1 /* test whether fcntl locking works between threads on this Linux system */
2
3 #include <unistd.h>
4
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <sys/types.h>
8
9 #include <fcntl.h>
10
11 #include <sys/fcntl.h>
12
13 #include <sys/wait.h>
14
15 #include <errno.h>
16 #include <pthread.h>
17
sys_waitpid(pid_t pid,int * status,int options)18 static int sys_waitpid(pid_t pid,int *status,int options)
19 {
20 return waitpid(pid,status,options);
21 }
22
23 #define DATA "conftest.fcntl"
24
25 #define SEEK_SET 0
26
test_thread(void * thread_parm)27 static void *test_thread(void *thread_parm)
28 {
29 int *status = thread_parm;
30 int fd, ret;
31 struct flock lock;
32
33 sleep(2);
34 fd = open(DATA, O_RDWR);
35
36 if (fd == -1) {
37 fprintf(stderr,"ERROR: failed to open %s (errno=%d)\n",
38 DATA, (int)errno);
39 pthread_exit(thread_parm);
40 }
41
42 lock.l_type = F_WRLCK;
43 lock.l_whence = SEEK_SET;
44 lock.l_start = 0;
45 lock.l_len = 4;
46 lock.l_pid = 0;
47
48 /* check if a lock applies */
49 ret = fcntl(fd,F_SETLK,&lock);
50 if ((ret != -1)) {
51 fprintf(stderr,"ERROR: lock test failed (ret=%d errno=%d)\n", ret, (int)errno);
52 } else {
53 *status = 0; /* SUCCESS! */
54 }
55 pthread_exit(thread_parm);
56 }
57
58 /* lock a byte range in a open file */
main(int argc,char * argv[])59 int main(int argc, char *argv[])
60 {
61 struct flock lock;
62 int fd, ret, status=1, rc;
63 pid_t pid;
64 char *testdir = NULL;
65 pthread_t thread_id;
66 pthread_attr_t thread_attr;
67
68 testdir = getenv("TESTDIR");
69 if (testdir) chdir(testdir);
70
71 alarm(10);
72
73 pthread_attr_init(&thread_attr);
74 pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
75 rc = pthread_create(&thread_id, &thread_attr, &test_thread, &status);
76 pthread_attr_destroy(&thread_attr);
77 if (rc == 0) {
78 fprintf(stderr,"created thread_id=%lu\n",
79 (unsigned long int)thread_id);
80 } else {
81 fprintf(stderr,"ERROR: thread create failed, rc=%d\n", rc);
82 }
83
84 unlink(DATA);
85 fd = open(DATA, O_RDWR|O_CREAT|O_RDWR, 0600);
86
87 if (fd == -1) {
88 fprintf(stderr,"ERROR: failed to open %s (errno=%d)\n",
89 DATA, (int)errno);
90 exit(1);
91 }
92
93 lock.l_type = F_WRLCK;
94 lock.l_whence = SEEK_SET;
95 lock.l_start = 0;
96 lock.l_len = 4;
97 lock.l_pid = getpid();
98
99 /* set a 4 byte write lock */
100 fcntl(fd,F_SETLK,&lock);
101
102 sleep(4); /* allow thread to try getting lock */
103
104 unlink(DATA);
105
106 #if defined(WIFEXITED) && defined(WEXITSTATUS)
107 if(WIFEXITED(status)) {
108 status = WEXITSTATUS(status);
109 } else {
110 status = 1;
111 }
112 #else /* defined(WIFEXITED) && defined(WEXITSTATUS) */
113 status = (status == 0) ? 0 : 1;
114 #endif /* defined(WIFEXITED) && defined(WEXITSTATUS) */
115
116 if (status) {
117 fprintf(stderr,"ERROR: lock test failed with status=%d\n",
118 status);
119 }
120
121 exit(status);
122 }
123