.
-    LOG_ALWAYS_FATAL_IF(mVrFlingerRequestsDisplay,
-        "Starting with vr flinger active is not currently supported.");
-    mRealHwc = new HWComposer(mHwcServiceName);
-    mHwc = mRealHwc;
-    mHwc->setEventHandler(static_cast<HWComposer::EventHandler*>(this));
+    // Get a RenderEngine for the given display / config (can't fail)
+    mRenderEngine = RenderEngine::create(mEGLDisplay,
+            HAL_PIXEL_FORMAT_RGBA_8888,
+            hasWideColorDisplay ? RenderEngine::WIDE_COLOR_SUPPORT : 0);
 
-    Mutex::Autolock _l(mStateLock);
+    // retrieve the EGL context that was selected/created
+    mEGLContext = mRenderEngine->getEGLContext();
+
+    LOG_ALWAYS_FATAL_IF(mEGLContext == EGL_NO_CONTEXT,
+            "couldn't create EGLContext");
+
+    LOG_ALWAYS_FATAL_IF(mVrFlingerRequestsDisplay,
+            "Starting with vr flinger active is not currently supported.");
+    mHwc.reset(new HWComposer(mHwcServiceName));
+    mHwc->registerCallback(this, mComposerSequenceId);
 
     if (useVrFlinger) {
         auto vrFlingerRequestDisplayCallback = [this] (bool requestDisplay) {
@@ -639,16 +651,6 @@
         }
     }
 
-    // retrieve the EGL context that was selected/created
-    mEGLContext = mRenderEngine->getEGLContext();
-
-    LOG_ALWAYS_FATAL_IF(mEGLContext == EGL_NO_CONTEXT,
-            "couldn't create EGLContext");
-
-    // make the GLContext current so that we can create textures when creating
-    // Layers (which may happens before we render something)
-    getDefaultDisplayDeviceLocked()->makeCurrent(mEGLDisplay, mEGLContext);
-
     mEventControlThread = new EventControlThread(this);
     mEventControlThread->run("EventControl", PRIORITY_URGENT_DISPLAY);
 
@@ -1218,11 +1220,16 @@
     sLastResyncAttempted = now;
 }
 
-void SurfaceFlinger::onVSyncReceived(HWComposer* composer, int32_t type,
-                                     nsecs_t timestamp) {
+void SurfaceFlinger::onVsyncReceived(int32_t sequenceId,
+        hwc2_display_t displayId, int64_t timestamp) {
     Mutex::Autolock lock(mStateLock);
-    // Ignore any vsyncs from the non-active hardware composer.
-    if (composer != mHwc) {
+    // Ignore any vsyncs from a previous hardware composer.
+    if (sequenceId != mComposerSequenceId) {
+        return;
+    }
+
+    int32_t type;
+    if (!mHwc->onVsync(displayId, timestamp, &type)) {
         return;
     }
 
@@ -1230,7 +1237,7 @@
 
     { // Scope for the lock
         Mutex::Autolock _l(mHWVsyncLock);
-        if (type == 0 && mPrimaryHWVsyncEnabled) {
+        if (type == DisplayDevice::DISPLAY_PRIMARY && mPrimaryHWVsyncEnabled) {
             needsHwVsync = mPrimaryDispSync.addResyncSample(timestamp);
         }
     }
@@ -1248,7 +1255,7 @@
 }
 
 void SurfaceFlinger::createDefaultDisplayDevice() {
-    const int32_t type = DisplayDevice::DISPLAY_PRIMARY;
+    const DisplayDevice::DisplayType type = DisplayDevice::DISPLAY_PRIMARY;
     wp<IBinder> token = mBuiltinDisplays[type];
 
     // All non-virtual displays are currently considered secure.
@@ -1279,28 +1286,49 @@
     mDisplays.add(token, hw);
     setActiveColorModeInternal(hw, HAL_COLOR_MODE_NATIVE);
     hw->setCompositionDataSpace(HAL_DATASPACE_UNKNOWN);
+
+    // Add the primary display token to mDrawingState so we don't try to
+    // recreate the DisplayDevice for the primary display.
+    mDrawingState.displays.add(token, DisplayDeviceState(type, true));
+
+    // make the GLContext current so that we can create textures when creating
+    // Layers (which may happens before we render something)
+    hw->makeCurrent(mEGLDisplay, mEGLContext);
 }
 
-void SurfaceFlinger::onHotplugReceived(HWComposer* composer, int32_t disp, bool connected) {
-    ALOGV("onHotplugReceived(%d, %s)", disp, connected ? "true" : "false");
+void SurfaceFlinger::onHotplugReceived(int32_t sequenceId,
+        hwc2_display_t display, HWC2::Connection connection,
+        bool primaryDisplay) {
+    ALOGV("onHotplugReceived(%d, %" PRIu64 ", %s, %s)",
+          sequenceId, display,
+          connection == HWC2::Connection::Connected ?
+                  "connected" : "disconnected",
+          primaryDisplay ? "primary" : "external");
 
-    if (composer->isUsingVrComposer()) {
-        // We handle initializing the primary display device for the VR
-        // window manager hwc explicitly at the time of transition.
-        if (disp != DisplayDevice::DISPLAY_PRIMARY) {
-            ALOGE("External displays are not supported by the vr hardware composer.");
+    // Only lock if we're not on the main thread. This function is normally
+    // called on a hwbinder thread, but for the primary display it's called on
+    // the main thread with the state lock already held, so don't attempt to
+    // acquire it here.
+    ConditionalLock lock(mStateLock,
+            std::this_thread::get_id() != mMainThreadId);
+
+    if (primaryDisplay) {
+        mHwc->onHotplug(display, connection);
+        if (!mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY].get()) {
+            createBuiltinDisplayLocked(DisplayDevice::DISPLAY_PRIMARY);
         }
-        return;
-    }
-
-    if (disp == DisplayDevice::DISPLAY_PRIMARY) {
-        Mutex::Autolock lock(mStateLock);
-        createBuiltinDisplayLocked(DisplayDevice::DISPLAY_PRIMARY);
         createDefaultDisplayDevice();
     } else {
+        if (sequenceId != mComposerSequenceId) {
+            return;
+        }
+        if (mHwc->isUsingVrComposer()) {
+            ALOGE("External displays are not supported by the vr hardware composer.");
+            return;
+        }
+        mHwc->onHotplug(display, connection);
         auto type = DisplayDevice::DISPLAY_EXTERNAL;
-        Mutex::Autolock _l(mStateLock);
-        if (connected) {
+        if (connection == HWC2::Connection::Connected) {
             createBuiltinDisplayLocked(type);
         } else {
             mCurrentState.displays.removeItem(mBuiltinDisplays[type]);
@@ -1312,46 +1340,31 @@
     }
 }
 
-void SurfaceFlinger::onInvalidateReceived(HWComposer* composer) {
+void SurfaceFlinger::onRefreshReceived(int sequenceId,
+                                       hwc2_display_t /*display*/) {
     Mutex::Autolock lock(mStateLock);
-    if (composer == mHwc) {
-        repaintEverything();
-    } else {
-        // This isn't from our current hardware composer. If it's a callback
-        // from the real composer, forward the refresh request to vr
-        // flinger. Otherwise ignore it.
-        if (!composer->isUsingVrComposer()) {
-            mVrFlinger->OnHardwareComposerRefresh();
-        }
+    if (sequenceId != mComposerSequenceId) {
+        return;
     }
+    repaintEverything();
 }
 
 void SurfaceFlinger::setVsyncEnabled(int disp, int enabled) {
     ATRACE_CALL();
+    Mutex::Autolock lock(mStateLock);
     getHwComposer().setVsyncEnabled(disp,
             enabled ? HWC2::Vsync::Enable : HWC2::Vsync::Disable);
 }
 
 // Note: it is assumed the caller holds |mStateLock| when this is called
-void SurfaceFlinger::resetHwcLocked() {
+void SurfaceFlinger::resetDisplayState() {
     disableHardwareVsync(true);
-    clearHwcLayers(mDrawingState.layersSortedByZ);
-    clearHwcLayers(mCurrentState.layersSortedByZ);
-    for (size_t disp = 0; disp < mDisplays.size(); ++disp) {
-        clearHwcLayers(mDisplays[disp]->getVisibleLayersSortedByZ());
-    }
     // Clear the drawing state so that the logic inside of
     // handleTransactionLocked will fire. It will determine the delta between
     // mCurrentState and mDrawingState and re-apply all changes when we make the
     // transition.
     mDrawingState.displays.clear();
-    // Release virtual display hwcId during vr mode transition.
-    for (size_t displayId = 0; displayId < mDisplays.size(); ++displayId) {
-        const sp<DisplayDevice>& displayDevice = mDisplays[displayId];
-        if (displayDevice->getDisplayType() == DisplayDevice::DISPLAY_VIRTUAL) {
-            displayDevice->disconnect(getHwComposer());
-        }
-    }
+    eglMakeCurrent(mEGLDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
     mDisplays.clear();
 }
 
@@ -1363,57 +1376,54 @@
         return;
     }
 
-    if (vrFlingerRequestsDisplay && !mVrHwc) {
-        // Construct new HWComposer without holding any locks.
-        mVrHwc = new HWComposer("vr");
-
-        // Set up the event handlers. This step is neccessary to initialize the internal state of
-        // the hardware composer object properly. Our callbacks are designed such that if they are
-        // triggered between now and the point where the display is properly re-initialized, they
-        // will not have any effect, so this is safe to do here, before the lock is aquired.
-        mVrHwc->setEventHandler(static_cast<HWComposer::EventHandler*>(this));
-        ALOGV("Vr HWC created");
+    if (vrFlingerRequestsDisplay && !mHwc->getComposer()->isRemote()) {
+        ALOGE("Vr flinger is only supported for remote hardware composer"
+              " service connections. Ignoring request to transition to vr"
+              " flinger.");
+        mVrFlingerRequestsDisplay = false;
+        return;
     }
 
     Mutex::Autolock _l(mStateLock);
 
-    if (vrFlingerRequestsDisplay) {
-        resetHwcLocked();
+    int currentDisplayPowerMode = getDisplayDeviceLocked(
+            mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY])->getPowerMode();
 
-        mHwc = mVrHwc;
-        mVrFlinger->GrantDisplayOwnership();
-
-    } else {
+    if (!vrFlingerRequestsDisplay) {
         mVrFlinger->SeizeDisplayOwnership();
+    }
 
-        resetHwcLocked();
+    resetDisplayState();
+    mHwc.reset();  // Delete the current instance before creating the new one
+    mHwc.reset(new HWComposer(
+            vrFlingerRequestsDisplay ? "vr" : mHwcServiceName));
+    mHwc->registerCallback(this, ++mComposerSequenceId);
 
-        mHwc = mRealHwc;
+    LOG_ALWAYS_FATAL_IF(!mHwc->getComposer()->isRemote(),
+            "Switched to non-remote hardware composer");
+
+    if (vrFlingerRequestsDisplay) {
+        mVrFlinger->GrantDisplayOwnership();
+    } else {
         enableHardwareVsync();
     }
 
     mVisibleRegionsDirty = true;
     invalidateHwcGeometry();
 
-    // Explicitly re-initialize the primary display. This is because some other
-    // parts of this class rely on the primary display always being available.
-    createDefaultDisplayDevice();
-
     // Re-enable default display.
-    sp<LambdaMessage> requestMessage = new LambdaMessage([&]() {
-        sp<DisplayDevice> hw(getDisplayDevice(mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY]));
-        setPowerModeInternal(hw, HWC_POWER_MODE_NORMAL);
+    sp<DisplayDevice> hw(getDisplayDeviceLocked(
+            mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY]));
+    setPowerModeInternal(hw, currentDisplayPowerMode, /*stateLockHeld*/ true);
 
-        // Reset the timing values to account for the period of the swapped in HWC
-        const auto& activeConfig = mHwc->getActiveConfig(HWC_DISPLAY_PRIMARY);
-        const nsecs_t period = activeConfig->getVsyncPeriod();
-        mAnimFrameTracker.setDisplayRefreshPeriod(period);
+    // Reset the timing values to account for the period of the swapped in HWC
+    const auto& activeConfig = mHwc->getActiveConfig(HWC_DISPLAY_PRIMARY);
+    const nsecs_t period = activeConfig->getVsyncPeriod();
+    mAnimFrameTracker.setDisplayRefreshPeriod(period);
 
-        // Use phase of 0 since phase is not known.
-        // Use latency of 0, which will snap to the ideal latency.
-        setCompositorTimingSnapped(0, period, 0);
-    });
-    postMessageAsync(requestMessage);
+    // Use phase of 0 since phase is not known.
+    // Use latency of 0, which will snap to the ideal latency.
+    setCompositorTimingSnapped(0, period, 0);
 
     android_atomic_or(1, &mRepaintEverything);
     setTransactionFlags(eDisplayTransactionNeeded);
@@ -1749,15 +1759,14 @@
                         } else {
                             // Clear out the HWC layer if this layer was
                             // previously visible, but no longer is
-                            layer->setHwcLayer(displayDevice->getHwcDisplayId(),
-                                    nullptr);
+                            layer->destroyHwcLayer(
+                                    displayDevice->getHwcDisplayId());
                         }
                     } else {
                         // WM changes displayDevice->layerStack upon sleep/awake.
                         // Here we make sure we delete the HWC layers even if
                         // WM changed their layer stack.
-                        layer->setHwcLayer(displayDevice->getHwcDisplayId(),
-                                nullptr);
+                        layer->destroyHwcLayer(displayDevice->getHwcDisplayId());
                     }
                 });
             }
@@ -1872,10 +1881,7 @@
                 for (size_t i = 0; i < currentLayers.size(); i++) {
                     const auto& layer = currentLayers[i];
                     if (!layer->hasHwcLayer(hwcId)) {
-                        auto hwcLayer = mHwc->createLayer(hwcId);
-                        if (hwcLayer) {
-                            layer->setHwcLayer(hwcId, std::move(hwcLayer));
-                        } else {
+                        if (!layer->createHwcLayer(mHwc.get(), hwcId)) {
                             layer->forceClientComposition(hwcId);
                             continue;
                         }
@@ -2161,7 +2167,7 @@
                         if (state.surface != NULL) {
 
                             // Allow VR composer to use virtual displays.
-                            if (mUseHwcVirtualDisplays || mHwc == mVrHwc) {
+                            if (mUseHwcVirtualDisplays || mHwc->isUsingVrComposer()) {
                                 int width = 0;
                                 int status = state.surface->query(
                                         NATIVE_WINDOW_WIDTH, &width);
@@ -3285,7 +3291,8 @@
     d.height = 0;
     displays.add(d);
     setTransactionState(state, displays, 0);
-    setPowerModeInternal(getDisplayDevice(d.token), HWC_POWER_MODE_NORMAL);
+    setPowerModeInternal(getDisplayDevice(d.token), HWC_POWER_MODE_NORMAL,
+                         /*stateLockHeld*/ false);
 
     const auto& activeConfig = mHwc->getActiveConfig(HWC_DISPLAY_PRIMARY);
     const nsecs_t period = activeConfig->getVsyncPeriod();
@@ -3311,7 +3318,7 @@
 }
 
 void SurfaceFlinger::setPowerModeInternal(const sp<DisplayDevice>& hw,
-        int mode) {
+             int mode, bool stateLockHeld) {
     ALOGD("Set power mode=%d, type=%d flinger=%p", mode, hw->getDisplayType(),
             this);
     int32_t type = hw->getDisplayType();
@@ -3328,7 +3335,7 @@
     }
 
     if (mInterceptor.isEnabled()) {
-        Mutex::Autolock _l(mStateLock);
+        ConditionalLock lock(mStateLock, !stateLockHeld);
         ssize_t idx = mCurrentState.displays.indexOfKey(hw->getDisplayToken());
         if (idx < 0) {
             ALOGW("Surface Interceptor SavePowerMode: invalid display token");
@@ -3414,7 +3421,8 @@
                 ALOGW("Attempt to set power mode = %d for virtual display",
                         mMode);
             } else {
-                mFlinger.setPowerModeInternal(hw, mMode);
+                mFlinger.setPowerModeInternal(
+                        hw, mMode, /*stateLockHeld*/ false);
             }
             return true;
         }
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5123b58..058f4a1 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -60,13 +60,20 @@
 #include "SurfaceInterceptor.h"
 #include "StartPropertySetThread.h"
 
+#ifdef USE_HWC2
+#include "DisplayHardware/HWC2.h"
 #include "DisplayHardware/HWComposer.h"
+#else
+#include "DisplayHardware/HWComposer_hwc1.h"
+#endif
+
 #include "Effects/Daltonizer.h"
 
 #include <map>
 #include <mutex>
 #include <queue>
 #include <string>
+#include <thread>
 #include <utility>
 
 namespace android {
@@ -99,7 +106,11 @@
 
 class SurfaceFlinger : public BnSurfaceComposer,
                        private IBinder::DeathRecipient,
+#ifdef USE_HWC2
+                       private HWC2::ComposerCallback
+#else
                        private HWComposer::EventHandler
+#endif
 {
 public:
 
@@ -314,11 +325,20 @@
     virtual void onFirstRef();
 
     /* ------------------------------------------------------------------------
-     * HWComposer::EventHandler interface
+     * HWC2::ComposerCallback / HWComposer::EventHandler interface
      */
-    virtual void onVSyncReceived(HWComposer* composer, int type, nsecs_t timestamp);
-    virtual void onHotplugReceived(HWComposer* composer, int disp, bool connected);
-    virtual void onInvalidateReceived(HWComposer* composer);
+#ifdef USE_HWC2
+    void onVsyncReceived(int32_t sequenceId, hwc2_display_t display,
+                         int64_t timestamp) override;
+    void onHotplugReceived(int32_t sequenceId, hwc2_display_t display,
+                           HWC2::Connection connection,
+                           bool primaryDisplay) override;
+    void onRefreshReceived(int32_t sequenceId, hwc2_display_t display) override;
+#else
+    void onVSyncReceived(HWComposer* composer, int type, nsecs_t timestamp) override;
+    void onHotplugReceived(HWComposer* composer, int disp, bool connected) override;
+    void onInvalidateReceived(HWComposer* composer) override;
+#endif
 
     /* ------------------------------------------------------------------------
      * Message handling
@@ -333,7 +353,12 @@
     // called on the main thread in response to setActiveConfig()
     void setActiveConfigInternal(const sp<DisplayDevice>& hw, int mode);
     // called on the main thread in response to setPowerMode()
+#ifdef USE_HWC2
+    void setPowerModeInternal(const sp<DisplayDevice>& hw, int mode,
+                              bool stateLockHeld);
+#else
     void setPowerModeInternal(const sp<DisplayDevice>& hw, int mode);
+#endif
 
     // Called on the main thread in response to setActiveColorMode()
     void setActiveColorModeInternal(const sp<DisplayDevice>& hw, android_color_mode_t colorMode);
@@ -591,13 +616,7 @@
     /* ------------------------------------------------------------------------
      * VrFlinger
      */
-    template<typename T>
-    void clearHwcLayers(const T& layers) {
-        for (size_t i = 0; i < layers.size(); ++i) {
-            layers[i]->clearHwcLayers();
-        }
-    }
-    void resetHwcLocked();
+    void resetDisplayState();
 
     // Check to see if we should handoff to vr flinger.
     void updateVrFlinger();
@@ -624,13 +643,14 @@
     // access must be protected by mInvalidateLock
     volatile int32_t mRepaintEverything;
 
-    // current, real and vr hardware composers.
-    HWComposer* mHwc;
+    // The current hardware composer interface. When switching into and out of
+    // vr, our HWComposer instance will be recreated.
+    std::unique_ptr<HWComposer> mHwc;
+
 #ifdef USE_HWC2
-    HWComposer* mRealHwc;
-    HWComposer* mVrHwc;
     const std::string mHwcServiceName; // "default" for real use, something else for testing.
 #endif
+
     // constant members (no synchronization needed for access)
     RenderEngine* mRenderEngine;
     nsecs_t mBootTime;
@@ -644,10 +664,6 @@
     EGLDisplay mEGLDisplay;
     sp<IBinder> mBuiltinDisplays[DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES];
 
-#ifdef USE_HWC2
-    std::unique_ptr<dvr::VrFlinger> mVrFlinger;
-#endif
-
     // Can only accessed from the main thread, these members
     // don't need synchronization
     State mDrawingState{LayerVector::StateSet::Drawing};
@@ -769,8 +785,14 @@
     status_t CheckTransactCodeCredentials(uint32_t code);
 
 #ifdef USE_HWC2
+    std::unique_ptr<dvr::VrFlinger> mVrFlinger;
     std::atomic<bool> mVrFlingerRequestsDisplay;
     static bool useVrFlinger;
+    std::thread::id mMainThreadId;
+    // The composer sequence id is a monotonically increasing integer that we
+    // use to differentiate callbacks from different hardware composer
+    // instances. Each hardware composer instance gets a different sequence id.
+    int32_t mComposerSequenceId;
 #endif
 
     float mSaturation = 1.0f;
diff --git a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
index 7aaa42a..78a04e0 100644
--- a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
+++ b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
@@ -535,8 +535,8 @@
 
     // Initialize the H/W composer object.  There may or may not be an
     // actual hardware composer underneath.
-    mHwc = new HWComposer(this,
-            *static_cast<HWComposer::EventHandler *>(this));
+    mHwc.reset(new HWComposer(this,
+            *static_cast<HWComposer::EventHandler *>(this)));
 
     // get a RenderEngine for the given display / config (can't fail)
     mRenderEngine = RenderEngine::create(mEGLDisplay,