/*
 * Copyright (C) 2017 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.
 */

#include "config.h"
#include "RuntimeApplicationChecks.h"

#include <wtf/NeverDestroyed.h>
#include <wtf/Optional.h>
#include <wtf/ProcessID.h>
#include <wtf/RunLoop.h>

namespace WebCore {

#if !ASSERT_MSG_DISABLED
static bool presentingApplicationPIDOverrideWasQueried;
#endif

static Optional<int>& presentingApplicationPIDOverride()
{
    static NeverDestroyed<Optional<int>> pid;
#if !ASSERT_MSG_DISABLED
    presentingApplicationPIDOverrideWasQueried = true;
#endif
    return pid;
}

int presentingApplicationPID()
{
    const auto& pid = presentingApplicationPIDOverride();
    ASSERT(!pid || RunLoop::isMain());
    return pid ? pid.value() : getCurrentProcessID();
}

void setPresentingApplicationPID(int pid)
{
    ASSERT(RunLoop::isMain());
    ASSERT_WITH_MESSAGE(!presentingApplicationPIDOverrideWasQueried, "presentingApplicationPID() should not be called before setPresentingApplicationPID()");
    presentingApplicationPIDOverride() = pid;
}

} // namespace WebCore