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Diffstat (limited to 'REORG.TODO/nptl/tst-rwlock16.c')
| -rw-r--r-- | REORG.TODO/nptl/tst-rwlock16.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/tst-rwlock16.c b/REORG.TODO/nptl/tst-rwlock16.c new file mode 100644 index 0000000000..d19293198a --- /dev/null +++ b/REORG.TODO/nptl/tst-rwlock16.c @@ -0,0 +1,183 @@ +/* Copyright (C) 2015-2017 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 + <http://www.gnu.org/licenses/>. */ + +/* This tests that with a reader-preferring rwlock, all readers are woken if + one reader "steals" lock ownership from a blocked writer. */ + +#include <errno.h> +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +#include <semaphore.h> +#include <unistd.h> + +/* If we strictly prefer writers over readers, a program must not expect + that, in the presence of concurrent writers, one reader will also acquire + the lock when another reader has already done so. Thus, use the + default rwlock type that does not strictly prefer writers. */ +static pthread_rwlock_t r = PTHREAD_RWLOCK_INITIALIZER; + +static pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER; +static pthread_cond_t cv = PTHREAD_COND_INITIALIZER; + +/* Avoid using glibc-internal atomic operations. */ +static sem_t stop; +static int consumer_stop = 0; + +static void * +writer (void *arg) +{ + int s; + + do + { + if (pthread_rwlock_wrlock (&r) != 0) + { + puts ("wrlock failed"); + exit (EXIT_FAILURE); + } + if (pthread_rwlock_unlock (&r) != 0) + { + puts ("unlock failed"); + exit (EXIT_FAILURE); + } + sem_getvalue (&stop, &s); + } + while (s == 0); + return NULL; +} + +static void * +reader_producer (void *arg) +{ + int s; + + do + { + if (pthread_rwlock_rdlock (&r) != 0) + { + puts ("rdlock reader failed"); + exit (EXIT_FAILURE); + } + + sem_getvalue (&stop, &s); + + pthread_mutex_lock (&m); + if (s != 0) + consumer_stop = 1; + pthread_cond_signal (&cv); + pthread_mutex_unlock (&m); + + if (pthread_rwlock_unlock (&r) != 0) + { + puts ("unlock reader failed"); + exit (EXIT_FAILURE); + } + } + while (s == 0); + puts ("producer finished"); + return NULL; +} + +static void * +reader_consumer (void *arg) +{ + int s; + + do + { + if (pthread_rwlock_rdlock (&r) != 0) + { + puts ("rdlock reader failed"); + exit (EXIT_FAILURE); + } + + pthread_mutex_lock (&m); + s = consumer_stop; + if (s == 0) + pthread_cond_wait (&cv, &m); + pthread_mutex_unlock (&m); + + if (pthread_rwlock_unlock (&r) != 0) + { + puts ("unlock reader failed"); + exit (EXIT_FAILURE); + } + } + while (s == 0); + puts ("consumer finished"); + return NULL; +} + + +static int +do_test (void) +{ + pthread_t w1, w2, rp, rc; + + if (pthread_create (&w1, NULL, writer, NULL) != 0) + { + puts ("create failed"); + return 1; + } + if (pthread_create (&w2, NULL, writer, NULL) != 0) + { + puts ("create failed"); + return 1; + } + if (pthread_create (&rc, NULL, reader_consumer, NULL) != 0) + { + puts ("create failed"); + return 1; + } + if (pthread_create (&rp, NULL, reader_producer, NULL) != 0) + { + puts ("create failed"); + return 1; + } + + sleep (2); + sem_post (&stop); + + if (pthread_join (w1, NULL) != 0) + { + puts ("w1 join failed"); + return 1; + } + if (pthread_join (w2, NULL) != 0) + { + puts ("w2 join failed"); + return 1; + } + if (pthread_join (rp, NULL) != 0) + { + puts ("reader_producer join failed"); + return 1; + } + if (pthread_join (rc, NULL) != 0) + { + puts ("reader_consumer join failed"); + return 1; + } + + return 0; +} + + +#define TIMEOUT 3 +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" |