1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: no-exceptions
// UNSUPPORTED: libcpp-has-no-threads
// <condition_variable>
// class condition_variable_any;
// RUN: %{build}
// RUN: %{run} 1
// RUN: %{run} 2
// RUN: %{run} 3
// RUN: %{run} 4
// RUN: %{run} 5
// RUN: %{run} 6
// -----------------------------------------------------------------------------
// Overview
// Check that std::terminate is called if wait(...) fails to meet its post
// conditions. This can happen when reacquiring the mutex throws
// an exception.
//
// The following methods are tested within this file
// 1. void wait(Lock& lock);
// 2. void wait(Lock& lock, Pred);
// 3. void wait_for(Lock& lock, Duration);
// 4. void wait_for(Lock& lock, Duration, Pred);
// 5. void wait_until(Lock& lock, TimePoint);
// 6. void wait_until(Lock& lock, TimePoint, Pred);
//
// Plan
// 1 Create a mutex type, 'ThrowingMutex', that throws when the lock is acquired
// for the *second* time.
//
// 2 Replace the terminate handler with one that exits with a '0' exit code.
//
// 3 Create a 'condition_variable_any' object 'cv' and a 'ThrowingMutex'
// object 'm' and lock 'm'.
//
// 4 Start a thread 'T2' that will notify 'cv' once 'm' has been unlocked.
//
// 5 From the main thread call the specified wait method on 'cv' with 'm'.
// When 'T2' notifies 'cv' and the wait method attempts to re-lock
// 'm' an exception will be thrown from 'm.lock()'.
//
// 6 Check that control flow does not return from the wait method and that
// terminate is called (If the program exits with a 0 exit code we know
// that terminate has been called)
#include <condition_variable>
#include <atomic>
#include <thread>
#include <chrono>
#include <string>
#include <cstdlib>
#include <cassert>
#include "make_test_thread.h"
void my_terminate() {
std::_Exit(0); // Use _Exit to prevent cleanup from taking place.
}
// The predicate used in the cv.wait calls.
bool pred = false;
bool pred_function() {
return pred == true;
}
class ThrowingMutex
{
std::atomic_bool locked;
unsigned state = 0;
ThrowingMutex(const ThrowingMutex&) = delete;
ThrowingMutex& operator=(const ThrowingMutex&) = delete;
public:
ThrowingMutex() {
locked = false;
}
~ThrowingMutex() = default;
void lock() {
locked = true;
if (++state == 2) {
assert(pred); // Check that we actually waited until we were signaled.
throw 1; // this throw should end up calling terminate()
}
}
void unlock() { locked = false; }
bool isLocked() const { return locked == true; }
};
ThrowingMutex mut;
std::condition_variable_any cv;
void signal_me() {
while (mut.isLocked()) {} // wait until T1 releases mut inside the cv.wait call.
pred = true;
cv.notify_one();
}
typedef std::chrono::system_clock Clock;
typedef std::chrono::milliseconds MS;
int main(int argc, char **argv) {
assert(argc == 2);
int id = std::stoi(argv[1]);
assert(id >= 1 && id <= 6);
std::set_terminate(my_terminate); // set terminate after std::stoi because it can throw.
MS wait(250);
try {
mut.lock();
assert(pred == false);
support::make_test_thread(signal_me).detach();
switch (id) {
case 1: cv.wait(mut); break;
case 2: cv.wait(mut, pred_function); break;
case 3: cv.wait_for(mut, wait); break;
case 4: cv.wait_for(mut, wait, pred_function); break;
case 5: cv.wait_until(mut, Clock::now() + wait); break;
case 6: cv.wait_until(mut, Clock::now() + wait, pred_function); break;
default: assert(false);
}
} catch (...) {}
assert(false);
return 0;
}
|
