| //===-- main.cpp ------------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // This test is intended to create a situation in which one thread will be |
| // created while a the debugger is stepping in another thread. |
| |
| #include <pthread.h> |
| #include <atomic> |
| |
| // Note that although hogging the CPU while waiting for a variable to change |
| // would be terrible in production code, it's great for testing since it |
| // avoids a lot of messy context switching to get multiple threads synchronized. |
| #define do_nothing() |
| |
| #define pseudo_barrier_wait(bar) \ |
| --bar; \ |
| while (bar > 0) \ |
| do_nothing(); |
| |
| #define pseudo_barrier_init(bar, count) (bar = count) |
| |
| std::atomic_int g_barrier; |
| |
| volatile int g_thread_created = 0; |
| volatile int g_test = 0; |
| |
| void * |
| step_thread_func (void *input) |
| { |
| g_test = 0; // Set breakpoint here |
| |
| while (!g_thread_created) |
| g_test++; |
| |
| // One more time to provide a continue point |
| g_test++; // Continue from here |
| |
| // Return |
| return NULL; |
| } |
| |
| void * |
| create_thread_func (void *input) |
| { |
| pthread_t *step_thread = (pthread_t*)input; |
| |
| // Wait until the main thread knows this thread is started. |
| pseudo_barrier_wait(g_barrier); |
| |
| // Wait until the other thread is done. |
| pthread_join(*step_thread, NULL); |
| |
| // Return |
| return NULL; |
| } |
| |
| int main () |
| { |
| pthread_t thread_1; |
| pthread_t thread_2; |
| |
| // Use a simple count to simulate a barrier. |
| pseudo_barrier_init(g_barrier, 2); |
| |
| // Create a thread to hit the breakpoint. |
| pthread_create (&thread_1, NULL, step_thread_func, NULL); |
| |
| // Wait until the step thread is stepping |
| while (g_test < 1) |
| do_nothing(); |
| |
| // Create a thread to exit while we're stepping. |
| pthread_create (&thread_2, NULL, create_thread_func, &thread_1); |
| |
| // Wait until that thread is started |
| pseudo_barrier_wait(g_barrier); |
| |
| // Let the stepping thread know the other thread is there |
| g_thread_created = 1; |
| |
| // Wait for the threads to finish. |
| pthread_join(thread_2, NULL); |
| pthread_join(thread_1, NULL); |
| |
| return 0; |
| } |