On Nov 20, 10:54 pm, Jon Harrop <[email protected]> wrote: > On Tuesday 17 November 2009 04:14:10 Charles Oliver Nutter wrote:
> > On the JVM, at least on Hotspot, threads get their own thread-local > > allocation buffers (TLABs), which reduces most allocations to > > pointer-bumping. > > Only for the mutator. For the GC, the object is then reallocated on the shared > heap and copied. That is expensive and it doesn't scale because the shared > heap is a global resource. I haven't studied Sun's algorithms in great detail, but my understanding was that (depending on the specific algorithm chosen) objects remain in the local heap until they are promoted, which might not be for 2-3 GCs. The "server" mode on IBM iSeries "classic" Java maintains objects in "chunks" which are initially thread-allocated and only made global when they "fill up" with long-lived objects. (This is a non-copying algorithm.) -- You received this message because you are subscribed to the Google Groups "JVM Languages" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jvm-languages?hl=.
