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d0b96690 DG |
1 | /* |
2 | * Copyright (C) 2010 Pierre-Marc Fournier | |
3 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; version 2.1 of | |
8 | * the License. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | */ | |
19 | ||
20 | #ifndef _UST_CLOCK_H | |
21 | #define _UST_CLOCK_H | |
22 | ||
23 | #include <time.h> | |
24 | #include <sys/time.h> | |
25 | #include <stdint.h> | |
26 | #include <stddef.h> | |
27 | #include <stdio.h> | |
28 | #include <errno.h> | |
29 | ||
30 | #include <common/compat/uuid.h> | |
31 | ||
32 | /* TRACE CLOCK */ | |
33 | ||
34 | /* | |
35 | * Currently using the kernel MONOTONIC clock, waiting for kernel-side | |
36 | * LTTng to implement mmap'd trace clock. | |
37 | */ | |
38 | ||
39 | /* Choosing correct trace clock */ | |
40 | ||
41 | static __inline__ | |
42 | uint64_t trace_clock_read64(void) | |
43 | { | |
44 | struct timespec ts; | |
45 | ||
46 | clock_gettime(CLOCK_MONOTONIC, &ts); | |
47 | return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec; | |
48 | } | |
49 | ||
50 | static __inline__ | |
51 | uint64_t trace_clock_freq(void) | |
52 | { | |
53 | return 1000000000ULL; | |
54 | } | |
55 | ||
56 | static __inline__ | |
57 | int trace_clock_uuid(char *uuid) | |
58 | { | |
59 | int ret = 0; | |
60 | size_t len; | |
61 | FILE *fp; | |
62 | ||
63 | /* | |
64 | * boot_id needs to be read once before being used concurrently | |
65 | * to deal with a Linux kernel race. A fix is proposed for | |
66 | * upstream, but the work-around is needed for older kernels. | |
67 | */ | |
68 | fp = fopen("/proc/sys/kernel/random/boot_id", "r"); | |
69 | if (!fp) { | |
70 | return -ENOENT; | |
71 | } | |
72 | len = fread(uuid, 1, UUID_STR_LEN - 1, fp); | |
73 | if (len < UUID_STR_LEN - 1) { | |
74 | ret = -EINVAL; | |
75 | goto end; | |
76 | } | |
77 | uuid[UUID_STR_LEN - 1] = '\0'; | |
78 | end: | |
79 | fclose(fp); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | #endif /* _UST_CLOCK_H */ |