[Gc] Incremental collection in gcj?
hans.boehm at hp.com
Thu May 26 17:20:51 PDT 2005
I suspect the problem here is an old bug, and a patch that never made it
into the 3.4 branch. If you want to fix it, the patch was applied in
1.2 of pthread_stop_world.c in the gcc tree on savannah.gnu.org.
4.0 should not have this particular problem, since it uses version 1.3
Incremental/generational gc is not supported in gcj, though you
might be able to get it to work. I don't think anyone has ever
gone through and made sure that no system calls in libgcj write into
pointer-containing heap objects. If they do, those system calls may
fail, since incremental GC write-protects heap pages. Unlike
store instructions, system calls are not always transparently restarted
after unprotecting the page.
> -----Original Message-----
> From: gc-bounces at napali.hpl.hp.com
> [mailto:gc-bounces at napali.hpl.hp.com] On Behalf Of kus Kusche Klaus
> Sent: Wednesday, May 25, 2005 6:15 AM
> To: gc at napali.hpl.hp.com
> Subject: [Gc] Incremental collection in gcj?
> I tried to run a gcj-compiled program with incremental gc.
> It failed with a SIGSEGV in GC_restart_handler,
> executed in a signal handling context within a sigsuspend.
> Without GC_ENABLE_INCREMENTAL, the same program works fine.
> My platform is Linux, i686, posix threads, gcc 3.4.3.
> What's the state of incremental boehm gc for gcj?
> I was unable to find a definite word about it.
> Is it expected to work?
> Is it a known bug being worked on?
> Doesn't it work by design?
> Any hope for the future?
> Are there any other incremental / generational gc's for gcj
> (to reduce non-responsive times due to gc)?
> Please reply directly, I'm not subscribed.
> Klaus Kusche
> Entwicklung Software - Steuerung
> Software Development - Control
> KEBA AG
> A-4041 Linz
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> Tel +43 / 732 / 7090-3120
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> E-Mail: kus at keba.com
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