Update.

2003-02-16  Ulrich Drepper  <drepper@redhat.com>

	* libc-cancellation.c (__libc_enable_asynccancel): Rwrite to avoid
	going into an endless loop.
	* Makefile (tests): Add tst-cancel9.
	* tst-cancel9.c: New file.

	* pthread_cancel.c (pthread_cancel): Use the result of __pthread_kill.

nptl/ChangeLog

@@ -1,3 +1,12 @@
+2003-02-16  Ulrich Drepper  <drepper@redhat.com>
+
+	* libc-cancellation.c (__libc_enable_asynccancel): Rwrite to avoid
+	going into an endless loop.
+	* Makefile (tests): Add tst-cancel9.
+	* tst-cancel9.c: New file.
+
+	* pthread_cancel.c (pthread_cancel): Use the result of __pthread_kill.
+
 2003-02-15  Ulrich Drepper  <drepper@redhat.com>
 
 	* tst-mutex5.c (do_test): Add more timedlock tests.

nptl/Makefile

@@ -142,7 +142,7 @@ tests = tst-attr1 tst-attr2 \
 	tst-fork1 tst-fork2 tst-fork3 \
 	tst-atfork1 \
 	tst-cancel1 tst-cancel2 tst-cancel3 tst-cancel4 tst-cancel5 \
-	tst-cancel6 tst-cancel7 tst-cancel8 \
+	tst-cancel6 tst-cancel7 tst-cancel8 tst-cancel9 \
 	tst-cleanup1 tst-cleanup2 tst-cleanup3 \
 	tst-flock1 tst-flock2 \
 	tst-signal1 tst-signal2 tst-signal3 \

nptl/libc-cancellation.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2002 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -40,20 +40,30 @@ __libc_enable_asynccancel (void)
       oldval = THREAD_GETMEM (self, cancelhandling);
       int newval = oldval | CANCELTYPE_BITMASK;
 
-      if (newval == oldval)
+      if (__builtin_expect ((oldval & CANCELED_BITMASK) != 0, 0))
-	break;
+	{
+	  /* If we are already exiting stop right here.  */
+	  if ((oldval & EXITING_BITMASK) != 0)
+	    break;
+
+	  if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval,
+					       oldval) == 0)
+	    /* Somebody else modified the word, try again.  */
+	    continue;
+
+	  THREAD_SETMEM (self, result, PTHREAD_CANCELED);
+
+	  /* The thread is exiting now.  */
+	  atomic_bit_set (&self->cancelhandling, EXITING_BIT);
+
+	  __do_cancel ();
+
+	  /* NOTREACHED */
+	}
 
       if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval,
 					   oldval) == 0)
-	{
+	break;
-	  if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
-	    {
-	      THREAD_SETMEM (self, result, PTHREAD_CANCELED);
-	      __do_cancel ();
-	    }
-
-	  break;
-	}
     }
 
   return oldval;

nptl/tst-cancel9.c

@@ -0,0 +1,126 @@
+/* Copyright (C) 2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   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 <fcntl.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+static pthread_barrier_t b;
+
+
+static void
+cleanup (void *arg)
+{
+  fprintf (stderr, "in cleanup\n");
+}
+
+
+static void *
+tf (void *arg)
+{
+  int fd = open ("/dev/null", O_RDWR);
+  if (fd == -1)
+    {
+      puts ("cannot open /dev/null");
+      exit (1);
+    }
+  FILE *fp = fdopen (fd, "w");
+  if (fp == NULL)
+    {
+      puts ("fdopen failed");
+      exit (1);
+    }
+
+  pthread_cleanup_push (cleanup, NULL);
+
+  int e = pthread_barrier_wait (&b);
+  if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
+    {
+      puts ("barrier_wait failed");
+      exit (1);
+    }
+
+  while (1)
+    /* fprintf() uses write() which is a cancallation point.  */
+    fprintf (fp, "foo");
+
+  pthread_cleanup_pop (0);
+
+  return NULL;
+}
+
+
+static int
+do_test (void)
+{
+  if (pthread_barrier_init (&b, NULL, 2) != 0)
+    {
+      puts ("barrier_init failed");
+      exit (1);
+    }
+
+  pthread_t th;
+  if (pthread_create (&th, NULL, tf, NULL) != 0)
+    {
+      puts ("create failed");
+      return 1;
+    }
+
+  int e = pthread_barrier_wait (&b);
+  if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
+    {
+      puts ("barrier_wait failed");
+      exit (1);
+    }
+
+  sleep (1);
+
+  puts ("cancel now");
+
+  if (pthread_cancel (th) != 0)
+    {
+      puts ("cancel failed");
+      exit (1);
+    }
+
+  puts ("waiting for the child");
+
+  void *r;
+  if (pthread_join (th, &r) != 0)
+    {
+      puts ("join failed");
+      exit (1);
+    }
+
+  if (r != PTHREAD_CANCELED)
+    {
+      puts ("thread wasn't canceled");
+      exit (1);
+    }
+
+  return 0;
+}
+
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"