[Haskell-cafe] Windows: openFile gives permission denied when file in use

[Andrew Coppin]

On 29/12/2011 04:29 AM, Antoine Latter wrote:
> On Wed, Dec 28, 2011 at 3:52 PM, Michael Snoyman<michael at snoyman.com>  wrote:
>> Hi all,
>>
>> I just received a bug report from a client that, when an input file is
>> open in FrameMaker, my program gives a "permission denied error". This
>> bug is reproducible with a simple Haskell program:
>>
>
> This bug and its discussion is similar, but not identical:
> http://hackage.haskell.org/trac/ghc/ticket/4363

This one has been rumbling on for ages. As others have said, the Report 
demands that locking occur, which is probably a mistake. The daft thing 
is, apparently Linux doesn't really support locking, so on that platform 
these types of thing all work fine, and only on Windows, which does and 
always has supported propper locking, people get these errors. And yet, 
many people seem surprised to hear that Windows can actually turn off 
the locking; they seem completely unaware of the extensive and highly 
flexible locking facilities that Windows provides. Every time I hear 
"oh, I don't think Windows can handle that", I sigh with resignation.

Whatever we change the default to, it would be useful if we could expose 
locking mechanisms in a reasonably portable way so that people who care 
about such things can alter the default if it is not what they want.