std::mutex::try_lock() On Mutex In Cpp11 Threading

TOPIC: std::mutex::try_lock() On Mutex In C++11 Threading

0. try_lock() Tries to lock the mutex. Returns immediately. On successful lock acquisition returns true otherwise returns false.

1. If try_lock() is not able to lock mutex, then it doesn't get blocked that's why it is called non-blocking.

2. If try_lock is called again by the same thread which owns the mutex, the behavior is undefined.

   It is a dead lock situation with undefined behaviour. (if you want to be able to lock the same mutex by same thread

   more than one time the go for recursive_mutex)

#include <iostream>

#include <thread>

#include <mutex>

using namespace std;

int counter =0;

std::mutex mtx;

void increaseTheCounterFor100000Time() {

  for (int i=0; i<100000; ++i) {

    if (mtx.try_lock()) {

      ++counter;

      mtx.unlock();

    }

  }

}

int main ()

{

  std::thread t1(increaseTheCounterFor100000Time);

  std::thread t2(increaseTheCounterFor100000Time);

  t1.join();

  t2.join();

  cout << " counter could increases upto : " << counter << endl;

  return 0;

}

// There are so many try_lock function

// 1. std::try_lock

// 2. std::mutex::try_lock

// 3. std::shared_lock::try_lock

// 4. std::timed_mutex::try_lock

// 5. std::unique_lock::try_lock

// 6. std::shared_mutex::try_lock

// 7. std::recursive_mutex::try_lock

// 8. std::shared_timed_mutex::try_lock

// 9. std::recursive_timed_mutex::try_lock