Re: [AD] replace xlock/xunlock with synchronized{}

[Peter Wang <tjaden@xxxxxxxxxx>]

On 2006-04-05, Jon Rafkind <workmin@xxxxxxxxxx> wrote:
> Would anyone be opposed to replacing all the XLOCK()/XUNLOCK() blocks in 
> the x11 code of Allegro with a #define'd syntax that does the same 
> thing, with preferably the same name as java's sychnronization keyword 
> 'synchronized' ?
> 
> Basically do this
> 
> #define synchronized for ( XLOCK(); XUNLOCK(); /**/ )

Clever.

> and then instead of
> 
> int _xwin_create_window(void)
> {
>   int result;
>   XLOCK();
>   result = (*_xwin_window_creator)();
>   XUNLOCK();
>   return result;
> }
> 
> would be
> 
> int _xwin_create_window(void)
> {
>   int result;
>   synchronized{
>       result = (*_xwin_window_creator)();
>    }
>   return result;
> }
> 
> Yes I use Java a lot these days and I find this very clean. Plus it 
> would prevent the mistake of forgetting to use XUNLOCK() occasionally.

Unfortunately there is the risk of incorrect but seemingly correct code
like this:

    synchronized {
	if (foo) {
	    return 1;
	}
    }

For a while I was writing mutex lock/unlock pairs as

    lock();
    {
	body
    }
    unlock();

which I think is more transparent.

Peter