Track webcore worker message loops in chromium.

webkit/glue/worker_task_runner.cc

+// Copyright (c) 2011 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/callback.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+#include "webkit/glue/worker_task_runner.h"
+
+using WebKit::WebWorkerRunLoop;
+
+namespace {
+
+class RunClosureTask : public WebWorkerRunLoop::Task {
+ public:
+  RunClosureTask(const base::Closure& task) : task_(task) {}
+  virtual ~RunClosureTask() {}
+  virtual void Run() {
+    task_.Run();
+  }
+ private:
+  base::Closure task_;
+};
+
+} // unnamed namespace
+
+namespace webkit_glue {
+
+struct WorkerTaskRunner::ThreadLocalState {
+  ThreadLocalState(int id, const WebWorkerRunLoop& loop)
+      : id_(id), run_loop_(loop) {
+  }
+  int id_;
+  WebWorkerRunLoop run_loop_;
+  ObserverList<WorkerTaskRunner::Observer> stop_observers_;
+};
+
+WorkerTaskRunner::WorkerTaskRunner() {
+  // Start worker ids at 1, 0 is reserved for the main thread.
+  int id = id_sequence_.GetNext();
+  DCHECK(!id);
+}
+
+void WorkerTaskRunner::PostTask(
+    int id, const base::Closure& closure) {
+  DCHECK(id > 0);
+  base::AutoLock locker(loop_map_lock_);
+  IDToLoopMap::iterator found = loop_map_.find(id);
+  if (found != loop_map_.end())
+    found->second.postTask(new RunClosureTask(closure));
+}
+
+int WorkerTaskRunner::CurrentWorkerId() {
+  if (!current_tls_.Get())
+    return 0;
+  return current_tls_.Get()->id_;
+}
+
+WorkerTaskRunner* WorkerTaskRunner::Instance() {
+  static base::LazyInstance<WorkerTaskRunner,
+      base::LeakyLazyInstanceTraits<WorkerTaskRunner> >
+          worker_task_runner = LAZY_INSTANCE_INITIALIZER;
+  return worker_task_runner.Pointer();
+}
+
+void WorkerTaskRunner::AddStopObserver(Observer* obs) {
+  DCHECK(CurrentWorkerId() > 0);
+  current_tls_.Get()->stop_observers_.AddObserver(obs);
+}
+
+void WorkerTaskRunner::RemoveStopObserver(Observer* obs) {
+  DCHECK(CurrentWorkerId() > 0);
+  current_tls_.Get()->stop_observers_.RemoveObserver(obs);
+}
+
+WorkerTaskRunner::~WorkerTaskRunner() {
+}
+
+void WorkerTaskRunner::OnWorkerRunLoopStarted(const WebWorkerRunLoop& loop) {
+  DCHECK(!current_tls_.Get());
+  int id = id_sequence_.GetNext();
+  current_tls_.Set(new ThreadLocalState(id, loop));
+
+  base::AutoLock locker_(loop_map_lock_);
+  loop_map_[id] = loop;
+}
+
+void WorkerTaskRunner::OnWorkerRunLoopStopped(const WebWorkerRunLoop& loop) {
+  DCHECK(current_tls_.Get());
+  FOR_EACH_OBSERVER(Observer, current_tls_.Get()->stop_observers_,
+                    OnWorkerRunLoopStopped());
+  {
+    base::AutoLock locker(loop_map_lock_);
+    DCHECK(loop_map_[CurrentWorkerId()] == loop);
+    loop_map_.erase(CurrentWorkerId());
+  }
+  delete current_tls_.Get();
+  current_tls_.Set(NULL);
+}
+
+}  // namespace webkit_glue