Re: [boost] Lock unification

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-07-15 11:00:09

Christopher Currie wrote:
> The differences between
>
> {
>    scoped_lock l( m );
> }
>
> and
>
> {
>    scoped_timed_lock l( m, t );
> }
>
> are much more descriptive me than
>
> {
>    scoped_lock( m );
> }
>
> {
>    scoped_lock( m, t );
> }

The "unified" timed lock case is

{
    scoped_lock l( m, false );

    if( l.timed_lock( t ) )
    {
        // do stuff
    }
    else
    {
        // what do we do here? presumably either:

        // setup for unbounded wait
        l.lock();
        // do stuff

        // or signal failure
    }
}

The scoped_timed_lock use case also needs to eventually contain an if( l )
statement; you can't do much if you don't know whether your timed lock
succeeded. One might also argue that a separate scoped_timed_lock makes
accidentally omitting the if() statement more likely and harder to spot.

But it's hard to tell without real use cases.