commit 055b96e76b6f7b8937828b89361f609a55a3df0f
Author: Jeremie Koenig <jk@jk.fr.eu.org>
Date:   Wed Jul 20 00:55:34 2011 +0000

    fix sigwait for pending signals

diff --git a/sysdeps/mach/hurd/sigwait.c b/sysdeps/mach/hurd/sigwait.c
index af50f74..61316bc 100644
--- a/sysdeps/mach/hurd/sigwait.c
+++ b/sysdeps/mach/hurd/sigwait.c
@@ -11,41 +11,41 @@
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, write to the Free
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
 #include <errno.h>
 #include <hurd.h>
 #include <hurd/signal.h>
 #include <hurd/msg.h>
 #include <hurd/sigpreempt.h>
 #include <assert.h>
 
 /* Select any of pending signals from SET or wait for any to arrive.  */
 int
 __sigwait (const sigset_t *set, int *sig)
 {
   struct hurd_sigstate *ss;
-  sigset_t mask, ready, blocked;
+  sigset_t mask, blocked;
   int signo = 0;
   struct hurd_signal_preemptor preemptor;
   jmp_buf buf;
   mach_port_t wait;
   mach_msg_header_t msg;
 
   sighandler_t
     preempt_fun (struct hurd_signal_preemptor *pe,
 		 struct hurd_sigstate *ss,
 		 int *sigp,
 		 struct hurd_signal_detail *detail)
     {
       if (signo)
 	/* We've already been run; don't interfere. */
 	return SIG_ERR;
 
       signo = *sigp;
 
       /* Make sure this is all kosher */
       assert (__sigismember (&mask, signo));
@@ -57,82 +57,74 @@ __sigwait (const sigset_t *set, int *sig)
     }
 
   void
     handler (int sig)
     {
       assert (sig == signo);
       longjmp (buf, 1);
     }
 
   wait = __mach_reply_port ();
 
   if (set != NULL)
     /* Crash before locking */
     mask = *set;
   else
     __sigemptyset (&mask);
 
   ss = _hurd_self_sigstate ();
   _hurd_sigstate_lock (ss);
 
-  /* See if one of these signals is currently pending.  */
-  sigset_t pending = _hurd_sigstate_pending (ss);
-  __sigandset (&ready, &pending, &mask);
-  if (! __sigisemptyset (&ready))
-    {
-      for (signo = 1; signo < NSIG; signo++)
-	if (__sigismember (&ready, signo))
-	  {
-	    __sigdelset (&ready, signo);
-	    goto all_done;
-	  }
-      /* Huh?  Where'd it go? */
-      abort ();
-    }
-
-  /* Wait for one of them to show up.  */
+  /* Wait for one of the signals in MASK to show up.  */
 
   if (!setjmp (buf))
     {
       /* Make the preemptor */
       preemptor.signals = mask;
       preemptor.first = 0;
       preemptor.last = -1;
       preemptor.preemptor = preempt_fun;
       preemptor.handler = handler;
 
       /* Install this preemptor */
       preemptor.next = ss->preemptors;
       ss->preemptors = &preemptor;
 
       /* Unblock the expected signals */
       blocked = ss->blocked;
       ss->blocked &= ~mask;
 
+      /* See if one of them is currently pending.  */
+      sigset_t ready = _hurd_sigstate_pending (ss);
+      __sigandset (&ready, &ready, &mask);
+
       _hurd_sigstate_unlock (ss);
 
+      if (! __sigisemptyset (&ready))
+	/* Send a message to the signal thread so it
+	   will wake up and check for pending signals.  */
+	__msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());
+
       /* Wait. */
       __mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,
 		  MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
       abort ();
     }
   else
     {
       assert (signo);
 
       _hurd_sigstate_lock (ss);
 
       /* Delete our preemptor. */
       assert (ss->preemptors == &preemptor);
       ss->preemptors = preemptor.next;
     }
 
-
-all_done:
   _hurd_sigstate_unlock (ss);
 
   __mach_port_destroy (__mach_task_self (), wait);
   *sig = signo;
   return 0;
 }
 
 weak_alias (__sigwait, sigwait)