How: multiple program instances sharing same data

[Zytan]

Re: How: multiple program instances sharing same data

What counts here is the Private part, so you should watch the Private

Process counters for your process. The GC heap is part of the private
memory
of a process, the amount of memory you consume from the GC heap depends
on
your allocation scheme, the more and the larger the objects you create
,the
larger the GC heap grows and consequently the larger your Private bytes.

Process Explorer shows a graph of history of private bytes, so this is
very useful.

Zytan

[Zytan]

Re: How: multiple program instances sharing same data

I could probably reduce the stack space by half or more, I bet,

without causing problems, I forgot about that. I'll have to see how I
can change that.

>
You can't do this for the 3 threads created by the run-time, you can only
change the default size of the stack of the threads you create explicitely.

This page http://www.thescripts.com/forum/thread229335.html says

"The stack is set to an arbitrarily small value when the program is
first loaded. The stack then grows on demand to meet the needs of the
thread. This is implemented by placing a page with PAGE_GUARD access
at the end of the current stack. When your code causes the stack
pointer to point to an address on this page, an exception occurs. The
system will commit your desired page. The 1M was the default maximum
stack size that can be commit."

So, it looks like it wouldn't make any difference, anyway.

Zytan

[Willy Denoyette [MVP]]

Re: How: multiple program instances sharing same data

"Zytan" <zytanlithium@g mail.comwrote in message
news:1195063458 .174344.38190@i 38g2000prf.goog legroups.com...

I could probably reduce the stack space by half or more, I bet,
without causing problems, I forgot about that. I'll have to see how I
can change that.

>>
>You can't do this for the 3 threads created by the run-time, you can only
>change the default size of the stack of the threads you create
>explicitely.

>
This page http://www.thescripts.com/forum/thread229335.html says
>
"The stack is set to an arbitrarily small value when the program is
first loaded. The stack then grows on demand to meet the needs of the
thread. This is implemented by placing a page with PAGE_GUARD access
at the end of the current stack. When your code causes the stack
pointer to point to an address on this page, an exception occurs. The
system will commit your desired page. The 1M was the default maximum
stack size that can be commit."
>
So, it looks like it wouldn't make any difference, anyway.
>
Zytan
>

This article is based on the V1.X Framework and not quite correct.
In V2, you can create threads with other stack sizes than the 1MB default,
but the threads created before your program runs will still be 1MB max. Of
course you can edit the PE file header and set all stacks to a lower value
for the whole process, but that's in general a bad idea, CLR application
are quite stack "hungry".
Note that stack space is always pre-committed for CLR threads, this is *not*
the case for unmanaged threads which is what the above describes.


Willy.

[Zytan]

Re: How: multiple program instances sharing same data

This article is based on the V1.X Framework and not quite correct.

Ok, good catch.

In V2, you can create threads with other stack sizes than the 1MB default,
but the threads created before your program runs will still be 1MB max.

My program makes a few threads, and they shouldn't need 1 MB each, so
I should reduce their sizes.

Of course you can edit the PE file header and set all stacks to a lower value
for the whole process, but that's in general a bad idea, CLR application
are quite stack "hungry".

Ok, so any thread stacks that I can't easily change (without hacking
the .exe) are better off left as-is... good enough.

Note that stack space is always pre-committed for CLR threads, this is *not*
the case for unmanaged threads which is what the above describes.

Oh, wait, so for CLR threads that start implicitly, their stack memory
are commited. Fine. But, for threads that *I* make, with Thread(),
their stack space is NOT commited? That means I don't need to worry
that they are 1 MB each, since that memory won't actually be committed
unless they really use it, right?

Thanks very much as always, Willy

Zytan

[Zytan]

Re: How: multiple program instances sharing same data

Is NGEN "Native Image Generator"?

>

Yep.
Use it whenever you need to run several instances of the same application,
it produces sharable code images (see above). You can't live without it when
running on Terminal Server for instance.

>
I still haven't tried this, yet, and I will when I find some time, and
report back here.

I tried it, and it worked. Didn't change a lot, but it reduced memory
usage by about 5%. I found this page useful in describing how to use
it: http://www.codeproject.com/useritems/Ngen.asp

Zytan