#10149: The argument of mask does not always restore the masking state -------------------------------------+------------------------------------- Reporter: | Owner: facundo.dominguez | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.4 Component: libraries/base | Keywords: Resolution: | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Description changed by facundo.dominguez: Old description:
In the documentation of `mask` and `uninterruptibleMask` it is claimed that the `restore` argument restores the masking state. However this is not true in the following programs:
{{{#!hs mask_ $ -- start with exceptions masked mask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}}
{{{#!hs uninterruptibleMask_ $ -- start with exceptions uninterruptibly masked uninterruptibleMask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}}
The expected state is that `getMaskingState` would produce `MaskedInterruptible` and `MaskedUninterruptible`, however, in both cases it gives Unmasked.
Either the documentation needs to be changed, or the implementation must really restore the masking state in these cases.
New description: In the documentation of `mask` and `uninterruptibleMask` it is claimed that the `restore` argument restores the masking state. However this is not true in the following programs: {{{#!hs mask_ $ -- start with exceptions masked mask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}} {{{#!hs uninterruptibleMask_ $ -- start with exceptions uninterruptibly masked uninterruptibleMask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}} The expected result is that `getMaskingState` would produce `MaskedInterruptible` and `MaskedUninterruptible`, however, in both cases it gives Unmasked. Either the documentation needs to be changed, or the implementation must really restore the masking state in these cases. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10149#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler