Damien Neil <[EMAIL PROTECTED]> wrote: > On Thu, Jan 15, 2004 at 09:31:39AM +0100, Leopold Toetsch wrote: >> I don't see any advantage of such a model. The more as it doesn't >> gurantee any atomic access to e.g. long or doubles. The atomic access to >> ints and pointers seems to rely on the architecture but is of course >> reasonable.
> You *can't* guarantee atomic access to longs and doubles on some > architectures, unless you wrap every read or write to one with a > lock. The CPU support isn't there. Yes, that's what I'm saying. I don't see an advantage of JVMs multi-step variable access, because it even doesn't provide such atomic access. Parrot deals with PMCs, which can contain (lets consider scalars only) e.g. a PerlInt or a PerlNumer. Now we would have atomic access (normally) to the former and very likely non-atomic access to the latter just depending on the value which happened to be stored in the PMC. This implies, that we have to wrap almost[1] all shared write *and* read PMC access with LOCK/UNLOCK. [1] except plain ints and pointers on current platforms > - Damien leo
