projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 */ |