text: /*
   * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * high precision timer, useful to profile code
   */
  
  #ifndef AVUTIL_TIMER_H
  #define AVUTIL_TIMER_H
  
  #include "config.h"
  
  #if CONFIG_LINUX_PERF
  # ifndef _GNU_SOURCE
  #  define _GNU_SOURCE
  # endif
  # include <unistd.h> // read(3)
  # include <sys/ioctl.h>
  # include <asm/unistd.h>
  # include <linux/perf_event.h>
  #endif
  
  #include <stdlib.h>
  #include <stdint.h>
  #include <inttypes.h>
  
  #if HAVE_MACH_MACH_TIME_H
  #include <mach/mach_time.h>
  #endif
  
  #include "libavutil/log.h"
  
  #if   ARCH_AARCH64
  #   include "aarch64/timer.h"
  #elif ARCH_ARM
  #   include "arm/timer.h"
  #elif ARCH_PPC
  #   include "ppc/timer.h"
  #elif ARCH_X86
  #   include "x86/timer.h"
  #endif
  
  #if !defined(AV_READ_TIME)
  #   if HAVE_GETHRTIME
  #       define AV_READ_TIME gethrtime
  #   elif HAVE_MACH_ABSOLUTE_TIME
  #       define AV_READ_TIME mach_absolute_time
  #   endif
  #endif
  
  #ifndef FF_TIMER_UNITS
  #   define FF_TIMER_UNITS "UNITS"
  #endif
  
  #define TIMER_REPORT(id, tdiff)                                           \
      {                                                                     \
          static uint64_t tsum   = 0;                                       \
          static int tcount      = 0;                                       \
          static int tskip_count = 0;                                       \
          static int thistogram[32] = {0};                                  \
          thistogram[av_log2(tdiff)]++;                                     \
          if (tcount < 2                ||                                  \
              (tdiff) < 8 * tsum / tcount ||                                \
              (tdiff) < 2000) {                                             \
              tsum += (tdiff);                                              \
              tcount++;                                                     \
          } else                                                            \
              tskip_count++;                                                \
          if (((tcount + tskip_count) & (tcount + tskip_count - 1)) == 0) { \
              int i;                                                        \
              av_log(NULL, AV_LOG_ERROR,                                    \
                     "%7"PRIu64" " FF_TIMER_UNITS " in %s,%8d runs,%7d skips",          \
                     tsum * 10 / tcount, id, tcount, tskip_count);          \
              for (i = 0; i < 32; i++)                                      \
                  av_log(NULL, AV_LOG_VERBOSE, " %2d", av_log2(2*thistogram[i]));\
              av_log(NULL, AV_LOG_ERROR, "\n");                             \
          }                                                                 \
      }
  
  #if CONFIG_LINUX_PERF
  
  #define START_TIMER                                                         \
      static int linux_perf_fd;                                               \
      uint64_t tperf;                                                         \
      if (!linux_perf_fd) {                                                   \
          struct perf_event_attr attr = {                                     \
              .type           = PERF_TYPE_HARDWARE,                           \
              .size           = sizeof(struct perf_event_attr),               \
              .config         = PERF_COUNT_HW_CPU_CYCLES,                     \
              .disabled       = 1,                                            \
              .exclude_kernel = 1,                                            \
              .exclude_hv     = 1,                                            \
          };                                                                  \
          linux_perf_fd = syscall(__NR_perf_event_open, &attr,                \
                                  0, -1, -1, 0);                              \
      }                                                                       \
      if (linux_perf_fd == -1) {                                              \
          av_log(NULL, AV_LOG_ERROR, "perf_event_open failed: %s\n",          \
                 av_err2str(AVERROR(errno)));                                 \
      } else {                                                                \
          ioctl(linux_perf_fd, PERF_EVENT_IOC_RESET, 0);                      \
          ioctl(linux_perf_fd, PERF_EVENT_IOC_ENABLE, 0);                     \
      }
  
  #define STOP_TIMER(id)                                                      \
      ioctl(linux_perf_fd, PERF_EVENT_IOC_DISABLE, 0);                        \
      read(linux_perf_fd, &tperf, sizeof(tperf));                             \
      TIMER_REPORT(id, tperf)
  
  #elif defined(AV_READ_TIME)
  #define START_TIMER                             \
      uint64_t tend;                              \
      uint64_t tstart = AV_READ_TIME();           \
  
  #define STOP_TIMER(id)                                                    \
      tend = AV_READ_TIME();                                                \
      TIMER_REPORT(id, tend - tstart)
  #else
  #define START_TIMER
  #define STOP_TIMER(id) { }
  #endif
  
  #endif /* AVUTIL_TIMER_H */
  