Subj : Re: [RFC] Boost.Threads on its way to C++0x
To   : comp.programming.threads
From : David Holmes
Date : Fri Apr 29 2005 05:47 pm

"Joe Seigh" <jseigh_01@xemaps.com> wrote in message
news:opspyz19x2qm36vk@grunion...
> ** case in point.  In Java 1.0 you could do multiple condition variables
using a
> slight hack.  They removed the ability to do the hack for no discernable
reason
> other than maybe the hack offended somebody's sensibilities.  They added
the
> capability for multiple condition variables back in but it doesn't work
with
> normal monitor locks, only a new lock type that can't be used in the
normal
> synchronized statement.  What's really strange is the fix they orginally
put
> in is that monitor unlocks had to match and be in the same frame that did
the
> monitor lock, yet AFAICT the new locks are just library implementations
and
> have no such restriction.

They changed the rules so that HotSpot could safely use stack-allocation for
lock records.

The new stuff is implemented mostly at the user-level with lock-free queues
and a VM API for parking and unparking a thread.

David Holmes

.