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glibc/nptl/tst-sem3.c
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/* Copyright (C) 2002-2016 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
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/>. */ | |
#include <errno.h> | |
#include <semaphore.h> | |
#include <stdint.h> | |
#include <stdio.h> | |
#include <stdlib.h> | |
#include <string.h> | |
#include <unistd.h> | |
#include <sys/mman.h> | |
#include <sys/wait.h> | |
int | |
do_test (void) | |
{ | |
size_t ps = sysconf (_SC_PAGESIZE); | |
char tmpfname[] = "/tmp/tst-sem3.XXXXXX"; | |
char data[ps]; | |
void *mem; | |
int fd; | |
sem_t *s; | |
pid_t pid; | |
char *p; | |
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; | |
} | |
s = (sem_t *) (((uintptr_t) mem + __alignof (sem_t)) | |
& ~(__alignof (sem_t) - 1)); | |
p = (char *) (s + 1); | |
if (sem_init (s, 1, 1) == -1) | |
{ | |
puts ("init failed"); | |
return 1; | |
} | |
if (TEMP_FAILURE_RETRY (sem_wait (s)) == -1) | |
{ | |
puts ("1st wait failed"); | |
return 1; | |
} | |
errno = 0; | |
if (TEMP_FAILURE_RETRY (sem_trywait (s)) != -1) | |
{ | |
puts ("trywait succeeded"); | |
return 1; | |
} | |
else if (errno != EAGAIN) | |
{ | |
puts ("trywait didn't return EAGAIN"); | |
return 1; | |
} | |
*p = 0; | |
puts ("going to fork now"); | |
pid = fork (); | |
if (pid == -1) | |
{ | |
puts ("fork failed"); | |
return 1; | |
} | |
else if (pid == 0) | |
{ | |
/* Play some lock ping-pong. It's our turn to unlock first. */ | |
if ((*p)++ != 0) | |
{ | |
puts ("child: *p != 0"); | |
return 1; | |
} | |
if (sem_post (s) == -1) | |
{ | |
puts ("child: 1st post failed"); | |
return 1; | |
} | |
puts ("child done"); | |
} | |
else | |
{ | |
if (TEMP_FAILURE_RETRY (sem_wait (s)) == -1) | |
{ | |
printf ("parent: 2nd wait failed: %m\n"); | |
return 1; | |
} | |
if (*p != 1) | |
{ | |
puts ("*p != 1"); | |
return 1; | |
} | |
puts ("parent done"); | |
} | |
return 0; | |
} | |
#define TEST_FUNCTION do_test () | |
#include "../test-skeleton.c" |