[src/trunk]: src/tests/lib/libpthread Try to trigger the cond_timedwait_race ...

[jmmv <jmmv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3eb13173f7b2
branches:  trunk
changeset: 785518:3eb13173f7b2
user:      jmmv <jmmv%NetBSD.org@localhost>
date:      Sun Mar 17 05:13:13 2013 +0000

description:
Try to trigger the cond_timedwait_race race several times.

Sometime this tests passes (after all, it's exercising a race condition) and
when it does it's reported as a failure.  By giving the test a few chances
to expose the problem, we prevent this noisy signal.  When the race is really
addressed, this will start failing consistently as expected.

diffstat:

 tests/lib/libpthread/t_cond.c |  26 ++++++++++++++++----------
 1 files changed, 16 insertions(+), 10 deletions(-)

diffs (52 lines):

diff -r 54f415ed5288 -r 3eb13173f7b2 tests/lib/libpthread/t_cond.c
--- a/tests/lib/libpthread/t_cond.c     Sun Mar 17 05:02:13 2013 +0000
+++ b/tests/lib/libpthread/t_cond.c     Sun Mar 17 05:13:13 2013 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: t_cond.c,v 1.3 2011/03/27 16:45:15 jruoho Exp $ */
+/* $NetBSD: t_cond.c,v 1.4 2013/03/17 05:13:13 jmmv Exp $ */
 
 /*
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -29,7 +29,7 @@
 #include <sys/cdefs.h>
 __COPYRIGHT("@(#) Copyright (c) 2008\
  The NetBSD Foundation, inc. All rights reserved.");
-__RCSID("$NetBSD: t_cond.c,v 1.3 2011/03/27 16:45:15 jruoho Exp $");
+__RCSID("$NetBSD: t_cond.c,v 1.4 2013/03/17 05:13:13 jmmv Exp $");
 
 #include <sys/time.h>
 
@@ -349,19 +349,25 @@
 ATF_TC_BODY(cond_timedwait_race, tc)
 {
        pthread_t tid[64];
-       size_t i;
+       size_t i, j;
 
        atf_tc_expect_fail("PR lib/44756");
-
-       for (i = 0; i < __arraycount(tid); i++) {
+       /* This outer loop is to ensure that a false positive of this race
+        * test does not report the test as broken (due to the test not
+        * triggering the expected failure).  However, we want to make this
+        * fail consistently when the race is resolved, and this approach
+        * will have the desired effect. */
+       for (j = 0; j < 10; j++ ) {
+               for (i = 0; i < __arraycount(tid); i++) {
 
-               PTHREAD_REQUIRE(pthread_create(&tid[i], NULL,
-                       pthread_cond_timedwait_func, NULL));
-       }
+                       PTHREAD_REQUIRE(pthread_create(&tid[i], NULL,
+                           pthread_cond_timedwait_func, NULL));
+               }
 
-       for (i = 0; i < __arraycount(tid); i++) {
+               for (i = 0; i < __arraycount(tid); i++) {
 
-               PTHREAD_REQUIRE(pthread_join(tid[i], NULL));
+                       PTHREAD_REQUIRE(pthread_join(tid[i], NULL));
+               }
        }
 }