Commit | Line | Data |
---|---|---|
f9364363 MD |
1 | /* |
2 | * lttng-clock-override-example.c | |
3 | * | |
4 | * Copyright (c) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
19 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
22 | * SOFTWARE. | |
23 | */ | |
24 | ||
25 | #include <stdlib.h> | |
26 | #include <time.h> | |
27 | #include <string.h> | |
28 | #include <stdio.h> | |
29 | #include <lttng/ust-clock.h> | |
30 | ||
31 | static | |
32 | uint64_t plugin_read64(void) | |
33 | { | |
34 | struct timespec ts; | |
35 | ||
36 | clock_gettime(CLOCK_MONOTONIC, &ts); | |
37 | /* | |
38 | * This is a rather dumb example, but it illustrates the plugin | |
39 | * mechanism: we take the monotonic clock, and transform it into | |
40 | * a very coarse clock, which increment only at 1KHz frequency. | |
41 | */ | |
42 | return ((uint64_t) ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL); | |
43 | } | |
44 | ||
45 | static | |
46 | uint64_t plugin_freq(void) | |
47 | { | |
48 | return 1000; /* 1KHz clock (very coarse!) */ | |
49 | } | |
50 | ||
51 | static | |
52 | int plugin_uuid(char *uuid) | |
53 | { | |
54 | const char myuuid[] = "123456789012345678901234567890123456"; | |
55 | ||
56 | /* | |
57 | * Should read some unique identifier for this clock shared | |
58 | * across all components of the system using this clock for | |
59 | * tracing. | |
60 | */ | |
61 | memcpy(uuid, myuuid, LTTNG_UST_UUID_STR_LEN); | |
62 | return 0; | |
63 | } | |
64 | ||
65 | static | |
66 | const char *plugin_name(void) | |
67 | { | |
68 | return "my_example_clock"; | |
69 | } | |
70 | ||
71 | static | |
72 | const char *plugin_description(void) | |
73 | { | |
74 | return "Coarse monotonic clock at 1KHz"; | |
75 | } | |
76 | ||
77 | void lttng_ust_clock_plugin_init(void) | |
78 | { | |
79 | int ret; | |
80 | ||
81 | ret = lttng_ust_trace_clock_set_read64_cb(plugin_read64); | |
82 | if (ret) { | |
83 | fprintf(stderr, "Error setting clock override read64 callback: %s\n", | |
84 | strerror(-ret)); | |
85 | goto error; | |
86 | } | |
87 | ret = lttng_ust_trace_clock_set_freq_cb(plugin_freq); | |
88 | if (ret) { | |
89 | fprintf(stderr, "Error setting clock override freq callback: %s\n", | |
90 | strerror(-ret)); | |
91 | goto error; | |
92 | } | |
93 | ret = lttng_ust_trace_clock_set_uuid_cb(plugin_uuid); | |
94 | if (ret) { | |
95 | fprintf(stderr, "Error setting clock override uuid callback: %s\n", | |
96 | strerror(-ret)); | |
97 | goto error; | |
98 | } | |
99 | ||
100 | ret = lttng_ust_trace_clock_set_name_cb(plugin_name); | |
101 | if (ret) { | |
102 | fprintf(stderr, "Error setting clock override name callback: %s\n", | |
103 | strerror(-ret)); | |
104 | goto error; | |
105 | } | |
106 | ||
107 | ret = lttng_ust_trace_clock_set_description_cb(plugin_description); | |
108 | if (ret) { | |
109 | fprintf(stderr, "Error setting clock override description callback: %s\n", | |
110 | strerror(-ret)); | |
111 | goto error; | |
112 | } | |
113 | ||
114 | ret = lttng_ust_enable_trace_clock_override(); | |
115 | if (ret) { | |
116 | fprintf(stderr, "Error enabling clock override: %s\n", | |
117 | strerror(-ret)); | |
118 | goto error; | |
119 | } | |
120 | ||
121 | return; | |
122 | ||
123 | error: | |
124 | exit(EXIT_FAILURE); | |
125 | } |