[D-runtime] A mechanism to kill threads

[Sean Kelly]

If the thread holds a lock on any mutexes, they will never be released and any other thread trying to acquire those locks will deadlock.

On May 16, 2012, at 2:19 PM, David Simcha wrote:

> For the sake of argument, what are the most non-obvious reasons why killing threads is bad?  The ones I can think of are because the thread may be in the middle of doing something important and bad things will happen if it's interrupted and because the thread might hold resources that will never get freed if it's killed before it gets to free them.
> 
> I was thinking at one point that I wanted a kill() primitive when I was designing std.parallelism, but I don't remember why I wanted it and obviously I've managed to do without it.  Is it ok to kill threads if they're not doing useful work at the time and they're not holding onto any resources that will never get freed if you kill them?
> 
> On Wed, May 16, 2012 at 5:04 PM, Jonathan M Davis <jmdavisProg at gmx.com> wrote:
> On Wednesday, May 16, 2012 20:57:15 Alex Rønne Petersen wrote:
> > Of course it's unsafe, but no less than arbitrarily suspending a
> > thread. Once you've suspended a thread, you may as well kill it.
> > You've effectively halted it anyway. We have lots of unsafe primitives
> > in core.thread already (and my critical regions and cooperative
> > suspension patches add even more!).
> >
> > Is there anything speaking against adding this to core.thread with a
> > big fat "THIS IS UNSAFE" warning?
> 
> Well, I wasn't saying that it's necessarily the case that we shouldn't add it.
> I was pointing out that it's a very unsafe thing to do and rarely needed such
> that it's not exactly surprising that it hasn't been added previously. If
> there's a real use case for it, it makes sense to add it given that it _is_
> something that's platform dependent, and part of the whole point of Thread is
> to provide a platform-independent API for handling threads. It probably
> _should_ have a big fat warning on it though, given that not all developers
> seem to get how insanely bad it is to kill a thread (at least, that seems to
> be the case given some thread-related questions I've seen in the past).
> 
> - Jonathan M Davis
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime
> 
> _______________________________________________
> D-runtime mailing list
> D-runtime at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/d-runtime