/*
 * Copyright (C) 2013 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:
 *
 * 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 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "sky/engine/core/dom/Microtask.h"

#include "base/bind.h"
#include "base/trace_event/trace_event.h"
#include "sky/engine/public/platform/WebThread.h"
#include "sky/engine/wtf/OwnPtr.h"
#include "sky/engine/wtf/Vector.h"

namespace blink {

namespace {

class Task : public WebThread::Task {
public:
    explicit Task(const base::Closure& closure)
        : m_closure(closure)
    {
    }

    virtual void run() override
    {
        m_closure.Run();
    }

private:
    base::Closure m_closure;
};

}

// TODO(dart): Integrate this microtask queue with darts.
typedef Vector<OwnPtr<WebThread::Task> > MicrotaskQueue;
static MicrotaskQueue& microtaskQueue()
{
    DEFINE_STATIC_LOCAL(OwnPtr<MicrotaskQueue>, queue, (adoptPtr(new MicrotaskQueue())));
    return *queue;
}

void Microtask::performCheckpoint()
{
    MicrotaskQueue& queue = microtaskQueue();
    while(!queue.isEmpty()) {
        TRACE_EVENT0("sky", "Microtask::performCheckpoint");

        MicrotaskQueue local;
        swap(queue, local);
        for (const auto& task : local)
            task->run();
    }
}

void Microtask::enqueueMicrotask(PassOwnPtr<WebThread::Task> callback)
{
    microtaskQueue().append(callback);
}

void Microtask::enqueueMicrotask(const base::Closure& callback)
{
    enqueueMicrotask(adoptPtr(new Task(callback)));
}

} // namespace blink