code.delx.au - pulseaudio/blob - src/pulsecore/rtclock.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as
   9   published by the Free Software Foundation; either version 2.1 of the
  10   License, or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stddef.h>
  28 #include <time.h>
  29 #include <sys/time.h>
  30 #include <errno.h>
  31
  32 #ifdef HAVE_SYS_PRCTL_H
  33 #include <sys/prctl.h>
  34 #endif
  35
  36 #include <pulse/timeval.h>
  37 #include <pulsecore/macro.h>
  38 #include <pulsecore/core-error.h>
  39
  40 #include "rtclock.h"
  41
  42 pa_usec_t pa_rtclock_age(const struct timeval *tv) {
  43     struct timeval now;
  44     pa_assert(tv);
  45
  46     return pa_timeval_diff(pa_rtclock_get(&now), tv);
  47 }
  48
  49 struct timeval *pa_rtclock_get(struct timeval *tv) {
  50 #ifdef HAVE_CLOCK_GETTIME
  51     struct timespec ts;
  52
  53 #ifdef CLOCK_MONOTONIC
  54     /* No locking or atomic ops for no_monotonic here */
  55     static pa_bool_t no_monotonic = FALSE;
  56
  57     if (!no_monotonic)
  58         if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
  59             no_monotonic = TRUE;
  60
  61     if (no_monotonic)
  62 #endif
  63         pa_assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
  64
  65     pa_assert(tv);
  66
  67     tv->tv_sec = ts.tv_sec;
  68     tv->tv_usec = ts.tv_nsec / 1000;
  69
  70     return tv;
  71
  72 #else /* HAVE_CLOCK_GETTIME */
  73
  74     return pa_gettimeofday(tv);
  75
  76 #endif
  77 }
  78
  79 pa_bool_t pa_rtclock_hrtimer(void) {
  80 #ifdef HAVE_CLOCK_GETTIME
  81     struct timespec ts;
  82
  83 #ifdef CLOCK_MONOTONIC
  84     if (clock_getres(CLOCK_MONOTONIC, &ts) >= 0)
  85         return ts.tv_sec == 0 && ts.tv_nsec <= PA_HRTIMER_THRESHOLD_USEC*1000;
  86 #endif
  87
  88     pa_assert_se(clock_getres(CLOCK_REALTIME, &ts) == 0);
  89     return ts.tv_sec == 0 && ts.tv_nsec <= PA_HRTIMER_THRESHOLD_USEC*1000;
  90
  91 #else /* HAVE_CLOCK_GETTIME */
  92
  93     return FALSE;
  94
  95 #endif
  96 }
  97
  98 void pa_rtclock_hrtimer_enable(void) {
  99 #ifdef PR_SET_TIMERSLACK
 100     int slack_ns;
 101
 102     if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
 103         pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
 104         return;
 105     }
 106
 107     pa_log_debug("Timer slack set to %i us.", slack_ns/1000);
 108
 109     slack_ns = 500000000;
 110
 111     pa_log_debug("Setting timer slack to %i us.", slack_ns/1000);
 112
 113     if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
 114         pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
 115         return;
 116     }
 117
 118 #endif
 119 }
 120
 121 pa_usec_t pa_rtclock_usec(void) {
 122     struct timeval tv;
 123
 124     return pa_timeval_load(pa_rtclock_get(&tv));
 125 }
 126
 127 struct timeval* pa_rtclock_from_wallclock(struct timeval *tv) {
 128
 129 #ifdef HAVE_CLOCK_GETTIME
 130     struct timeval wc_now, rt_now;
 131
 132     pa_gettimeofday(&wc_now);
 133     pa_rtclock_get(&rt_now);
 134
 135     pa_assert(tv);
 136
 137     if (pa_timeval_cmp(&wc_now, tv) < 0)
 138         pa_timeval_add(&rt_now, pa_timeval_diff(tv, &wc_now));
 139     else
 140         pa_timeval_sub(&rt_now, pa_timeval_diff(&wc_now, tv));
 141
 142     *tv = rt_now;
 143 #endif
 144
 145     return tv;
 146 }
 147
 148 pa_usec_t pa_timespec_load(const struct timespec *ts) {
 149     pa_assert(ts);
 150
 151     return
 152         (pa_usec_t) ts->tv_sec * PA_USEC_PER_SEC +
 153         (pa_usec_t) ts->tv_nsec / PA_NSEC_PER_USEC;
 154 }