gdb/testsuite/gdb.threads/watchthreads.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19    This file is copied from schedlock.c.  */
  20
  21 #include <stdio.h>
  22 #include <unistd.h>
  23 #include <stdlib.h>
  24 #include <pthread.h>
  25
  26 void *thread_function (void *arg); /* Function executed by each thread.  */
  27
  28 #define NUM 5
  29
  30 unsigned int args[NUM+1];
  31
  32 int
  33 main ()
  34 {
  35     int res;
  36     pthread_t threads[NUM];
  37     void *thread_result;
  38     long i;
  39
  40     /* To keep the test determinative, initialize args first,
  41        then start all the threads.  Otherwise, the way watchthreads.exp
  42        is written, we have to worry about things like threads[0] getting
  43        to 29 hits of args[0] before args[1] gets changed.  */
  44
  45     for (i = 0; i < NUM; i++)
  46       {
  47         /* The call to usleep is so that when the watchpoint triggers,
  48            the pc is still on the same line.  */
  49         args[i] = 1; usleep (1); /* Init value.  */
  50       }
  51
  52     for (i = 0; i < NUM; i++)
  53       {
  54         res = pthread_create (&threads[i],
  55                               NULL,
  56                               thread_function,
  57                               (void *) i);
  58       }
  59
  60     args[i] = 1;
  61     thread_function ((void *) i);
  62
  63     exit (EXIT_SUCCESS);
  64 }
  65
  66 void *
  67 thread_function (void *arg)
  68 {
  69     int my_number =  (long) arg;
  70     int *myp = (int *) &args[my_number];
  71
  72     /* Don't run forever.  Run just short of it :)  */
  73     while (*myp > 0)
  74       {
  75         (*myp) ++; usleep (1);  /* Loop increment.  */
  76       }
  77
  78     pthread_exit (NULL);
  79 }
  80