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 // This test verifies the correct handling of child thread exits.
11
12 #include <pthread.h>
13 #include <atomic>
14
15 // Note that although hogging the CPU while waiting for a variable to change
16 // would be terrible in production code, it's great for testing since it
17 // avoids a lot of messy context switching to get multiple threads synchronized.
18 #define do_nothing()
19
20 #define pseudo_barrier_wait(bar) \
21 --bar; \
22 while (bar > 0) \
23 do_nothing();
24
25 #define pseudo_barrier_init(bar, count) (bar = count)
26
27 std::atomic_int g_barrier1;
28 std::atomic_int g_barrier2;
29 std::atomic_int g_barrier3;
30
31 void *
thread1(void * input)32 thread1 (void *input)
33 {
34 // Synchronize with the main thread.
35 pseudo_barrier_wait(g_barrier1);
36
37 // Synchronize with the main thread and thread2.
38 pseudo_barrier_wait(g_barrier2);
39
40 // Return
41 return NULL; // Set second breakpoint here
42 }
43
44 void *
thread2(void * input)45 thread2 (void *input)
46 {
47 // Synchronize with thread1 and the main thread.
48 pseudo_barrier_wait(g_barrier2);
49
50 // Synchronize with the main thread.
51 pseudo_barrier_wait(g_barrier3);
52
53 // Return
54 return NULL;
55 }
56
main()57 int main ()
58 {
59 pthread_t thread_1;
60 pthread_t thread_2;
61 pthread_t thread_3;
62
63 pseudo_barrier_init(g_barrier1, 2);
64 pseudo_barrier_init(g_barrier2, 3);
65 pseudo_barrier_init(g_barrier3, 2);
66
67 // Create a thread.
68 pthread_create (&thread_1, NULL, thread1, NULL);
69
70 // Wait for thread1 to start.
71 pseudo_barrier_wait(g_barrier1);
72
73 // Create another thread.
74 pthread_create (&thread_2, NULL, thread2, NULL); // Set first breakpoint here
75
76 // Wait for thread2 to start.
77 pseudo_barrier_wait(g_barrier2);
78
79 // Wait for the first thread to finish
80 pthread_join(thread_1, NULL);
81
82 // Synchronize with the remaining thread
83 pseudo_barrier_wait(g_barrier3); // Set third breakpoint here
84
85 // Wait for the second thread to finish
86 pthread_join(thread_2, NULL);
87
88 return 0; // Set fourth breakpoint here
89 }
90