| /* This testcase is part of GDB, the GNU debugger. |
| |
| Copyright 2018-2019 Free Software Foundation, Inc. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include <pthread.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <assert.h> |
| #define NUM_THREADS 4 |
| |
| /* Crude spin lock. Threads all spin until this is set to 0. */ |
| int go = 1; |
| |
| /* Thread function, just spin until GO is set to 0. */ |
| void * |
| perform_work (void *argument) |
| { |
| /* Cast to volatile to ensure that ARGUMENT is loaded each time around |
| the loop. */ |
| while (*((volatile int*) argument)) |
| { |
| /* Nothing. */ |
| } |
| return NULL; |
| } |
| |
| /* The spin loop for the main thread. */ |
| void |
| function (void) |
| { |
| (void) perform_work (&go); |
| printf ("Finished from function\n"); |
| } |
| |
| /* Main program, create some threads which all spin waiting for GO to be |
| set to 0. */ |
| int |
| main (void) |
| { |
| pthread_t threads[NUM_THREADS]; |
| int result_code; |
| unsigned index; |
| |
| /* Create some threads. */ |
| for (index = 0; index < NUM_THREADS; ++index) |
| { |
| printf ("In main: creating thread %d\n", index); |
| result_code = pthread_create (&threads[index], NULL, perform_work, &go); |
| assert (!result_code); |
| } |
| |
| function (); |
| |
| /* Wait for each thread to complete. */ |
| for (index = 0; index < NUM_THREADS; ++index) |
| { |
| /* Block until thread INDEX completes. */ |
| result_code = pthread_join (threads[index], NULL); |
| assert (!result_code); |
| printf ("In main: thread %d has completed\n", index); |
| } |
| printf ("In main: All threads completed successfully\n"); |
| return 0; |
| } |