//===-- main.cpp ------------------------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // C includes #include <pthread.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> pthread_t g_thread_1 = NULL; pthread_t g_thread_2 = NULL; pthread_t g_thread_3 = NULL; uint32_t g_val = 0; uint32_t access_pool (uint32_t flag = 0); uint32_t access_pool (uint32_t flag) { static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER; if (flag == 0) ::pthread_mutex_lock (&g_access_mutex); uint32_t old_val = g_val; if (flag != 0) { printf("changing g_val to %d...\n", (old_val + 1)); g_val = old_val + 1; } if (flag == 0) ::pthread_mutex_unlock (&g_access_mutex); return g_val; } void * thread_func (void *arg) { uint32_t thread_index = *((uint32_t *)arg); // Break here in order to allow the thread // to inherit the global watchpoint state. printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index); uint32_t count = 0; uint32_t val; while (count++ < 15) { // random micro second sleep from zero to 3 seconds int usec = ::rand() % 3000000; printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec); ::usleep (usec); if (count < 7) val = access_pool (); else val = access_pool (1); printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count); } printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index); return NULL; } int main (int argc, char const *argv[]) { int err; void *thread_result = NULL; uint32_t thread_index_1 = 1; uint32_t thread_index_2 = 2; uint32_t thread_index_3 = 3; printf ("Before turning all three threads loose...\n"); // Set break point at this line, // in order to set our watchpoint. // Create 3 threads err = ::pthread_create (&g_thread_1, NULL, thread_func, &thread_index_1); err = ::pthread_create (&g_thread_2, NULL, thread_func, &thread_index_2); err = ::pthread_create (&g_thread_3, NULL, thread_func, &thread_index_3); // Join all of our threads err = ::pthread_join (g_thread_1, &thread_result); err = ::pthread_join (g_thread_2, &thread_result); err = ::pthread_join (g_thread_3, &thread_result); return 0; }