PERFORCE change 74695 for review

[David Xu]

http://perforce.freebsd.org/chv.cgi?CH=74695

Change 74695 by davidxu at davidxu_alona on 2005/04/07 22:37:08

	Reuse tid as a state indicating if the thread is exited by kernel,
	thr_exit will write a value into user given address, but there is a
	mistake that it writes out 1. :( fortunately, thread id 1 is never
	assigned to user thread, so we are safe to test if a thread is dead
	by comparing it with 1.

Affected files ...

.. //depot/projects/davidxu_thread/src/lib/libthr/pthread.map#6 edit
.. //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_create.c#5 edit
.. //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_exit.c#4 edit
.. //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_private.h#11 edit
.. //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_symbols.c#4 edit
.. //depot/projects/davidxu_thread/src/lib/libthread_db/libthr_db.c#7 edit

Differences ...

==== //depot/projects/davidxu_thread/src/lib/libthr/pthread.map#6 (text+ko) ====

@@ -358,7 +358,6 @@
 	_thread_off_state;
 	_thread_off_thr_locklevel;
 	_thread_off_tlsindex;
-	_thread_off_isdead;
 	_thread_off_enable_event;
 	_thread_size_key;
 	_thread_state_running;

==== //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_create.c#5 (text+ko) ====

@@ -93,9 +93,10 @@
 	else if (_thr_scope_system < 0)
 		new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 
+	new_thread->tid = TID_TERMINATED;
+
 	if (create_stack(&new_thread->attr) != 0) {
 		/* Insufficient memory to create a stack: */
-		new_thread->terminated = 1;
 		_thr_free(curthread, new_thread);
 		return (EAGAIN);
 	}
@@ -182,7 +183,7 @@
 free_thread(struct pthread *curthread, struct pthread *thread)
 {
 	free_stack(curthread, &thread->attr);
-	curthread->terminated = 1;
+	curthread->tid = TID_TERMINATED;
 	_thr_free(curthread, thread);
 }
 

==== //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_exit.c#4 (text+ko) ====

@@ -132,7 +132,7 @@
 		_thr_umtx_wake(&curthread->state, INT_MAX);
 	if (__predict_false(_libthr_debug))
 		_thr_report_death(curthread);
-	thr_exit(&curthread->terminated);
+	thr_exit(&curthread->tid);
 	PANIC("thr_exit() returned");
 	/* Never reach! */
 }

==== //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_private.h#11 (text+ko) ====

@@ -345,11 +345,9 @@
 	 */
 	umtx_t			lock;
 
-	/* Thread is terminated in kernel, written by kernel. */
-	long			terminated;
-
 	/* Kernel thread id. */
 	long			tid;
+#define	TID_TERMINATED		1
 
 	/* Internal condition variable cycle number. */
 	umtx_t			cycle;

==== //depot/projects/davidxu_thread/src/lib/libthr/thread/thr_symbols.c#4 (text+ko) ====

@@ -48,7 +48,6 @@
 int _thread_off_thr_locklevel = offsetof(struct pthread, locklevel);
 int _thread_off_linkmap = offsetof(Obj_Entry, linkmap);
 int _thread_off_tlsindex = offsetof(Obj_Entry, tlsindex);
-int _thread_off_isdead = offsetof(struct pthread, terminated);
 int _thread_off_enable_event = offsetof(struct pthread, enable_event);
 int _thread_size_key = sizeof(struct pthread_key);
 int _thread_off_key_allocated = offsetof(struct pthread_key, allocated);

==== //depot/projects/davidxu_thread/src/lib/libthread_db/libthr_db.c#7 (text+ko) ====

@@ -66,7 +66,6 @@
 	int		thread_off_thr_locklevel;
 	int		thread_off_next;
 	int		thread_off_state;
-	int		thread_off_isdead;
 	int		thread_off_tid;
 	int		thread_max_keys;
 	int		thread_off_key_allocated;
@@ -214,7 +213,6 @@
 	LOOKUP_VAL(ph, "_thread_off_thr_locklevel",	&ta->thread_off_thr_locklevel);
 	LOOKUP_VAL(ph, "_thread_off_next",	&ta->thread_off_next);
 	LOOKUP_VAL(ph, "_thread_off_state",	&ta->thread_off_state);
-	LOOKUP_VAL(ph, "_thread_off_isdead",	&ta->thread_off_isdead);
 	LOOKUP_VAL(ph, "_thread_max_keys",	&ta->thread_max_keys);
 	LOOKUP_VAL(ph, "_thread_off_key_allocated", &ta->thread_off_key_allocated);
 	LOOKUP_VAL(ph, "_thread_off_key_destructor", &ta->thread_off_key_destructor);
@@ -260,7 +258,8 @@
 	prgregset_t gregs;
 	TAILQ_HEAD(, pthread) thread_list;
 	psaddr_t pt;
-	int ret, isdead;
+	int ret;
+	long lwp;
 
 	TDBG_FUNC();
 
@@ -295,11 +294,11 @@
 			return (TD_NOTHR);
 		}
 		ret = ps_pread(ta->ph,
-			pt + ta->thread_off_isdead,
-			&isdead, sizeof(isdead));
+			pt + ta->thread_off_tid,
+			&lwp, sizeof(long));
 		if (ret != 0)
 			return (P2T(ret));
-		if (isdead) {
+		if (lwp == 1) {
 			ta->map[id].used = 0;
 			return (TD_NOTHR);
 		}
@@ -372,24 +371,18 @@
 
 	pt = (psaddr_t)thread_list.tqh_first;
 	while (pt != 0) {
-		ret = ps_pread(ta->ph, pt + ta->thread_off_isdead, &isdead,
-			sizeof(isdead));
+		ret = ps_pread(ta->ph, pt + ta->thread_off_tid, &tmp_lwp, 
+			      sizeof(tmp_lwp));
 		if (ret != 0)
 			return (P2T(ret));
-		if (!isdead) {
-			ret = ps_pread(ta->ph, pt + ta->thread_off_tid, &tmp_lwp, 
-				      sizeof(tmp_lwp));
-			if (ret != 0)
-				return (P2T(ret));
-			if (tmp_lwp != 0) {
-				th.th_ta  = ta;
-				th.th_tid = pt_map_thread(ta, tmp_lwp, pt);
-				th.th_thread = pt;
-				if (th.th_tid == -1)
-					return (TD_MALLOC);
-				if ((*callback)(&th, cbdata_p))
-					return (TD_DBERR);
-			}
+		if (tmp_lwp != 0 && tmp_lwp != 1) {
+			th.th_ta  = ta;
+			th.th_tid = pt_map_thread(ta, tmp_lwp, pt);
+			th.th_thread = pt;
+			if (th.th_tid == -1)
+				return (TD_MALLOC);
+			if ((*callback)(&th, cbdata_p))
+				return (TD_DBERR);
 		}
 		/* get next thread */
 		ret = ps_pread(ta->ph, pt + ta->thread_off_next, &pt,