Re: address@hidden: Emacs 22.1 hung after delete-process]

[dhruva]

Hi,

On 8/18/07, Jason Rumney <address@hidden> wrote:
> dhruva wrote:
> > It is the call to read in _sys_read_ahead which continues to block
> > even after the sub process is killed. If we change that read to use
> > ReadFile using OVERLAPPED structure, we could handle canceling of IO
> > when we want to terminate the thread more elegantly. But, that would
> > be more changes as we need to use the HANDLE and not fd.
> >
>
> This would be a good change, not just here, but in sys_select in
> w32proc.c, which is overcomplicated due to a past design decision to

I have made a new patch using ASYNC Read in _sys_read_ahead. We now
have an IO that can be canceled. With this, the call to
TerminateThread in the delete_child in w32proc.c should ideally never
happen. Once this gets well tested, I will try to implement similar
ASYNC mechanisms in sys_select.
 In the patch, I have made a call to memset in the _sys_read_ahead.
Since we read char at a time, this could be considered as an overhead.
I did not want to
Since I have XP, I request others to test the patch on different
supported windows flavors of emacs. I have tested with the reproducer
(calling perl), invoking a command shell and typing various dos
commands. I have not noticed any failures so far.

-dky

-- 
Dhruva Krishnamurthy
Contents reflect my personal views only!

async.patch
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