1/*
2 * Copyright (C) 2012 University of Szeged. 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 UNIVERSITY OF SZEGED ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include <wtf/NumberOfCores.h>
28
29#include <cstdio>
30
31#if OS(DARWIN)
32#include <sys/param.h>
33// sys/types.h must come before sys/sysctl.h because the latter uses
34// data types defined in the former. See sysctl(3) and style(9).
35#include <sys/types.h>
36#include <sys/sysctl.h>
37#elif OS(LINUX) || OS(AIX) || OS(OPENBSD) || OS(NETBSD) || OS(FREEBSD)
38#include <unistd.h>
39#elif OS(WINDOWS)
40#include <windows.h>
41#endif
42
43namespace WTF {
44
45int numberOfProcessorCores()
46{
47 const int defaultIfUnavailable = 1;
48 static int s_numberOfCores = -1;
49
50 if (s_numberOfCores > 0)
51 return s_numberOfCores;
52
53 if (const char* coresEnv = getenv("WTF_numberOfProcessorCores")) {
54 unsigned numberOfCores;
55 if (sscanf(coresEnv, "%u", &numberOfCores) == 1) {
56 s_numberOfCores = numberOfCores;
57 return s_numberOfCores;
58 } else
59 fprintf(stderr, "WARNING: failed to parse WTF_numberOfProcessorCores=%s\n", coresEnv);
60 }
61
62#if OS(DARWIN)
63 unsigned result;
64 size_t length = sizeof(result);
65 int name[] = {
66 CTL_HW,
67 HW_AVAILCPU
68 };
69 int sysctlResult = sysctl(name, sizeof(name) / sizeof(int), &result, &length, 0, 0);
70
71 s_numberOfCores = sysctlResult < 0 ? defaultIfUnavailable : result;
72#elif OS(LINUX) || OS(AIX) || OS(OPENBSD) || OS(NETBSD) || OS(FREEBSD)
73 long sysconfResult = sysconf(_SC_NPROCESSORS_ONLN);
74
75 s_numberOfCores = sysconfResult < 0 ? defaultIfUnavailable : static_cast<int>(sysconfResult);
76#elif OS(WINDOWS)
77 UNUSED_PARAM(defaultIfUnavailable);
78 SYSTEM_INFO sysInfo;
79 GetSystemInfo(&sysInfo);
80
81 s_numberOfCores = sysInfo.dwNumberOfProcessors;
82#else
83 s_numberOfCores = defaultIfUnavailable;
84#endif
85 return s_numberOfCores;
86}
87
88}
89