gdb/testsuite/gdb.threads/watchthreads2.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2009-2022 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    Check that watchpoints get propagated to all existing threads when the
  19    watchpoint is created.
  20 */
  21
  22 #include <stdio.h>
  23 #include <unistd.h>
  24 #include <stdlib.h>
  25 #include <stdint.h>
  26 #include <pthread.h>
  27
  28 #ifndef NR_THREADS
  29 #define NR_THREADS 4
  30 #endif
  31
  32 #ifndef X_INCR_COUNT
  33 #define X_INCR_COUNT 10
  34 #endif
  35
  36 void *thread_function (void *arg); /* Function executed by each thread.  */
  37
  38 pthread_mutex_t x_mutex;
  39 int x;
  40
  41 /* Used to hold threads back until watchthreads2.exp is ready.  */
  42 int test_ready = 0;
  43
  44 int
  45 main ()
  46 {
  47   int res;
  48   pthread_t threads[NR_THREADS];
  49   int i;
  50
  51   pthread_mutex_init (&x_mutex, NULL);
  52
  53   for (i = 0; i < NR_THREADS; ++i)
  54     {
  55       res = pthread_create (&threads[i],
  56                             NULL,
  57                             thread_function,
  58                             (void *) (intptr_t) i);
  59       if (res != 0)
  60         {
  61           fprintf (stderr, "error in thread %d create\n", i);
  62           abort ();
  63         }
  64     }
  65
  66   for (i = 0; i < NR_THREADS; ++i)
  67     {
  68       res = pthread_join (threads[i], NULL);
  69       if (res != 0)
  70         {
  71           fprintf (stderr, "error in thread %d join\n", i);
  72           abort ();
  73         }
  74     }
  75
  76   exit (EXIT_SUCCESS);
  77 }
  78
  79 /* Easy place for a breakpoint.
  80    watchthreads2.exp uses this to track when all threads are running
  81    instead of, for example, the program keeping track
  82    because we don't need the program to know when all threads are running,
  83    instead we need gdb to know when all threads are running.
  84    There is a delay between when a thread has started and when the thread
  85    has been registered with gdb.  */
  86
  87 void
  88 thread_started ()
  89 {
  90 }
  91
  92 void *
  93 thread_function (void *arg)
  94 {
  95   int i;
  96
  97   thread_started ();
  98
  99   /* Don't start incrementing X until watchthreads2.exp is ready.  */
 100   while (! test_ready)
 101     usleep (1);
 102
 103   for (i = 0; i < X_INCR_COUNT; ++i)
 104     {
 105       pthread_mutex_lock (&x_mutex);
 106       /* For debugging.  */
 107       printf ("Thread %ld changing x %d -> %d\n", (long) arg, x, x + 1);
 108       /* The call to usleep is so that when the watchpoint triggers,
 109          the pc is still on the same line.  */
 110       ++x; usleep (1);  /* X increment.  */
 111       pthread_mutex_unlock (&x_mutex);
 112     }
 113
 114   pthread_exit (NULL);
 115 }