| /* |
| * Copyright (C) 2014 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef WaitableEvent_h |
| #define WaitableEvent_h |
| |
| #include "platform/PlatformExport.h" |
| #include "wtf/Vector.h" |
| #include <memory> |
| |
| namespace base { |
| class WaitableEvent; |
| }; // namespace base |
| |
| namespace blink { |
| |
| // Provides a thread synchronization that can be used to allow one thread to |
| // wait until another thread to finish some work. |
| class PLATFORM_EXPORT WaitableEvent { |
| public: |
| // If ResetPolicy::Manual is specified on creation, to set the event state |
| // to non-signaled, a consumer must call reset(). Otherwise, the system |
| // automatically resets the event state to non-signaled after a single |
| // waiting thread has been released. |
| enum class ResetPolicy { Auto, Manual }; |
| |
| // Specify the initial state on creation. |
| enum class InitialState { NonSignaled, Signaled }; |
| |
| explicit WaitableEvent(ResetPolicy = ResetPolicy::Auto, |
| InitialState = InitialState::NonSignaled); |
| |
| ~WaitableEvent(); |
| |
| // Puts the event in the un-signaled state. |
| void reset(); |
| |
| // Waits indefinitely for the event to be signaled. |
| void wait(); |
| |
| // Puts the event in the signaled state. Causing any thread blocked on Wait |
| // to be woken up. The event state is reset to non-signaled after |
| // a waiting thread has been released. |
| void signal(); |
| |
| // Waits on multiple events and returns the index of the object that |
| // has been signaled. Any event objects given to this method must |
| // not deleted while this wait is happening. |
| static size_t waitMultiple(const WTF::Vector<WaitableEvent*>& events); |
| |
| private: |
| WaitableEvent(const WaitableEvent&) = delete; |
| void operator=(const WaitableEvent&) = delete; |
| |
| std::unique_ptr<base::WaitableEvent> m_impl; |
| }; |
| |
| } // namespace blink |
| |
| #endif // WaitableEvent_h |