580 lines
17 KiB
C++
580 lines
17 KiB
C++
/* -*- 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) || defined (OS_SOLARIS)
|
|
#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) || defined(OS_SOLARIS)
|
|
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
|