1/* This testcase is part of GDB, the GNU debugger.
2
3   Copyright 2021-2023 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#define _GNU_SOURCE
19#include <assert.h>
20#include <pthread.h>
21#include <stdlib.h>
22#include <stdio.h>
23#include <unistd.h>
24#include <string.h>
25#include <signal.h>
26
27/* Number of threads we'll create.  */
28int n_threads = 10;
29
30int mypid;
31
32static void
33setup_done (void)
34{
35}
36
37/* Entry point for threads.  Loops forever.  */
38
39void *
40thread_func (void *arg)
41{
42  /* Avoid setting the breakpoint at an instruction that wouldn't
43     require a fixup phase, like a branch/jump.  In such a case, even
44     if GDB manages to detach the inferior with an incomplete
45     displaced step, GDB inferior may still not crash.  A breakpoint
46     at a line that increments a variable is good bet that we end up
47     setting a breakpoint at an instruction that will require a fixup
48     phase to move the PC from the scratch pad to the instruction
49     after the breakpoint.  */
50  volatile unsigned counter = 0;
51
52  while (1)
53    {
54      counter++; /* Set breakpoint here.  */
55      counter++;
56      counter++;
57    }
58
59  return NULL;
60}
61
62/* Allow for as much timeout as DejaGnu wants, plus a bit of
63   slack.  */
64#define SECONDS (TIMEOUT + 20)
65
66/* We'll exit after this many seconds.  */
67unsigned int seconds_left = SECONDS;
68
69/* GDB sets this whenever it's about to start a new detach/attach
70   sequence.  We react by resetting the seconds-left counter.  */
71volatile int again = 0;
72
73int
74main (int argc, char **argv)
75{
76  int i;
77
78  signal (SIGUSR1, SIG_IGN);
79
80  mypid = getpid ();
81  setup_done ();
82
83  if (argc > 1)
84    n_threads = atoi (argv[1]);
85
86  /* Spawn the test threads.  */
87  for (i = 0; i < n_threads; ++i)
88    {
89      pthread_t child;
90      int rc;
91
92      rc = pthread_create (&child, NULL, thread_func, NULL);
93      assert (rc == 0);
94    }
95
96  /* Exit after a while if GDB is gone/crashes.  But wait long enough
97     for one attach/detach sequence done by the .exp file.  */
98  while (--seconds_left > 0)
99    {
100      sleep (1);
101
102      if (again)
103	{
104	  /* GDB should be reattaching soon.  Restart the timer.  */
105	  again = 0;
106	  seconds_left = SECONDS;
107	}
108    }
109
110  printf ("timeout, exiting\n");
111  return 0;
112}
113