Luke Kenneth Casson Leighton wrote: > > On Sat, Jun 09, 2001 at 06:34:21PM +0100, Ben Laurie wrote: > > Luke Kenneth Casson Leighton wrote: > > > > > > uh... i thought i should point out: the original proposal > > > i recommended for the sms locking routine should pass > > > in the area of memory to be locked and its length, > > > and ditto for the unlocking. > > > > +1. > > > > > in this way, let's say you do mmap on a file, you can > > > use posix locking as the implementation of the locking > > > on the memory. > > > > > > [or can you? i dunno, for sure :) ] > > > > I believe so. > > > > > and, if the argument is NULL, it means ' do a Global Lock'. > > > > > > if the unlock() argument is NULL, it means 'do a Global > > > Unlock - i.e. free all locks'. > > > > And if the locking mechanism doesn't support regions? (This is > > particularly important if you allow unlocking of subregions). The > > obvious answer being that we implement them in APR, of course. > > well, that is what made me think that perhaps a separate > lock and lock_region be done, such that one or other > cold be supported. > > or, you mandate providing locking, emulating regions by > ... errr.... providing ref-counting on a global lock (yuck!) > > hm, that don't work. nope: have to do the lock and > lock_region, then have a means for Users to detect > that a lock_region function is available / supported. > > you know, this is all tending to suggest having a > 'apr_sms_get_features()' fn, returning a bitfield > of supported features.
You can emulate regions with global locks and shared memory, of course. And still tell people which you support natively. Don't know whether its worth it - does anyone have any views? Cheers, Ben. -- http://www.apache-ssl.org/ben.html "There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit." - Robert Woodruff
