xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.threads/schedlock.c (revision 8b657b0747480f8989760d71343d6dd33f8d4cf9)
1 /* This testcase is part of GDB, the GNU debugger.
2 
3    Copyright 2002-2023 Free Software Foundation, Inc.
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 3 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 the
13    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, see <http://www.gnu.org/licenses/>.  */
17 
18 #include <stdio.h>
19 #include <unistd.h>
20 #include <stdlib.h>
21 #include <pthread.h>
22 
23 void *thread_function(void *arg); /* Pointer to function executed by each thread */
24 
25 #define NUM 1
26 
27 unsigned int args[NUM+1];
28 
29 int main() {
30     int res;
31     pthread_t threads[NUM];
32     void *thread_result;
33     long i;
34 
35     for (i = 1; i <= NUM; i++)
36       {
37 	args[i] = 1;
38 	res = pthread_create(&threads[i - 1],
39 		             NULL,
40 			     thread_function,
41 			     (void *) i);
42       }
43 
44     /* schedlock.exp: last thread start.  */
45     args[0] = 1;
46     thread_function ((void *) 0);
47 
48     exit(EXIT_SUCCESS);
49 }
50 
51 void some_function (void) {
52   /* Sleep a bit to give the other threads a chance to run, if not
53      locked.  This also ensure that even if the compiler optimizes out
54      or inlines some_function, there's still be some function that
55      needs to be stepped over.  */
56   usleep (1);
57 }
58 
59 /* When testing "next", this is set to have the loop call
60    some_function, which GDB should step over.  When testing "step",
61    that would step into the function, which is not what we want.  */
62 volatile int call_function = 0;
63 
64 /* Call some_function if CALL_FUNCTION is set.  This is wrapped in a
65    macro so that it's a single source line in the main loop.  */
66 #define MAYBE_CALL_SOME_FUNCTION()		\
67   do						\
68     {						\
69       if (call_function)			\
70 	some_function ();			\
71     } while (0)
72 
73 void *thread_function(void *arg) {
74     int my_number =  (long) arg;
75     int *myp = (int *) &args[my_number];
76 
77     /* Don't run forever.  Run just short of it :)  */
78     while (*myp > 0)
79       {
80 	/* schedlock.exp: main loop.  */
81 	MAYBE_CALL_SOME_FUNCTION(); (*myp) ++;
82       }
83 
84     pthread_exit(NULL);
85 }
86 
87