72 lines · cpp
1#include <chrono>2#include <cstdio>3#include <mutex>4#include <random>5#include <thread>6 7std::default_random_engine g_random_engine{std::random_device{}()};8std::uniform_int_distribution<> g_distribution{0, 3000};9 10uint32_t g_val = 0;11uint32_t lldb_val = 0;12 13uint32_t14access_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 29void30thread_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 seconds40 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 line43 44 if (count < 2)45 val = access_pool ();46 else47 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 55int main (int argc, char const *argv[])56{57 std::thread threads[3];58 // Break here to set up the stop hook59 printf("Stop hooks engaged.\n");60 // Create 3 threads61 for (auto &thread : threads)62 thread = std::thread{thread_func, std::distance(threads, &thread)};63 64 // Join all of our threads65 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