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// <mutex> 11 12// class recursive_mutex; 13 14// bool try_lock(); 15 16#include <mutex> 17#include <thread> 18#include <cstdlib> 19#include <cassert> 20 21std::recursive_mutex m; 22 23typedef std::chrono::system_clock Clock; 24typedef Clock::time_point time_point; 25typedef Clock::duration duration; 26typedef std::chrono::milliseconds ms; 27typedef std::chrono::nanoseconds ns; 28 29void f() 30{ 31 time_point t0 = Clock::now(); 32 assert(!m.try_lock()); 33 assert(!m.try_lock()); 34 assert(!m.try_lock()); 35 while(!m.try_lock()) 36 ; 37 time_point t1 = Clock::now(); 38 assert(m.try_lock()); 39 m.unlock(); 40 m.unlock(); 41 ns d = t1 - t0 - ms(250); 42 assert(d < ms(200)); // within 200ms 43} 44 45int main() 46{ 47 m.lock(); 48 std::thread t(f); 49 std::this_thread::sleep_for(ms(250)); 50 m.unlock(); 51 t.join(); 52} 53