Mark Wielaard wrote:
On Thu, 2005-10-20 at 17:56 -0500, Archie Cobbs wrote:
Off tanget, but IMHO this is not strictly true: it depends on whether
VM native code relies on finalize() to free up its (non-heap) memory.
Here's an exmaple of this:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4797189
That problem doesn't occur with GNU Classpath since our zip
implementation is written in java itself. But we have a similar example
in the mauve testsuite (one that I also observed while getting JBoss to
work with GNU Classpath and JamVM). There is a test that opens lots of
FileInputStreams and then expects the garbage collector to finalize
these and free up the open file descriptors. gcj explicitly handles this
by forcing a garbage collect and finalization pass when it cannot create
a new file descriptor. We currently don't have any convention for
marking VMObjects or finalizers as (scarce) holding native resources or
make the native code signal the runtime to do a finalization of such
objects.
Right, and so this is a bug (although in a different form than
the ZIP example above) in Classpath too. It could be fixed
by creating a new VM method e.g. VMRuntime.runFinalizers()
that would "try hard" to run finalizers.. then the other thread
could loop, calling this method each iteration. There might still
be some more subtlety to this (finalizers have not guarantee of
returning quickly, etc.)
-Archie
__________________________________________________________________________
Archie Cobbs * CTO, Awarix * http://www.awarix.com
