1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: libcpp-has-no-threads
10 // ALLOW_RETRIES: 2
11 
12 // TODO(ldionne): This test fails on Ubuntu Focal on our CI nodes (and only there), in 32 bit mode.
13 // UNSUPPORTED: linux && 32bits-on-64bits
14 
15 // <mutex>
16 
17 // class recursive_mutex;
18 
19 // void lock();
20 
21 #include <mutex>
22 #include <thread>
23 #include <cstdlib>
24 #include <cassert>
25 
26 #include "make_test_thread.h"
27 #include "test_macros.h"
28 
29 std::recursive_mutex m;
30 
31 typedef std::chrono::system_clock Clock;
32 typedef Clock::time_point time_point;
33 typedef Clock::duration duration;
34 typedef std::chrono::milliseconds ms;
35 typedef std::chrono::nanoseconds ns;
36 
37 void f()
38 {
39     time_point t0 = Clock::now();
40     m.lock();
41     time_point t1 = Clock::now();
42     m.lock();
43     m.unlock();
44     m.unlock();
45     ns d = t1 - t0 - ms(250);
46     assert(d < ms(200));  // within 200ms
47 }
48 
49 int main(int, char**)
50 {
51     m.lock();
52     std::thread t = support::make_test_thread(f);
53     std::this_thread::sleep_for(ms(250));
54     m.unlock();
55     t.join();
56 
57   return 0;
58 }
59