Thread pause and resume

[Fawzi Mohamed]

On 2009-04-06 20:49:50 +0200, Steve Teale <steve.teale at britseyeview.com> said:

> Steve Teale Wrote:
> 
>> Sean Kelly Wrote:
>> 
>>> == Quote from Steve Teale (steve.teale at britseyeview.com)'s article
>>>> 
>>>> In some code I wrote at that time, I had a worker thread pool. When a 
>>>> thread had done its job it would mark itself as available then
>>> pause. The listener thread would then resume it or start one that had 
>>> never been started. I'm trying to get it running in 2.26. There
>>> are functions of the same name there but they are nested inside 
>>> SuspendAll and ResumeAll, and so not accessible.
>>> 
>>> This sounds like a classic producer/consumer case.  I suggest using condition
>>> variables (core.sync.condition with core.sync.mutex).
>> 
>> The problem is at the moment, that the D documentation covers the 
>> language, and Phobos - the latter option exposes Object to some extent.
>> 
>> Anything that is in core.* is undocumented and you have to 'rtfsc' - if 
>> you can find it. I can't even find "core.sync" in D files under dmd. 
>> Can you point me in the right direction please.
>> 
>> Thanks Steve
>> 
> As an aside, I realize that Thread.suspend is dodgy, it's been 
> deprecated in Java and C#. Can the metaprogrammers out there come up 
> with a way to insist that a particular member function is called only 
> from the instance that it 'belongs' to. Then presumably it could be 
> made safe.

no pause and resume remains a bad idea because it can stop the thread 
in any state, even while it has acquired a lock in any non signal safe 
kernel function, which means that any other thread could block calling 
one of these functions until the thread is released, which if you are 
not very careful might stop the thread that should release it, 
deadlocking the whole program.

Fawzi