/*
* 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>
#include <urcu/system.h>
#include <urcu/arch.h>
#include <lttng/ust-clock.h>
#include "lttng-ust-uuid.h"
struct lttng_trace_clock {
uint64_t (*read64)(void);
uint64_t (*freq)(void);
int (*uuid)(char *uuid);
const char *(*name)(void);
const char *(*description)(void);
};
extern struct lttng_trace_clock *lttng_trace_clock;
void lttng_ust_clock_init(void);
/* Use the kernel MONOTONIC clock. */
static __inline__
uint64_t trace_clock_read64_monotonic(void)
{
struct timespec ts;
if (caa_unlikely(clock_gettime(CLOCK_MONOTONIC, &ts))) {
ts.tv_sec = 0;
ts.tv_nsec = 0;
}
return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
}
static __inline__
uint64_t trace_clock_freq_monotonic(void)
{
return 1000000000ULL;
}
static __inline__
int trace_clock_uuid_monotonic(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, LTTNG_UST_UUID_STR_LEN - 1, fp);
if (len < LTTNG_UST_UUID_STR_LEN - 1) {
ret = -EINVAL;
goto end;
}
uuid[LTTNG_UST_UUID_STR_LEN - 1] = '\0';
end:
fclose(fp);
return ret;
}
static __inline__
const char *trace_clock_name_monotonic(void)
{
return "monotonic";
}
static __inline__
const char *trace_clock_description_monotonic(void)
{
return "Monotonic Clock";
}
static __inline__
uint64_t trace_clock_read64(void)
{
struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
if (caa_likely(!ltc)) {
return trace_clock_read64_monotonic();
} else {
cmm_read_barrier_depends(); /* load ltc before content */
return ltc->read64();
}
}
static __inline__
uint64_t trace_clock_freq(void)
{
struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
if (!ltc) {
return trace_clock_freq_monotonic();
} else {
cmm_read_barrier_depends(); /* load ltc before content */
return ltc->freq();
}
}
static __inline__
int trace_clock_uuid(char *uuid)
{
struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
cmm_read_barrier_depends(); /* load ltc before content */
/* Use default UUID cb when NULL */
if (!ltc || !ltc->uuid) {
return trace_clock_uuid_monotonic(uuid);
} else {
return ltc->uuid(uuid);
}
}
static __inline__
const char *trace_clock_name(void)
{
struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
if (!ltc) {
return trace_clock_name_monotonic();
} else {
cmm_read_barrier_depends(); /* load ltc before content */
return ltc->name();
}
}
static __inline__
const char *trace_clock_description(void)
{
struct lttng_trace_clock *ltc = CMM_LOAD_SHARED(lttng_trace_clock);
if (!ltc) {
return trace_clock_description_monotonic();
} else {
cmm_read_barrier_depends(); /* load ltc before content */
return ltc->description();
}
}
#endif /* _UST_CLOCK_H */