PERFORCE change 67980 for review
David Xu
davidxu at FreeBSD.org
Fri Dec 31 06:58:09 PST 2004
http://perforce.freebsd.org/chv.cgi?CH=67980
Change 67980 by davidxu at davidxu_tiger on 2004/12/31 14:57:08
rework join related code.
Affected files ...
.. //depot/projects/davidxu_thread/src/lib/libthread/thread/thr_join.c#3 edit
Differences ...
==== //depot/projects/davidxu_thread/src/lib/libthread/thread/thr_join.c#3 (text+ko) ====
@@ -37,121 +37,131 @@
__weak_reference(_pthread_join, pthread_join);
+static void backout_join(void *arg)
+{
+ struct pthread *curthread = _get_curthread();
+ struct pthread *pthread = (struct pthread *)arg;
+
+ THREAD_LIST_LOCK(curthread);
+ if (_thr_find_thread(curthread, pthread, /*include dead*/1) == 0) {
+ if (pthread->joiner == curthread)
+ pthread->joiner = NULL;
+ }
+ THREAD_LIST_UNLOCK(curthread);
+}
+
int
_pthread_join(pthread_t pthread, void **thread_return)
{
struct pthread *curthread = _get_curthread();
void *tmp;
+ int oldcancel;
int ret = 0;
- _thr_cancel_enter(curthread);
-
- /* Check if the caller has specified an invalid thread: */
- if (pthread == NULL || pthread->magic != THR_MAGIC) {
- /* Invalid thread: */
- _thr_cancel_leave(curthread, 1);
+ if (pthread == NULL) {
return (EINVAL);
}
- /* Check if the caller has specified itself: */
if (pthread == curthread) {
- /* Avoid a deadlock condition: */
- _thr_cancel_leave(curthread, 1);
return (EDEADLK);
}
- /*
- * Find the thread in the list of active threads or in the
- * list of dead threads:
- */
- if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/1)) != 0) {
- /* Return an error: */
- _thr_cancel_leave(curthread, 1);
+ THREAD_LIST_LOCK(curthread);
+ if ((ret = _thr_find_thread(curthread, pthread, /*include dead*/1)) != 0) {
+ THREAD_LIST_UNLOCK(curthread);
return (ESRCH);
}
+ /* Check if this thread has been detached. */
+ if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) {
+ THREAD_LIST_UNLOCK(curthread);
+ return (ESRCH);
+ }
+
THR_THREAD_LOCK(curthread, pthread);
- /* Check if this thread has been detached: */
- if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
+ /* Lock the target thread while checking its state. */
+ if (pthread->state == PS_DEAD) {
+ /* Return the thread's return value. */
+ tmp = pthread->ret;
+
THR_THREAD_UNLOCK(curthread, pthread);
- /* Remove the reference and return an error: */
- _thr_ref_delete(curthread, pthread);
- ret = ESRCH;
- } else {
- /* Lock the target thread while checking its state. */
- if (pthread->state == PS_DEAD) {
- /* Return the thread's return value: */
- tmp = pthread->ret;
+
+ /* Detach the thread. */
+ pthread->tlflags |= TLFLAGS_DETACHED;
+
+ /*
+ * Remove the thread from the list of active
+ * threads and add it to the GC list.
+ */
+ THR_LIST_REMOVE(pthread);
+ THR_GCLIST_ADD(pthread);
+
+ /* Unlock the thread list. */
+ THREAD_LIST_UNLOCK(curthread);
- /* Detach the thread. */
- pthread->attr.flags |= PTHREAD_DETACHED;
+ if (thread_return != NULL)
+ *thread_return = tmp;
+ return (0);
+ }
+ THR_THREAD_UNLOCK(curthread, pthread);
- /* Unlock the thread. */
- THR_THREAD_UNLOCK(curthread, pthread);
+ if (pthread->joiner != NULL) {
+ THREAD_LIST_UNLOCK(curthread);
- /*
- * Remove the thread from the list of active
- * threads and add it to the GC list.
- */
- THR_LOCK_ACQUIRE(curthread, &_thread_list_lock);
- THR_LIST_REMOVE(pthread);
- THR_GCLIST_ADD(pthread);
- THR_LOCK_RELEASE(curthread, &_thread_list_lock);
+ /* Multiple joiners are not supported. */
+ return (ENOTSUP);
+ }
- /* Remove the reference. */
- _thr_ref_delete(curthread, pthread);
- if (thread_return != NULL)
- *thread_return = tmp;
- }
- else if (pthread->joiner != NULL) {
- /* Unlock the thread and remove the reference. */
- THR_THREAD_UNLOCK(curthread, pthread);
- _thr_ref_delete(curthread, pthread);
+ /* Set the running thread to be the joiner: */
+ pthread->joiner = curthread;
- /* Multiple joiners are not supported. */
- ret = ENOTSUP;
- }
- else {
- /* Set the running thread to be the joiner: */
- pthread->joiner = curthread;
+ /* Keep track of which thread we're joining to: */
+ curthread->join_status.error = 0;
+ curthread->join_status.thread = pthread;
- /* Keep track of which thread we're joining to: */
- curthread->join_status.thread = pthread;
+ THREAD_LIST_UNLOCK(curthread);
- /* Unlock the thread and remove the reference. */
- THR_THREAD_UNLOCK(curthread, pthread);
- _thr_ref_delete(curthread, pthread);
+ THR_CLEANUP_PUSH(curthread, backout_join, pthread);
- THR_LOCK_SWITCH(curthread);
- while (curthread->join_status.thread == pthread) {
- THR_SET_STATE(curthread, PS_JOIN);
- /* Schedule the next thread: */
- _thr_sched_switch_unlocked(curthread);
- THR_LOCK_SWITCH(curthread);
- }
- THR_UNLOCK_SWITCH(curthread);
+ long cycle;
+ THR_LOCK(curthread);
+ while (curthread->join_status.thread == pthread) {
+ cycle = curthread->cycle;
+ THR_UNLOCK(curthread);
+ oldcancel = _thr_cancel_enter(curthread);
+ umtx_wait((struct umtx *)&curthread->cycle, cycle);
+ _thr_cancel_leave(curthread, oldcancel);
+ THR_LOCK(curthread);
+ }
+ THR_UNLOCK(curthread);
+ THR_CLEANUP_POP(curthread, 0);
- if ((curthread->cancelflags & THR_CANCELLING) &&
- !(curthread->cancelflags & PTHREAD_CANCEL_DISABLE)) {
- if (_thr_ref_add(curthread, pthread, 1) == 0) {
- THR_THREAD_LOCK(curthread, pthread);
- pthread->joiner = NULL;
- THR_THREAD_UNLOCK(curthread, pthread);
- _thr_ref_delete(curthread, pthread);
- }
- pthread_exit(PTHREAD_CANCELED);
+ if (curthread->join_status.error == 0) {
+ THREAD_LIST_LOCK(curthread);
+ if (_thr_find_thread(curthread, pthread, /*include dead*/1) == 0) {
+ if (pthread->joiner == curthread) {
+ pthread->tlflags |= TLFLAGS_DETACHED;
+ /*
+ * Remove the thread from the list of active
+ * threads and add it to the GC list.
+ */
+ THR_LIST_REMOVE(pthread);
+ THR_GCLIST_ADD(pthread);
}
-
- /*
- * The thread return value and error are set by the
- * thread we're joining to when it exits or detaches:
- */
- ret = curthread->join_status.error;
- if ((ret == 0) && (thread_return != NULL))
- *thread_return = curthread->join_status.ret;
+ THREAD_LIST_UNLOCK(curthread);
+ } else {
+ THREAD_LIST_UNLOCK(curthread);
+ /* Return an error: */
+ return (ESRCH);
}
}
- _thr_cancel_leave(curthread, 1);
+ /*
+ * The thread return value and error are set by the
+ * thread we're joining to when it exits or detaches:
+ */
+ ret = curthread->join_status.error;
+ if ((ret == 0) && (thread_return != NULL))
+ *thread_return = curthread->join_status.ret;
/* Return the completion status: */
return (ret);
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