Question

I’m looking for code shortening idea. I’m using boost::scoped_lock to lock a boost::mutex but I want to shorten the amount of code I’m writing.

Currently I have a mutex defined in my class and the member field called _sync. When I want to lock, I have to write:

scoped_lock<mutex> lock(_sync);

The tricky part is that this is a scoped lock, so I assume that if I write a static function to return the scoped_lock, then it will unlock as soon as it gets out of the function scope of the static function:

static scoped_lock<mutex> lock(mutex& sync)
{
    return scoped_lock<mutex>(sync);
}

This approach would make it really easy to type:

public void Object::modify()
{
    lock(_sync); // <-- nice and short! ;)

    // do something to modify the object
    //..
    // the mutex is unlocked when we leave the scope of modify
}

Is my assumption correct? Will the scoped_lock unlock immediately when it’s returned by my static function?

Answer 1

#define LOCK(a) scoped_lock<mutex> scopedLockVar(a)

public void Object::modify()
{
    LOCK(_sync); // <-- nice and short! ;)

    // do something to modify the object
    //..
    // the mutex is unlocked when we leave the scope of modify
}

You should use a safe name for the define… The compiler just uses find and replace for defines…