Move to kernel style SPDX license identifiers
[lttng-ust.git] / liblttng-ust / lttng-clock.c
CommitLineData
e11fcffc 1/*
c0c0989a 2 * SPDX-License-Identifier: LGPL-2.1-only
e11fcffc 3 *
c0c0989a 4 * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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5 */
6
3fbec7dc 7#define _LGPL_SOURCE
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8#include <error.h>
9#include <dlfcn.h>
10#include <stdlib.h>
fb31eb73 11#include <stdint.h>
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12#include <usterr-signal-safe.h>
13#include <lttng/ust-clock.h>
14#include <urcu/system.h>
15#include <urcu/arch.h>
16
17#include "clock.h"
730bf2af 18#include "getenv.h"
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19
20struct lttng_trace_clock *lttng_trace_clock;
21
22static
23struct lttng_trace_clock user_tc;
24
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25static
26void *clock_handle;
27
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28int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void))
29{
30 if (CMM_LOAD_SHARED(lttng_trace_clock))
31 return -EBUSY;
32 user_tc.read64 = read64;
33 return 0;
34}
35
36int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void))
37{
38 if (CMM_LOAD_SHARED(lttng_trace_clock))
39 return -EBUSY;
40 user_tc.freq = freq;
41 return 0;
42}
43
44int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid))
45{
46 if (CMM_LOAD_SHARED(lttng_trace_clock))
47 return -EBUSY;
48 user_tc.uuid = uuid;
49 return 0;
50}
51
52int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void))
53{
54 if (CMM_LOAD_SHARED(lttng_trace_clock))
55 return -EBUSY;
56 user_tc.name = name;
57 return 0;
58}
59
60int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void))
61{
62 if (CMM_LOAD_SHARED(lttng_trace_clock))
63 return -EBUSY;
64 user_tc.description = description;
65 return 0;
66}
67
68int lttng_ust_enable_trace_clock_override(void)
69{
70 if (CMM_LOAD_SHARED(lttng_trace_clock))
71 return -EBUSY;
72 if (!user_tc.read64)
73 return -EINVAL;
74 if (!user_tc.freq)
75 return -EINVAL;
76 if (!user_tc.name)
77 return -EINVAL;
78 if (!user_tc.description)
79 return -EINVAL;
80 /* Use default uuid cb when NULL */
81 cmm_smp_mb(); /* Store callbacks before trace clock */
82 CMM_STORE_SHARED(lttng_trace_clock, &user_tc);
83 return 0;
84}
85
86void lttng_ust_clock_init(void)
87{
88 const char *libname;
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89 void (*libinit)(void);
90
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91 if (clock_handle)
92 return;
6f626d28 93 libname = lttng_getenv("LTTNG_UST_CLOCK_PLUGIN");
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94 if (!libname)
95 return;
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96 clock_handle = dlopen(libname, RTLD_NOW);
97 if (!clock_handle) {
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98 PERROR("Cannot load LTTng UST clock override library %s",
99 libname);
100 return;
101 }
102 dlerror();
4bc1ccd7 103 libinit = (void (*)(void)) dlsym(clock_handle,
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104 "lttng_ust_clock_plugin_init");
105 if (!libinit) {
106 PERROR("Cannot find LTTng UST clock override library %s initialization function lttng_ust_clock_plugin_init()",
107 libname);
108 return;
109 }
110 libinit();
111}
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