1/*
2 *
3 *   Copyright (c) International Business Machines  Corp., 2002
4 *
5 *   This program is free software;  you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation; either version 2 of the License, or
8 *   (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13 *   the GNU General Public License for more details.
14 *
15 *   You should have received a copy of the GNU General Public License
16 *   along with this program;  if not, write to the Free Software
17 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/*
21 *  FILE        : sem02.c
22 *
23 *  DESCRIPTION : The application creates several threads using pthread_create().
24 *  One thread performs a semop() with the SEM_UNDO flag set. The change in
25 *  sempaphore value performed by that semop should be "undone" only when the
26 *  last pthread exits.
27 *
28 *  EXPECTED OUTPUT:
29 *  Waiter, pid = <pid#>
30 *  Poster, pid = <pid#>, posting
31 *  Poster posted
32 *  Poster exiting
33 *  Waiter waiting, pid = <pid#>
34 *  Waiter done waiting
35 *
36 *  HISTORY:
37 *    written by Dave Olien (oliend@us.ibm.com)
38 *    03/06/2002 Robbie Williamson (robbiew@us.ibm.com)
39 *      -ported
40 *    07/04/2003 Paul Larson (plars@linuxtestproject.org)
41 *      -ported to LTP
42 *
43 */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <unistd.h>
48#include <errno.h>
49#include <pthread.h>
50#include <sys/types.h>
51#include <sys/ipc.h>
52#include "lapi/sem.h"
53#include "test.h"
54
55#define KEY IPC_PRIVATE
56
57#define NUMTHREADS 2
58
59void *retval[NUMTHREADS];
60void *waiter(void *);
61void *poster(void *);
62void cleanup(void);
63
64char *TCID = "sem02";
65int TST_TOTAL = 1;
66
67struct sembuf Psembuf = { 0, -1, SEM_UNDO };
68struct sembuf Vsembuf = { 0, 1, SEM_UNDO };
69
70int sem_id;
71int err_ret;			/* This is used to determine PASS/FAIL status */
72int main(int argc, char **argv)
73{
74	int i, rc;
75	union semun semunion;
76
77	pthread_t pt[NUMTHREADS];
78	pthread_attr_t attr;
79
80	tst_parse_opts(argc, argv, NULL, NULL);
81	/* Create the semaphore set */
82	sem_id = semget(KEY, 1, 0666 | IPC_CREAT);
83	if (sem_id < 0) {
84		printf("semget failed, errno = %d\n", errno);
85		exit(1);
86	}
87	/* initialize data  structure associated to the semaphore */
88	semunion.val = 1;
89	semctl(sem_id, 0, SETVAL, semunion);
90
91	/* setup the attributes of the thread        */
92	/* set the scope to be system to make sure the threads compete on a  */
93	/* global scale for cpu   */
94	pthread_attr_init(&attr);
95	pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
96
97	err_ret = 1;		/* Set initial error value to 1 */
98	/* Create the threads */
99	for (i = 0; i < NUMTHREADS; i++) {
100		if (i == 0)
101			rc = pthread_create(&pt[i], &attr, waiter, retval[i]);
102		else
103			rc = pthread_create(&pt[i], &attr, poster, retval[i]);
104	}
105
106	/* Sleep long enough to see that the other threads do what they are supposed to do */
107	sleep(20);
108	semunion.val = 1;
109	semctl(sem_id, 0, IPC_RMID, semunion);
110	if (err_ret == 1)
111		tst_resm(TFAIL, "failed");
112	else
113		tst_resm(TPASS, "passed");
114	cleanup();
115
116	tst_exit();
117}
118
119/* This thread sleeps 10 seconds then waits on the semaphore.  As long
120   as someone has posted on the semaphore, and no undo has taken
121   place, the semop should complete and we'll print "Waiter done
122   waiting." */
123void *waiter(void *foo)
124{
125	int pid;
126	pid = getpid();
127
128	tst_resm(TINFO, "Waiter, pid = %d", pid);
129	sleep(10);
130
131	tst_resm(TINFO, "Waiter waiting, pid = %d", pid);
132	semop(sem_id, &Psembuf, 1);
133	tst_resm(TINFO, "Waiter done waiting");
134	err_ret = 0;		/* If the message above is displayed, the test is a PASS */
135	pthread_exit(0);
136}
137
138/* This thread immediately posts on the semaphore and then immediately
139   exits.  If the *thread* exits, the undo should not happen, and the
140   waiter thread which will start waiting on it in 10 seconds, should
141   still get it.   */
142void *poster(void *foo)
143{
144	int pid;
145
146	pid = getpid();
147	tst_resm(TINFO, "Poster, pid = %d, posting", pid);
148	semop(sem_id, &Vsembuf, 1);
149	tst_resm(TINFO, "Poster posted");
150	tst_resm(TINFO, "Poster exiting");
151
152	pthread_exit(0);
153}
154
155void cleanup(void)
156{
157}
158