xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.c (revision 9616dacfef448e70e3fbbd865bddf60d54b656c5)
1 /* This testcase is part of GDB, the GNU debugger.
2 
3    Copyright 2015 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 <assert.h>
19 #include <pthread.h>
20 #include <unistd.h>
21 #include <stdio.h>
22 #include <sys/types.h>
23 #include <sys/wait.h>
24 #include <stdlib.h>
25 
26 /* Number of threads.  Each thread continuously spawns a fork and wait
27    for it.  If we have another thread continuously start a step over,
28    gdbserver should end up finding new forks while suspending
29    threads.  */
30 #define NTHREADS 10
31 
32 pthread_t threads[NTHREADS];
33 
34 pthread_barrier_t barrier;
35 
36 #define NFORKS 10
37 
38 /* Used to create a conditional breakpoint that always fails.  */
39 volatile int zero;
40 
41 static void *
42 thread_forks (void *arg)
43 {
44   int i;
45 
46   pthread_barrier_wait (&barrier);
47 
48   for (i = 0; i < NFORKS; i++)
49     {
50       pid_t pid;
51 
52       pid = fork ();
53 
54       if (pid > 0)
55 	{
56 	  int status;
57 
58 	  /* Parent.  */
59 	  pid = waitpid (pid, &status, 0);
60 	  if (pid == -1)
61 	    {
62 	      perror ("wait");
63 	      exit (1);
64 	    }
65 
66 	  if (!WIFEXITED (status))
67 	    {
68 	      printf ("Unexpected wait status 0x%x from child %d\n",
69 		      status, pid);
70 	    }
71 	}
72       else if (pid == 0)
73 	{
74 	  /* Child.  */
75 	  exit (0);
76 	}
77       else
78 	{
79 	  perror ("fork");
80 	  exit (1);
81 	}
82     }
83 }
84 
85 /* Set this to tell the thread_breakpoint thread to exit.  */
86 volatile int break_out;
87 
88 static void *
89 thread_breakpoint (void *arg)
90 {
91   pthread_barrier_wait (&barrier);
92 
93   while (!break_out)
94     {
95       usleep (1); /* set break here */
96     }
97 
98   return NULL;
99 }
100 
101 pthread_barrier_t barrier;
102 
103 int
104 main (void)
105 {
106   int i;
107   int ret;
108   pthread_t bp_thread;
109 
110   /* Don't run forever.  */
111   alarm (180);
112 
113   pthread_barrier_init (&barrier, NULL, NTHREADS + 1);
114 
115   /* Start the threads that constantly fork.  */
116   for (i = 0; i < NTHREADS; i++)
117     {
118       ret = pthread_create (&threads[i], NULL, thread_forks, NULL);
119       assert (ret == 0);
120     }
121 
122   /* Start the thread that constantly hit a conditional breakpoint
123      that needs to be stepped over.  */
124   ret = pthread_create (&bp_thread, NULL, thread_breakpoint, NULL);
125   assert (ret == 0);
126 
127   /* Wait for forking to stop.  */
128   for (i = 0; i < NTHREADS; i++)
129     {
130       ret = pthread_join (threads[i], NULL);
131       assert (ret == 0);
132     }
133 
134   break_out = 1;
135   pthread_join (bp_thread, NULL);
136   assert (ret == 0);
137 
138   return 0;
139 }
140