1 #include <chrono>
2 #include <cstdio>
3 #include <mutex>
4 #include <random>
5 #include <thread>
6
7 std::default_random_engine g_random_engine{std::random_device{}()};
8 std::uniform_int_distribution<> g_distribution{0, 3000};
9
10 uint32_t g_val = 0;
11 uint32_t lldb_val = 0;
12
13 uint32_t
access_pool(bool flag=false)14 access_pool (bool flag = false)
15 {
16 static std::mutex g_access_mutex;
17 if (!flag)
18 g_access_mutex.lock();
19
20 uint32_t old_val = g_val;
21 if (flag)
22 g_val = old_val + 1;
23
24 if (!flag)
25 g_access_mutex.unlock();
26 return g_val;
27 }
28
29 void
thread_func(uint32_t thread_index)30 thread_func (uint32_t thread_index)
31 {
32 // Break here to test that the stop-hook mechanism works for multiple threads.
33 printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
34
35 uint32_t count = 0;
36 uint32_t val;
37 while (count++ < 4)
38 {
39 // random micro second sleep from zero to .3 seconds
40 int usec = g_distribution(g_random_engine);
41 printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
42 std::this_thread::sleep_for(std::chrono::microseconds{usec}); // Set break point at this line
43
44 if (count < 2)
45 val = access_pool ();
46 else
47 val = access_pool (true);
48
49 printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
50 }
51 printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
52 }
53
54
main(int argc,char const * argv[])55 int main (int argc, char const *argv[])
56 {
57 std::thread threads[3];
58 // Break here to set up the stop hook
59 printf("Stop hooks engaged.\n");
60 // Create 3 threads
61 for (auto &thread : threads)
62 thread = std::thread{thread_func, std::distance(threads, &thread)};
63
64 // Join all of our threads
65 for (auto &thread : threads)
66 thread.join();
67
68 // print lldb_val so we can check it here.
69 printf ("lldb_val was set to: %d.\n", lldb_val);
70 return 0;
71 }
72