summaryrefslogtreecommitdiffstats
path: root/libdimension/platform.c
blob: e0de578760090d7b837095aea55405d65d815ca1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*************************************************************************
 * Copyright (C) 2010-2014 Tavian Barnes <tavianator@tavianator.com>     *
 *                                                                       *
 * This file is part of The Dimension Library.                           *
 *                                                                       *
 * The Dimension Library is free software; you can redistribute it and/  *
 * or modify it under the terms of the GNU Lesser General Public License *
 * as published by the Free Software Foundation; either version 3 of the *
 * License, or (at your option) any later version.                       *
 *                                                                       *
 * The Dimension Library is distributed in the hope that it will be      *
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
 * Lesser General Public License for more details.                       *
 *                                                                       *
 * You should have received a copy of the GNU Lesser General Public      *
 * License along with this program.  If not, see                         *
 * <http://www.gnu.org/licenses/>.                                       *
 *************************************************************************/

/**
 * @file
 * Platform abstractions.
 */

#define _GNU_SOURCE
#include "dimension-internal.h"

#if HAVE_UNISTD_H
  #include <unistd.h>
#endif
#ifdef _WIN32
  #include <windows.h>
#endif
#if DMNSN_BACKTRACE
  #include <execinfo.h>    // For backtrace() etc.
#endif
#if DMNSN_GETTID
  #include <sys/syscall.h> // For gettid() where supported
#endif
#if DMNSN_SCHED_GETAFFINITY
  #include <sched.h>       // For sched_getaffinity()
#endif
#if DMNSN_TIMES
  #include <sys/times.h>
#endif
#if DMNSN_GETRUSAGE
  #include <sys/time.h>
  #include <sys/resource.h>
#endif

void
dmnsn_backtrace(FILE *file)
{
#if DMNSN_BACKTRACE
  const size_t size = 128;
  void *buffer[size];

  int nptrs = backtrace(buffer, size);
  int fd = fileno(file);
  if (fd != -1) {
    backtrace_symbols_fd(buffer, nptrs, fd);
  }
#endif
}

bool
dmnsn_is_main_thread(void)
{
#if DMNSN_GETTID
  return getpid() == syscall(SYS_gettid);
#else
  return true;
#endif
}

bool
dmnsn_is_little_endian(void)
{
  // Undefined behaviour, but quite portable
  union {
    unsigned int i;
    unsigned char c;
  } u = { .i = 1 };
  return u.c == 1;
}

size_t
dmnsn_ncpus(void)
{
#if DMNSN_SCHED_GETAFFINITY
  cpu_set_t cpuset;
  if (sched_getaffinity(0, sizeof(cpuset), &cpuset) == 0) {
    return CPU_COUNT(&cpuset);
  } else {
    dmnsn_warning("sched_getaffinity() failed.");
    return 1;
  }
#elif DMNSN_SC_NPROCESSORS_ONLN
  long nprocs = sysconf(_SC_NPROCESSORS_ONLN);
  if (nprocs > 0) {
    return nprocs;
  } else {
    dmnsn_warning("sysconf(_SC_NPROCESSORS_ONLN) failed.");
    return 1;
  }
#elif defined(_WIN32)
  SYSTEM_INFO sysinfo;
  GetSystemInfo(&sysinfo);
  return sysinfo.dwNumberOfProcessors;
#else
  return 1;
#endif
}

#if DMNSN_GETRUSAGE
/// Convert a struct timeval to a double.
static inline double
dmnsn_timeval2double(struct timeval tv)
{
  return tv.tv_sec + tv.tv_usec/1.0e6;
}
#endif

void
dmnsn_get_times(dmnsn_timer *timer)
{
#if DMNSN_GETRUSAGE
  struct timeval real;
  gettimeofday(&real, NULL);

  struct rusage usage;
  if (getrusage(RUSAGE_SELF, &usage) == 0) {
    timer->real   = dmnsn_timeval2double(real);
    timer->user   = dmnsn_timeval2double(usage.ru_utime);
    timer->system = dmnsn_timeval2double(usage.ru_stime);
  } else {
    dmnsn_warning("getrusage() failed.");
    timer->real = timer->user = timer->system = 0.0;
  }
#elif DMNSN_TIMES
  static long clk_tck = 0;

  // Figure out the clock ticks per second
  if (!clk_tck) {
    clk_tck = sysconf(_SC_CLK_TCK);
    if (clk_tck == -1) {
      dmnsn_warning("sysconf(_SC_CLK_TCK) failed.");
      clk_tck = 1000000L;
    }
  }

  struct tms buf;
  clock_t real = times(&buf);
  if (real == (clock_t)-1) {
    dmnsn_warning("times() failed.");
    timer->real = timer->user = timer->system = 0.0;
  } else {
    timer->real   = (double)real/clk_tck;
    timer->user   = (double)buf.tms_utime/clk_tck;
    timer->system = (double)buf.tms_stime/clk_tck;
  }
#elif defined(_WIN32)
  FILETIME real;
  GetSystemTimeAsFileTime(&real);

  FILETIME user, system, creation, exit;
  HANDLE current_process = GetCurrentProcess();
  if (GetProcessTimes(current_process,
                      &creation, &exit, &system, &user) != 0)
  {
    timer->real
      = (((uint64_t)real.dwHighDateTime << 32) + real.dwLowDateTime)/1.0e7;
    timer->user
      = (((uint64_t)user.dwHighDateTime << 32) + user.dwLowDateTime)/1.0e7;
    timer->system
      = (((uint64_t)system.dwHighDateTime << 32) + system.dwLowDateTime)/1.0e7;
  } else {
    dmnsn_warning("GetProcessTimes() failed.");
    timer->real = timer->user = timer->system = 0.0;
  }
#else
  timer->real = timer->user = timer->system = 0.0;
#endif
}