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      1 /*
      2  * Copyright (c) 2002, Intel Corporation. All rights reserved.
      3  * Created by:  crystal.xiong REMOVE-THIS AT intel DOT com
      4  * This file is licensed under the GPL license.  For the full content
      5  * of this license, see the COPYING file at the top level of this
      6  * source tree.
      7  *
      8  * This test use semaphore to protect critical section between several
      9  * processes.
     10  */
     11 #include <stdio.h>
     12 #include <unistd.h>
     13 #include <fcntl.h>
     14 #include <stdlib.h>
     15 #include <sys/wait.h>
     16 #include <sys/mman.h>
     17 #include <string.h>
     18 #include <errno.h>
     19 #include <semaphore.h>
     20 
     21 #include "posixtest.h"
     22 
     23 #define SEM_NAME       "/tmp/semaphore"
     24 #define BUF_SIZE	200
     25 #define DEFAULT_THREADS 5
     26 
     27 int main(int argc, char *argv[])
     28 {
     29 	sem_t *sem_lock;
     30 	int shared = 1;
     31 	int value = 1;
     32 	pid_t pid = 0;
     33 	int i, num = 0;
     34 	char buf[BUF_SIZE];
     35 	char *c;
     36 
     37 #ifndef	_POSIX_SEMAPHORES
     38 	printf("_POSIX_SEMAPHORES is not defined \n");
     39 	return PTS_UNRESOLVED;
     40 #endif
     41 	if ((2 != argc) || ((num = atoi(argv[1])) <= 0)) {
     42 		printf("Setting num_of_processes to default value: %d\n",
     43 		       DEFAULT_THREADS);
     44 		num = DEFAULT_THREADS;
     45 	}
     46 	if ((sem_lock = malloc(sizeof(sem_t))) == NULL) {
     47 		perror("malloc");
     48 		return PTS_UNRESOLVED;
     49 	}
     50 	if (sem_init(sem_lock, shared, value) == -1) {
     51 		perror("sem_init didn't return success\n");
     52 		return PTS_UNRESOLVED;
     53 	}
     54 	for (i = 1; i < num; i++)
     55 		switch ((pid = fork())) {
     56 		case -1:
     57 			perror("fork");
     58 			return PTS_UNRESOLVED;
     59 		case 0:
     60 			break;
     61 		default:
     62 			sleep(2);
     63 			break;
     64 		}
     65 
     66 	sprintf(buf, "%d process_ID: %ld parent_process_ID: %ld "
     67 		"child_process_ID: %ld\n", i, (long)getpid(),
     68 		(long)getppid(), (long)pid);
     69 
     70 	if (sem_wait(sem_lock) == -1) {
     71 		perror("sem_wait didn't return success\n");
     72 		return PTS_UNRESOLVED;
     73 	}
     74 	for (i = 1; i <= 10; i++) {
     75 		c = buf;
     76 		while (*c != '\n') {
     77 			fputc(*c, stdout);
     78 			c++;
     79 		}
     80 		fputc('\n', stdout);
     81 	}
     82 
     83 	if (sem_post(sem_lock) == -1) {
     84 		perror("sem_wait didn't return success\n");
     85 		return PTS_UNRESOLVED;
     86 	}
     87 
     88 	return PTS_PASS;
     89 }
     90