On 27 March 2006 18:51, Neil Mitchell wrote:

* Its simulated concurrency, if you have two processors, only one will ever be used. The only exception is FFI, where a number of FFI calls can run in parallel with some Haskell code. This means that no locking is needed on the global heap.

I don't consider this to be "simulated" concurrency. The fact that you don't get any actual parallelism on a multiprocessor is a performance issue, not a semantic one. In other words, your implementation is fine. Until very recently GHC had the same restriction, incedentally. Cheers, Simon