diff options
Diffstat (limited to 'gps/utils/loc_timer.c')
| -rw-r--r-- | gps/utils/loc_timer.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/gps/utils/loc_timer.c b/gps/utils/loc_timer.c new file mode 100644 index 0000000..2beca5f --- /dev/null +++ b/gps/utils/loc_timer.c @@ -0,0 +1,202 @@ +/* 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)); + } +} |