code.delx.au - pulseaudio/blob - src/pulsecore/core-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 "core-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 / PA_NSEC_PER_USEC;
  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 <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
  86 #endif
  87
  88     pa_assert_se(clock_getres(CLOCK_REALTIME, &ts) == 0);
  89     return ts.tv_sec == 0 && ts.tv_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
  90
  91 #else /* HAVE_CLOCK_GETTIME */
  92
  93     return FALSE;
  94
  95 #endif
  96 }
  97
  98 #define TIMER_SLACK_NS (int) ((500 * PA_NSEC_PER_USEC))
  99
 100 void pa_rtclock_hrtimer_enable(void) {
 101 #ifdef PR_SET_TIMERSLACK
 102     int slack_ns;
 103
 104     if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
 105         pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
 106         return;
 107     }
 108
 109     pa_log_debug("Timer slack is set to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 110
 111     if (slack_ns > TIMER_SLACK_NS) {
 112         slack_ns = TIMER_SLACK_NS;
 113
 114         pa_log_debug("Setting timer slack to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 115
 116         if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
 117             pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
 118             return;
 119         }
 120     }
 121
 122 #endif
 123 }
 124
 125 struct timeval* pa_rtclock_from_wallclock(struct timeval *tv) {
 126
 127 #ifdef HAVE_CLOCK_GETTIME
 128     struct timeval wc_now, rt_now;
 129
 130     pa_gettimeofday(&wc_now);
 131     pa_rtclock_get(&rt_now);
 132
 133     pa_assert(tv);
 134
 135     if (pa_timeval_cmp(&wc_now, tv) < 0)
 136         pa_timeval_add(&rt_now, pa_timeval_diff(tv, &wc_now));
 137     else
 138         pa_timeval_sub(&rt_now, pa_timeval_diff(&wc_now, tv));
 139
 140     *tv = rt_now;
 141 #endif
 142
 143     return tv;
 144 }
 145
 146 pa_usec_t pa_timespec_load(const struct timespec *ts) {
 147     pa_assert(ts);
 148
 149     return
 150         (pa_usec_t) ts->tv_sec * PA_USEC_PER_SEC +
 151         (pa_usec_t) ts->tv_nsec / PA_NSEC_PER_USEC;
 152 }
 153
 154 struct timespec* pa_timespec_store(struct timespec *ts, pa_usec_t v) {
 155     pa_assert(ts);
 156
 157     if (PA_UNLIKELY(v == PA_USEC_INVALID)) {
 158         ts->tv_sec = PA_INT_TYPE_MAX(time_t);
 159         ts->tv_nsec = (long) (PA_NSEC_PER_SEC-1);
 160         return NULL;
 161     }
 162
 163     ts->tv_sec = (time_t) (v / PA_USEC_PER_SEC);
 164     ts->tv_nsec = (long) ((v % PA_USEC_PER_SEC) * PA_NSEC_PER_USEC);
 165
 166     return ts;
 167 }
 168
 169 static struct timeval* wallclock_from_rtclock(struct timeval *tv) {
 170
 171 #ifdef HAVE_CLOCK_GETTIME
 172     struct timeval wc_now, rt_now;
 173
 174     pa_gettimeofday(&wc_now);
 175     pa_rtclock_get(&rt_now);
 176
 177     pa_assert(tv);
 178
 179     if (pa_timeval_cmp(&rt_now, tv) < 0)
 180         pa_timeval_add(&wc_now, pa_timeval_diff(tv, &rt_now));
 181     else
 182         pa_timeval_sub(&wc_now, pa_timeval_diff(&rt_now, tv));
 183
 184     *tv = wc_now;
 185 #endif
 186
 187     return tv;
 188 }
 189
 190 struct timeval* pa_timeval_rtstore(struct timeval *tv, pa_usec_t v, pa_bool_t rtclock) {
 191     pa_assert(tv);
 192
 193     if (v == PA_USEC_INVALID)
 194         return NULL;
 195
 196     pa_timeval_store(tv, v);
 197
 198     if (rtclock)
 199         tv->tv_usec |= PA_TIMEVAL_RTCLOCK;
 200     else
 201         wallclock_from_rtclock(tv);
 202
 203     return tv;
 204 }