notify_all.pass.cpp
1.6 KB
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
//===----------------------------------------------------------------------===//
//
// 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: libcpp-has-no-threads
// <condition_variable>
// class condition_variable_any;
// void notify_all();
#include <condition_variable>
#include <mutex>
#include <thread>
#include <vector>
#include <atomic>
#include <cassert>
#include "test_macros.h"
std::condition_variable_any cv;
typedef std::timed_mutex L0;
typedef std::unique_lock<L0> L1;
L0 m0;
const unsigned threadCount = 2;
bool pleaseExit = false;
std::atomic<unsigned> notReady;
void helper() {
L1 lk(m0);
--notReady;
while (pleaseExit == false)
cv.wait(lk);
}
int main(int, char**)
{
notReady = threadCount;
std::vector<std::thread> threads(threadCount);
for (unsigned i = 0; i < threadCount; i++)
threads[i] = std::thread(helper);
{
while (notReady > 0)
std::this_thread::yield();
// At this point, both threads have had a chance to acquire the lock and are
// either waiting on the condition variable or about to wait.
L1 lk(m0);
pleaseExit = true;
// POSIX does not guarantee reliable scheduling if notify_all is called
// without the lock being held.
cv.notify_all();
}
// The test will hang if not all of the threads were woken.
for (unsigned i = 0; i < threadCount; i++)
threads[i].join();
return 0;
}