pthread: implement try/timed join variants

include/pthread.h

@@ -214,6 +214,8 @@ struct cpu_set_t;
 int pthread_getaffinity_np(pthread_t, size_t, struct cpu_set_t *);
 int pthread_setaffinity_np(pthread_t, size_t, const struct cpu_set_t *);
 int pthread_getattr_np(pthread_t, pthread_attr_t *);
+int pthread_tryjoin_np(pthread_t, void **);
+int pthread_timedjoin_np(pthread_t, void **, const struct timespec *);
 #endif
 
 #ifdef __cplusplus

src/thread/pthread_join.c

@@ -5,18 +5,32 @@ int __munmap(void *, size_t);
 void __pthread_testcancel(void);
 int __pthread_setcancelstate(int, int *);
 
-int __pthread_join(pthread_t t, void **res)
+int __pthread_timedjoin_np(pthread_t t, void **res, const struct timespec *at)
 {
-	int tmp, cs;
+	int tmp, cs, r = 0;
 	__pthread_testcancel();
 	__pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 	if (cs == PTHREAD_CANCEL_ENABLE) __pthread_setcancelstate(cs, 0);
-	while ((tmp = t->tid)) __timedwait_cp(&t->tid, tmp, 0, 0, 0);
+	while ((tmp = t->tid) && r != ETIMEDOUT && r != EINVAL)
+		r = __timedwait_cp(&t->tid, tmp, CLOCK_REALTIME, at, 0);
 	__pthread_setcancelstate(cs, 0);
+	if (r == ETIMEDOUT || r == EINVAL) return r;
 	a_barrier();
 	if (res) *res = t->result;
 	if (t->map_base) __munmap(t->map_base, t->map_size);
 	return 0;
 }
 
+int __pthread_join(pthread_t t, void **res)
+{
+	return __pthread_timedjoin_np(t, res, 0);
+}
+
+int __pthread_tryjoin_np(pthread_t t, void **res)
+{
+	return t->tid ? EBUSY : __pthread_join(t, res);
+}
+
+weak_alias(__pthread_tryjoin_np, pthread_tryjoin_np);
+weak_alias(__pthread_timedjoin_np, pthread_timedjoin_np);
 weak_alias(__pthread_join, pthread_join);