1/*
2 * Copyright (C) 2012 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "RAMSize.h"
28
29#include "StdLibExtras.h"
30#if OS(DARWIN)
31#include <sys/param.h>
32#include <sys/types.h>
33#include <sys/sysctl.h>
34#elif OS(UNIX)
35#include <unistd.h>
36#elif OS(WINDOWS)
37#include <windows.h>
38#endif
39
40namespace WTF {
41
42static const size_t ramSizeGuess = 128 * MB;
43
44static size_t computeRAMSize()
45{
46#if OS(DARWIN)
47    int mib[2];
48    uint64_t ramSize;
49    size_t length;
50
51    mib[0] = CTL_HW;
52    mib[1] = HW_MEMSIZE;
53    length = sizeof(int64_t);
54    int sysctlResult = sysctl(mib, 2, &ramSize, &length, 0, 0);
55    if (sysctlResult == -1)
56        return ramSizeGuess;
57    return ramSize > std::numeric_limits<size_t>::max() ? std::numeric_limits<size_t>::max() : static_cast<size_t>(ramSize);
58#elif OS(UNIX)
59    long pages = sysconf(_SC_PHYS_PAGES);
60    long pageSize = sysconf(_SC_PAGE_SIZE);
61    if (pages == -1 || pageSize == -1)
62        return ramSizeGuess;
63    return pages * pageSize;
64#elif OS(WINCE)
65    MEMORYSTATUS status;
66    status.dwLength = sizeof(status);
67    GlobalMemoryStatus(&status);
68    if (status.dwTotalPhys <= 0)
69        return ramSizeGuess;
70    return status.dwTotalPhys;
71#elif OS(WINDOWS)
72    MEMORYSTATUSEX status;
73    status.dwLength = sizeof(status);
74    bool result = GlobalMemoryStatusEx(&status);
75    if (!result)
76        return ramSizeGuess;
77    return status.ullTotalPhys;
78#endif
79}
80
81size_t ramSize()
82{
83    static const size_t ramSize = computeRAMSize();
84    return ramSize;
85}
86
87} // namespace WTF
88