gdb/testsuite/gdb.threads/watchthreads.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2002-2024 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    This file is copied from schedlock.c.  */
  19
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <pthread.h>
  24
  25 void *thread_function (void *arg); /* Function executed by each thread.  */
  26
  27 #define NUM 5
  28
  29 unsigned int args[NUM+1];
  30
  31 int
  32 main ()
  33 {
  34     int res;
  35     pthread_t threads[NUM];
  36     void *thread_result;
  37     long i;
  38
  39     /* To keep the test determinative, initialize args first,
  40        then start all the threads.  Otherwise, the way watchthreads.exp
  41        is written, we have to worry about things like threads[0] getting
  42        to 29 hits of args[0] before args[1] gets changed.  */
  43
  44     for (i = 0; i < NUM; i++)
  45       {
  46         /* The call to usleep is so that when the watchpoint triggers,
  47            the pc is still on the same line.  */
  48         args[i] = 1; usleep (1); /* Init value.  */
  49       }
  50
  51     for (i = 0; i < NUM; i++)
  52       {
  53         res = pthread_create (&threads[i],
  54                               NULL,
  55                               thread_function,
  56                               (void *) i);
  57       }
  58
  59     args[i] = 1;
  60     thread_function ((void *) i);
  61
  62     exit (EXIT_SUCCESS);
  63 }
  64
  65 void *
  66 thread_function (void *arg)
  67 {
  68     int my_number =  (long) arg;
  69     int *myp = (int *) &args[my_number];
  70
  71     /* Don't run forever.  Run just short of it :)  */
  72     while (*myp > 0)
  73       {
  74         (*myp) ++; usleep (1);  /* Loop increment.  */
  75       }
  76
  77     pthread_exit (NULL);
  78 }
  79