harmony-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jimmy, Jing Lv" <firep...@gmail.com>
Subject Re: [General VM] GC strategy:how to garbage collect short-lived objects quickly.
Date Thu, 14 Sep 2006 10:27:23 GMT
Leo Li wrote:
> Hi,all:
>    As we all know, java objects are allocated on heap instead of stack,
> thus there is a problem about how to garbage collect short-lived objects
> quickly.
>    In a recent real project I involved, a server built on java tries to
> send thousands of messages to client per second. A lot of short-lived
> messages is created as objects and discarded. (Although I can recycle these
> memory, there is still a byte array created during per call of nio read and
> write.) Since current GC strategy adopted by current RI starts to work only
> when the memory allocated approaching the limit of java heap, the work 
> of GC
> is huge and will raise a wave on the server performance. Furthermore, after
> a long run, although I know GC will merge memory, the operating system
> reports there is memory fragment and in the worst case the OS will even
> report real memory is exhausted.
>    Of course it is possible to limit the java heap so as to force gc
> frequently as a workround, is it preferrable to collect short-lived objects
> quickly such as adopt aged-related object queues as one of the gc strategy?
>   What about the VMs here, drlvm or J9?

Interesting topic, I'm still dreaming of "free()" in Java (This dream 
begins at the very beginning when I see Java, as C/C++ is my first 
program language )However, it seems RI will never give us "free()". :)

Only a thought, Java may offer a key word "temp", indicating that this 
variety can be freed at once.

> Leo Li
> China Software Development Lab, IBM


Best Regards!

Jimmy, Jing Lv
China Software Development Lab, IBM

Terms of use : http://incubator.apache.org/harmony/mailing.html
To unsubscribe, e-mail: harmony-dev-unsubscribe@incubator.apache.org
For additional commands, e-mail: harmony-dev-help@incubator.apache.org

View raw message