/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation, nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include<stdio.h>
#include<stdlib.h>
#include<sys/time.h>
#include "loc_timer.h"
#include<time.h>
#include<errno.h>
enum timer_state {
READY = 100,
WAITING,
DONE,
ABORT
};
typedef struct {
loc_timer_callback callback_func;
void *user_data;
unsigned int time_msec;
pthread_cond_t timer_cond;
pthread_mutex_t timer_mutex;
enum timer_state state;
}timer_data;
static void *timer_thread(void *thread_data)
{
int ret = -ETIMEDOUT;
struct timespec ts;
struct timeval tv;
timer_data* t = (timer_data*)thread_data;
LOC_LOGD("%s:%d]: Enter. Delay = %d\n", __func__, __LINE__, t->time_msec);
gettimeofday(&tv, NULL);
clock_gettime(CLOCK_REALTIME, &ts);
if(t->time_msec >= 1000) {
ts.tv_sec += t->time_msec/1000;
t->time_msec = t->time_msec % 1000;
}
if(t->time_msec)
ts.tv_nsec += t->time_msec * 1000000;
if(ts.tv_nsec > 999999999) {
LOC_LOGD("%s:%d]: Large nanosecs\n", __func__, __LINE__);
ts.tv_sec += 1;
ts.tv_nsec -= 1000000000;
}
LOC_LOGD("%s:%d]: ts.tv_sec:%d; ts.tv_nsec:%d\n"
"\t Current time: %d sec; %d nsec",
__func__, __LINE__, (int)ts.tv_sec, (int)ts.tv_nsec,
(int)tv.tv_sec, (int)tv.tv_usec*1000);
pthread_mutex_lock(&(t->timer_mutex));
if (READY == t->state) {
t->state = WAITING;
ret = pthread_cond_timedwait(&t->timer_cond, &t->timer_mutex, &ts);
t->state = DONE;
}
pthread_mutex_unlock(&(t->timer_mutex));
switch (ret) {
case ETIMEDOUT:
LOC_LOGV("%s:%d]: loc_timer timed out", __func__, __LINE__);
break;
case 0:
LOC_LOGV("%s:%d]: loc_timer stopped", __func__, __LINE__);
break;
case -ETIMEDOUT:
LOC_LOGV("%s:%d]: loc_timer cancelled", __func__, __LINE__);
break;
default:
LOC_LOGE("%s:%d]: Call to pthread timedwait failed; ret=%d\n",
__func__, __LINE__, ret);
break;
}
if(ETIMEDOUT == ret)
t->callback_func(t->user_data, ret);
// A (should be rare) race condition is that, when the loc_time_stop is called
// and acquired mutex, we reach here. pthread_mutex_destroy will fail with
// error code EBUSY. We give it 6 tries in 5 seconds. Should be eanough time
// for loc_timer_stop to complete. With the 7th try, we also perform unlock
// prior to destroy.
{
int i;
for (i = 0; EBUSY == pthread_mutex_destroy(&t->timer_mutex) && i <= 5; i++) {
if (i < 5) {
sleep(1);
} else {
// nah, forget it, something is seriously wrong. Mutex has been
// held too long. Unlock the mutext here.
pthread_mutex_unlock(&t->timer_mutex);
}
}
}
pthread_cond_destroy(&t->timer_cond);
free(t);
LOC_LOGD("%s:%d]: Exit\n", __func__, __LINE__);
return NULL;
}
void* loc_timer_start(unsigned int msec, loc_timer_callback cb_func,
void* caller_data)
{
timer_data *t=NULL;
pthread_attr_t tattr;
pthread_t id;
LOC_LOGD("%s:%d]: Enter\n", __func__, __LINE__);
if(cb_func == NULL || msec == 0) {
LOC_LOGE("%s:%d]: Error: Wrong parameters\n", __func__, __LINE__);
goto _err;
}
t = (timer_data *)calloc(1, sizeof(timer_data));
if(t == NULL) {
LOC_LOGE("%s:%d]: Could not allocate memory. Failing.\n",
__func__, __LINE__);
goto _err;
}
if(pthread_cond_init(&(t->timer_cond), NULL)) {
LOC_LOGE("%s:%d]: Pthread cond init failed\n", __func__, __LINE__);
goto t_err;
}
if(pthread_mutex_init(&(t->timer_mutex), NULL)) {
LOC_LOGE("%s:%d]: Pthread mutex init failed\n", __func__, __LINE__);
goto cond_err;
}
t->callback_func = cb_func;
t->user_data = caller_data;
t->time_msec = msec;
t->state = READY;
if (pthread_attr_init(&tattr)) {
LOC_LOGE("%s:%d]: Pthread mutex init failed\n", __func__, __LINE__);
goto mutex_err;
}
pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED);
if(pthread_create(&(id), &tattr, timer_thread, (void *)t)) {
LOC_LOGE("%s:%d]: Could not create thread\n", __func__, __LINE__);
goto attr_err;
}
LOC_LOGD("%s:%d]: Created thread with id: %d\n",
__func__, __LINE__, (int)id);
goto _err;
attr_err:
pthread_attr_destroy(&tattr);
mutex_err:
pthread_mutex_destroy(&t->timer_mutex);
cond_err:
pthread_cond_destroy(&t->timer_cond);
t_err:
free(t);
_err:
LOC_LOGD("%s:%d]: Exit\n", __func__, __LINE__);
return t;
}
void loc_timer_stop(void* handle) {
timer_data* t = (timer_data*)handle;
if (NULL != t && (READY == t->state || WAITING == t->state) &&
pthread_mutex_lock(&(t->timer_mutex)) == 0) {
if (READY == t->state || WAITING == t->state) {
pthread_cond_signal(&t->timer_cond);
t->state = ABORT;
}
pthread_mutex_unlock(&(t->timer_mutex));
}
}