Bug in phobos Thread module?

[Regan Heath]

Walter Bright Wrote:
> Babele Dunnit wrote:
> 
> > I am a newbie with D but experienced C++ developer.. this is my first post, so I MUST say that D ROCKS! Really impressive language. Walter, you are definitely the Lord of Compilers. Back to the subject, I am writing a massively multithreaded piece of code, and after some time I get a "failed to start" error. I digged in the forums and found someone else with same problem, but no answer. So was time to dig into Thread sources...
> > 
> > ...and I see a static destructor cleaning a single handle (the main thread, I suppose), but no CloseHandle on any other handle created via _beginthreadex (I am talking about Windows, I should have specified before, sorry). 
> > 
> > I believe there should be an explicit Thread destructor able to free the handle via CloseHandle; also, because thread handles under Windows are a limited resource, probably a RIAA scheme (or explicit "delete" call) should be used, instead of waiting for the GC to pass by..
> > 
> > So, I added a CloseHandle(mythread.hdl) call and now my handles count (in the Task Manager) is much more under control...
> 
> I'm not too experienced with threading, so if you could post a patch 
> that would be welcome.

I've no idea how to do a patch as such but I believe all you need is a call to CloseHandle in:

extern (Windows) static uint threadstart(void *p)

as this wrapper is used for all threads and the stuff at the end of the wrapper removes the thread from allThreads and does cleanup.

eg

	debug (thread) printf("Ending thread %d\n", t.idx);
                version (Win32) {
                       CloseHandle(t.hdl);
                       t.hdl = cast(thread_hdl)0;
                }
	t.state = TS.TERMINATED;
	allThreads[t.idx] = null;

I cannot recall (nor do I have old code I can refer to, sadly) whether there is a similar call required on Linux etc, I suspect not given that pthread_create returns a thread id, as opposed to a handle per-se.

I have vague recollections of calling kill, but that may be to forcibly terminate a thread as opposed to cleaning up a handle.

Regan Heath