Source/WebCore/platform/ios/SystemMemoryIOS.cpp

/*
 * Copyright (C) 2008 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 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;
 * 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 "SystemMemory.h"

#if PLATFORM(IOS_FAMILY)

#include <sys/sysctl.h>
#include <wtf/Assertions.h>
#include <wtf/WallTime.h>

namespace WebCore {

int systemMemoryLevel()
{
#if PLATFORM(IOS_FAMILY_SIMULATOR)
    return 35;
#else
    static int memoryFreeLevel = -1;
    static WallTime previousCheckTime;
    WallTime time = WallTime::now();
    if (time - previousCheckTime < 100_ms)
        return memoryFreeLevel;
    previousCheckTime = time;
    size_t size = sizeof(memoryFreeLevel);
    sysctlbyname("kern.memorystatus_level", &memoryFreeLevel, &size, nullptr, 0);
    return memoryFreeLevel;
#endif
}

} // namespace WebCore

#endif // PLATFORM(IOS_FAMILY)