/*
* Copyright (C) 2014 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
*/
#define _GNU_SOURCE
#include <error.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <usterr-signal-safe.h>
#include <lttng/ust-clock.h>
#include <urcu/system.h>
#include <urcu/arch.h>
#include "clock.h"
#include "getenv.h"
struct lttng_trace_clock *lttng_trace_clock;
static
struct lttng_trace_clock user_tc;
static
void *clock_handle;
int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void))
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
user_tc.read64 = read64;
return 0;
}
int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void))
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
user_tc.freq = freq;
return 0;
}
int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid))
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
user_tc.uuid = uuid;
return 0;
}
int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void))
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
user_tc.name = name;
return 0;
}
int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void))
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
user_tc.description = description;
return 0;
}
int lttng_ust_enable_trace_clock_override(void)
{
if (CMM_LOAD_SHARED(lttng_trace_clock))
return -EBUSY;
if (!user_tc.read64)
return -EINVAL;
if (!user_tc.freq)
return -EINVAL;
if (!user_tc.name)
return -EINVAL;
if (!user_tc.description)
return -EINVAL;
/* Use default uuid cb when NULL */
cmm_smp_mb(); /* Store callbacks before trace clock */
CMM_STORE_SHARED(lttng_trace_clock, &user_tc);
return 0;
}
void lttng_ust_clock_init(void)
{
const char *libname;
void (*libinit)(void);
if (clock_handle)
return;
libname = lttng_secure_getenv("LTTNG_UST_CLOCK_PLUGIN");
if (!libname)
return;
clock_handle = dlopen(libname, RTLD_NOW);
if (!clock_handle) {
PERROR("Cannot load LTTng UST clock override library %s",
libname);
return;
}
dlerror();
libinit = (void (*)(void)) dlsym(clock_handle,
"lttng_ust_clock_plugin_init");
if (!libinit) {
PERROR("Cannot find LTTng UST clock override library %s initialization function lttng_ust_clock_plugin_init()",
libname);
return;
}
libinit();
}