cpp3ds::Lock Class Reference

Automatic wrapper for locking and unlocking mutexes. More...

#include <Lock.hpp>

Inheritance diagram for cpp3ds::Lock:

Public Member Functions
	Lock (Mutex &mutex)
	Construct the lock with a target mutex. More...
	~Lock ()
	Destructor. More...

Detailed Description

Automatic wrapper for locking and unlocking mutexes.

cpp3ds::Lock is a RAII wrapper for cpp3ds::Mutex.

By unlocking it in its destructor, it ensures that the mutex will always be released when the current scope (most likely a function) ends. This is even more important when an exception or an early return statement can interrupt the execution flow of the function.

For maximum robustness, cpp3ds::Lock should always be used to lock/unlock a mutex.

Usage example:

cpp3ds::Mutex mutex;

void function()
{
    cpp3ds::Lock lock(mutex); // mutex is now locked

    functionThatMayThrowAnException(); // mutex is unlocked if this function throws

    if (someCondition)
        return; // mutex is unlocked

} // mutex is unlocked

Because the mutex is not explicitely unlocked in the code, it may remain locked longer than needed. If the region of the code that needs to be protected by the mutex is not the entire function, a good practice is to create a smaller, inner scope so that the lock is limited to this part of the code.

cpp3ds::Mutex mutex;

void function()
{
    {
      cpp3ds::Lock lock(mutex);
      codeThatRequiresProtection();

    } // mutex is unlocked here

    codeThatDoesntCareAboutTheMutex();
}

Having a mutex locked longer than required is a bad practice which can lead to bad performances. Don't forget that when a mutex is locked, other threads may be waiting doing nothing until it is released.

See also

cpp3ds::Mutex

Definition at line 42 of file Lock.hpp.

Constructor & Destructor Documentation

cpp3ds::Lock::Lock ( Mutex &  mutex )

explicit

Construct the lock with a target mutex.

The mutex passed to cpp3ds::Lock is automatically locked.

Parameters

mutex

Mutex to lock

cpp3ds::Lock::~Lock

(

)

Destructor.

The destructor of cpp3ds::Lock automatically unlocks its mutex.

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The documentation for this class was generated from the following file:

• Lock.hpp