| //===-- main.cpp ------------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include <chrono> |
| #include <cstdio> |
| #include <mutex> |
| #include <random> |
| #include <thread> |
| |
| std::default_random_engine g_random_engine{std::random_device{}()}; |
| std::uniform_int_distribution<> g_distribution{0, 3000000}; |
| |
| uint32_t g_val = 0; |
| |
| uint32_t |
| access_pool (bool flag = false) |
| { |
| static std::mutex g_access_mutex; |
| if (!flag) |
| g_access_mutex.lock(); |
| |
| uint32_t old_val = g_val; |
| if (flag) |
| g_val = old_val + 1; |
| |
| if (!flag) |
| g_access_mutex.unlock(); |
| return g_val; |
| } |
| |
| void |
| thread_func (uint32_t thread_index) |
| { |
| // Break here to test that the stop-hook mechanism works for multiple threads. |
| printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index); |
| |
| uint32_t count = 0; |
| uint32_t val; |
| while (count++ < 15) |
| { |
| // random micro second sleep from zero to 3 seconds |
| int usec = g_distribution(g_random_engine); |
| printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec); |
| std::this_thread::sleep_for(std::chrono::microseconds{usec}); |
| |
| if (count < 7) |
| val = access_pool (); |
| else |
| val = access_pool (true); |
| |
| printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count); |
| } |
| printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index); |
| } |
| |
| |
| int main (int argc, char const *argv[]) |
| { |
| std::thread threads[3]; |
| |
| printf ("Before turning all three threads loose...\n"); // Set break point at this line, and add a stop-hook. |
| // Create 3 threads |
| for (auto &thread : threads) |
| thread = std::thread{thread_func, std::distance(threads, &thread)}; |
| |
| // Join all of our threads |
| for (auto &thread : threads) |
| thread.join(); |
| |
| return 0; |
| } |