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 #ifdef OS_IS_DARWIN
  28 #define _POSIX_C_SOURCE 1
  29 #endif
  30
  31 #include <stddef.h>
  32 #include <time.h>
  33 #include <sys/time.h>
  34 #include <errno.h>
  35
  36 #ifdef HAVE_SYS_PRCTL_H
  37 #include <sys/prctl.h>
  38 #endif
  39
  40 #ifdef OS_IS_DARWIN
  41 #include <CoreServices/CoreServices.h>
  42 #include <mach/mach.h>
  43 #include <mach/mach_time.h>
  44 #include <unistd.h>
  45 #endif
  46
  47 #ifdef HAVE_WINDOWS_H
  48 #include <windows.h>
  49 #endif
  50
  51 #include <pulse/timeval.h>
  52 #include <pulsecore/macro.h>
  53 #include <pulsecore/core-error.h>
  54
  55 #include "core-rtclock.h"
  56
  57 #ifdef OS_IS_WIN32
  58 static int64_t counter_freq = 0;
  59 #endif
  60
  61 pa_usec_t pa_rtclock_age(const struct timeval *tv) {
  62     struct timeval now;
  63     pa_assert(tv);
  64
  65     return pa_timeval_diff(pa_rtclock_get(&now), tv);
  66 }
  67
  68 struct timeval *pa_rtclock_get(struct timeval *tv) {
  69
  70 #if defined(OS_IS_DARWIN)
  71     uint64_t val, abs_time = mach_absolute_time();
  72     Nanoseconds nanos;
  73
  74     nanos = AbsoluteToNanoseconds(*(AbsoluteTime *) &abs_time);
  75     val = *(uint64_t *) &nanos;
  76
  77     tv->tv_sec = val / PA_NSEC_PER_SEC;
  78     tv->tv_usec = (val % PA_NSEC_PER_SEC) / PA_NSEC_PER_USEC;
  79
  80     return tv;
  81
  82 #elif defined(HAVE_CLOCK_GETTIME)
  83     struct timespec ts;
  84
  85 #ifdef CLOCK_MONOTONIC
  86     /* No locking or atomic ops for no_monotonic here */
  87     static bool no_monotonic = false;
  88
  89     if (!no_monotonic)
  90         if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
  91             no_monotonic = true;
  92
  93     if (no_monotonic)
  94 #endif /* CLOCK_MONOTONIC */
  95         pa_assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
  96
  97     pa_assert(tv);
  98
  99     tv->tv_sec = ts.tv_sec;
 100     tv->tv_usec = ts.tv_nsec / PA_NSEC_PER_USEC;
 101
 102     return tv;
 103 #elif defined(OS_IS_WIN32)
 104     if (counter_freq > 0) {
 105         LARGE_INTEGER count;
 106
 107         pa_assert_se(QueryPerformanceCounter(&count));
 108
 109         tv->tv_sec = count.QuadPart / counter_freq;
 110         tv->tv_usec = (count.QuadPart % counter_freq) * PA_USEC_PER_SEC / counter_freq;
 111
 112         return tv;
 113     }
 114 #endif /* HAVE_CLOCK_GETTIME */
 115
 116     return pa_gettimeofday(tv);
 117 }
 118
 119 bool pa_rtclock_hrtimer(void) {
 120
 121 #if defined (OS_IS_DARWIN)
 122     mach_timebase_info_data_t tbi;
 123     uint64_t time_nsec;
 124
 125     mach_timebase_info(&tbi);
 126
 127     /* nsec = nticks * (N/D) - we want 1 tick == resolution !? */
 128     time_nsec = tbi.numer / tbi.denom;
 129     return time_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 130
 131 #elif defined(HAVE_CLOCK_GETTIME)
 132     struct timespec ts;
 133
 134 #ifdef CLOCK_MONOTONIC
 135
 136     if (clock_getres(CLOCK_MONOTONIC, &ts) >= 0)
 137         return ts.tv_sec == 0 && ts.tv_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 138
 139 #endif /* CLOCK_MONOTONIC */
 140
 141     pa_assert_se(clock_getres(CLOCK_REALTIME, &ts) == 0);
 142     return ts.tv_sec == 0 && ts.tv_nsec <= (long) (PA_HRTIMER_THRESHOLD_USEC*PA_NSEC_PER_USEC);
 143
 144 #elif defined(OS_IS_WIN32)
 145
 146     if (counter_freq > 0)
 147         return counter_freq >= (int64_t) (PA_USEC_PER_SEC/PA_HRTIMER_THRESHOLD_USEC);
 148
 149 #endif /* HAVE_CLOCK_GETTIME */
 150
 151     return false;
 152 }
 153
 154 #define TIMER_SLACK_NS (int) ((500 * PA_NSEC_PER_USEC))
 155
 156 void pa_rtclock_hrtimer_enable(void) {
 157
 158 #ifdef PR_SET_TIMERSLACK
 159     int slack_ns;
 160
 161     if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
 162         pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
 163         return;
 164     }
 165
 166     pa_log_debug("Timer slack is set to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 167
 168     if (slack_ns > TIMER_SLACK_NS) {
 169         slack_ns = TIMER_SLACK_NS;
 170
 171         pa_log_debug("Setting timer slack to %i us.", (int) (slack_ns/PA_NSEC_PER_USEC));
 172
 173         if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
 174             pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
 175             return;
 176         }
 177     }
 178
 179 #elif defined(OS_IS_WIN32)
 180     LARGE_INTEGER freq;
 181
 182     pa_assert_se(QueryPerformanceFrequency(&freq));
 183     counter_freq = freq.QuadPart;
 184
 185 #endif
 186 }
 187
 188 struct timeval* pa_rtclock_from_wallclock(struct timeval *tv) {
 189     struct timeval wc_now, rt_now;
 190
 191     pa_assert(tv);
 192
 193     pa_gettimeofday(&wc_now);
 194     pa_rtclock_get(&rt_now);
 195
 196     /* pa_timeval_sub() saturates on underflow! */
 197
 198     if (pa_timeval_cmp(&wc_now, tv) < 0)
 199         pa_timeval_add(&rt_now, pa_timeval_diff(tv, &wc_now));
 200     else
 201         pa_timeval_sub(&rt_now, pa_timeval_diff(&wc_now, tv));
 202
 203     *tv = rt_now;
 204
 205     return tv;
 206 }
 207
 208 #ifdef HAVE_CLOCK_GETTIME
 209 pa_usec_t pa_timespec_load(const struct timespec *ts) {
 210
 211     if (PA_UNLIKELY(!ts))
 212         return PA_USEC_INVALID;
 213
 214     return
 215         (pa_usec_t) ts->tv_sec * PA_USEC_PER_SEC +
 216         (pa_usec_t) ts->tv_nsec / PA_NSEC_PER_USEC;
 217 }
 218
 219 struct timespec* pa_timespec_store(struct timespec *ts, pa_usec_t v) {
 220     pa_assert(ts);
 221
 222     if (PA_UNLIKELY(v == PA_USEC_INVALID)) {
 223         ts->tv_sec = PA_INT_TYPE_MAX(time_t);
 224         ts->tv_nsec = (long) (PA_NSEC_PER_SEC-1);
 225         return NULL;
 226     }
 227
 228     ts->tv_sec = (time_t) (v / PA_USEC_PER_SEC);
 229     ts->tv_nsec = (long) ((v % PA_USEC_PER_SEC) * PA_NSEC_PER_USEC);
 230
 231     return ts;
 232 }
 233 #endif
 234
 235 static struct timeval* wallclock_from_rtclock(struct timeval *tv) {
 236     struct timeval wc_now, rt_now;
 237
 238     pa_assert(tv);
 239
 240     pa_gettimeofday(&wc_now);
 241     pa_rtclock_get(&rt_now);
 242
 243     /* pa_timeval_sub() saturates on underflow! */
 244
 245     if (pa_timeval_cmp(&rt_now, tv) < 0)
 246         pa_timeval_add(&wc_now, pa_timeval_diff(tv, &rt_now));
 247     else
 248         pa_timeval_sub(&wc_now, pa_timeval_diff(&rt_now, tv));
 249
 250     *tv = wc_now;
 251
 252     return tv;
 253 }
 254
 255 struct timeval* pa_timeval_rtstore(struct timeval *tv, pa_usec_t v, bool rtclock) {
 256     pa_assert(tv);
 257
 258     if (v == PA_USEC_INVALID)
 259         return NULL;
 260
 261     pa_timeval_store(tv, v);
 262
 263     if (rtclock)
 264         tv->tv_usec |= PA_TIMEVAL_RTCLOCK;
 265     else
 266         wallclock_from_rtclock(tv);
 267
 268     return tv;
 269 }