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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /ipc/chromium/src/base/message_loop.cc
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'ipc/chromium/src/base/message_loop.cc')
-rw-r--r--ipc/chromium/src/base/message_loop.cc579
1 files changed, 579 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/message_loop.cc b/ipc/chromium/src/base/message_loop.cc
new file mode 100644
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+++ b/ipc/chromium/src/base/message_loop.cc
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/message_loop.h"
+
+#include <algorithm>
+
+#include "mozilla/Atomics.h"
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/message_pump_default.h"
+#include "base/string_util.h"
+#include "base/thread_local.h"
+
+#if defined(OS_MACOSX)
+#include "base/message_pump_mac.h"
+#endif
+#if defined(OS_POSIX)
+#include "base/message_pump_libevent.h"
+#endif
+#if defined(OS_LINUX) || defined(OS_BSD)
+#if defined(MOZ_WIDGET_GTK)
+#include "base/message_pump_glib.h"
+#endif
+#endif
+#ifdef ANDROID
+#include "base/message_pump_android.h"
+#endif
+#ifdef MOZ_TASK_TRACER
+#include "GeckoTaskTracer.h"
+#include "TracedTaskCommon.h"
+#endif
+
+#include "MessagePump.h"
+
+using base::Time;
+using base::TimeDelta;
+using base::TimeTicks;
+
+using mozilla::Move;
+using mozilla::Runnable;
+
+static base::ThreadLocalPointer<MessageLoop>& get_tls_ptr() {
+ static base::ThreadLocalPointer<MessageLoop> tls_ptr;
+ return tls_ptr;
+}
+
+//------------------------------------------------------------------------------
+
+// Logical events for Histogram profiling. Run with -message-loop-histogrammer
+// to get an accounting of messages and actions taken on each thread.
+static const int kTaskRunEvent = 0x1;
+static const int kTimerEvent = 0x2;
+
+// Provide range of message IDs for use in histogramming and debug display.
+static const int kLeastNonZeroMessageId = 1;
+static const int kMaxMessageId = 1099;
+static const int kNumberOfDistinctMessagesDisplayed = 1100;
+
+//------------------------------------------------------------------------------
+
+#if defined(OS_WIN)
+
+// Upon a SEH exception in this thread, it restores the original unhandled
+// exception filter.
+static int SEHFilter(LPTOP_LEVEL_EXCEPTION_FILTER old_filter) {
+ ::SetUnhandledExceptionFilter(old_filter);
+ return EXCEPTION_CONTINUE_SEARCH;
+}
+
+// Retrieves a pointer to the current unhandled exception filter. There
+// is no standalone getter method.
+static LPTOP_LEVEL_EXCEPTION_FILTER GetTopSEHFilter() {
+ LPTOP_LEVEL_EXCEPTION_FILTER top_filter = NULL;
+ top_filter = ::SetUnhandledExceptionFilter(0);
+ ::SetUnhandledExceptionFilter(top_filter);
+ return top_filter;
+}
+
+#endif // defined(OS_WIN)
+
+//------------------------------------------------------------------------------
+
+// static
+MessageLoop* MessageLoop::current() {
+ return get_tls_ptr().Get();
+}
+
+static mozilla::Atomic<int32_t> message_loop_id_seq(0);
+
+MessageLoop::MessageLoop(Type type, nsIThread* aThread)
+ : type_(type),
+ id_(++message_loop_id_seq),
+ nestable_tasks_allowed_(true),
+ exception_restoration_(false),
+ state_(NULL),
+ run_depth_base_(1),
+#ifdef OS_WIN
+ os_modal_loop_(false),
+#endif // OS_WIN
+ transient_hang_timeout_(0),
+ permanent_hang_timeout_(0),
+ next_sequence_num_(0) {
+ DCHECK(!current()) << "should only have one message loop per thread";
+ get_tls_ptr().Set(this);
+
+ switch (type_) {
+ case TYPE_MOZILLA_PARENT:
+ MOZ_RELEASE_ASSERT(!aThread);
+ pump_ = new mozilla::ipc::MessagePump(aThread);
+ return;
+ case TYPE_MOZILLA_CHILD:
+ MOZ_RELEASE_ASSERT(!aThread);
+ pump_ = new mozilla::ipc::MessagePumpForChildProcess();
+ // There is a MessageLoop Run call from XRE_InitChildProcess
+ // and another one from MessagePumpForChildProcess. The one
+ // from MessagePumpForChildProcess becomes the base, so we need
+ // to set run_depth_base_ to 2 or we'll never be able to process
+ // Idle tasks.
+ run_depth_base_ = 2;
+ return;
+ case TYPE_MOZILLA_NONMAINTHREAD:
+ pump_ = new mozilla::ipc::MessagePumpForNonMainThreads(aThread);
+ return;
+#if defined(OS_WIN)
+ case TYPE_MOZILLA_NONMAINUITHREAD:
+ pump_ = new mozilla::ipc::MessagePumpForNonMainUIThreads(aThread);
+ return;
+#endif
+ default:
+ // Create one of Chromium's standard MessageLoop types below.
+ break;
+ }
+
+#if defined(OS_WIN)
+ // TODO(rvargas): Get rid of the OS guards.
+ if (type_ == TYPE_DEFAULT) {
+ pump_ = new base::MessagePumpDefault();
+ } else if (type_ == TYPE_IO) {
+ pump_ = new base::MessagePumpForIO();
+ } else {
+ DCHECK(type_ == TYPE_UI);
+ pump_ = new base::MessagePumpForUI();
+ }
+#elif defined(OS_POSIX)
+ if (type_ == TYPE_UI) {
+#if defined(OS_MACOSX)
+ pump_ = base::MessagePumpMac::Create();
+#elif defined(OS_LINUX) || defined(OS_BSD)
+ pump_ = new base::MessagePumpForUI();
+#endif // OS_LINUX
+ } else if (type_ == TYPE_IO) {
+ pump_ = new base::MessagePumpLibevent();
+ } else {
+ pump_ = new base::MessagePumpDefault();
+ }
+#endif // OS_POSIX
+}
+
+MessageLoop::~MessageLoop() {
+ DCHECK(this == current());
+
+ // Let interested parties have one last shot at accessing this.
+ FOR_EACH_OBSERVER(DestructionObserver, destruction_observers_,
+ WillDestroyCurrentMessageLoop());
+
+ DCHECK(!state_);
+
+ // Clean up any unprocessed tasks, but take care: deleting a task could
+ // result in the addition of more tasks (e.g., via DeleteSoon). We set a
+ // limit on the number of times we will allow a deleted task to generate more
+ // tasks. Normally, we should only pass through this loop once or twice. If
+ // we end up hitting the loop limit, then it is probably due to one task that
+ // is being stubborn. Inspect the queues to see who is left.
+ bool did_work;
+ for (int i = 0; i < 100; ++i) {
+ DeletePendingTasks();
+ ReloadWorkQueue();
+ // If we end up with empty queues, then break out of the loop.
+ did_work = DeletePendingTasks();
+ if (!did_work)
+ break;
+ }
+ DCHECK(!did_work);
+
+ // OK, now make it so that no one can find us.
+ get_tls_ptr().Set(NULL);
+}
+
+void MessageLoop::AddDestructionObserver(DestructionObserver *obs) {
+ DCHECK(this == current());
+ destruction_observers_.AddObserver(obs);
+}
+
+void MessageLoop::RemoveDestructionObserver(DestructionObserver *obs) {
+ DCHECK(this == current());
+ destruction_observers_.RemoveObserver(obs);
+}
+
+void MessageLoop::Run() {
+ AutoRunState save_state(this);
+ RunHandler();
+}
+
+// Runs the loop in two different SEH modes:
+// enable_SEH_restoration_ = false : any unhandled exception goes to the last
+// one that calls SetUnhandledExceptionFilter().
+// enable_SEH_restoration_ = true : any unhandled exception goes to the filter
+// that was existed before the loop was run.
+void MessageLoop::RunHandler() {
+#if defined(OS_WIN)
+ if (exception_restoration_) {
+ LPTOP_LEVEL_EXCEPTION_FILTER current_filter = GetTopSEHFilter();
+ MOZ_SEH_TRY {
+ RunInternal();
+ } MOZ_SEH_EXCEPT(SEHFilter(current_filter)) {
+ }
+ return;
+ }
+#endif
+
+ RunInternal();
+}
+
+//------------------------------------------------------------------------------
+
+void MessageLoop::RunInternal() {
+ DCHECK(this == current());
+ pump_->Run(this);
+}
+
+//------------------------------------------------------------------------------
+// Wrapper functions for use in above message loop framework.
+
+bool MessageLoop::ProcessNextDelayedNonNestableTask() {
+ if (state_->run_depth > run_depth_base_)
+ return false;
+
+ if (deferred_non_nestable_work_queue_.empty())
+ return false;
+
+ RefPtr<Runnable> task = deferred_non_nestable_work_queue_.front().task.forget();
+ deferred_non_nestable_work_queue_.pop();
+
+ RunTask(task.forget());
+ return true;
+}
+
+//------------------------------------------------------------------------------
+
+void MessageLoop::Quit() {
+ DCHECK(current() == this);
+ if (state_) {
+ state_->quit_received = true;
+ } else {
+ NOTREACHED() << "Must be inside Run to call Quit";
+ }
+}
+
+void MessageLoop::PostTask(already_AddRefed<Runnable> task) {
+ PostTask_Helper(Move(task), 0);
+}
+
+void MessageLoop::PostDelayedTask(already_AddRefed<Runnable> task, int delay_ms) {
+ PostTask_Helper(Move(task), delay_ms);
+}
+
+void MessageLoop::PostIdleTask(already_AddRefed<Runnable> task) {
+ DCHECK(current() == this);
+ MOZ_ASSERT(NS_IsMainThread());
+
+ PendingTask pending_task(Move(task), false);
+ deferred_non_nestable_work_queue_.push(Move(pending_task));
+}
+
+// Possibly called on a background thread!
+void MessageLoop::PostTask_Helper(already_AddRefed<Runnable> task, int delay_ms) {
+ if (nsIEventTarget* target = pump_->GetXPCOMThread()) {
+ nsresult rv;
+ if (delay_ms) {
+ rv = target->DelayedDispatch(Move(task), delay_ms);
+ } else {
+ rv = target->Dispatch(Move(task), 0);
+ }
+ MOZ_ALWAYS_SUCCEEDS(rv);
+ return;
+ }
+
+ PendingTask pending_task(Move(task), true);
+
+ if (delay_ms > 0) {
+ pending_task.delayed_run_time =
+ TimeTicks::Now() + TimeDelta::FromMilliseconds(delay_ms);
+ } else {
+ DCHECK(delay_ms == 0) << "delay should not be negative";
+ }
+
+ // Warning: Don't try to short-circuit, and handle this thread's tasks more
+ // directly, as it could starve handling of foreign threads. Put every task
+ // into this queue.
+
+ RefPtr<base::MessagePump> pump;
+ {
+ AutoLock locked(incoming_queue_lock_);
+ incoming_queue_.push(Move(pending_task));
+ pump = pump_;
+ }
+ // Since the incoming_queue_ may contain a task that destroys this message
+ // loop, we cannot exit incoming_queue_lock_ until we are done with |this|.
+ // We use a stack-based reference to the message pump so that we can call
+ // ScheduleWork outside of incoming_queue_lock_.
+
+ pump->ScheduleWork();
+}
+
+void MessageLoop::SetNestableTasksAllowed(bool allowed) {
+ if (nestable_tasks_allowed_ != allowed) {
+ nestable_tasks_allowed_ = allowed;
+ if (!nestable_tasks_allowed_)
+ return;
+ // Start the native pump if we are not already pumping.
+ pump_->ScheduleWorkForNestedLoop();
+ }
+}
+
+void MessageLoop::ScheduleWork() {
+ // Start the native pump if we are not already pumping.
+ pump_->ScheduleWork();
+}
+
+bool MessageLoop::NestableTasksAllowed() const {
+ return nestable_tasks_allowed_;
+}
+
+//------------------------------------------------------------------------------
+
+void MessageLoop::RunTask(already_AddRefed<Runnable> aTask) {
+ DCHECK(nestable_tasks_allowed_);
+ // Execute the task and assume the worst: It is probably not reentrant.
+ nestable_tasks_allowed_ = false;
+
+ RefPtr<Runnable> task = aTask;
+ task->Run();
+ task = nullptr;
+
+ nestable_tasks_allowed_ = true;
+}
+
+bool MessageLoop::DeferOrRunPendingTask(PendingTask&& pending_task) {
+ if (pending_task.nestable || state_->run_depth <= run_depth_base_) {
+ RunTask(pending_task.task.forget());
+ // Show that we ran a task (Note: a new one might arrive as a
+ // consequence!).
+ return true;
+ }
+
+ // We couldn't run the task now because we're in a nested message loop
+ // and the task isn't nestable.
+ deferred_non_nestable_work_queue_.push(Move(pending_task));
+ return false;
+}
+
+void MessageLoop::AddToDelayedWorkQueue(const PendingTask& pending_task) {
+ // Move to the delayed work queue. Initialize the sequence number
+ // before inserting into the delayed_work_queue_. The sequence number
+ // is used to faciliate FIFO sorting when two tasks have the same
+ // delayed_run_time value.
+ PendingTask new_pending_task(pending_task);
+ new_pending_task.sequence_num = next_sequence_num_++;
+ delayed_work_queue_.push(Move(new_pending_task));
+}
+
+void MessageLoop::ReloadWorkQueue() {
+ // We can improve performance of our loading tasks from incoming_queue_ to
+ // work_queue_ by waiting until the last minute (work_queue_ is empty) to
+ // load. That reduces the number of locks-per-task significantly when our
+ // queues get large.
+ if (!work_queue_.empty())
+ return; // Wait till we *really* need to lock and load.
+
+ // Acquire all we can from the inter-thread queue with one lock acquisition.
+ {
+ AutoLock lock(incoming_queue_lock_);
+ if (incoming_queue_.empty())
+ return;
+ std::swap(incoming_queue_, work_queue_);
+ DCHECK(incoming_queue_.empty());
+ }
+}
+
+bool MessageLoop::DeletePendingTasks() {
+ MOZ_ASSERT(work_queue_.empty());
+ bool did_work = !deferred_non_nestable_work_queue_.empty();
+ while (!deferred_non_nestable_work_queue_.empty()) {
+ deferred_non_nestable_work_queue_.pop();
+ }
+ did_work |= !delayed_work_queue_.empty();
+ while (!delayed_work_queue_.empty()) {
+ delayed_work_queue_.pop();
+ }
+ return did_work;
+}
+
+bool MessageLoop::DoWork() {
+ if (!nestable_tasks_allowed_) {
+ // Task can't be executed right now.
+ return false;
+ }
+
+ for (;;) {
+ ReloadWorkQueue();
+ if (work_queue_.empty())
+ break;
+
+ // Execute oldest task.
+ do {
+ PendingTask pending_task = Move(work_queue_.front());
+ work_queue_.pop();
+ if (!pending_task.delayed_run_time.is_null()) {
+ // NB: Don't move, because we use this later!
+ AddToDelayedWorkQueue(pending_task);
+ // If we changed the topmost task, then it is time to re-schedule.
+ if (delayed_work_queue_.top().task == pending_task.task)
+ pump_->ScheduleDelayedWork(pending_task.delayed_run_time);
+ } else {
+ if (DeferOrRunPendingTask(Move(pending_task)))
+ return true;
+ }
+ } while (!work_queue_.empty());
+ }
+
+ // Nothing happened.
+ return false;
+}
+
+bool MessageLoop::DoDelayedWork(TimeTicks* next_delayed_work_time) {
+ if (!nestable_tasks_allowed_ || delayed_work_queue_.empty()) {
+ *next_delayed_work_time = TimeTicks();
+ return false;
+ }
+
+ if (delayed_work_queue_.top().delayed_run_time > TimeTicks::Now()) {
+ *next_delayed_work_time = delayed_work_queue_.top().delayed_run_time;
+ return false;
+ }
+
+ PendingTask pending_task = delayed_work_queue_.top();
+ delayed_work_queue_.pop();
+
+ if (!delayed_work_queue_.empty())
+ *next_delayed_work_time = delayed_work_queue_.top().delayed_run_time;
+
+ return DeferOrRunPendingTask(Move(pending_task));
+}
+
+bool MessageLoop::DoIdleWork() {
+ if (ProcessNextDelayedNonNestableTask())
+ return true;
+
+ if (state_->quit_received)
+ pump_->Quit();
+
+ return false;
+}
+
+//------------------------------------------------------------------------------
+// MessageLoop::AutoRunState
+
+MessageLoop::AutoRunState::AutoRunState(MessageLoop* loop) : loop_(loop) {
+ // Make the loop reference us.
+ previous_state_ = loop_->state_;
+ if (previous_state_) {
+ run_depth = previous_state_->run_depth + 1;
+ } else {
+ run_depth = 1;
+ }
+ loop_->state_ = this;
+
+ // Initialize the other fields:
+ quit_received = false;
+#if defined(OS_WIN)
+ dispatcher = NULL;
+#endif
+}
+
+MessageLoop::AutoRunState::~AutoRunState() {
+ loop_->state_ = previous_state_;
+}
+
+//------------------------------------------------------------------------------
+// MessageLoop::PendingTask
+
+bool MessageLoop::PendingTask::operator<(const PendingTask& other) const {
+ // Since the top of a priority queue is defined as the "greatest" element, we
+ // need to invert the comparison here. We want the smaller time to be at the
+ // top of the heap.
+
+ if (delayed_run_time < other.delayed_run_time)
+ return false;
+
+ if (delayed_run_time > other.delayed_run_time)
+ return true;
+
+ // If the times happen to match, then we use the sequence number to decide.
+ // Compare the difference to support integer roll-over.
+ return (sequence_num - other.sequence_num) > 0;
+}
+
+//------------------------------------------------------------------------------
+// MessageLoopForUI
+
+#if defined(OS_WIN)
+
+void MessageLoopForUI::Run(Dispatcher* dispatcher) {
+ AutoRunState save_state(this);
+ state_->dispatcher = dispatcher;
+ RunHandler();
+}
+
+void MessageLoopForUI::AddObserver(Observer* observer) {
+ pump_win()->AddObserver(observer);
+}
+
+void MessageLoopForUI::RemoveObserver(Observer* observer) {
+ pump_win()->RemoveObserver(observer);
+}
+
+void MessageLoopForUI::WillProcessMessage(const MSG& message) {
+ pump_win()->WillProcessMessage(message);
+}
+void MessageLoopForUI::DidProcessMessage(const MSG& message) {
+ pump_win()->DidProcessMessage(message);
+}
+void MessageLoopForUI::PumpOutPendingPaintMessages() {
+ pump_ui()->PumpOutPendingPaintMessages();
+}
+
+#endif // defined(OS_WIN)
+
+//------------------------------------------------------------------------------
+// MessageLoopForIO
+
+#if defined(OS_WIN)
+
+void MessageLoopForIO::RegisterIOHandler(HANDLE file, IOHandler* handler) {
+ pump_io()->RegisterIOHandler(file, handler);
+}
+
+bool MessageLoopForIO::WaitForIOCompletion(DWORD timeout, IOHandler* filter) {
+ return pump_io()->WaitForIOCompletion(timeout, filter);
+}
+
+#elif defined(OS_POSIX)
+
+bool MessageLoopForIO::WatchFileDescriptor(int fd,
+ bool persistent,
+ Mode mode,
+ FileDescriptorWatcher *controller,
+ Watcher *delegate) {
+ return pump_libevent()->WatchFileDescriptor(
+ fd,
+ persistent,
+ static_cast<base::MessagePumpLibevent::Mode>(mode),
+ controller,
+ delegate);
+}
+
+bool
+MessageLoopForIO::CatchSignal(int sig,
+ SignalEvent* sigevent,
+ SignalWatcher* delegate)
+{
+ return pump_libevent()->CatchSignal(sig, sigevent, delegate);
+}
+
+#endif