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
17 pthread_t g_thread_1 = NULL;
18 pthread_t g_thread_2 = NULL;
19 pthread_t g_thread_3 = NULL;
20
21 typedef enum {
22 eGet,
23 eAssign,
24 eClearBits
25 } MaskAction;
26
27 uint32_t mask_access (MaskAction action, uint32_t mask = 0);
28
29 uint32_t
mask_access(MaskAction action,uint32_t mask)30 mask_access (MaskAction action, uint32_t mask)
31 {
32 static pthread_mutex_t g_mask_mutex = PTHREAD_MUTEX_INITIALIZER;
33 static uint32_t g_mask = 0;
34 ::pthread_mutex_lock (&g_mask_mutex);
35 switch (action)
36 {
37 case eGet:
38 break;
39
40 case eAssign:
41 g_mask |= mask;
42 break;
43
44 case eClearBits:
45 g_mask &= ~mask;
46 break;
47 }
48 uint32_t new_mask = g_mask;
49 ::pthread_mutex_unlock (&g_mask_mutex);
50 return new_mask;
51 }
52
53 void *
thread_func(void * arg)54 thread_func (void *arg)
55 {
56 uint32_t thread_index = *((uint32_t *)arg);
57 uint32_t thread_mask = (1u << (thread_index));
58 printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
59
60 while (mask_access(eGet) & thread_mask)
61 {
62 // random micro second sleep from zero to 3 seconds
63 int usec = ::rand() % 3000000;
64 printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
65 ::usleep (usec);
66 printf ("%s (thread = %u) after usleep ...\n", __FUNCTION__, thread_index); // Set break point at this line.
67 }
68 printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
69 return NULL;
70 }
71
72
main(int argc,char const * argv[])73 int main (int argc, char const *argv[])
74 {
75 int err;
76 void *thread_result = NULL;
77 uint32_t thread_index_1 = 1;
78 uint32_t thread_index_2 = 2;
79 uint32_t thread_index_3 = 3;
80 uint32_t thread_mask_1 = (1u << thread_index_1);
81 uint32_t thread_mask_2 = (1u << thread_index_2);
82 uint32_t thread_mask_3 = (1u << thread_index_3);
83
84 // Make a mask that will keep all threads alive
85 mask_access (eAssign, thread_mask_1 | thread_mask_2 | thread_mask_3); // And that line.
86
87 // Create 3 threads
88 err = ::pthread_create (&g_thread_1, NULL, thread_func, &thread_index_1);
89 err = ::pthread_create (&g_thread_2, NULL, thread_func, &thread_index_2);
90 err = ::pthread_create (&g_thread_3, NULL, thread_func, &thread_index_3);
91
92 char line[64];
93 while (mask_access(eGet) != 0)
94 {
95 printf ("Enter thread index to kill or ENTER for all:\n");
96 fflush (stdout);
97 // Kill threads by index, or ENTER for all threads
98
99 if (fgets (line, sizeof(line), stdin))
100 {
101 if (line[0] == '\n' || line[0] == '\r' || line[0] == '\0')
102 {
103 printf ("Exiting all threads...\n");
104 break;
105 }
106 int32_t index = strtoul (line, NULL, 0);
107 switch (index)
108 {
109 case 1: mask_access (eClearBits, thread_mask_1); break;
110 case 2: mask_access (eClearBits, thread_mask_2); break;
111 case 3: mask_access (eClearBits, thread_mask_3); break;
112 }
113 continue;
114 }
115
116 break;
117 }
118
119 // Clear all thread bits to they all exit
120 mask_access (eClearBits, UINT32_MAX);
121
122 // Join all of our threads
123 err = ::pthread_join (g_thread_1, &thread_result);
124 err = ::pthread_join (g_thread_2, &thread_result);
125 err = ::pthread_join (g_thread_3, &thread_result);
126
127 return 0;
128 }
129