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      1 /**************************************************************************
      2  *
      3  * Copyright 2008-2010 VMware, Inc.
      4  * All Rights Reserved.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sub license, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice (including the
     15  * next paragraph) shall be included in all copies or substantial portions
     16  * of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
     21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
     22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
     23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
     24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  *
     26  **************************************************************************/
     27 
     28 /**
     29  * @file
     30  * OS independent time-manipulation functions.
     31  *
     32  * @author Jose Fonseca <jfonseca (at) vmware.com>
     33  */
     34 
     35 
     36 #include "pipe/p_defines.h"
     37 #include "util/u_atomic.h"
     38 
     39 #if defined(PIPE_OS_UNIX)
     40 #  include <time.h> /* timeval */
     41 #  include <sys/time.h> /* timeval */
     42 #  include <sched.h> /* sched_yield */
     43 #  include <errno.h>
     44 #elif defined(PIPE_SUBSYSTEM_WINDOWS_USER)
     45 #  include <windows.h>
     46 #else
     47 #  error Unsupported OS
     48 #endif
     49 
     50 #include "os_time.h"
     51 
     52 
     53 int64_t
     54 os_time_get_nano(void)
     55 {
     56 #if defined(PIPE_OS_LINUX)
     57 
     58    struct timespec tv;
     59    clock_gettime(CLOCK_MONOTONIC, &tv);
     60    return tv.tv_nsec + tv.tv_sec*INT64_C(1000000000);
     61 
     62 #elif defined(PIPE_OS_UNIX)
     63 
     64    struct timeval tv;
     65    gettimeofday(&tv, NULL);
     66    return tv.tv_usec*INT64_C(1000) + tv.tv_sec*INT64_C(1000000000);
     67 
     68 #elif defined(PIPE_SUBSYSTEM_WINDOWS_USER)
     69 
     70    static LARGE_INTEGER frequency;
     71    LARGE_INTEGER counter;
     72    if(!frequency.QuadPart)
     73       QueryPerformanceFrequency(&frequency);
     74    QueryPerformanceCounter(&counter);
     75    return counter.QuadPart*INT64_C(1000000000)/frequency.QuadPart;
     76 
     77 #else
     78 
     79 #error Unsupported OS
     80 
     81 #endif
     82 }
     83 
     84 
     85 
     86 void
     87 os_time_sleep(int64_t usecs)
     88 {
     89 #if defined(PIPE_OS_LINUX)
     90    struct timespec time;
     91    time.tv_sec = usecs / 1000000;
     92    time.tv_nsec = (usecs % 1000000) * 1000;
     93    while (clock_nanosleep(CLOCK_MONOTONIC, 0, &time, &time) == EINTR);
     94 
     95 #elif defined(PIPE_OS_UNIX)
     96    usleep(usecs);
     97 
     98 #elif defined(PIPE_SUBSYSTEM_WINDOWS_USER)
     99    DWORD dwMilliseconds = (DWORD) ((usecs + 999) / 1000);
    100    /* Avoid Sleep(O) as that would cause to sleep for an undetermined duration */
    101    if (dwMilliseconds) {
    102       Sleep(dwMilliseconds);
    103    }
    104 #else
    105 #  error Unsupported OS
    106 #endif
    107 }
    108 
    109 
    110 
    111 int64_t
    112 os_time_get_absolute_timeout(uint64_t timeout)
    113 {
    114    int64_t time, abs_timeout;
    115 
    116    /* Also check for the type upper bound. */
    117    if (timeout == PIPE_TIMEOUT_INFINITE || timeout > INT64_MAX)
    118       return PIPE_TIMEOUT_INFINITE;
    119 
    120    time = os_time_get_nano();
    121    abs_timeout = time + (int64_t)timeout;
    122 
    123    /* Check for overflow. */
    124    if (abs_timeout < time)
    125       return PIPE_TIMEOUT_INFINITE;
    126 
    127    return abs_timeout;
    128 }
    129 
    130 
    131 bool
    132 os_wait_until_zero(volatile int *var, uint64_t timeout)
    133 {
    134    if (!p_atomic_read(var))
    135       return true;
    136 
    137    if (!timeout)
    138       return false;
    139 
    140    if (timeout == PIPE_TIMEOUT_INFINITE) {
    141       while (p_atomic_read(var)) {
    142 #if defined(PIPE_OS_UNIX)
    143          sched_yield();
    144 #endif
    145       }
    146       return true;
    147    }
    148    else {
    149       int64_t start_time = os_time_get_nano();
    150       int64_t end_time = start_time + timeout;
    151 
    152       while (p_atomic_read(var)) {
    153          if (os_time_timeout(start_time, end_time, os_time_get_nano()))
    154             return false;
    155 
    156 #if defined(PIPE_OS_UNIX)
    157          sched_yield();
    158 #endif
    159       }
    160       return true;
    161    }
    162 }
    163 
    164 
    165 bool
    166 os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout)
    167 {
    168    if (!p_atomic_read(var))
    169       return true;
    170 
    171    if (timeout == PIPE_TIMEOUT_INFINITE)
    172       return os_wait_until_zero(var, PIPE_TIMEOUT_INFINITE);
    173 
    174    while (p_atomic_read(var)) {
    175       if (os_time_get_nano() >= timeout)
    176          return false;
    177 
    178 #if defined(PIPE_OS_UNIX)
    179       sched_yield();
    180 #endif
    181    }
    182    return true;
    183 }
    184