src/webkit/child/worker_task_runner.cc

   1 // Copyright (c) 2012 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 "base/callback.h"
   6 #include "base/lazy_instance.h"
   7 #include "base/logging.h"
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/observer_list.h"
  10 #include "webkit/child/worker_task_runner.h"
  11
  12 using WebKit::WebWorkerRunLoop;
  13
  14 namespace {
  15
  16 class RunClosureTask : public WebWorkerRunLoop::Task {
  17  public:
  18   RunClosureTask(const base::Closure& task) : task_(task) {}
  19   virtual ~RunClosureTask() {}
  20   virtual void Run() {
  21     task_.Run();
  22   }
  23  private:
  24   base::Closure task_;
  25 };
  26
  27 } // unnamed namespace
  28
  29 namespace webkit_glue {
  30
  31 struct WorkerTaskRunner::ThreadLocalState {
  32   ThreadLocalState(int id, const WebWorkerRunLoop& loop)
  33       : id_(id), run_loop_(loop) {
  34   }
  35   int id_;
  36   WebWorkerRunLoop run_loop_;
  37   ObserverList<WorkerTaskRunner::Observer> stop_observers_;
  38 };
  39
  40 WorkerTaskRunner::WorkerTaskRunner() {
  41   // Start worker ids at 1, 0 is reserved for the main thread.
  42   int id = id_sequence_.GetNext();
  43   DCHECK(!id);
  44 }
  45
  46 bool WorkerTaskRunner::PostTask(
  47     int id, const base::Closure& closure) {
  48   DCHECK(id > 0);
  49   base::AutoLock locker(loop_map_lock_);
  50   IDToLoopMap::iterator found = loop_map_.find(id);
  51   if (found == loop_map_.end())
  52     return false;
  53   return found->second.postTask(new RunClosureTask(closure));
  54 }
  55
  56 int WorkerTaskRunner::PostTaskToAllThreads(const base::Closure& closure) {
  57   base::AutoLock locker(loop_map_lock_);
  58   IDToLoopMap::iterator it;
  59   for (it = loop_map_.begin(); it != loop_map_.end(); ++it)
  60     it->second.postTask(new RunClosureTask(closure));
  61   return static_cast<int>(loop_map_.size());
  62 }
  63
  64 int WorkerTaskRunner::CurrentWorkerId() {
  65   if (!current_tls_.Get())
  66     return 0;
  67   return current_tls_.Get()->id_;
  68 }
  69
  70 WorkerTaskRunner* WorkerTaskRunner::Instance() {
  71   static base::LazyInstance<WorkerTaskRunner>::Leaky
  72       worker_task_runner = LAZY_INSTANCE_INITIALIZER;
  73   return worker_task_runner.Pointer();
  74 }
  75
  76 void WorkerTaskRunner::AddStopObserver(Observer* obs) {
  77   DCHECK(CurrentWorkerId() > 0);
  78   current_tls_.Get()->stop_observers_.AddObserver(obs);
  79 }
  80
  81 void WorkerTaskRunner::RemoveStopObserver(Observer* obs) {
  82   DCHECK(CurrentWorkerId() > 0);
  83   current_tls_.Get()->stop_observers_.RemoveObserver(obs);
  84 }
  85
  86 WorkerTaskRunner::~WorkerTaskRunner() {
  87 }
  88
  89 void WorkerTaskRunner::OnWorkerRunLoopStarted(const WebWorkerRunLoop& loop) {
  90   DCHECK(!current_tls_.Get());
  91   int id = id_sequence_.GetNext();
  92   current_tls_.Set(new ThreadLocalState(id, loop));
  93
  94   base::AutoLock locker_(loop_map_lock_);
  95   loop_map_[id] = loop;
  96 }
  97
  98 void WorkerTaskRunner::OnWorkerRunLoopStopped(const WebWorkerRunLoop& loop) {
  99   DCHECK(current_tls_.Get());
 100   FOR_EACH_OBSERVER(Observer, current_tls_.Get()->stop_observers_,
 101                     OnWorkerRunLoopStopped());
 102   {
 103     base::AutoLock locker(loop_map_lock_);
 104     DCHECK(loop_map_[CurrentWorkerId()] == loop);
 105     loop_map_.erase(CurrentWorkerId());
 106   }
 107   delete current_tls_.Get();
 108   current_tls_.Set(NULL);
 109 }
 110
 111 }  // namespace webkit_glue