On Sat, 11 Feb 2012 23:47:06 +0100 Juan Jose Garcia-Ripoll <juanjose.garciarip...@googlemail.com> wrote:
> On Sat, Feb 11, 2012 at 10:14 PM, Juan Jose Garcia-Ripoll < > juanjose.garciarip...@googlemail.com> wrote: > > > I believe this would still work in the Windows implementation, where locks > > are always recursive, but it strongly relies on having libatomics compiled > > in for CAS support. > > > > Sorry, I mixed up the code of the two functions a bit. I notice that there > is still a problem when the code gets interrupted before the owner is set > and the user does not unwind. This would happen, for instance, when the > thread is suspended by the garbage collector. > > I have been toying for the last hour with alternatives, but while there are > some that profit from POSIX's error detection by forcing all locks to be > non-recursive, those do not work at all in Windows. > > Definitely this all is rather messy :) I wonder whether it would make sense > to use CAS + wait times as SBCL does. It's unfortunately a rather complex problem and I'll have to carefully re-read your last messages more than once, it seems :) One of the reasons for me to use ECL on NetBSD (apart from the awesome C integration) is that threads are supported. SBCL only supports threads on a few specific systems, yet I think that there is work ongoing on that lately, which I haven't followed much. CAS being almost universally supported by architectures (implementations might be slow on a few specific ones such as VAX), yet totally OS-independent, I guess that it'd be a good research area for an experimental lock implementation, indeed... PThread Mutex code is generally also dealing with issues such as memory barriers, I wonder if a custom implementation would also have to. I'm not sure yet about other OSs, but NetBSD exports those along with its atomic_ops(3). -- Matt ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Ecls-list mailing list Ecls-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ecls-list
