I wrote:
[...] Note that the fact that only one Haskell thread may execute at a time remains unchanged. [...]
Sven Panne wrote:
I haven't thought very deeply about your proposal yet, but I don't understand the remark above: What about e.g. a multi-processor Solaris machine (where pthreads work as intended, [...]
We can't currently allow several Haskell threads to really run simultaneosly [e.g. on two separate processors, or preemtively scheduled on a single processor], because they always mutate the same global heap. Currently, GHC switches its green threads only at times when the heap is in a defined state [not truly preemptively]. There seems to be some SMP support in the RTS, I don't know if it ever worked. If anyone wants to fix/finish it, that would be great, but it's not what I'm proposing here. My proposal is only a minimum solution intended to resolve the inherent incompatibility between the "threaded RTS" and libraries like OpenGL, which require thread-local-state. Cheers, Wolfgang