/*
* Free the stack for the current thread
*/
void _st_stack_free(_st_stack_t *ts)
{
if (!ts)
return;
/* Put the stack on the free list *///走这里
ST_APPEND_LINK(&ts->links, _st_free_stacks.prev);
_st_num_free_stacks++;
}
void _st_add_sleep_q(st_thread_t *thread, st_utime_t timeout)
{
st_utime_t sleep;
st_clist_t *q;
st_thread_t *t;
/* sort onto global sleep queue */
sleep = timeout;
/* Check if we are longest timeout */
if (timeout >= _ST_SLEEPQMAX) {
ST_APPEND_LINK(&thread->links, &_ST_SLEEPQ);
thread->sleep = timeout - _ST_SLEEPQMAX;
_ST_SLEEPQMAX = timeout;
}
else {
/* Sort thread into global sleep queue at appropriate point */
q = _ST_SLEEPQ.next;
/* Now scan the list for where to insert this entry */
while (q != &_ST_SLEEPQ) {
t = _ST_THREAD_PTR(q);
if (sleep < t->sleep) {
/* Found sleeper to insert in front of */
break;
}
sleep -= t->sleep;
q = q->next;
}
thread->sleep = sleep;
ST_INSERT_BEFORE(&thread->links, q);
/* Subtract our sleep time from the sleeper that follows us */
ST_ASSERT(thread->links.next != &_ST_SLEEPQ);
t = _ST_THREAD_PTR(thread->links.next);
ST_ASSERT(_ST_THREAD_PTR(t->links.prev) == thread);
t->sleep -= sleep;
}
thread->flags |= _ST_FL_ON_SLEEPQ;
}
int st_mutex_lock(_st_mutex_t *lock)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
if (lock->owner == NULL) {
/* Got the mutex */
lock->owner = me;
return 0;
}
if (lock->owner == me) {
errno = EDEADLK;
return -1;
}
/* Put caller thread on the mutex's wait queue */
me->state = _ST_ST_LOCK_WAIT;
ST_APPEND_LINK(&me->wait_links, &lock->wait_q);
_ST_SWITCH_CONTEXT(me);
ST_REMOVE_LINK(&me->wait_links);
if ((me->flags & _ST_FL_INTERRUPT) && lock->owner != me) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
return 0;
}
int st_cond_timedwait(_st_cond_t *cvar, st_utime_t timeout)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
int rv;
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
/* Put caller thread on the condition variable's wait queue */
me->state = _ST_ST_COND_WAIT;
ST_APPEND_LINK(&me->wait_links, &cvar->wait_q);
if (timeout != ST_UTIME_NO_TIMEOUT)
_ST_ADD_SLEEPQ(me, timeout);
_ST_SWITCH_CONTEXT(me);
ST_REMOVE_LINK(&me->wait_links);
rv = 0;
if (me->flags & _ST_FL_TIMEDOUT) {
me->flags &= ~_ST_FL_TIMEDOUT;
errno = ETIME;
rv = -1;
}
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
rv = -1;
}
return rv;
}
