src/util/os_time.c

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  27
  28 /**
  29  * @file
  30  * OS independent time-manipulation functions.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  */
  34
  35 #include "os_time.h"
  36
  37 /* TODO: fix this dependency */
  38 #include "gallium/include/pipe/p_config.h"
  39
  40 #include "util/u_atomic.h"
  41
  42 #if defined(PIPE_OS_UNIX)
  43 #  include <unistd.h> /* usleep */
  44 #  include <time.h> /* timeval */
  45 #  include <sys/time.h> /* timeval */
  46 #  include <sched.h> /* sched_yield */
  47 #  include <errno.h>
  48 #elif DETECT_OS_WINDOWS
  49 #  include <windows.h>
  50 #else
  51 #  error Unsupported OS
  52 #endif
  53
  54
  55 int64_t
  56 os_time_get_nano(void)
  57 {
  58 #if defined(PIPE_OS_LINUX) || defined(PIPE_OS_BSD)
  59
  60    struct timespec tv;
  61    clock_gettime(CLOCK_MONOTONIC, &tv);
  62    return tv.tv_nsec + tv.tv_sec*INT64_C(1000000000);
  63
  64 #elif defined(PIPE_OS_UNIX)
  65
  66    struct timeval tv;
  67    gettimeofday(&tv, NULL);
  68    return tv.tv_usec*INT64_C(1000) + tv.tv_sec*INT64_C(1000000000);
  69
  70 #elif DETECT_OS_WINDOWS
  71
  72    static LARGE_INTEGER frequency;
  73    LARGE_INTEGER counter;
  74    int64_t secs, nanosecs;
  75    if(!frequency.QuadPart)
  76       QueryPerformanceFrequency(&frequency);
  77    QueryPerformanceCounter(&counter);
  78    /* Compute seconds and nanoseconds parts separately to
  79     * reduce severity of precision loss.
  80     */
  81    secs = counter.QuadPart / frequency.QuadPart;
  82    nanosecs = (counter.QuadPart % frequency.QuadPart) * INT64_C(1000000000)
  83       / frequency.QuadPart;
  84    return secs*INT64_C(1000000000) + nanosecs;
  85
  86 #else
  87
  88 #error Unsupported OS
  89
  90 #endif
  91 }
  92
  93
  94
  95 void
  96 os_time_sleep(int64_t usecs)
  97 {
  98 #if defined(PIPE_OS_LINUX)
  99    struct timespec time;
 100    time.tv_sec = usecs / 1000000;
 101    time.tv_nsec = (usecs % 1000000) * 1000;
 102    while (clock_nanosleep(CLOCK_MONOTONIC, 0, &time, &time) == EINTR);
 103
 104 #elif defined(PIPE_OS_UNIX)
 105    usleep(usecs);
 106
 107 #elif DETECT_OS_WINDOWS
 108    DWORD dwMilliseconds = (DWORD) ((usecs + 999) / 1000);
 109    /* Avoid Sleep(O) as that would cause to sleep for an undetermined duration */
 110    if (dwMilliseconds) {
 111       Sleep(dwMilliseconds);
 112    }
 113 #else
 114 #  error Unsupported OS
 115 #endif
 116 }
 117
 118
 119
 120 int64_t
 121 os_time_get_absolute_timeout(uint64_t timeout)
 122 {
 123    int64_t time, abs_timeout;
 124
 125    /* Also check for the type upper bound. */
 126    if (timeout == OS_TIMEOUT_INFINITE || timeout > INT64_MAX)
 127       return OS_TIMEOUT_INFINITE;
 128
 129    time = os_time_get_nano();
 130    abs_timeout = time + (int64_t)timeout;
 131
 132    /* Check for overflow. */
 133    if (abs_timeout < time)
 134       return OS_TIMEOUT_INFINITE;
 135
 136    return abs_timeout;
 137 }
 138
 139
 140 bool
 141 os_wait_until_zero(volatile int *var, uint64_t timeout)
 142 {
 143    if (!p_atomic_read(var))
 144       return true;
 145
 146    if (!timeout)
 147       return false;
 148
 149    if (timeout == OS_TIMEOUT_INFINITE) {
 150       while (p_atomic_read(var)) {
 151 #if defined(PIPE_OS_UNIX)
 152          sched_yield();
 153 #endif
 154       }
 155       return true;
 156    }
 157    else {
 158       int64_t start_time = os_time_get_nano();
 159       int64_t end_time = start_time + timeout;
 160
 161       while (p_atomic_read(var)) {
 162          if (os_time_timeout(start_time, end_time, os_time_get_nano()))
 163             return false;
 164
 165 #if defined(PIPE_OS_UNIX)
 166          sched_yield();
 167 #endif
 168       }
 169       return true;
 170    }
 171 }
 172
 173
 174 bool
 175 os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout)
 176 {
 177    if (!p_atomic_read(var))
 178       return true;
 179
 180    if (timeout == OS_TIMEOUT_INFINITE)
 181       return os_wait_until_zero(var, OS_TIMEOUT_INFINITE);
 182
 183    while (p_atomic_read(var)) {
 184       if (os_time_get_nano() >= timeout)
 185          return false;
 186
 187 #if defined(PIPE_OS_UNIX)
 188       sched_yield();
 189 #endif
 190    }
 191    return true;
 192 }