/*
 * Copyright (C) 2007, 2008, 2013 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE 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 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;
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "platform/TaskSynchronizer.h"

#include "platform/heap/SafePoint.h"
#include "platform/heap/ThreadState.h"

namespace blink {

TaskSynchronizer::TaskSynchronizer()
    : m_taskCompleted(false)
{
}

void TaskSynchronizer::waitForTaskCompletion()
{
    if (ThreadState::current()) {
        // Prevent the deadlock between park request by other threads and blocking
        // by m_synchronousCondition.
        SafePointScope scope(BlinkGC::HeapPointersOnStack);
        waitForTaskCompletionInternal();
    } else {
        // If this thread is already detached, we no longer need to enter a safe point scope.
        waitForTaskCompletionInternal();
    }
}

void TaskSynchronizer::waitForTaskCompletionInternal()
{
    m_synchronousMutex.lock();
    while (!m_taskCompleted)
        m_synchronousCondition.wait(m_synchronousMutex);
    m_synchronousMutex.unlock();
}

void TaskSynchronizer::taskCompleted()
{
    m_synchronousMutex.lock();
    m_taskCompleted = true;
    m_synchronousCondition.signal();
    m_synchronousMutex.unlock();
}

} // namespace blink