[PATCH] Fix pthread_rwlock_wrlock hang with nptl

[Jakub Jelinek <jakub at redhat dot com>]

On Wed, Feb 18, 2004 at 11:13:39AM +0100, Andreas Jaeger wrote:
> 
> The following program (extracted from mysql) hangs with nptl but not
> with linuxthreads on x86-64.

Should be fixed by the following patch:

2004-02-18  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_unlock.S
	(__pthread_rwlock_unlock): Access WRITER as 32-bit value.
	* Makefile (tests): Add tst-rwlock13.
	* tst-rwlock13.c: New test.

--- libc/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_unlock.S.jj	2003-09-22 06:40:52.000000000 +0200
+++ libc/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_unlock.S	2004-02-18 13:22:16.620462840 +0100
@@ -49,12 +49,12 @@ __pthread_rwlock_unlock:
 #endif
 	jnz	1f
 
-2:	cmpq	$0, WRITER(%rdi)
+2:	cmpl	$0, WRITER(%rdi)
 	jne	5f
 	decl	NR_READERS(%rdi)
 	jnz	6f
 
-5:	movq	$0, WRITER(%rdi)
+5:	movl	$0, WRITER(%rdi)
 
 	movq	$1, %rsi
 	leaq	WRITERS_WAKEUP(%rdi), %r10
--- libc/nptl/Makefile.jj	2004-01-12 10:52:36.000000000 +0100
+++ libc/nptl/Makefile	2004-02-18 13:34:31.600728856 +0100
@@ -196,7 +196,7 @@ tests = tst-attr1 tst-attr2 tst-attr3 \
 	tst-cond8 tst-cond9 tst-cond10 tst-cond11 tst-cond12 tst-cond13 \
 	tst-rwlock1 tst-rwlock2 tst-rwlock3 tst-rwlock4 tst-rwlock5 \
 	tst-rwlock6 tst-rwlock7 tst-rwlock8 tst-rwlock9 tst-rwlock10 \
-	tst-rwlock11 tst-rwlock12 \
+	tst-rwlock11 tst-rwlock12 tst-rwlock13 \
 	tst-once1 tst-once2 tst-once3 tst-once4 \
 	tst-key1 tst-key2 tst-key3 tst-key4 \
 	tst-sem1 tst-sem2 tst-sem3 tst-sem4 tst-sem5 tst-sem6 tst-sem7 \
--- libc/nptl/tst-rwlock13.c.jj	2004-02-18 13:27:50.189752600 +0100
+++ libc/nptl/tst-rwlock13.c	2004-02-18 13:27:45.499465632 +0100
@@ -0,0 +1,71 @@
+/* Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <pthread.h>
+#include <stdio.h>
+#include <string.h>
+
+
+static int
+do_test (void)
+{
+  pthread_rwlock_t r;
+  int ret;
+
+  memset (&r, 0xaa, sizeof (r));
+  if ((ret = pthread_rwlock_init (&r, NULL)) != 0)
+    {
+      printf ("rwlock_init failed: %d\n", ret);
+      return 1;
+    }
+
+  if ((ret = pthread_rwlock_rdlock (&r)) != 0)
+    {
+      printf ("rwlock_rdlock failed: %d\n", ret);
+      return 1;
+    }
+
+  if ((ret = pthread_rwlock_unlock (&r)) != 0)
+    {
+      printf ("rwlock_unlock failed: %d\n", ret);
+      return 1;
+    }
+
+  if ((ret = pthread_rwlock_wrlock (&r)) != 0)
+    {
+      printf ("rwlock_wrlock failed: %d\n", ret);
+      return 1;
+    }
+
+  if ((ret = pthread_rwlock_unlock (&r)) != 0)
+    {
+      printf ("second rwlock_unlock failed: %d\n", ret);
+      return 1;
+    }
+
+  if ((ret = pthread_rwlock_destroy (&r)) != 0)
+    {
+      printf ("second rwlock_destroy failed: %d\n", ret);
+      return 1;
+    }
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"

	Jakub