1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // UNSUPPORTED: libcpp-no-exceptions 11 // UNSUPPORTED: libcpp-has-no-threads 12 13 // <condition_variable> 14 15 // class condition_variable_any; 16 17 // RUN: %build 18 // RUN: %run 1 19 // RUN: %run 2 20 // RUN: %run 3 21 // RUN: %run 4 22 // RUN: %run 5 23 // RUN: %run 6 24 25 // ----------------------------------------------------------------------------- 26 // Overview 27 // Check that std::terminate is called if wait(...) fails to meet its post 28 // conditions. This can happen when reacquiring the mutex throws 29 // an exception. 30 // 31 // The following methods are tested within this file 32 // 1. void wait(Lock& lock); 33 // 2. void wait(Lock& lock, Pred); 34 // 3. void wait_for(Lock& lock, Duration); 35 // 4. void wait_for(Lock& lock, Duration, Pred); 36 // 5. void wait_until(Lock& lock, TimePoint); 37 // 6. void wait_until(Lock& lock, TimePoint, Pred); 38 // 39 // Plan 40 // 1 Create a mutex type, 'ThrowingMutex', that throws when the lock is acquired 41 // for the *second* time. 42 // 43 // 2 Replace the terminate handler with one that exits with a '0' exit code. 44 // 45 // 3 Create a 'condition_variable_any' object 'cv' and a 'ThrowingMutex' 46 // object 'm' and lock 'm'. 47 // 48 // 4 Start a thread 'T2' that will notify 'cv' once 'm' has been unlocked. 49 // 50 // 5 From the main thread call the specified wait method on 'cv' with 'm'. 51 // When 'T2' notifies 'cv' and the wait method attempts to re-lock 52 // 'm' an exception will be thrown from 'm.lock()'. 53 // 54 // 6 Check that control flow does not return from the wait method and that 55 // terminate is called (If the program exits with a 0 exit code we know 56 // that terminate has been called) 57 58 59 #include <condition_variable> 60 #include <atomic> 61 #include <thread> 62 #include <chrono> 63 #include <string> 64 #include <cstdlib> 65 #include <cassert> 66 67 void my_terminate() { 68 std::_Exit(0); // Use _Exit to prevent cleanup from taking place. 69 } 70 71 // The predicate used in the cv.wait calls. 72 bool pred = false; 73 bool pred_function() { 74 return pred == true; 75 } 76 77 class ThrowingMutex 78 { 79 std::atomic_bool locked; 80 unsigned state = 0; 81 ThrowingMutex(const ThrowingMutex&) = delete; 82 ThrowingMutex& operator=(const ThrowingMutex&) = delete; 83 public: 84 ThrowingMutex() { 85 locked = false; 86 } 87 ~ThrowingMutex() = default; 88 89 void lock() { 90 locked = true; 91 if (++state == 2) { 92 assert(pred); // Check that we actually waited until we were signaled. 93 throw 1; // this throw should end up calling terminate() 94 } 95 } 96 97 void unlock() { locked = false; } 98 bool isLocked() const { return locked == true; } 99 }; 100 101 ThrowingMutex mut; 102 std::condition_variable_any cv; 103 104 void signal_me() { 105 while (mut.isLocked()) {} // wait until T1 releases mut inside the cv.wait call. 106 pred = true; 107 cv.notify_one(); 108 } 109 110 typedef std::chrono::system_clock Clock; 111 typedef std::chrono::milliseconds MS; 112 113 int main(int argc, char** argv) { 114 assert(argc == 2); 115 int id = std::stoi(argv[1]); 116 assert(id >= 1 && id <= 6); 117 std::set_terminate(my_terminate); // set terminate after std::stoi because it can throw. 118 MS wait(250); 119 try { 120 mut.lock(); 121 assert(pred == false); 122 std::thread(signal_me).detach(); 123 switch (id) { 124 case 1: cv.wait(mut); break; 125 case 2: cv.wait(mut, pred_function); break; 126 case 3: cv.wait_for(mut, wait); break; 127 case 4: cv.wait_for(mut, wait, pred_function); break; 128 case 5: cv.wait_until(mut, Clock::now() + wait); break; 129 case 6: cv.wait_until(mut, Clock::now() + wait, pred_function); break; 130 default: assert(false); 131 } 132 } catch (...) {} 133 assert(false); 134 } 135
