Rename uprobe files to userspace-probe
[lttng-tools.git] / src / bin / lttng-sessiond / ust-clock.h
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d0b96690 1/*
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2 * Copyright (C) 2010 Pierre-Marc Fournier
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
d0b96690 4 *
ab5be9fa 5 * SPDX-License-Identifier: GPL-2.0-only
d0b96690 6 *
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7 */
8
9#ifndef _UST_CLOCK_H
10#define _UST_CLOCK_H
11
389fbf04 12#include <common/compat/time.h>
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13#include <sys/time.h>
14#include <stdint.h>
15#include <stddef.h>
16#include <stdio.h>
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17#include <urcu/system.h>
18#include <urcu/arch.h>
19#include <lttng/ust-clock.h>
d0b96690 20
c70636a7 21#include <common/uuid.h>
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22
23/* TRACE CLOCK */
24
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25struct lttng_trace_clock {
26 uint64_t (*read64)(void);
27 uint64_t (*freq)(void);
28 int (*uuid)(char *uuid);
29 const char *(*name)(void);
30 const char *(*description)(void);
31};
32
33extern struct lttng_trace_clock *lttng_trace_clock;
34
35void lttng_ust_clock_init(void);
36
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37/*
38 * Currently using the kernel MONOTONIC clock, waiting for kernel-side
39 * LTTng to implement mmap'd trace clock.
40 */
41
42/* Choosing correct trace clock */
43
44static __inline__
fc0bb9fa 45uint64_t trace_clock_read64_monotonic(void)
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46{
47 struct timespec ts;
48
389fbf04 49 if (lttng_clock_gettime(CLOCK_MONOTONIC, &ts)) {
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50 /* TODO Report error cleanly up the chain. */
51 PERROR("clock_gettime CLOCK_MONOTONIC");
52 ts.tv_sec = 0;
53 ts.tv_nsec = 0;
54 }
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55 return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
56}
57
58static __inline__
fc0bb9fa 59uint64_t trace_clock_freq_monotonic(void)
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60{
61 return 1000000000ULL;
62}
63
64static __inline__
fc0bb9fa 65int trace_clock_uuid_monotonic(char *uuid)
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66{
67 int ret = 0;
68 size_t len;
69 FILE *fp;
70
71 /*
72 * boot_id needs to be read once before being used concurrently
73 * to deal with a Linux kernel race. A fix is proposed for
74 * upstream, but the work-around is needed for older kernels.
75 */
76 fp = fopen("/proc/sys/kernel/random/boot_id", "r");
77 if (!fp) {
78 return -ENOENT;
79 }
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80 len = fread(uuid, 1, LTTNG_UST_UUID_STR_LEN - 1, fp);
81 if (len < LTTNG_UST_UUID_STR_LEN - 1) {
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82 ret = -EINVAL;
83 goto end;
84 }
fc0bb9fa 85 uuid[LTTNG_UST_UUID_STR_LEN - 1] = '\0';
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86end:
87 fclose(fp);
88 return ret;
89}
90
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91static __inline__
92const char *trace_clock_name_monotonic(void)
93{
94 return "monotonic";
95}
96
97static __inline__
98const char *trace_clock_description_monotonic(void)
99{
100 return "Monotonic Clock";
101}
102
103static __inline__
104uint64_t trace_clock_read64(void)
105{
106 struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
107
108 if (caa_likely(!ltc)) {
109 return trace_clock_read64_monotonic();
110 } else {
111 cmm_read_barrier_depends(); /* load ltc before content */
112 return ltc->read64();
113 }
114}
115
116static __inline__
117uint64_t trace_clock_freq(void)
118{
119 struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
120
121 if (!ltc) {
122 return trace_clock_freq_monotonic();
123 } else {
124 cmm_read_barrier_depends(); /* load ltc before content */
125 return ltc->freq();
126 }
127}
128
129static __inline__
130int trace_clock_uuid(char *uuid)
131{
132 struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
133
134 cmm_read_barrier_depends(); /* load ltc before content */
135 /* Use default UUID cb when NULL */
136 if (!ltc || !ltc->uuid) {
137 return trace_clock_uuid_monotonic(uuid);
138 } else {
139 return ltc->uuid(uuid);
140 }
141}
142
143static __inline__
144const char *trace_clock_name(void)
145{
146 struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
147
148 if (!ltc) {
149 return trace_clock_name_monotonic();
150 } else {
151 cmm_read_barrier_depends(); /* load ltc before content */
152 return ltc->name();
153 }
154}
155
156static __inline__
157const char *trace_clock_description(void)
158{
159 struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
160
161 if (!ltc) {
162 return trace_clock_description_monotonic();
163 } else {
164 cmm_read_barrier_depends(); /* load ltc before content */
165 return ltc->description();
166 }
167}
168
d0b96690 169#endif /* _UST_CLOCK_H */
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