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// Copyright 2022 Proyectos y Sistemas de Mantenimiento SL (eProsima).
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @file check_shared_mutex_priority.cpp
*
*/
#include <atomic>
#include <condition_variable>
#include <iostream>
#include <mutex>
#include <shared_mutex>
#include <thread>
using namespace std;
int main()
{
shared_mutex sm;
atomic_bool mark = false;
// take first shared lock
sm.lock_shared();
// signal is taken
thread exclusive([&]()
{
mark = true;
lock_guard<shared_mutex> guard(sm);
});
// Wait till the thread takes the lock
do
{
this_thread::sleep_for(chrono::milliseconds(100));
}
while (!mark);
// try take the second shared lock
bool success = sm.try_lock_shared();
if (success)
{
sm.unlock_shared();
cout << "PTHREAD_RWLOCK_PREFER_READER_NP" << endl;
}
else
{
cout << "PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP" << endl;
}
// release first lock
sm.unlock_shared();
// wait for the main thread
exclusive.join();
return 0;
}
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