2003-03-18 Roland McGrath <roland@redhat.com>

	* td_thr_event_getmsg.c (td_thr_event_getmsg): Splice the thread out
	of the ->nextevent linkage.

1 files changed, 48 insertions, 3 deletions

diff --git a/nptl_db/td_thr_event_getmsg.c b/nptl_db/td_thr_event_getmsg.c
index ffd0baa..9008633 100644
--- a/nptl_db/td_thr_event_getmsg.c
+++ b/nptl_db/td_thr_event_getmsg.c
@@ -1,5 +1,5 @@
 /* Retrieve event.
-   Copyright (C) 1999, 2001, 2002 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2001, 2002, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
 
@@ -31,7 +31,7 @@ td_thr_event_getmsg (const td_thrhandle_t *th, td_event_msg_t *msg)
 
   LOG ("td_thr_event_getmsg");
 
-  /* Read the even structure from the target.  */
+  /* Read the event structure from the target.  */
   if (ps_pdread (th->th_ta_p->ph,
 		 ((char *) th->th_unique
 		  + offsetof (struct pthread, eventbuf)),
@@ -56,5 +56,50 @@ td_thr_event_getmsg (const td_thrhandle_t *th, td_event_msg_t *msg)
 		  &event, sizeof (td_eventbuf_t)) != PS_OK)
     return TD_ERR;	/* XXX Other error value?  */
 
-  return TD_OK;
+  /* Get the pointer to the thread descriptor with the last event.
+     If it doesn't match TH, then walk down the list until we find it.
+     We must splice it out of the list so that there is no dangling
+     pointer to it later when it dies.  */
+  psaddr_t thp, prevp = th->th_ta_p->pthread_last_event;
+  if (ps_pdread (th->th_ta_p->ph,
+		 prevp, &thp, sizeof (struct pthread *)) != PS_OK)
+    return TD_ERR;	/* XXX Other error value?  */
+
+  psaddr_t next;
+  while (thp != 0)
+    {
+      if (ps_pdread (th->th_ta_p->ph,
+		     (char *) thp + offsetof (struct pthread, nextevent),
+		     &next, sizeof (struct pthread *)) != PS_OK)
+	return TD_ERR;	/* XXX Other error value?  */
+
+      if (next == thp)
+	return TD_DBERR;
+
+      if (thp == th->th_unique)
+	{
+	  /* PREVP points at this thread, splice it out.  */
+	  if (prevp == (char *) next + offsetof (struct pthread, nextevent))
+	    return TD_DBERR;
+
+	  if (ps_pdwrite (th->th_ta_p->ph, prevp, &next, sizeof next) != PS_OK)
+	    return TD_ERR;	/* XXX Other error value?  */
+
+	  /* Now clear this thread's own next pointer so it's not dangling
+	     when the thread resumes and then chains on for its next event.  */
+	  next = NULL;
+	  if (ps_pdwrite (th->th_ta_p->ph,
+			  (char *) thp + offsetof (struct pthread, nextevent),
+			  &next, sizeof next) != PS_OK)
+	    return TD_ERR;	/* XXX Other error value?  */
+
+	  return TD_OK;
+	}
+
+      prevp = (char *) thp + offsetof (struct pthread, nextevent);
+      thp = next;
+    }
+
+  /* Ack!  This should not happen.  */
+  return TD_DBERR;
 }