1//===-- main.cpp ------------------------------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10// C includes 11#include <pthread.h> 12#include <stdio.h> 13#include <stdint.h> 14#include <stdlib.h> 15#include <unistd.h> 16 17pthread_t g_thread_1 = NULL; 18pthread_t g_thread_2 = NULL; 19pthread_t g_thread_3 = NULL; 20 21uint32_t g_val = 0; 22 23uint32_t access_pool (uint32_t flag = 0); 24 25uint32_t 26access_pool (uint32_t flag) 27{ 28 static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER; 29 if (flag == 0) 30 ::pthread_mutex_lock (&g_access_mutex); 31 32 uint32_t old_val = g_val; 33 if (flag != 0) { 34 printf("changing g_val to %d...\n", (old_val + 1)); 35 g_val = old_val + 1; 36 } 37 38 if (flag == 0) 39 ::pthread_mutex_unlock (&g_access_mutex); 40 return g_val; 41} 42 43void * 44thread_func (void *arg) 45{ 46 uint32_t thread_index = *((uint32_t *)arg); // Break here in order to allow the thread 47 // to inherit the global watchpoint state. 48 printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index); 49 50 uint32_t count = 0; 51 uint32_t val; 52 while (count++ < 15) 53 { 54 // random micro second sleep from zero to 3 seconds 55 int usec = ::rand() % 3000000; 56 printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec); 57 ::usleep (usec); 58 59 if (count < 7) 60 val = access_pool (); 61 else 62 val = access_pool (1); 63 64 printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count); 65 } 66 printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index); 67 return NULL; 68} 69 70 71int main (int argc, char const *argv[]) 72{ 73 int err; 74 void *thread_result = NULL; 75 uint32_t thread_index_1 = 1; 76 uint32_t thread_index_2 = 2; 77 uint32_t thread_index_3 = 3; 78 79 printf ("Before turning all three threads loose...\n"); // Set break point at this line, 80 // in order to set our watchpoint. 81 // Create 3 threads 82 err = ::pthread_create (&g_thread_1, NULL, thread_func, &thread_index_1); 83 err = ::pthread_create (&g_thread_2, NULL, thread_func, &thread_index_2); 84 err = ::pthread_create (&g_thread_3, NULL, thread_func, &thread_index_3); 85 86 // Join all of our threads 87 err = ::pthread_join (g_thread_1, &thread_result); 88 err = ::pthread_join (g_thread_2, &thread_result); 89 err = ::pthread_join (g_thread_3, &thread_result); 90 91 return 0; 92} 93