581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
88 lines
2.6 KiB
C
88 lines
2.6 KiB
C
/* Test rwlock with PREFER_WRITER_NONRECURSIVE_NP (bug 23861).
|
|
Copyright (C) 2018-2022 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <pthread.h>
|
|
#include <support/xthread.h>
|
|
|
|
/* We choose 10 iterations because this happens to be able to trigger the
|
|
stall on contemporary hardware. */
|
|
#define LOOPS 10
|
|
/* We need 3 threads to trigger bug 23861. One thread as a writer, and
|
|
two reader threads. The test verifies that the second-to-last reader
|
|
is able to notify the *last* reader that it should be done waiting.
|
|
If the second-to-last reader fails to notify the last reader or does
|
|
so incorrectly then the last reader may stall indefinitely. */
|
|
#define NTHREADS 3
|
|
|
|
_Atomic int do_exit;
|
|
pthread_rwlockattr_t mylock_attr;
|
|
pthread_rwlock_t mylock;
|
|
|
|
void *
|
|
run_loop (void *a)
|
|
{
|
|
while (!do_exit)
|
|
{
|
|
if (random () & 1)
|
|
{
|
|
xpthread_rwlock_wrlock (&mylock);
|
|
xpthread_rwlock_unlock (&mylock);
|
|
}
|
|
else
|
|
{
|
|
xpthread_rwlock_rdlock (&mylock);
|
|
xpthread_rwlock_unlock (&mylock);
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int
|
|
do_test (void)
|
|
{
|
|
xpthread_rwlockattr_init (&mylock_attr);
|
|
xpthread_rwlockattr_setkind_np (&mylock_attr,
|
|
PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
|
|
xpthread_rwlock_init (&mylock, &mylock_attr);
|
|
|
|
for (int n = 0; n < LOOPS; n++)
|
|
{
|
|
pthread_t tids[NTHREADS];
|
|
do_exit = 0;
|
|
for (int i = 0; i < NTHREADS; i++)
|
|
tids[i] = xpthread_create (NULL, run_loop, NULL);
|
|
/* Let the threads run for some time. */
|
|
sleep (1);
|
|
printf ("Exiting...");
|
|
fflush (stdout);
|
|
do_exit = 1;
|
|
for (int i = 0; i < NTHREADS; i++)
|
|
xpthread_join (tids[i]);
|
|
printf ("done.\n");
|
|
}
|
|
pthread_rwlock_destroy (&mylock);
|
|
pthread_rwlockattr_destroy (&mylock_attr);
|
|
return 0;
|
|
}
|
|
|
|
#define TIMEOUT (DEFAULT_TIMEOUT + 3 * LOOPS)
|
|
#include <support/test-driver.c>
|