From 5aded6f2abbe19bc77e563b7db10aa9dd037a90d Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Wed, 13 Jan 2016 16:04:42 +0100 Subject: Don't do lock elision on an error checking mutex (bug 17514) Error checking mutexes are not supposed to be subject to lock elision. That would defeat the error checking nature of the mutex because lock elision doesn't record ownership. --- nptl/tst-mutex-errorcheck.c | 61 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 nptl/tst-mutex-errorcheck.c (limited to 'nptl/tst-mutex-errorcheck.c') diff --git a/nptl/tst-mutex-errorcheck.c b/nptl/tst-mutex-errorcheck.c new file mode 100644 index 0000000000..7b756112a9 --- /dev/null +++ b/nptl/tst-mutex-errorcheck.c @@ -0,0 +1,61 @@ +/* Check that error checking mutexes are not subject to lock elision. + Copyright (C) 2016 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, see + . */ + +#include +#include +#include +#include + +static int +do_test (void) +{ + struct timespec tms = { 0 }; + pthread_mutex_t mutex; + pthread_mutexattr_t mutexattr; + int ret = 0; + + if (pthread_mutexattr_init (&mutexattr) != 0) + return 1; + if (pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_ERRORCHECK) != 0) + return 1; + + if (pthread_mutex_init (&mutex, &mutexattr) != 0) + return 1; + if (pthread_mutexattr_destroy (&mutexattr) != 0) + return 1; + + /* The call to pthread_mutex_timedlock erroneously enabled lock elision + on the mutex, which then triggered an assertion failure in + pthread_mutex_unlock. It would also defeat the error checking nature + of the mutex. */ + if (pthread_mutex_timedlock (&mutex, &tms) != 0) + return 1; + if (pthread_mutex_timedlock (&mutex, &tms) != EDEADLK) + { + printf ("Failed error checking on locked mutex\n"); + ret = 1; + } + + if (pthread_mutex_unlock (&mutex) != 0) + ret = 1; + + return ret; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" -- cgit v1.2.3