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 #ifdef OS_IS_DARWIN
  37 #include <CoreServices/CoreServices.h>
  38 #include <mach/mach.h>
  39 #include <mach/mach_time.h>
  40 #include <unistd.h>
  41 #endif
  42
  43 #ifdef HAVE_WINDOWS_H
  44 #include <windows.h>
  45 #endif
  46
  47 #include <pulse/timeval.h>
  48 #include <pulsecore/macro.h>
  49 #include <pulsecore/core-error.h>
  50
  51 #include "core-rtclock.h"
  52
  53 #ifdef OS_IS_WIN32
  54 static int64_t counter_freq = 0;
  55 #endif
  56
  57 pa_usec_t pa_rtclock_age(const struct timeval *tv) {
  58     struct timeval now;
  59     pa_assert(tv);
  60
  61     return pa_timeval_diff(pa_rtclock_get(&now), tv);
  62 }
  63
  64 struct timeval *pa_rtclock_get(struct timeval *tv) {
  65
  66 #if defined(OS_IS_DARWIN)
  67     uint64_t val, abs_time = mach_absolute_time();
  68     Nanoseconds nanos;
  69
  70     nanos = AbsoluteToNanoseconds(*(AbsoluteTime *) &abs_time);
  71     val = *(uint64_t *) &nanos;
  72
  73     tv->tv_sec = val / PA_NSEC_PER_SEC;
  74     tv->tv_usec = (val % PA_NSEC_PER_SEC) / PA_NSEC_PER_USEC;
  75
  76     return tv;
  77
  78 #elif defined(HAVE_CLOCK_GETTIME)
  79     struct timespec ts;
  80
  81 #ifdef CLOCK_MONOTONIC
  82     /* No locking or atomic ops for no_monotonic here */
  83     static pa_bool_t no_monotonic = FALSE;
  84
  85     if (!no_monotonic)
  86         if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
  87             no_monotonic = TRUE;
  88
  89     if (no_monotonic)
  90 #endif /* CLOCK_MONOTONIC */
  91         pa_assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
  92
  93     pa_assert(tv);
  94
  95     tv->tv_sec = ts.tv_sec;
  96     tv->tv_usec = ts.tv_nsec / PA_NSEC_PER_USEC;
  97
  98     return tv;
  99 #elif defined(OS_IS_WIN32)
 100     if (counter_freq > 0) {
 101         LARGE_INTEGER count;
 102
 103         pa_assert_se(QueryPerformanceCounter(&count));
 104
 105         tv->tv_sec = count.QuadPart / counter_freq;
 106         tv->tv_usec = (count.QuadPart % counter_freq) * PA_USEC_PER_SEC / counter_freq;
 107
 108         return tv;
 109     }
 110 #endif /* HAVE_CLOCK_GETTIME */
 111
 112     return pa_gettimeofday(tv);
 113 }
 114
 115 pa_bool_t pa_rtclock_hrtimer(void) {
 116
 117 #if defined (OS_IS_DARWIN)
 118     mach_timebase_info_data_t tbi;
 119     uint64_t time_nsec;
 120
 121     mach_timebase_info(&tbi);
 122
 123     /* nsec = nticks * (N/D) - we want 1 tick == resolution !? */
 124     time_nsec = tbi.numer / tbi.denom;
 125     return time_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 126
 127 #elif defined(HAVE_CLOCK_GETTIME)
 128     struct timespec ts;
 129
 130 #ifdef CLOCK_MONOTONIC
 131
 132     if (clock_getres(CLOCK_MONOTONIC, &ts) >= 0)
 133         return ts.tv_sec == 0 && ts.tv_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 134
 135 #endif /* CLOCK_MONOTONIC */
 136
 137     pa_assert_se(clock_getres(CLOCK_REALTIME, &ts) == 0);
 138     return ts.tv_sec == 0 && ts.tv_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 139
 140 #elif defined(OS_IS_WIN32)
 141
 142     if (counter_freq > 0)
 143         return counter_freq >= (int64_t) (PA_USEC_PER_SEC/PA_HRTIMER_THRESHOLD_USEC);
 144
 145 #endif /* HAVE_CLOCK_GETTIME */
 146
 147     return FALSE;
 148 }
 149
 150 #define TIMER_SLACK_NS (int) ((500 * PA_NSEC_PER_USEC))
 151
 152 void pa_rtclock_hrtimer_enable(void) {
 153
 154 #ifdef PR_SET_TIMERSLACK
 155     int slack_ns;
 156
 157     if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
 158         pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
 159         return;
 160     }
 161
 162     pa_log_debug("Timer slack is set to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 163
 164     if (slack_ns > TIMER_SLACK_NS) {
 165         slack_ns = TIMER_SLACK_NS;
 166
 167         pa_log_debug("Setting timer slack to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 168
 169         if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
 170             pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
 171             return;
 172         }
 173     }
 174
 175 #elif defined(OS_IS_WIN32)
 176     LARGE_INTEGER freq;
 177
 178     pa_assert_se(QueryPerformanceFrequency(&freq));
 179     counter_freq = freq.QuadPart;
 180
 181 #endif
 182 }
 183
 184 struct timeval* pa_rtclock_from_wallclock(struct timeval *tv) {
 185
 186 #ifdef HAVE_CLOCK_GETTIME
 187     struct timeval wc_now, rt_now;
 188
 189     pa_gettimeofday(&wc_now);
 190     pa_rtclock_get(&rt_now);
 191
 192     pa_assert(tv);
 193
 194     /* pa_timeval_sub() saturates on underflow! */
 195
 196     if (pa_timeval_cmp(&wc_now, tv) < 0)
 197         pa_timeval_add(&rt_now, pa_timeval_diff(tv, &wc_now));
 198     else
 199         pa_timeval_sub(&rt_now, pa_timeval_diff(&wc_now, tv));
 200
 201     *tv = rt_now;
 202 #endif
 203
 204     return tv;
 205 }
 206
 207 #ifdef HAVE_CLOCK_GETTIME
 208 pa_usec_t pa_timespec_load(const struct timespec *ts) {
 209
 210     if (PA_UNLIKELY(!ts))
 211         return PA_USEC_INVALID;
 212
 213     return
 214         (pa_usec_t) ts->tv_sec * PA_USEC_PER_SEC +
 215         (pa_usec_t) ts->tv_nsec / PA_NSEC_PER_USEC;
 216 }
 217
 218 struct timespec* pa_timespec_store(struct timespec *ts, pa_usec_t v) {
 219     pa_assert(ts);
 220
 221     if (PA_UNLIKELY(v == PA_USEC_INVALID)) {
 222         ts->tv_sec = PA_INT_TYPE_MAX(time_t);
 223         ts->tv_nsec = (long) (PA_NSEC_PER_SEC-1);
 224         return NULL;
 225     }
 226
 227     ts->tv_sec = (time_t) (v / PA_USEC_PER_SEC);
 228     ts->tv_nsec = (long) ((v % PA_USEC_PER_SEC) * PA_NSEC_PER_USEC);
 229
 230     return ts;
 231 }
 232 #endif
 233
 234 static struct timeval* wallclock_from_rtclock(struct timeval *tv) {
 235
 236 #ifdef HAVE_CLOCK_GETTIME
 237     struct timeval wc_now, rt_now;
 238
 239     pa_gettimeofday(&wc_now);
 240     pa_rtclock_get(&rt_now);
 241
 242     pa_assert(tv);
 243
 244     /* pa_timeval_sub() saturates on underflow! */
 245
 246     if (pa_timeval_cmp(&rt_now, tv) < 0)
 247         pa_timeval_add(&wc_now, pa_timeval_diff(tv, &rt_now));
 248     else
 249         pa_timeval_sub(&wc_now, pa_timeval_diff(&rt_now, tv));
 250
 251     *tv = wc_now;
 252 #endif
 253
 254     return tv;
 255 }
 256
 257 struct timeval* pa_timeval_rtstore(struct timeval *tv, pa_usec_t v, pa_bool_t rtclock) {
 258     pa_assert(tv);
 259
 260     if (v == PA_USEC_INVALID)
 261         return NULL;
 262
 263     pa_timeval_store(tv, v);
 264
 265     if (rtclock)
 266         tv->tv_usec |= PA_TIMEVAL_RTCLOCK;
 267     else
 268         wallclock_from_rtclock(tv);
 269
 270     return tv;
 271 }