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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 */
142