[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Chicken-users] remove enable/disable interrupt flag

From: Alaric Snell-Pym
Subject: Re: [Chicken-users] remove enable/disable interrupt flag
Date: Thu, 29 Sep 2011 16:35:04 +0100
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20110617 Thunderbird/3.1.11

Hash: SHA1

On 09/29/2011 04:25 PM, Jörg F. Wittenberger wrote:

>> POSIX says that fork needs to produce only a single surviving POSIX
>> thread in the child. Perhaps Chicken fork needs to do the same with
>> Chicken threads.
> Alaric, that's exactly the effect and reason why I'm using this
> disable-interrupts/enable-interrupts around fork: to make sure
> there is only this one Chicken-threads running in the child.
> With interrupts disabled there is no scheduling in chicken.
> (At least not until you run into a thread-yield! anyway.)
> And therefore I'd really recommend to keep it in the runtime.

I think a better mechanism would be a way to abort all threads but the
current one, triggered after the fork in the child, with no interrupts
until the thread murder is complete.

If you just go off and exec after the fork it'd be better to
uninterruptably vfork-then-exec, but we have procedures to do that already!

Aborting all threads but the one that asked for the fork also gives one
the opportunity to inform them of this fact, should any of them leave
useful data structures in incosistent states with locks held. There's
something to be said for requesting permission to fork from all threads
before doing so, so they can make sure they finish any operations on
shared state in the parent, but that'll be complex, and a potential
performance bottleneck, so probably not worth it!


- --
Alaric Snell-Pym
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla -


reply via email to

[Prev in Thread] Current Thread [Next in Thread]