Proposal: Add tryReadChan to Chan

[Simon Marlow]

On 01/12/2010 12:22, Duncan Coutts wrote:
> On Wed, 2010-12-01 at 01:28 +0100, Mitar wrote:
>> Hi!
>>
>> On Wed, Dec 1, 2010 at 12:37 AM, Duncan Coutts
>> <duncan.coutts at googlemail.com>  wrote:
>>> I've not looked at it in detail, I just wanted to mention that I would
>>> be nervous about accepting this unless someone like Simon Marlow reads
>>> it over and decides the locking works.
>>
>> I think he did?
>>
>> http://hackage.haskell.org/trac/ghc/ticket/4535#comment:2
>
> Oh sorry. When I said I've not looked at it in detail, that included not
> reading the ticket, just your email :-)
>
>>> This sort of stuff is notoriously subtle, for example Neil Mitchell is
>>> convinced we have a deadlock bug in the current Chan code (without using
>>> isEmptyChan), but he cannot pin it down (but using his own trivial Chan
>>> impl cures the deadlock).
>>
>> Can you give me a link to a test code which fails with current
>> implementation of Chan? Or does this problems with pinning it down
>> means that there wasn't yet simple code which would show the problem?
>
> You can ask him, since it was some time ago when he mentioned it, but I
> think narrowing it down was part of the problem.

Was it this?

http://hackage.haskell.org/trac/ghc/ticket/4154


Cheers,
	Simon