On Tue, Aug 03, 2010 at 02:54:40PM -0700, Gregory Crosswhite wrote:
Could someone explain to me the logic behind having "unsafe" calls block other threads from executing? It seems to me that if anything it would make more sense for "safe" calls to block other threads since the call can call back into the Haskell runtime, as opposed to "unsafe" calls which (by assertion) will never call back into Haskell and therefore should be safer to run in parallel with other threads. What am I missing here?
It is more an accident of ghc's design than anything, the same mechanism that allowed threads to call back into the runtime also allowed them to be non blocking so the previously used 'safe' and 'unsafe' terms got re-used. personally, I really don't like those terms, they are non-descriptive in terms of what they actually mean and presuppose a RTS similar to ghcs current design. 'reentrant' and 'blocking' which could be specified independently would be better and would be more future-proof against changes in the RTS or between compilers. John -- John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/