1/* This testcase is part of GDB, the GNU debugger.
2
3   Copyright 2015-2020 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 <pthread.h>
19#include <unistd.h>
20#include "trace-common.h"
21
22/* Called if the testcase failed.  */
23static void
24fail (void)
25{
26}
27
28static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
29
30/* This function overrides gdb_collect in the in-process agent library.
31   See gdbserver/tracepoint.c (gdb_collect).  We want this function to
32   be ran instead of the one from the library to easily check that only
33   one thread is tracing at a time.
34
35   This works as expected because GDBserver will ask GDB about symbols
36   present in the inferior with the 'qSymbol' packet.  And GDB will
37   reply with the address of this function instead of the one from the
38   in-process agent library.  */
39
40void
41gdb_agent_gdb_collect (void *tpoint, unsigned char *regs)
42{
43  /* If we cannot acquire a lock, then this means another thread is
44     tracing and the lock implemented by the jump pad is not working!  */
45  if (pthread_mutex_trylock (&mutex) != 0)
46    {
47      fail ();
48      return;
49    }
50
51  sleep (1);
52
53  if (pthread_mutex_unlock (&mutex) != 0)
54    {
55      fail ();
56      return;
57    }
58}
59
60static void *
61thread_function (void *arg)
62{
63  FAST_TRACEPOINT_LABEL(set_point);
64}
65
66static void
67end (void)
68{
69}
70
71int
72main (int argc, char *argv[], char *envp[])
73{
74  pthread_t threads[NUM_THREADS];
75  int i;
76
77  for (i = 0; i < NUM_THREADS; i++)
78    pthread_create (&threads[i], NULL, thread_function, NULL);
79
80  for (i = 0; i < NUM_THREADS; i++)
81    pthread_join (threads[i], NULL);
82
83  end ();
84
85  return 0;
86}
87