New asynchronous exception control API (ghc parts)
As discussed on the libraries/haskell-cafe mailing lists
http://www.haskell.org/pipermail/libraries/2010-April/013420.html
This is a replacement for block/unblock in the asychronous exceptions
API to fix a problem whereby a function could unblock asynchronous
exceptions even if called within a blocked context.
The new terminology is "mask" rather than "block" (to avoid confusion
due to overloaded meanings of the latter).
In GHC, we changed the names of some primops:
blockAsyncExceptions# -> maskAsyncExceptions#
unblockAsyncExceptions# -> unmaskAsyncExceptions#
asyncExceptionsBlocked# -> getMaskingState#
and added one new primop:
maskUninterruptible#
See the accompanying patch to libraries/base for the API changes.