adb: extract soon-to-be-common code.
As a side effect, delete FDE_ACTIVE, which was always set on every
fdevent, and FDE_PENDING, which was an internal implementation detail.
This patch removes spin detection, which will be reimplemented
separately later.
Test: adb_test on host
Test: adbd_test on blueline
Change-Id: I40be3504ce03c4fae5e071fa018542a051b7511d
diff --git a/adb/fdevent/fdevent.cpp b/adb/fdevent/fdevent.cpp
index 28b8f37..d215217 100644
--- a/adb/fdevent/fdevent.cpp
+++ b/adb/fdevent/fdevent.cpp
@@ -28,14 +28,21 @@
#include "fdevent.h"
#include "fdevent_poll.h"
+using namespace std::chrono_literals;
+using std::chrono::duration_cast;
+
+void invoke_fde(struct fdevent* fde, unsigned events) {
+ if (auto f = std::get_if<fd_func>(&fde->func)) {
+ (*f)(fde->fd.get(), events, fde->arg);
+ } else if (auto f = std::get_if<fd_func2>(&fde->func)) {
+ (*f)(fde, events, fde->arg);
+ } else {
+ __builtin_unreachable();
+ }
+}
+
std::string dump_fde(const fdevent* fde) {
std::string state;
- if (fde->state & FDE_ACTIVE) {
- state += "A";
- }
- if (fde->state & FDE_PENDING) {
- state += "P";
- }
if (fde->state & FDE_READ) {
state += "R";
}
@@ -53,9 +60,11 @@
CheckMainThread();
CHECK_GE(fd.get(), 0);
+ int fd_num = fd.get();
+
fdevent* fde = new fdevent();
fde->id = fdevent_id_++;
- fde->state = FDE_ACTIVE;
+ fde->state = 0;
fde->fd = std::move(fd);
fde->func = func;
fde->arg = arg;
@@ -66,6 +75,10 @@
LOG(ERROR) << "failed to set non-blocking mode for fd " << fde->fd.get();
}
+ auto [it, inserted] = this->installed_fdevents_.emplace(fd_num, fde);
+ CHECK(inserted);
+ UNUSED(it);
+
this->Register(fde);
return fde;
}
@@ -78,18 +91,22 @@
this->Unregister(fde);
+ auto erased = this->installed_fdevents_.erase(fde->fd.get());
+ CHECK_EQ(1UL, erased);
+
unique_fd result = std::move(fde->fd);
delete fde;
return result;
}
void fdevent_context::Add(fdevent* fde, unsigned events) {
- Set(fde, (fde->state & FDE_EVENTMASK) | events);
+ CHECK(!(events & FDE_TIMEOUT));
+ Set(fde, fde->state | events);
}
void fdevent_context::Del(fdevent* fde, unsigned events) {
CHECK(!(events & FDE_TIMEOUT));
- Set(fde, (fde->state & FDE_EVENTMASK) & ~events);
+ Set(fde, fde->state & ~events);
}
void fdevent_context::SetTimeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout) {
@@ -98,6 +115,56 @@
fde->last_active = std::chrono::steady_clock::now();
}
+std::optional<std::chrono::milliseconds> fdevent_context::CalculatePollDuration() {
+ std::optional<std::chrono::milliseconds> result = std::nullopt;
+ auto now = std::chrono::steady_clock::now();
+ CheckMainThread();
+
+ for (const auto& [fd, fde] : this->installed_fdevents_) {
+ UNUSED(fd);
+ auto timeout_opt = fde->timeout;
+ if (timeout_opt) {
+ auto deadline = fde->last_active + *timeout_opt;
+ auto time_left = duration_cast<std::chrono::milliseconds>(deadline - now);
+ if (time_left < 0ms) {
+ time_left = 0ms;
+ }
+
+ if (!result) {
+ result = time_left;
+ } else {
+ result = std::min(*result, time_left);
+ }
+ }
+ }
+
+ return result;
+}
+
+void fdevent_context::HandleEvents(const std::vector<fdevent_event>& events) {
+ for (const auto& event : events) {
+ invoke_fde(event.fde, event.events);
+ }
+ FlushRunQueue();
+}
+
+void fdevent_context::FlushRunQueue() {
+ // We need to be careful around reentrancy here, since a function we call can queue up another
+ // function.
+ while (true) {
+ std::function<void()> fn;
+ {
+ std::lock_guard<std::mutex> lock(this->run_queue_mutex_);
+ if (this->run_queue_.empty()) {
+ break;
+ }
+ fn = std::move(this->run_queue_.front());
+ this->run_queue_.pop_front();
+ }
+ fn();
+ }
+}
+
void fdevent_context::CheckMainThread() {
if (main_thread_id_) {
CHECK_EQ(*main_thread_id_, android::base::GetThreadId());
@@ -118,23 +185,6 @@
Interrupt();
}
-void fdevent_context::FlushRunQueue() {
- // We need to be careful around reentrancy here, since a function we call can queue up another
- // function.
- while (true) {
- std::function<void()> fn;
- {
- std::lock_guard<std::mutex> lock(this->run_queue_mutex_);
- if (this->run_queue_.empty()) {
- break;
- }
- fn = this->run_queue_.front();
- this->run_queue_.pop_front();
- }
- fn();
- }
-}
-
static auto& g_ambient_fdevent_context =
*new std::unique_ptr<fdevent_context>(new fdevent_context_poll());
diff --git a/adb/fdevent/fdevent.h b/adb/fdevent/fdevent.h
index 2424252..3d30d49 100644
--- a/adb/fdevent/fdevent.h
+++ b/adb/fdevent/fdevent.h
@@ -26,6 +26,7 @@
#include <functional>
#include <mutex>
#include <optional>
+#include <unordered_map>
#include <variant>
#include <android-base/thread_annotations.h>
@@ -38,19 +39,19 @@
#define FDE_ERROR 0x0004
#define FDE_TIMEOUT 0x0008
-// Internal states.
-#define FDE_EVENTMASK 0x00ff
-#define FDE_STATEMASK 0xff00
-
-#define FDE_ACTIVE 0x0100
-#define FDE_PENDING 0x0200
+struct fdevent;
typedef void (*fd_func)(int fd, unsigned events, void *userdata);
typedef void (*fd_func2)(struct fdevent* fde, unsigned events, void* userdata);
-struct fdevent;
+void invoke_fde(struct fdevent* fde, unsigned events);
std::string dump_fde(const fdevent* fde);
+struct fdevent_event {
+ fdevent* fde;
+ unsigned events;
+};
+
struct fdevent_context {
public:
virtual ~fdevent_context() = default;
@@ -62,11 +63,8 @@
unique_fd Destroy(fdevent* fde);
protected:
- // Register an fdevent that is being created by Create with the fdevent_context.
- virtual void Register(fdevent* fde) = 0;
-
- // Unregister an fdevent that is being destroyed by Destroy with the fdevent_context.
- virtual void Unregister(fdevent* fde) = 0;
+ virtual void Register(fdevent*) {}
+ virtual void Unregister(fdevent*) {}
public:
// Change which events should cause notifications.
@@ -80,6 +78,15 @@
// trigger repeatedly every |timeout| ms.
void SetTimeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout);
+ protected:
+ std::optional<std::chrono::milliseconds> CalculatePollDuration();
+ void HandleEvents(const std::vector<fdevent_event>& events);
+
+ private:
+ // Run all pending functions enqueued via Run().
+ void FlushRunQueue() EXCLUDES(run_queue_mutex_);
+
+ public:
// Loop until TerminateLoop is called, handling events.
// Implementations should call FlushRunQueue on every iteration, and check the value of
// terminate_loop_ to determine whether to stop.
@@ -100,12 +107,12 @@
// Interrupt the run loop.
virtual void Interrupt() = 0;
- // Run all pending functions enqueued via Run().
- void FlushRunQueue() EXCLUDES(run_queue_mutex_);
-
std::optional<uint64_t> main_thread_id_ = std::nullopt;
std::atomic<bool> terminate_loop_ = false;
+ protected:
+ std::unordered_map<int, fdevent*> installed_fdevents_;
+
private:
uint64_t fdevent_id_ = 0;
std::mutex run_queue_mutex_;
@@ -119,7 +126,6 @@
int force_eof = 0;
uint16_t state = 0;
- uint16_t events = 0;
std::optional<std::chrono::milliseconds> timeout;
std::chrono::steady_clock::time_point last_active;
diff --git a/adb/fdevent/fdevent_poll.cpp b/adb/fdevent/fdevent_poll.cpp
index 75ea081..85cbaf9 100644
--- a/adb/fdevent/fdevent_poll.cpp
+++ b/adb/fdevent/fdevent_poll.cpp
@@ -78,57 +78,10 @@
this->Destroy(this->interrupt_fde_);
}
-void fdevent_context_poll::Register(fdevent* fde) {
- auto pair = poll_node_map_.emplace(fde->fd.get(), PollNode(fde));
- CHECK(pair.second) << "install existing fd " << fde->fd.get();
-}
-
-void fdevent_context_poll::Unregister(fdevent* fde) {
- if (fde->state & FDE_ACTIVE) {
- poll_node_map_.erase(fde->fd.get());
-
- if (fde->state & FDE_PENDING) {
- pending_list_.remove(fde);
- }
- fde->state = 0;
- fde->events = 0;
- }
-}
-
void fdevent_context_poll::Set(fdevent* fde, unsigned events) {
CheckMainThread();
- events &= FDE_EVENTMASK;
- if ((fde->state & FDE_EVENTMASK) == events) {
- return;
- }
- CHECK(fde->state & FDE_ACTIVE);
-
- auto it = poll_node_map_.find(fde->fd.get());
- CHECK(it != poll_node_map_.end());
- PollNode& node = it->second;
- if (events & FDE_READ) {
- node.pollfd.events |= POLLIN;
- } else {
- node.pollfd.events &= ~POLLIN;
- }
-
- if (events & FDE_WRITE) {
- node.pollfd.events |= POLLOUT;
- } else {
- node.pollfd.events &= ~POLLOUT;
- }
- fde->state = (fde->state & FDE_STATEMASK) | events;
-
+ fde->state = events;
D("fdevent_set: %s, events = %u", dump_fde(fde).c_str(), events);
-
- if (fde->state & FDE_PENDING) {
- // If we are pending, make sure we don't signal an event that is no longer wanted.
- fde->events &= events;
- if (fde->events == 0) {
- pending_list_.remove(fde);
- fde->state &= ~FDE_PENDING;
- }
- }
}
static std::string dump_pollfds(const std::vector<adb_pollfd>& pollfds) {
@@ -146,204 +99,94 @@
return result;
}
-static std::optional<std::chrono::milliseconds> calculate_timeout(fdevent_context_poll* ctx) {
- std::optional<std::chrono::milliseconds> result = std::nullopt;
- auto now = std::chrono::steady_clock::now();
- ctx->CheckMainThread();
-
- for (const auto& [fd, pollnode] : ctx->poll_node_map_) {
- UNUSED(fd);
- auto timeout_opt = pollnode.fde->timeout;
- if (timeout_opt) {
- auto deadline = pollnode.fde->last_active + *timeout_opt;
- auto time_left = std::chrono::duration_cast<std::chrono::milliseconds>(deadline - now);
- if (time_left < std::chrono::milliseconds::zero()) {
- time_left = std::chrono::milliseconds::zero();
- }
-
- if (!result) {
- result = time_left;
- } else {
- result = std::min(*result, time_left);
- }
- }
- }
-
- return result;
-}
-
-static void fdevent_process(fdevent_context_poll* ctx) {
- std::vector<adb_pollfd> pollfds;
- for (const auto& pair : ctx->poll_node_map_) {
- pollfds.push_back(pair.second.pollfd);
- }
- CHECK_GT(pollfds.size(), 0u);
- D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str());
-
- auto timeout = calculate_timeout(ctx);
- int timeout_ms;
- if (!timeout) {
- timeout_ms = -1;
- } else {
- timeout_ms = timeout->count();
- }
-
- int ret = adb_poll(&pollfds[0], pollfds.size(), timeout_ms);
- if (ret == -1) {
- PLOG(ERROR) << "poll(), ret = " << ret;
- return;
- }
-
- auto post_poll = std::chrono::steady_clock::now();
-
- for (const auto& pollfd : pollfds) {
- if (pollfd.revents != 0) {
- D("for fd %d, revents = %x", pollfd.fd, pollfd.revents);
- }
- unsigned events = 0;
- if (pollfd.revents & POLLIN) {
- events |= FDE_READ;
- }
- if (pollfd.revents & POLLOUT) {
- events |= FDE_WRITE;
- }
- if (pollfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
- // We fake a read, as the rest of the code assumes that errors will
- // be detected at that point.
- events |= FDE_READ | FDE_ERROR;
- }
-#if defined(__linux__)
- if (pollfd.revents & POLLRDHUP) {
- events |= FDE_READ | FDE_ERROR;
- }
-#endif
- auto it = ctx->poll_node_map_.find(pollfd.fd);
- CHECK(it != ctx->poll_node_map_.end());
- fdevent* fde = it->second.fde;
-
- if (events == 0) {
- // Check for timeout.
- if (fde->timeout) {
- auto deadline = fde->last_active + *fde->timeout;
- if (deadline < post_poll) {
- events |= FDE_TIMEOUT;
- }
- }
- }
-
- if (events != 0) {
- CHECK_EQ(fde->fd.get(), pollfd.fd);
- fde->events |= events;
- fde->last_active = post_poll;
- D("%s got events %x", dump_fde(fde).c_str(), events);
- fde->state |= FDE_PENDING;
- ctx->pending_list_.push_back(fde);
- }
- }
-}
-
-template <class T>
-struct always_false : std::false_type {};
-
-static void fdevent_call_fdfunc(fdevent* fde) {
- unsigned events = fde->events;
- fde->events = 0;
- CHECK(fde->state & FDE_PENDING);
- fde->state &= (~FDE_PENDING);
- D("fdevent_call_fdfunc %s", dump_fde(fde).c_str());
- std::visit(
- [&](auto&& f) {
- using F = std::decay_t<decltype(f)>;
- if constexpr (std::is_same_v<fd_func, F>) {
- f(fde->fd.get(), events, fde->arg);
- } else if constexpr (std::is_same_v<fd_func2, F>) {
- f(fde, events, fde->arg);
- } else {
- static_assert(always_false<F>::value, "non-exhaustive visitor");
- }
- },
- fde->func);
-}
-
-static void fdevent_check_spin(fdevent_context_poll* ctx, uint64_t cycle) {
- // Check to see if we're spinning because we forgot about an fdevent
- // by keeping track of how long fdevents have been continuously pending.
- struct SpinCheck {
- fdevent* fde;
- android::base::boot_clock::time_point timestamp;
- uint64_t cycle;
- };
-
- // TODO: Move this into the base fdevent_context.
- static auto& g_continuously_pending = *new std::unordered_map<uint64_t, SpinCheck>();
- static auto last_cycle = android::base::boot_clock::now();
-
- auto now = android::base::boot_clock::now();
- if (now - last_cycle > 10ms) {
- // We're not spinning.
- g_continuously_pending.clear();
- last_cycle = now;
- return;
- }
- last_cycle = now;
-
- for (auto* fde : ctx->pending_list_) {
- auto it = g_continuously_pending.find(fde->id);
- if (it == g_continuously_pending.end()) {
- g_continuously_pending[fde->id] =
- SpinCheck{.fde = fde, .timestamp = now, .cycle = cycle};
- } else {
- it->second.cycle = cycle;
- }
- }
-
- for (auto it = g_continuously_pending.begin(); it != g_continuously_pending.end();) {
- if (it->second.cycle != cycle) {
- it = g_continuously_pending.erase(it);
- } else {
- // Use an absurdly long window, since all we really care about is
- // getting a bugreport eventually.
- if (now - it->second.timestamp > 300s) {
- LOG(FATAL_WITHOUT_ABORT)
- << "detected spin in fdevent: " << dump_fde(it->second.fde);
-#if defined(__linux__)
- int fd = it->second.fde->fd.get();
- std::string fd_path = android::base::StringPrintf("/proc/self/fd/%d", fd);
- std::string path;
- if (!android::base::Readlink(fd_path, &path)) {
- PLOG(FATAL_WITHOUT_ABORT) << "readlink of fd " << fd << " failed";
- }
- LOG(FATAL_WITHOUT_ABORT) << "fd " << fd << " = " << path;
-#endif
- abort();
- }
- ++it;
- }
- }
-}
-
void fdevent_context_poll::Loop() {
main_thread_id_ = android::base::GetThreadId();
- uint64_t cycle = 0;
while (true) {
if (terminate_loop_) {
break;
}
D("--- --- waiting for events");
+ std::vector<adb_pollfd> pollfds;
+ for (const auto& [fd, fde] : this->installed_fdevents_) {
+ adb_pollfd pfd;
+ pfd.fd = fd;
+ pfd.events = 0;
+ if (fde->state & FDE_READ) {
+ pfd.events |= POLLIN;
+ }
+ if (fde->state & FDE_WRITE) {
+ pfd.events |= POLLOUT;
+ }
+ if (fde->state & FDE_ERROR) {
+ pfd.events |= POLLERR;
+ }
+#if defined(__linux__)
+ pfd.events |= POLLRDHUP;
+#endif
+ pfd.revents = 0;
+ pollfds.push_back(pfd);
+ }
+ CHECK_GT(pollfds.size(), 0u);
+ D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str());
- fdevent_process(this);
-
- fdevent_check_spin(this, cycle++);
-
- while (!pending_list_.empty()) {
- fdevent* fde = pending_list_.front();
- pending_list_.pop_front();
- fdevent_call_fdfunc(fde);
+ auto timeout = CalculatePollDuration();
+ int timeout_ms;
+ if (!timeout) {
+ timeout_ms = -1;
+ } else {
+ timeout_ms = timeout->count();
}
- this->FlushRunQueue();
+ int ret = adb_poll(pollfds.data(), pollfds.size(), timeout_ms);
+ if (ret == -1) {
+ PLOG(ERROR) << "poll(), ret = " << ret;
+ return;
+ }
+
+ auto post_poll = std::chrono::steady_clock::now();
+ std::vector<fdevent_event> poll_events;
+
+ for (const auto& pollfd : pollfds) {
+ unsigned events = 0;
+ if (pollfd.revents & POLLIN) {
+ events |= FDE_READ;
+ }
+ if (pollfd.revents & POLLOUT) {
+ events |= FDE_WRITE;
+ }
+ if (pollfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
+ // We fake a read, as the rest of the code assumes that errors will
+ // be detected at that point.
+ events |= FDE_READ | FDE_ERROR;
+ }
+#if defined(__linux__)
+ if (pollfd.revents & POLLRDHUP) {
+ events |= FDE_READ | FDE_ERROR;
+ }
+#endif
+
+ auto it = this->installed_fdevents_.find(pollfd.fd);
+ CHECK(it != this->installed_fdevents_.end());
+ fdevent* fde = it->second;
+
+ if (events == 0) {
+ if (fde->timeout) {
+ auto deadline = fde->last_active + *fde->timeout;
+ if (deadline < post_poll) {
+ events |= FDE_TIMEOUT;
+ }
+ }
+ }
+
+ if (events != 0) {
+ D("%s got events %x", dump_fde(fde).c_str(), events);
+ poll_events.push_back({fde, events});
+ fde->last_active = post_poll;
+ }
+ }
+ this->HandleEvents(std::move(poll_events));
}
main_thread_id_.reset();
@@ -351,7 +194,7 @@
size_t fdevent_context_poll::InstalledCount() {
// We always have an installed fde for interrupt.
- return poll_node_map_.size() - 1;
+ return this->installed_fdevents_.size() - 1;
}
void fdevent_context_poll::Interrupt() {
diff --git a/adb/fdevent/fdevent_poll.h b/adb/fdevent/fdevent_poll.h
index db08301..8ff37f5 100644
--- a/adb/fdevent/fdevent_poll.h
+++ b/adb/fdevent/fdevent_poll.h
@@ -48,9 +48,6 @@
fdevent_context_poll();
virtual ~fdevent_context_poll();
- virtual void Register(fdevent* fde) final;
- virtual void Unregister(fdevent* fde) final;
-
virtual void Set(fdevent* fde, unsigned events) final;
virtual void Loop() final;
@@ -61,11 +58,6 @@
virtual void Interrupt() final;
public:
- // All operations to fdevent should happen only in the main thread.
- // That's why we don't need a lock for fdevent.
- std::unordered_map<int, PollNode> poll_node_map_;
- std::list<fdevent*> pending_list_;
-
unique_fd interrupt_fd_;
fdevent* interrupt_fde_ = nullptr;
};