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// Copyright 2015 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 "cc/raster/single_thread_task_graph_runner.h"
#include <string>
#include "base/threading/simple_thread.h"
#include "base/threading/thread_restrictions.h"
#include "base/trace_event/trace_event.h"
namespace cc {
SingleThreadTaskGraphRunner::SingleThreadTaskGraphRunner()
: lock_(),
has_ready_to_run_tasks_cv_(&lock_),
has_namespaces_with_finished_running_tasks_cv_(&lock_),
shutdown_(false) {}
SingleThreadTaskGraphRunner::~SingleThreadTaskGraphRunner() {}
void SingleThreadTaskGraphRunner::Start(
const std::string& thread_name,
const base::SimpleThread::Options& thread_options) {
thread_.reset(
new base::DelegateSimpleThread(this, thread_name, thread_options));
thread_->Start();
}
void SingleThreadTaskGraphRunner::Shutdown() {
{
base::AutoLock lock(lock_);
DCHECK(!work_queue_.HasReadyToRunTasks());
DCHECK(!work_queue_.HasAnyNamespaces());
DCHECK(!shutdown_);
shutdown_ = true;
// Wake up the worker so it knows it should exit.
has_ready_to_run_tasks_cv_.Signal();
}
thread_->Join();
}
NamespaceToken SingleThreadTaskGraphRunner::GetNamespaceToken() {
base::AutoLock lock(lock_);
return work_queue_.GetNamespaceToken();
}
void SingleThreadTaskGraphRunner::ScheduleTasks(NamespaceToken token,
TaskGraph* graph) {
TRACE_EVENT2("cc", "SingleThreadTaskGraphRunner::ScheduleTasks", "num_nodes",
graph->nodes.size(), "num_edges", graph->edges.size());
DCHECK(token.IsValid());
DCHECK(!TaskGraphWorkQueue::DependencyMismatch(graph));
{
base::AutoLock lock(lock_);
DCHECK(!shutdown_);
work_queue_.ScheduleTasks(token, graph);
// If there is more work available, wake up the worker thread.
if (work_queue_.HasReadyToRunTasks())
has_ready_to_run_tasks_cv_.Signal();
}
}
void SingleThreadTaskGraphRunner::WaitForTasksToFinishRunning(
NamespaceToken token) {
TRACE_EVENT0("cc",
"SingleThreadTaskGraphRunner::WaitForTasksToFinishRunning");
DCHECK(token.IsValid());
{
base::AutoLock lock(lock_);
base::ThreadRestrictions::ScopedAllowWait allow_wait;
auto* task_namespace = work_queue_.GetNamespaceForToken(token);
if (!task_namespace)
return;
while (!work_queue_.HasFinishedRunningTasksInNamespace(task_namespace))
has_namespaces_with_finished_running_tasks_cv_.Wait();
// There may be other namespaces that have finished running tasks, so wake
// up another origin thread.
has_namespaces_with_finished_running_tasks_cv_.Signal();
}
}
void SingleThreadTaskGraphRunner::CollectCompletedTasks(
NamespaceToken token,
Task::Vector* completed_tasks) {
TRACE_EVENT0("cc", "SingleThreadTaskGraphRunner::CollectCompletedTasks");
DCHECK(token.IsValid());
{
base::AutoLock lock(lock_);
work_queue_.CollectCompletedTasks(token, completed_tasks);
}
}
void SingleThreadTaskGraphRunner::Run() {
base::AutoLock lock(lock_);
while (true) {
if (!work_queue_.HasReadyToRunTasks()) {
// Exit when shutdown is set and no more tasks are pending.
if (shutdown_)
break;
// Wait for more tasks.
has_ready_to_run_tasks_cv_.Wait();
continue;
}
RunTaskWithLockAcquired();
}
}
void SingleThreadTaskGraphRunner::RunTaskWithLockAcquired() {
TRACE_EVENT0("toplevel",
"SingleThreadTaskGraphRunner::RunTaskWithLockAcquired");
lock_.AssertAcquired();
auto prioritized_task = work_queue_.GetNextTaskToRun();
Task* task = prioritized_task.task;
// Call WillRun() before releasing |lock_| and running task.
task->WillRun();
{
base::AutoUnlock unlock(lock_);
task->RunOnWorkerThread();
}
// This will mark task as finished running.
task->DidRun();
work_queue_.CompleteTask(prioritized_task);
// If namespace has finished running all tasks, wake up origin thread.
if (work_queue_.HasFinishedRunningTasksInNamespace(
prioritized_task.task_namespace))
has_namespaces_with_finished_running_tasks_cv_.Signal();
}
} // namespace cc
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