lldb/test/Shell/ExecControl/StopHook/Inputs/stop-hook-threads.cpp

   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
  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
  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
  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 }