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 <sys/prctl.h>
  31 #include <errno.h>
  32
  33 #include <pulse/timeval.h>
  34 #include <pulsecore/macro.h>
  35 #include <pulsecore/core-error.h>
  36
  37 #include "rtclock.h"
  38
  39 pa_usec_t pa_rtclock_age(const struct timeval *tv) {
  40     struct timeval now;
  41     pa_assert(tv);
  42
  43     return pa_timeval_diff(pa_rtclock_get(&now), tv);
  44 }
  45
  46 struct timeval *pa_rtclock_get(struct timeval *tv) {
  47 #ifdef HAVE_CLOCK_GETTIME
  48     struct timespec ts;
  49
  50 #ifdef CLOCK_MONOTONIC
  51     /* No locking or atomic ops for no_monotonic here */
  52     static pa_bool_t no_monotonic = FALSE;
  53
  54     if (!no_monotonic)
  55         if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
  56             no_monotonic = TRUE;
  57
  58     if (no_monotonic)
  59 #endif
  60         pa_assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
  61
  62     pa_assert(tv);
  63
  64     tv->tv_sec = ts.tv_sec;
  65     tv->tv_usec = ts.tv_nsec / 1000;
  66
  67     return tv;
  68
  69 #else /* HAVE_CLOCK_GETTIME */
  70
  71     return pa_gettimeofday(tv);
  72
  73 #endif
  74 }
  75
  76 pa_bool_t pa_rtclock_hrtimer(void) {
  77 #ifdef HAVE_CLOCK_GETTIME
  78     struct timespec ts;
  79
  80 #ifdef CLOCK_MONOTONIC
  81     if (clock_getres(CLOCK_MONOTONIC, &ts) >= 0)
  82         return ts.tv_sec == 0 && ts.tv_nsec <= PA_HRTIMER_THRESHOLD_USEC*1000;
  83 #endif
  84
  85     pa_assert_se(clock_getres(CLOCK_REALTIME, &ts) == 0);
  86     return ts.tv_sec == 0 && ts.tv_nsec <= PA_HRTIMER_THRESHOLD_USEC*1000;
  87
  88 #else /* HAVE_CLOCK_GETTIME */
  89
  90     return FALSE;
  91
  92 #endif
  93 }
  94
  95 void pa_rtclock_hrtimer_enable(void) {
  96 #ifdef PR_SET_TIMERSLACK
  97     int slack_ns;
  98
  99     if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
 100         pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
 101         return;
 102     }
 103
 104     pa_log_debug("Timer slack set to %i us.", slack_ns/1000);
 105
 106     slack_ns = 500000000;
 107
 108     pa_log_debug("Setting timer slack to %i us.", slack_ns/1000);
 109
 110     if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
 111         pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
 112         return;
 113     }
 114
 115 #endif
 116 }
 117
 118 pa_usec_t pa_rtclock_usec(void) {
 119     struct timeval tv;
 120
 121     return pa_timeval_load(pa_rtclock_get(&tv));
 122 }
 123
 124 struct timeval* pa_rtclock_from_wallclock(struct timeval *tv) {
 125
 126 #ifdef HAVE_CLOCK_GETTIME
 127     struct timeval wc_now, rt_now;
 128
 129     pa_gettimeofday(&wc_now);
 130     pa_rtclock_get(&rt_now);
 131
 132     pa_assert(tv);
 133
 134     if (pa_timeval_cmp(&wc_now, tv) < 0)
 135         pa_timeval_add(&rt_now, pa_timeval_diff(tv, &wc_now));
 136     else
 137         pa_timeval_sub(&rt_now, pa_timeval_diff(&wc_now, tv));
 138
 139     *tv = rt_now;
 140 #endif
 141
 142     return tv;
 143 }
 144
 145 pa_usec_t pa_timespec_load(const struct timespec *ts) {
 146     pa_assert(ts);
 147
 148     return
 149         (pa_usec_t) ts->tv_sec * PA_USEC_PER_SEC +
 150         (pa_usec_t) ts->tv_nsec / PA_NSEC_PER_USEC;
 151 }