Re: copile java 1.5 code

[Mark Wielaard <mark at klomp dot org>]

Hi,

On Thu, 2005-01-27 at 09:49 -0700, Tom Tromey wrote:
> >>>>> "Hans" == Boehm, Hans <hans.boehm@hp.com> writes:
> 
> Hans> _Jv_MonitorEnter and _Jv_MonitorExit are high, with 3.27 seconds
> Hans> each.  It looks like hash synchronization is enabled here?  We know we
> Hans> don't do this as well as we should.  The compiler could probably help
> Hans> by passing the hash table address from one to the other, and by
> Hans> avoiding checks in MonitorExit when it knows we hold the
> Hans> lock.
> 
> Interesting ideas.  For the latter I think this could only be done
> when there are no intervening calls as there is no guarantee that a
> call preserve the count on a lock.

If you are compiling source -> native you know this to be true when you
encounter a synchronized method or synchronize(someObject) { } block. 

(Yes, theoretically it could call a method that through byte code
manipulation or JNI does a MonitorExit on your lock, but that would by
such horribly nasty ugly code that I don't think we should worry about
it since it would also break your code in the normal case.)

Cheers,

Mark

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