What is OpenMutex?

What is OpenMutex?

The OpenMutex function enables multiple processes to open handles of the same mutex object. The function succeeds only if some process has already created the mutex by using the CreateMutex function.

What is WaitForSingleObject?

The WaitForSingleObject function checks the current state of the specified object. If the object’s state is nonsignaled, the calling thread enters the wait state until the object is signaled or the time-out interval elapses. The function modifies the state of some types of synchronization objects.

How do you use mutexes?

A mutex is initialized in the beginning of the main function. The same mutex is locked in the ‘doSomeThing()’ function while using the shared resource ‘counter’ At the end of the function ‘doSomeThing()’ the same mutex is unlocked. At the end of the main function when both the threads are done, the mutex is destroyed.

What is QueueUserAPC?

The Win32 API provides the QueueUserAPC function, which allows an application to queue an APC object to a thread. The queuing of an APC is a request for the thread to call the APC function. When a user-mode APC is queued, the thread is not directed to call the APC function unless it is in an alertable state.

What is CreateEventW?

CreateEventW function (synchapi.h) – Win32 apps Creates or opens a named or unnamed event object.

Does pthread_mutex_lock use any system calls?

There are three system calls which perform operations on a mutex, each of which takes a pointer to a pthread_mutex_t as an argument. int pthread_mutex_lock(pthread_mutex_t *mutex);

Can pthread_mutex_lock fail?

The pthread_mutex_lock() and pthread_mutex_trylock() functions shall fail if: [EINVAL] The mutex was created with the protocol attribute having the value PTHREAD_PRIO_PROTECT and the calling thread’s priority is higher than the mutex’s current priority ceiling.

What are mutexes and semaphores?

A Mutex is different than a semaphore as it is a locking mechanism while a semaphore is a signalling mechanism. A binary semaphore can be used as a Mutex but a Mutex can never be used as a semaphore.

How is mutex implemented in Linux?

Mutexes are represented by ‘struct mutex’, defined in include/linux/mutex. h and implemented in kernel/locking/mutex. c. These locks use an atomic variable (->owner) to keep track of the lock state during its lifetime.

Which is better mutex or semaphore?

If you have number of instances for resource it is better to use Binary semaphore. If you have single instance for resource it is better to use mutex.