Implementation of SequencedTaskRunner based on SequencedWorkerPool.

base/test/sequenced_worker_pool_owner.h

+// Copyright (c) 2012 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.
+
+#ifndef BASE_THREADING_SEQUENCED_WORKER_POOL_UNITTEST_H_
+#define BASE_THREADING_SEQUENCED_WORKER_POOL_UNITTEST_H_
+
+#include <cstddef>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/sequenced_worker_pool.h"
+
+class MessageLoop;
+
+namespace base {
+
+// Wrapper around SequencedWorkerPool for testing that blocks destruction
+// until the pool is actually destroyed.  This is so that a
+// SequencedWorkerPool from one test doesn't outlive its test and cause
+// strange races with other tests that touch global stuff (like histograms and
+// logging).  However, this requires that nothing else on this thread holds a
+// ref to the pool when the SequencedWorkerPoolOwner is destroyed.
+class SequencedWorkerPoolOwner : public SequencedWorkerPool::TestingObserver {
+ public:
+  SequencedWorkerPoolOwner(size_t max_threads,
+                           const std::string& thread_name_prefix);
+
+  virtual ~SequencedWorkerPoolOwner();
+
+  // Don't change the returned pool's testing observer.
+  const scoped_refptr<SequencedWorkerPool>& pool();
+
+  // The given callback will be called on WillWaitForShutdown().
+  void SetWillWaitForShutdownCallback(const Closure& callback);
+
+  int has_work_call_count() const;
+
+ private:
+  // SequencedWorkerPool::TestingObserver implementation.
+  virtual void OnHasWork() OVERRIDE;
+  virtual void WillWaitForShutdown() OVERRIDE;
+  virtual void OnDestruct() OVERRIDE;
+
+  MessageLoop* const constructor_message_loop_;
+  scoped_refptr<SequencedWorkerPool> pool_;
+  Closure will_wait_for_shutdown_callback_;
+
+  mutable Lock has_work_lock_;
+  int has_work_call_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(SequencedWorkerPoolOwner);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_SEQUENCED_WORKER_POOL_UNITTEST_H_