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/* Copyright (C) 2002-2022 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 <errno.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>
static int
do_test (void)
{
size_t ps = sysconf (_SC_PAGESIZE);
char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX";
char data[ps];
void *mem;
int fd;
pthread_mutex_t *m;
pthread_mutexattr_t ma;
pthread_rwlock_t *r;
pthread_rwlockattr_t ra;
pid_t pid;
int status = 0;
fd = mkstemp (tmpfname);
if (fd == -1)
{
printf ("cannot open temporary file: %m\n");
return 1;
}
/* Make sure it is always removed. */
unlink (tmpfname);
/* Create one page of data. */
memset (data, '\0', ps);
/* Write the data to the file. */
if (write (fd, data, ps) != (ssize_t) ps)
{
puts ("short write");
return 1;
}
mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (mem == MAP_FAILED)
{
printf ("mmap failed: %m\n");
return 1;
}
r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t))
& ~(__alignof (pthread_rwlock_t) - 1));
/* The following assumes alignment for a mutex is at least as high
as that for a rwlock. Which is true in our case. */
m = (pthread_mutex_t *) (r + 1);
if (pthread_rwlockattr_init (&ra) != 0)
{
puts ("rwlockattr_init failed");
return 1;
}
if (pthread_rwlockattr_setpshared (&ra, PTHREAD_PROCESS_SHARED) != 0)
{
puts ("rwlockattr_setpshared failed");
return 1;
}
if (pthread_rwlock_init (r, &ra) != 0)
{
puts ("rwlock_init failed");
return 1;
}
if (pthread_mutexattr_init (&ma) != 0)
{
puts ("rwlockattr_init failed");
return 1;
}
if (pthread_mutexattr_setpshared (&ma, PTHREAD_PROCESS_SHARED) != 0)
{
puts ("mutexattr_setpshared failed");
return 1;
}
if (pthread_mutex_init (m, &ma) != 0)
{
puts ("mutex_init failed");
return 1;
}
/* Lock the mutex. */
if (pthread_mutex_lock (m) != 0)
{
puts ("mutex_lock failed");
return 1;
}
puts ("going to fork now");
pid = fork ();
if (pid == -1)
{
puts ("fork failed");
return 1;
}
else if (pid == 0)
{
/* Lock the mutex. */
if (pthread_mutex_lock (m) != 0)
{
puts ("child: mutex_lock failed");
return 1;
}
/* Try to get the rwlock. */
if (pthread_rwlock_trywrlock (r) == 0)
{
puts ("rwlock_trywrlock succeeded");
return 1;
}
/* Try again. */
struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 };
int e = pthread_rwlock_timedwrlock (r, &ts);
if (e == 0)
{
puts ("rwlock_timedwrlock succeeded");
return 1;
}
if (e != ETIMEDOUT)
{
puts ("rwlock_timedwrlock didn't return ETIMEDOUT");
status = 1;
}
if (pthread_rwlock_tryrdlock (r) == 0)
{
puts ("rwlock_tryrdlock succeeded");
return 1;
}
e = pthread_rwlock_timedrdlock (r, &ts);
if (e == 0)
{
puts ("rwlock_timedrdlock succeeded");
return 1;
}
if (e != ETIMEDOUT)
{
puts ("rwlock_timedrdlock didn't return ETIMEDOUT");
status = 1;
}
}
else
{
/* Lock the rwlock for writing. */
if (pthread_rwlock_wrlock (r) != 0)
{
puts ("rwlock_wrlock failed");
kill (pid, SIGTERM);
return 1;
}
/* Allow the child to run. */
if (pthread_mutex_unlock (m) != 0)
{
puts ("mutex_unlock failed");
kill (pid, SIGTERM);
return 1;
}
/* Just wait for the child. */
if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid)
{
puts ("waitpid failed");
kill (pid, SIGTERM);
return 1;
}
}
return status;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
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