1 /* Test sem_wait cancellation for contended case.
2    Copyright (C) 2003-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library 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 the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <errno.h>
20 #include <pthread.h>
21 #include <semaphore.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 
27 
28 static pthread_barrier_t bar;
29 static sem_t sem;
30 
31 
32 static void
cleanup(void * arg)33 cleanup (void *arg)
34 {
35   static int ncall;
36 
37   if (++ncall != 1)
38     {
39       puts ("second call to cleanup");
40       exit (1);
41     }
42 }
43 
44 
45 static void *
tf(void * arg)46 tf (void *arg)
47 {
48   pthread_cleanup_push (cleanup, NULL);
49 
50   int e = pthread_barrier_wait (&bar);
51   if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
52     {
53       puts ("error: tf: 1st barrier_wait failed");
54       exit (1);
55     }
56 
57   /* This call should block and be cancelable.  */
58   sem_wait (&sem);
59 
60   pthread_cleanup_pop (0);
61 
62   return NULL;
63 }
64 
65 
66 static int
do_test(void)67 do_test (void)
68 {
69   pthread_t th;
70 
71   if (pthread_barrier_init (&bar, NULL, 2) != 0)
72     {
73       puts ("error: barrier_init failed");
74       exit (1);
75     }
76 
77   /* A value equal to 0 will check for contended pthread cancellation,
78      where the sem_wait operation will block.  */
79   if (sem_init (&sem, 0, 0) != 0)
80     {
81       puts ("error: sem_init failed");
82       exit (1);
83     }
84 
85   if (pthread_create (&th, NULL, tf, NULL) != 0)
86     {
87       puts ("error: create failed");
88       exit (1);
89     }
90 
91   int e = pthread_barrier_wait (&bar);
92   if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
93     {
94       puts ("error: 1st barrier_wait failed");
95       exit (1);
96     }
97 
98   /* Give the child a chance to go to sleep in sem_wait.  */
99   sleep (1);
100 
101   /* Check whether cancellation is honored when waiting in sem_wait.  */
102   if (pthread_cancel (th) != 0)
103     {
104       puts ("error: 1st cancel failed");
105       exit (1);
106     }
107 
108   void *r;
109   if (pthread_join (th, &r) != 0)
110     {
111       puts ("error: join failed");
112       exit (1);
113     }
114 
115   if (r != PTHREAD_CANCELED)
116     {
117       puts ("thread not canceled");
118       exit (1);
119     }
120 
121   return 0;
122 }
123 
124 
125 #define TEST_FUNCTION do_test ()
126 #include "../test-skeleton.c"
127