/*
** Copyright (C) 2004-2007 by Carnegie Mellon University.
**
** @OPENSOURCE_HEADER_START@
**
** Use of the SILK system and related source code is subject to the terms
** of the following licenses:
**
** GNU Public License (GPL) Rights pursuant to Version 2, June 1991
** Government Purpose License Rights (GPLR) pursuant to DFARS 252.225-7013
**
** NO WARRANTY
**
** ANY INFORMATION, MATERIALS, SERVICES, INTELLECTUAL PROPERTY OR OTHER
** PROPERTY OR RIGHTS GRANTED OR PROVIDED BY CARNEGIE MELLON UNIVERSITY
** PURSUANT TO THIS LICENSE (HEREINAFTER THE "DELIVERABLES") ARE ON AN
** "AS-IS" BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY
** KIND, EITHER EXPRESS OR IMPLIED AS TO ANY MATTER INCLUDING, BUT NOT
** LIMITED TO, WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE,
** MERCHANTABILITY, INFORMATIONAL CONTENT, NONINFRINGEMENT, OR ERROR-FREE
** OPERATION. CARNEGIE MELLON UNIVERSITY SHALL NOT BE LIABLE FOR INDIRECT,
** SPECIAL OR CONSEQUENTIAL DAMAGES, SUCH AS LOSS OF PROFITS OR INABILITY
** TO USE SAID INTELLECTUAL PROPERTY, UNDER THIS LICENSE, REGARDLESS OF
** WHETHER SUCH PARTY WAS AWARE OF THE POSSIBILITY OF SUCH DAMAGES.
** LICENSEE AGREES THAT IT WILL NOT MAKE ANY WARRANTY ON BEHALF OF
** CARNEGIE MELLON UNIVERSITY, EXPRESS OR IMPLIED, TO ANY PERSON
** CONCERNING THE APPLICATION OF OR THE RESULTS TO BE OBTAINED WITH THE
** DELIVERABLES UNDER THIS LICENSE.
**
** Licensee hereby agrees to defend, indemnify, and hold harmless Carnegie
** Mellon University, its trustees, officers, employees, and agents from
** all claims or demands made against them (and any related losses,
** expenses, or attorney's fees) arising out of, or relating to Licensee's
** and/or its sub licensees' negligent use or willful misuse of or
** negligent conduct or willful misconduct regarding the Software,
** facilities, or other rights or assistance granted by Carnegie Mellon
** University under this License, including, but not limited to, any
** claims of product liability, personal injury, death, damage to
** property, or violation of any laws or regulations.
**
** Carnegie Mellon University Software Engineering Institute authored
** documents are sponsored by the U.S. Department of Defense under
** Contract F19628-00-C-0003. Carnegie Mellon University retains
** copyrights in all material produced under this contract. The U.S.
** Government retains a non-exclusive, royalty-free license to publish or
** reproduce these documents, or allow others to do so, for U.S.
** Government purposes only pursuant to the copyright license under the
** contract clause at 252.227.7013.
**
** @OPENSOURCE_HEADER_END@
*/

/*
**  Generic timers which will run callback functions in a seperate
**  thread context after a given amount of time.
*/

#include "silk.h"

RCSIDENT("$SiLK: sktimer.c 6543 2007-03-05 00:52:42Z mwd $");

#include "sktimer.h"
#include "skthread.h"

typedef struct sk_timer_t {
    uint32_t secs;
    skTimerFn_t callBack;
    void *clientData;
    pthread_mutex_t mutex;
    pthread_cond_t cond;
    pthread_cond_t end;
    unsigned running : 1;
} sk_timer_t;

static void *sk_timer_thread(void *data) {
    sk_timer_t *ttd = (sk_timer_t *)data;
    struct timespec wait_time;
    struct timeval current_time;
    sigset_t sigs;
    int rv;
    skTimerRepeat_t repeat;

    /* Lock the mutex */
    pthread_mutex_lock(&ttd->mutex);

    /* Have we been asked to be destroyed before we've even started? */
    if (!ttd->running) {
        goto end;
    }

    gettimeofday(&current_time, NULL);

    sigfillset(&sigs);
    pthread_sigmask(SIG_SETMASK, &sigs, NULL); /* No signals */

    pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

    wait_time.tv_nsec = current_time.tv_usec * 1000;
    wait_time.tv_sec = current_time.tv_sec;

    do {
        wait_time.tv_sec += ttd->secs;

        /* Mutex should be released while within pthread_cond_timedwait */
        /* For some reason, this is getting interrupted by a signal, even
           though we know it shouldn't be. So handle the case. */
        do {
            rv = pthread_cond_timedwait(&ttd->cond, &ttd->mutex, &wait_time);
        } while (rv == EINTR);

        if (rv == ETIMEDOUT) {
            repeat = ttd->callBack(ttd->clientData);
        } else {
            repeat = SK_TIMER_END;
        }

    } while (repeat == SK_TIMER_REPEAT);

    ttd->running = 0;

  end:

    /* Notify destroy function that we have ended properly. */
    pthread_cond_broadcast(&ttd->end);

    pthread_mutex_unlock(&ttd->mutex);

    return NULL;
}

int skTimerCreate(
    sk_timer_t **timer,
    uint32_t secs,
    skTimerFn_t callBack,
    void *clientData)
{
    sk_timer_t *data;
    pthread_t thread;
    int err;

    data = (sk_timer_t *)malloc(sizeof(sk_timer_t));
    data->secs = secs;
    data->callBack = callBack;
    data->clientData = clientData;
    data->running = 1;
    pthread_mutex_init(&data->mutex, NULL);
    pthread_cond_init(&data->cond, NULL);
    pthread_cond_init(&data->end, NULL);

    /* Mutex starts locked */
    pthread_mutex_lock(&data->mutex);
    err = skthread_create_detatched("sktimer", &thread, sk_timer_thread, 
                                    (void *)data);
    if (err) {
        pthread_mutex_unlock(&data->mutex);
        pthread_mutex_destroy(&data->mutex);
        pthread_cond_destroy(&data->cond);
        pthread_cond_destroy(&data->end);
        free(data);
        return err;
    }

    pthread_mutex_unlock(&data->mutex);
    *timer = data;
    return 0;
}

int skTimerDestroy(sk_timer_t *timer)
{
    /* Grab the mutex */
    pthread_mutex_lock(&timer->mutex);
    if (timer->running) {
        timer->running = 0;
        /* Broadcast a stop to the timer */
        pthread_cond_broadcast(&timer->cond);
        /* Wait for timer process to end */
        pthread_cond_wait(&timer->end, &timer->mutex);
    }
    /* Unlock and destroy mutexes */
    pthread_mutex_unlock(&timer->mutex);
    pthread_mutex_destroy(&timer->mutex);
    pthread_cond_destroy(&timer->cond);
    pthread_cond_destroy(&timer->end);
    free(timer);
    return 0;
}