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        g_val = old_val + 1;
35
36    if (flag == 0)
37        ::pthread_mutex_unlock (&g_access_mutex);
38    return g_val;
39}
40
41void *
42thread_func (void *arg)
43{
44    uint32_t thread_index = *((uint32_t *)arg); // Break here to test that the stop-hook mechanism works for multiple threads.
45    printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
46
47    uint32_t count = 0;
48    uint32_t val;
49    while (count++ < 15)
50    {
51        // random micro second sleep from zero to 3 seconds
52        int usec = ::rand() % 3000000;
53        printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
54        ::usleep (usec);
55
56        if (count < 7)
57            val = access_pool ();
58        else
59            val = access_pool (1);
60
61        printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
62    }
63    printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
64    return NULL;
65}
66
67
68int main (int argc, char const *argv[])
69{
70    int err;
71    void *thread_result = NULL;
72    uint32_t thread_index_1 = 1;
73    uint32_t thread_index_2 = 2;
74    uint32_t thread_index_3 = 3;
75
76    printf ("Before turning all three threads loose...\n"); // Set break point at this line, and add a stop-hook.
77    // Create 3 threads
78    err = ::pthread_create (&g_thread_1, NULL, thread_func, &thread_index_1);
79    err = ::pthread_create (&g_thread_2, NULL, thread_func, &thread_index_2);
80    err = ::pthread_create (&g_thread_3, NULL, thread_func, &thread_index_3);
81
82    // Join all of our threads
83    err = ::pthread_join (g_thread_1, &thread_result);
84    err = ::pthread_join (g_thread_2, &thread_result);
85    err = ::pthread_join (g_thread_3, &thread_result);
86
87    return 0;
88}
89