src/content/renderer/scheduler_proxy_task_runner.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_SCHEDULER_PROXY_TASK_RUNNER_H_
   6 #define CONTENT_RENDERER_SCHEDULER_PROXY_TASK_RUNNER_H_
   7
   8 #include "base/debug/task_annotator.h"
   9 #include "base/pending_task.h"
  10 #include "content/renderer/render_thread_impl.h"
  11 #include "third_party/WebKit/public/platform/WebSchedulerProxy.h"
  12 #include "third_party/WebKit/public/platform/WebTraceLocation.h"
  13
  14 namespace content {
  15
  16 // Helper for forwarding posted tasks into different WebSchedulerProxy queues.
  17 template <void (blink::WebSchedulerProxy::*ProxyFunction)(
  18     const blink::WebTraceLocation& location,
  19     blink::WebThread::Task* task)>
  20 class SchedulerProxyTaskRunner : public base::SingleThreadTaskRunner {
  21  public:
  22   SchedulerProxyTaskRunner()
  23       : main_thread_id_(base::PlatformThread::CurrentId()),
  24         scheduler_proxy_(blink::WebSchedulerProxy::create()),
  25         next_sequence_num_(0) {}
  26
  27   // base::SingleThreadTaskRunner implementation:
  28   virtual bool RunsTasksOnCurrentThread() const OVERRIDE {
  29     return base::PlatformThread::CurrentId() == main_thread_id_;
  30   }
  31
  32   virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
  33                                const base::Closure& task,
  34                                base::TimeDelta delay) OVERRIDE {
  35     DCHECK(delay == base::TimeDelta());
  36     base::PendingTask pending_task(from_here, task);
  37     pending_task.sequence_num = ++next_sequence_num_;
  38     task_annotator_.DidQueueTask("SchedulerProxyTaskRunner::PostDelayedTask",
  39                                  pending_task);
  40     blink::WebTraceLocation location(from_here.function_name(),
  41                                      from_here.file_name());
  42     TaskAdapter* task_adapter = new TaskAdapter(&task_annotator_, pending_task);
  43     (scheduler_proxy_.*ProxyFunction)(location, task_adapter);
  44     return true;
  45   }
  46
  47   virtual bool PostNonNestableDelayedTask(
  48       const tracked_objects::Location& from_here,
  49       const base::Closure& task,
  50       base::TimeDelta delay) OVERRIDE {
  51     NOTREACHED();
  52     return false;
  53   }
  54
  55  protected:
  56   virtual ~SchedulerProxyTaskRunner() {}
  57
  58  private:
  59   class TaskAdapter : public blink::WebThread::Task {
  60    public:
  61     explicit TaskAdapter(base::debug::TaskAnnotator* task_annotator,
  62                          const base::PendingTask& pending_task)
  63         : task_annotator_(task_annotator), pending_task_(pending_task) {}
  64     virtual ~TaskAdapter() {}
  65
  66     virtual void run() {
  67       task_annotator_->RunTask("SchedulerProxyTaskRunner::PostDelayedTask",
  68                                "SchedulerProxyTaskRunner::RunTask",
  69                                pending_task_);
  70     }
  71
  72    private:
  73     base::debug::TaskAnnotator* task_annotator_;
  74     base::PendingTask pending_task_;
  75   };
  76
  77   const base::PlatformThreadId main_thread_id_;
  78   blink::WebSchedulerProxy scheduler_proxy_;
  79   base::debug::TaskAnnotator task_annotator_;
  80   int next_sequence_num_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(SchedulerProxyTaskRunner);
  83 };
  84
  85 }  // namespace content
  86
  87 #endif  // CONTENT_RENDERER_SCHEDULER_PROXY_TASK_RUNNER_H_