darling-WTF/wtf/RAMSize.cpp
2018-01-05 13:44:16 -08:00

81 lines
2.4 KiB
C++

/*
* 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.
*/
#include "config.h"
#include "RAMSize.h"
#include "StdLibExtras.h"
#include <mutex>
#if OS(WINDOWS)
#include <windows.h>
#elif defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC
#if OS(UNIX)
#include <sys/sysinfo.h>
#endif // OS(UNIX)
#else
#include <bmalloc/bmalloc.h>
#endif
namespace WTF {
#if OS(WINDOWS)
static const size_t ramSizeGuess = 512 * MB;
#endif
static size_t computeRAMSize()
{
#if OS(WINDOWS)
MEMORYSTATUSEX status;
status.dwLength = sizeof(status);
bool result = GlobalMemoryStatusEx(&status);
if (!result)
return ramSizeGuess;
return status.ullTotalPhys;
#elif defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC
#if OS(UNIX)
struct sysinfo si;
sysinfo(&si);
return si.totalram * si.mem_unit;
#else
#error "Missing a platform specific way of determining the available RAM"
#endif // OS(UNIX)
#else
return bmalloc::api::availableMemory();
#endif
}
size_t ramSize()
{
static size_t ramSize;
static std::once_flag onceFlag;
std::call_once(onceFlag, [] {
ramSize = computeRAMSize();
});
return ramSize;
}
} // namespace WTF