//===-- 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 exit // while a the debugger is stepping in another thread. #include <pthread.h> #include <unistd.h> // 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) // A barrier to synchronize thread start. volatile int g_barrier; volatile int g_thread_exited = 0; volatile int g_test = 0; void * step_thread_func (void *input) { // Wait until both threads are started. pseudo_barrier_wait(g_barrier); g_test = 0; // Set breakpoint here while (!g_thread_exited) g_test++; // One more time to provide a continue point g_test++; // Continue from here // Return return NULL; } void * exit_thread_func (void *input) { // Wait until both threads are started. pseudo_barrier_wait(g_barrier); // Wait until the other thread is stepping. while (g_test == 0) do_nothing(); // Return return NULL; } int main () { pthread_t thread_1; pthread_t thread_2; // Synchronize thread start so that doesn't happen during stepping. pseudo_barrier_init(g_barrier, 2); // Create a thread to hit the breakpoint. pthread_create (&thread_1, NULL, step_thread_func, NULL); // Create a thread to exit while we're stepping. pthread_create (&thread_2, NULL, exit_thread_func, NULL); // Wait for the exit thread to finish. pthread_join(thread_2, NULL); // Let the stepping thread know the other thread is gone. g_thread_exited = 1; // Wait for the stepping thread to finish. pthread_join(thread_1, NULL); return 0; }