void blockUntilComplete() {
// TODO
queue_enqueue(&prq,uthread_self());
uthread_block(); //block the thread while it is reading
}
/*
* uthread_mtx_lock
*
* Lock the mutex. This call will block if it's already locked. When the
* thread wakes up from waiting, it should own the mutex (see _unlock()).
*/
void
uthread_mtx_lock(uthread_mtx_t *mtx)
{
//NOT_YET_IMPLEMENTED("UTHREADS: uthread_mtx_lock");
assert(mtx != NULL);
if(mtx -> m_owner == NULL)
mtx -> m_owner = ut_curthr;
else{
assert(mtx->m_owner != ut_curthr);
//put current thread in the waiters queue
utqueue_enqueue(&mtx->m_waiters, ut_curthr);
//block current thread
uthread_block();
}
}
/*
* uthread_cond_wait
*
* Should behave just like a stripped down version of pthread_cond_wait.
* Block on the given condition variable.
* param cond: the pointer to the conditional variable object
* param mtx: the pointer to the mutex object
*/
void
uthread_cond_wait(uthread_cond_t *cond, uthread_mtx_t *mtx)
{
/* Make sure the mtx is locked by the current thread */
assert(mtx != NULL && cond != NULL);
assert(mtx->m_owner == ut_curthr);
utqueue_enqueue(&cond->uc_waiters, ut_curthr);
uthread_mtx_unlock(mtx);
/* Block on the conditional variable */
uthread_block();
/* Now it gets back, try lock the mutex */
uthread_mtx_lock(mtx);
}
