FFmpeg
timer.h
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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 HAVE_MACH_ABSOLUTE_TIME
46 #include <mach/mach_time.h>
47 #endif
48 
49 #include "log.h"
50 
51 #if ARCH_AARCH64
52 # include "aarch64/timer.h"
53 #elif ARCH_ARM
54 # include "arm/timer.h"
55 #elif ARCH_PPC
56 # include "ppc/timer.h"
57 #elif ARCH_X86
58 # include "x86/timer.h"
59 #endif
60 
61 #if !defined(AV_READ_TIME)
62 # if HAVE_GETHRTIME
63 # define AV_READ_TIME gethrtime
64 # elif HAVE_MACH_ABSOLUTE_TIME
65 # define AV_READ_TIME mach_absolute_time
66 # endif
67 #endif
68 
69 #ifndef FF_TIMER_UNITS
70 # define FF_TIMER_UNITS "UNITS"
71 #endif
72 
73 #define TIMER_REPORT(id, tdiff) \
74  { \
75  static uint64_t tsum = 0; \
76  static int tcount = 0; \
77  static int tskip_count = 0; \
78  static int thistogram[32] = {0}; \
79  thistogram[av_log2(tdiff)]++; \
80  if (tcount < 2 || \
81  (tdiff) < 8 * tsum / tcount || \
82  (tdiff) < 2000) { \
83  tsum += (tdiff); \
84  tcount++; \
85  } else \
86  tskip_count++; \
87  if (((tcount + tskip_count) & (tcount + tskip_count - 1)) == 0) { \
88  int i; \
89  av_log(NULL, AV_LOG_ERROR, \
90  "%7"PRIu64" " FF_TIMER_UNITS " in %s,%8d runs,%7d skips", \
91  tsum * 10 / tcount, id, tcount, tskip_count); \
92  for (i = 0; i < 32; i++) \
93  av_log(NULL, AV_LOG_VERBOSE, " %2d", av_log2(2*thistogram[i]));\
94  av_log(NULL, AV_LOG_ERROR, "\n"); \
95  } \
96  }
97 
98 #if CONFIG_LINUX_PERF
99 
100 #define START_TIMER \
101  static int linux_perf_fd; \
102  uint64_t tperf; \
103  if (!linux_perf_fd) { \
104  struct perf_event_attr attr = { \
105  .type = PERF_TYPE_HARDWARE, \
106  .size = sizeof(struct perf_event_attr), \
107  .config = PERF_COUNT_HW_CPU_CYCLES, \
108  .disabled = 1, \
109  .exclude_kernel = 1, \
110  .exclude_hv = 1, \
111  }; \
112  linux_perf_fd = syscall(__NR_perf_event_open, &attr, \
113  0, -1, -1, 0); \
114  } \
115  if (linux_perf_fd == -1) { \
116  av_log(NULL, AV_LOG_ERROR, "perf_event_open failed: %s\n", \
117  av_err2str(AVERROR(errno))); \
118  } else { \
119  ioctl(linux_perf_fd, PERF_EVENT_IOC_RESET, 0); \
120  ioctl(linux_perf_fd, PERF_EVENT_IOC_ENABLE, 0); \
121  }
122 
123 #define STOP_TIMER(id) \
124  ioctl(linux_perf_fd, PERF_EVENT_IOC_DISABLE, 0); \
125  read(linux_perf_fd, &tperf, sizeof(tperf)); \
126  TIMER_REPORT(id, tperf)
127 
128 #elif defined(AV_READ_TIME)
129 #define START_TIMER \
130  uint64_t tend; \
131  uint64_t tstart = AV_READ_TIME(); \
132 
133 #define STOP_TIMER(id) \
134  tend = AV_READ_TIME(); \
135  TIMER_REPORT(id, tend - tstart)
136 #else
137 #define START_TIMER
138 #define STOP_TIMER(id) { }
139 #endif
140 
141 #endif /* AVUTIL_TIMER_H */