OpenJDK: Java application Startup
Tom.Marble at Sun.COM
Wed Aug 29 11:53:15 UTC 2007
alexanderschunk at t-online.de wrote:
> i would like to contribute to OpenJDK by improving Java application
> start up times.
This is a common concern!
> There are two different kinds of application start up:
> cold start:
> this is a start immediately after system reboot
> warm start:
> I dont know if there is any active development on this for OpenJDK at
> present but i think this is crucial for any Java relase.
As David points out we've had a virtual team working on this
for several years. One of the issues which cannot be separated
from startup is memory footprint. There is often a trade-off between
these two. And, to complicate matters, measuring footprint and
accounting for it accurately (shared libs vs. per process memory)
is very difficult to do in a cross platform way. Hint: TaskManager
does *not* tell the whole story!
We have actually converted many JDK methods to lazy initialization
and done some fairly sophisticated things like re-ordering
classes in rt.jar.
In any case the most easy improvements have probably been made
so this work gets progressively harder.
As Roman points out... there is a new effort to pre-warm the
file system cache called Quickstarter which we are working on:
More information about the discuss