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/*
* Copyright (C) 2012 Apple 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 BlockingResponseMap_h
#define BlockingResponseMap_h
#include <wtf/Condition.h>
#include <wtf/HashMap.h>
#include <wtf/Lock.h>
#include <wtf/Noncopyable.h>
template<typename T>
class BlockingResponseMap {
WTF_MAKE_NONCOPYABLE(BlockingResponseMap);
public:
BlockingResponseMap() : m_canceled(false) { }
~BlockingResponseMap() { ASSERT(m_responses.isEmpty()); }
std::unique_ptr<T> waitForResponse(uint64_t requestID)
{
while (true) {
std::unique_lock<Lock> lock(m_mutex);
if (m_canceled)
return nullptr;
if (std::unique_ptr<T> response = m_responses.take(requestID))
return response;
m_condition.wait(lock);
}
return nullptr;
}
void didReceiveResponse(uint64_t requestID, std::unique_ptr<T> response)
{
std::lock_guard<Lock> lock(m_mutex);
ASSERT(!m_responses.contains(requestID));
m_responses.set(requestID, WTFMove(response));
// FIXME: Could get a slight speed-up from using notifyOne().
m_condition.notifyAll();
}
void cancel()
{
m_canceled = true;
// FIXME: Could get a slight speed-up from using notifyOne().
m_condition.notifyAll();
}
private:
Lock m_mutex;
Condition m_condition;
HashMap<uint64_t, std::unique_ptr<T>> m_responses;
bool m_canceled;
};
#endif // BlockingResponseMap_h
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