cxx/test/thread/thread.mutex/thread.lock/thread.lock.guard/adopt_lock.pass.cpp
Howard Hinnant b64f8b07c1 license change
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119395 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-16 22:09:02 +00:00

50 lines
1.1 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <mutex>
// template <class Mutex> class lock_guard;
// lock_guard(mutex_type& m, adopt_lock_t);
#include <mutex>
#include <thread>
#include <cstdlib>
#include <cassert>
std::mutex m;
typedef std::chrono::system_clock Clock;
typedef Clock::time_point time_point;
typedef Clock::duration duration;
typedef std::chrono::milliseconds ms;
typedef std::chrono::nanoseconds ns;
void f()
{
time_point t0 = Clock::now();
time_point t1;
{
m.lock();
std::lock_guard<std::mutex> lg(m, std::adopt_lock);
t1 = Clock::now();
}
ns d = t1 - t0 - ms(250);
assert(d < ns(2500000)); // within 2.5ms
}
int main()
{
m.lock();
std::thread t(f);
std::this_thread::sleep_for(ms(250));
m.unlock();
t.join();
}