Part 1 of cc/ directory shuffles: base

cc/completion_event.h

-// Copyright 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.
-
-#ifndef CC_COMPLETION_EVENT_H_
-#define CC_COMPLETION_EVENT_H_
-
-#include "base/synchronization/waitable_event.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/logging.h"
-
-namespace cc {
-
-// Used for making blocking calls from one thread to another. Use only when
-// absolutely certain that doing-so will not lead to a deadlock.
-//
-// It is safe to destroy this object as soon as wait() returns.
-class CompletionEvent {
-public:
-    CompletionEvent()
-        : m_event(false /* manual_reset */, false /* initially_signaled */)
-    {
-#ifndef NDEBUG
-        m_waited = false;
-        m_signaled = false;
-#endif
-    }
-
-    ~CompletionEvent()
-    {
-#ifndef NDEBUG
-        DCHECK(m_waited);
-        DCHECK(m_signaled);
-#endif
-    }
-
-    void wait()
-    {
-#ifndef NDEBUG
-        DCHECK(!m_waited);
-        m_waited = true;
-#endif
-        base::ThreadRestrictions::ScopedAllowWait allow_wait;
-        m_event.Wait();
-    }
-
-    void signal()
-    {
-#ifndef NDEBUG
-        DCHECK(!m_signaled);
-        m_signaled = true;
-#endif
-        m_event.Signal();
-    }
-
-private:
-    base::WaitableEvent m_event;
-#ifndef NDEBUG
-    // Used to assert that wait() and signal() are each called exactly once.
-    bool m_waited;
-    bool m_signaled;
-#endif
-};
-
-}
-
-#endif  // CC_COMPLETION_EVENT_H_