Support Closure in ALL the loops!

base/threading/worker_pool_posix.h

 // 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.
 //
 // The thread pool used in the POSIX implementation of WorkerPool dynamically
 // adds threads as necessary to handle all tasks.  It keeps old threads around
 // for a period of time to allow them to be reused.  After this waiting period,
 // the threads exit.  This thread pool uses non-joinable threads, therefore
 // worker threads are not joined during process shutdown.  This means that
 // potentially long running tasks (such as DNS lookup) do not block process
@@ skipping 11 matching lines @@
 // These symbols are exported in a header purely for testing purposes.
 
 #ifndef BASE_THREADING_WORKER_POOL_POSIX_H_
 #define BASE_THREADING_WORKER_POOL_POSIX_H_
 #pragma once
 
 #include <queue>
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
+#include "base/tracked.h"
 
 class Task;
 
 namespace base {
 
 class BASE_API PosixDynamicThreadPool

[darin (slow to review), 2011/07/25 19:47:37]

note: this class name doesn't match the file name.  it seems like this should
live in files named posix_dynamic_thread_pool.{h,cc}

[awong, 2011/07/26 01:38:13]

Yeah...will touch that in another CL.

     : public RefCountedThreadSafe<PosixDynamicThreadPool> {
  public:
   class PosixDynamicThreadPoolPeer;
 
+  struct PendingTask {
+    PendingTask(const tracked_objects::Location& posted_from,
+                const base::Closure& task);
+    ~PendingTask();
+    // TODO(ajwong): After we figure out why Mac's ~AtExitManager dies when
+    // destructing the lock, add in extra info so we can call
+    // tracked_objects::TallyADeathIfActive() and
+    // tracked_objects::TallyABirthIfActive correctly.
+
+    // The task to run.
+    base::Closure task;
+  };
+
   // All worker threads will share the same |name_prefix|.  They will exit after
   // |idle_seconds_before_exit|.
   PosixDynamicThreadPool(const std::string& name_prefix,
                          int idle_seconds_before_exit);
   ~PosixDynamicThreadPool();
 
   // Indicates that the thread pool is going away.  Stops handing out tasks to
   // worker threads.  Wakes up all the idle threads to let them exit.
   void Terminate();
 
   // Adds |task| to the thread pool.  PosixDynamicThreadPool assumes ownership
   // of |task|.
-  void PostTask(Task* task);
+  //
+  // TODO(ajwong): Remove this compatibility API once the Task -> Closure
+  // migration is finished.
+  void PostTask(const tracked_objects::Location& from_here, Task* task);
 
+  // Adds |task| to the thread pool.
+  void PostTask(const tracked_objects::Location& from_here,
+                const base::Closure& task);
   // Worker thread method to wait for up to |idle_seconds_before_exit| for more

[darin (slow to review), 2011/07/25 19:47:37]

nit: add a new line above this comment.

[awong, 2011/07/26 01:38:13]

Done.

   // work from the thread pool.  Returns NULL if no work is available.
-  Task* WaitForTask();
+  PendingTask WaitForTask();
 
  private:
   friend class PosixDynamicThreadPoolPeer;
 
+  // Adds pending_task to the thread pool.  This function will clear
+  // |pending_task->task|.
+  void AddTask(PendingTask* pending_task);
+
   const std::string name_prefix_;
   const int idle_seconds_before_exit_;
 
   Lock lock_;  // Protects all the variables below.
 
   // Signal()s worker threads to let them know more tasks are available.
   // Also used for Broadcast()'ing to worker threads to let them know the pool
   // is being deleted and they can exit.
-  ConditionVariable tasks_available_cv_;
+  ConditionVariable pending_tasks_available_cv_;
   int num_idle_threads_;
-  std::queue<Task*> tasks_;
+  std::queue<PendingTask> pending_tasks_;
   bool terminated_;
   // Only used for tests to ensure correct thread ordering.  It will always be
   // NULL in non-test code.
   scoped_ptr<ConditionVariable> num_idle_threads_cv_;
 
   DISALLOW_COPY_AND_ASSIGN(PosixDynamicThreadPool);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_WORKER_POOL_POSIX_H_