cc/trees/blocking_task_runner.cc

   1 // Copyright 2013 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 #include "cc/trees/blocking_task_runner.h"
   6
   7 #include <utility>
   8
   9 #include "base/callback.h"
  10 #include "base/logging.h"
  11
  12 namespace cc {
  13
  14 // static
  15 scoped_ptr<BlockingTaskRunner> BlockingTaskRunner::Create(
  16     scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
  17   return make_scoped_ptr(new BlockingTaskRunner(task_runner));
  18 }
  19
  20 BlockingTaskRunner::BlockingTaskRunner(
  21     scoped_refptr<base::SingleThreadTaskRunner> task_runner)
  22     : thread_id_(base::PlatformThread::CurrentId()),
  23       task_runner_(task_runner),
  24       capture_(0) {
  25 }
  26
  27 BlockingTaskRunner::~BlockingTaskRunner() {}
  28
  29 bool BlockingTaskRunner::BelongsToCurrentThread() {
  30   return base::PlatformThread::CurrentId() == thread_id_;
  31 }
  32
  33 bool BlockingTaskRunner::PostTask(const tracked_objects::Location& from_here,
  34                                   const base::Closure& task) {
  35   base::AutoLock lock(lock_);
  36   DCHECK(task_runner_.get() || capture_);
  37   if (!capture_)
  38     return task_runner_->PostTask(from_here, task);
  39   captured_tasks_.push_back(task);
  40   return true;
  41 }
  42
  43 void BlockingTaskRunner::SetCapture(bool capture) {
  44   DCHECK(BelongsToCurrentThread());
  45
  46   std::vector<base::Closure> tasks;
  47
  48   {
  49     base::AutoLock lock(lock_);
  50     capture_ += capture ? 1 : -1;
  51     DCHECK_GE(capture_, 0);
  52
  53     if (capture_)
  54       return;
  55
  56     // We're done capturing, so grab all the captured tasks and run them.
  57     tasks.swap(captured_tasks_);
  58   }
  59   for (size_t i = 0; i < tasks.size(); ++i)
  60     tasks[i].Run();
  61 }
  62
  63 BlockingTaskRunner::CapturePostTasks::CapturePostTasks(
  64     BlockingTaskRunner* blocking_runner)
  65     : blocking_runner_(blocking_runner) {
  66   blocking_runner_->SetCapture(true);
  67 }
  68
  69 BlockingTaskRunner::CapturePostTasks::~CapturePostTasks() {
  70   blocking_runner_->SetCapture(false);
  71 }
  72
  73 }  // namespace cc