libavutil/timer.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * high precision timer, useful to profile code
  24  */
  25
  26 #ifndef AVUTIL_TIMER_H
  27 #define AVUTIL_TIMER_H
  28
  29 #include "config.h"
  30
  31 #if CONFIG_LINUX_PERF
  32 # ifndef _GNU_SOURCE
  33 #  define _GNU_SOURCE
  34 # endif
  35 # include <unistd.h> // read(3)
  36 # include <sys/ioctl.h>
  37 # include <asm/unistd.h>
  38 # include <linux/perf_event.h>
  39 #endif
  40
  41 #include <stdlib.h>
  42 #include <stdint.h>
  43 #include <inttypes.h>
  44
  45 #if CONFIG_MACOS_KPERF
  46 #include "macos_kperf.h"
  47 #endif
  48
  49 #if HAVE_MACH_ABSOLUTE_TIME
  50 #include <mach/mach_time.h>
  51 #elif HAVE_CLOCK_GETTIME
  52 #include <time.h>
  53 #endif
  54
  55 #include "common.h"
  56 #include "log.h"
  57
  58 #if   ARCH_AARCH64
  59 #   include "aarch64/timer.h"
  60 #elif ARCH_ARM
  61 #   include "arm/timer.h"
  62 #elif ARCH_PPC
  63 #   include "ppc/timer.h"
  64 #elif ARCH_X86
  65 #   include "x86/timer.h"
  66 #elif ARCH_LOONGARCH
  67 #   include "loongarch/timer.h"
  68 #endif
  69
  70 #if !defined(AV_READ_TIME)
  71 #   if HAVE_GETHRTIME
  72 #       define AV_READ_TIME gethrtime
  73 #   elif HAVE_MACH_ABSOLUTE_TIME
  74 #       define AV_READ_TIME mach_absolute_time
  75 #   elif HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
  76         static inline int64_t ff_read_time(void)
  77         {
  78             struct timespec ts;
  79             clock_gettime(CLOCK_MONOTONIC, &ts);
  80             return ts.tv_sec * INT64_C(1000000000) + ts.tv_nsec;
  81         }
  82 #       define AV_READ_TIME ff_read_time
  83 #       define FF_TIMER_UNITS "ns"
  84 #   endif
  85 #endif
  86
  87 #ifndef FF_TIMER_UNITS
  88 #   define FF_TIMER_UNITS "UNITS"
  89 #endif
  90
  91 #define TIMER_REPORT(id, tdiff)                                           \
  92     {                                                                     \
  93         static uint64_t tsum   = 0;                                       \
  94         static int tcount      = 0;                                       \
  95         static int tskip_count = 0;                                       \
  96         static int thistogram[32] = {0};                                  \
  97         thistogram[av_log2(tdiff)]++;                                     \
  98         if (tcount < 2                ||                                  \
  99             (tdiff) < 8 * tsum / tcount ||                                \
 100             (tdiff) < 2000) {                                             \
 101             tsum += (tdiff);                                              \
 102             tcount++;                                                     \
 103         } else                                                            \
 104             tskip_count++;                                                \
 105         if (((tcount + tskip_count) & (tcount + tskip_count - 1)) == 0) { \
 106             int i;                                                        \
 107             av_log(NULL, AV_LOG_ERROR,                                    \
 108                    "%7" PRIu64 " " FF_TIMER_UNITS " in %s,%8d runs,%7d skips",\
 109                    tsum * 10 / tcount, id, tcount, tskip_count);          \
 110             for (i = 0; i < 32; i++)                                      \
 111                 av_log(NULL, AV_LOG_VERBOSE, " %2d", av_log2(2*thistogram[i]));\
 112             av_log(NULL, AV_LOG_ERROR, "\n");                             \
 113         }                                                                 \
 114     }
 115
 116 #if CONFIG_LINUX_PERF
 117
 118 #define START_TIMER                                                         \
 119     static int linux_perf_fd = -1;                                          \
 120     uint64_t tperf;                                                         \
 121     if (linux_perf_fd == -1) {                                              \
 122         struct perf_event_attr attr = {                                     \
 123             .type           = PERF_TYPE_HARDWARE,                           \
 124             .size           = sizeof(struct perf_event_attr),               \
 125             .config         = PERF_COUNT_HW_CPU_CYCLES,                     \
 126             .disabled       = 1,                                            \
 127             .exclude_kernel = 1,                                            \
 128             .exclude_hv     = 1,                                            \
 129         };                                                                  \
 130         linux_perf_fd = syscall(__NR_perf_event_open, &attr,                \
 131                                 0, -1, -1, 0);                              \
 132     }                                                                       \
 133     if (linux_perf_fd == -1) {                                              \
 134         av_log(NULL, AV_LOG_ERROR, "perf_event_open failed: %s\n",          \
 135                av_err2str(AVERROR(errno)));                                 \
 136     } else {                                                                \
 137         ioctl(linux_perf_fd, PERF_EVENT_IOC_RESET, 0);                      \
 138         ioctl(linux_perf_fd, PERF_EVENT_IOC_ENABLE, 0);                     \
 139     }
 140
 141 #define STOP_TIMER(id)                                                      \
 142     ioctl(linux_perf_fd, PERF_EVENT_IOC_DISABLE, 0);                        \
 143     read(linux_perf_fd, &tperf, sizeof(tperf));                             \
 144     TIMER_REPORT(id, tperf)
 145
 146 #elif CONFIG_MACOS_KPERF
 147
 148 #define START_TIMER                                                         \
 149     uint64_t tperf;                                                         \
 150     ff_kperf_init();                                                        \
 151     tperf = ff_kperf_cycles();
 152
 153 #define STOP_TIMER(id)                                                      \
 154     TIMER_REPORT(id, ff_kperf_cycles() - tperf);
 155
 156 #elif defined(AV_READ_TIME)
 157 #define START_TIMER                             \
 158     uint64_t tend;                              \
 159     uint64_t tstart = AV_READ_TIME();           \
 160
 161 #define STOP_TIMER(id)                                                    \
 162     tend = AV_READ_TIME();                                                \
 163     TIMER_REPORT(id, tend - tstart)
 164 #else
 165 #define START_TIMER
 166 #define STOP_TIMER(id) { }
 167 #endif
 168
 169 #endif /* AVUTIL_TIMER_H */