Re: MT: active threads limit

[Vladimir T. <vtz...@gm...>]

On 6/29/09, Sam Steingold <sd...@gn...> wrote:
> Vladimir Tzankov wrote:
>> On 6/28/09, Don Cohen <don...@is...> wrote:
>>> So it seems at least plausible to have > 128 threads.
>>
>> We can easily increase the limit (as far as we do not get overlap of
>> malloc-ed lisp stack and lisp heap). Sam?
>
> The bug you mentioned (overlap between mmaped and malloc'ed memory) is very
> scary.

Actually lisp heap overlaps at some time malloc-ed area - since it is
expanded via mmap() with MAP_FIXED. On osx large malloc() calls are
actually vm_allocate(). I'll check it in details but probably we will
get similar issues on other os-es.

On i386 linux I can spawn about 550 (sometimes more) before failure -
I did not inspect the failure reason but probably it is the
same/similar.
On win32 mingw - about 350-400.

If I decrease the default thread stack(s) - the numbers get higher.

These days will test more - but may be we should limit the number of
active threads (can be done easily from spvw.d: create_thread()).

> More to the point, I abhor arbitrary limits, so I think this one should go
> too.
> (In fact I wanted to replace the array of threads with a doubly linked
> list).

done

> BTW, I think we should signal an error when create_thread return NULL
> instead
> of make-thread returning NIL.

done