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| | #include "pthread_impl.h"
#include <threads.h>
void __pthread_testcancel(void);
struct cm {
cnd_t *c;
mtx_t *m;
};
static void unwait(cnd_t *c, mtx_t *m)
{
__THRD_ABI_MARK;
/* Removing a waiter is non-trivial if we could be using requeue
* based broadcast signals, due to mutex access issues, etc. */
while (a_swap(&c->_c_lock, 1))
__wait(&c->_c_lock, &c->_c_lockwait, 1, 1);
if (c->_c_waiters2) c->_c_waiters2--;
else a_dec(&m->_m_waiters);
a_store(&c->_c_lock, 0);
if (c->_c_lockwait) __wake(&c->_c_lock, 1, 1);
a_dec(&c->_c_waiters);
if (c->_c_destroy) __wake(&c->_c_waiters, 1, 1);
}
static void cleanup(void *p)
{
struct cm *cm = p;
unwait(cm->c, cm->m);
mtx_lock(cm->m);
}
int cnd_timedwait(cnd_t *restrict c, mtx_t *restrict m, const struct timespec *restrict ts)
{
struct cm cm = { .c=c, .m=m };
int r, e=0, seq;
if (m->_m_type && (m->_m_lock&INT_MAX) != __pthread_self()->tid)
return thrd_error;
if (ts && ts->tv_nsec >= 1000000000UL)
return thrd_error;
__pthread_testcancel();
a_inc(&c->_c_waiters);
c->_c_mutex = m;
while (a_swap(&c->_c_lock, 1))
__wait(&c->_c_lock, &c->_c_lockwait, 1, 1);
c->_c_waiters2++;
a_store(&c->_c_lock, 0);
if (c->_c_lockwait) __wake(&c->_c_lock, 1, 1);
seq = c->_c_seq;
mtx_unlock(m);
do e = __timedwait(&c->_c_seq, seq, CLOCK_REALTIME, ts, cleanup, &cm, 0);
while (c->_c_seq == seq && (!e || e==EINTR));
if (e == EINTR) e = 0;
unwait(c, m);
if (mtx_lock(m) != thrd_success)
return thrd_error;
switch (e) {
case 0:
if (thrd_success == 0) break;
else return thrd_success;
case ETIMEDOUT:
if (thrd_timedout == ETIMEDOUT) break;
else return thrd_timedout;
}
return e;
}
|