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/*
* Copyright (C) 2010 Pierre-Marc Fournier
* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; version 2.1 of
* the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _UST_CLOCK_H
#define _UST_CLOCK_H
#include <time.h>
#include <sys/time.h>
#include <stdint.h>
#include <stddef.h>
#include <stdio.h>
/*
* Includes final \0.
*/
#define CLOCK_UUID_LEN 37
/* TRACE CLOCK */
/*
* Currently using the kernel MONOTONIC clock, waiting for kernel-side
* LTTng to implement mmap'd trace clock.
*/
/* Choosing correct trace clock */
static __inline__
uint64_t trace_clock_read64(void)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
}
static __inline__
uint64_t trace_clock_freq(void)
{
return 1000000000ULL;
}
static __inline__
const int trace_clock_uuid(char *uuid)
{
int ret = 0;
size_t len;
FILE *fp;
/*
* boot_id needs to be read once before being used concurrently
* to deal with a Linux kernel race. A fix is proposed for
* upstream, but the work-around is needed for older kernels.
*/
fp = fopen("/proc/sys/kernel/random/boot_id", "r");
if (!fp) {
return -ENOENT;
}
len = fread(uuid, 1, CLOCK_UUID_LEN - 1, fp);
if (len < CLOCK_UUID_LEN - 1) {
ret = -EINVAL;
goto end;
}
uuid[CLOCK_UUID_LEN - 1] = '\0';
end:
fclose(fp);
return ret;
}
#endif /* _UST_CLOCK_H */
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