Unmanaged Code switch - how much does it cost.

[Mart Rogers]

We have been trying to avoid switches to unmanaged code in our development,
but have recently folded in a call to CDO by using System.Web.Mail as a
quick way to send email.

Yes this is a call to unmanaged code - but does anyone have any figures for
what that costs to do that switch?

How significant is a switch to unmanaged code (and back) bearing in mind
that it costs time to resolve the SMTP servers address and connecting to the
SMTP server.

Thanks in advance

Mart

[Scott Carter]

Here's a free option that might help you to avoid the question:
http://www.quiksoft.com/freesmtp/.

Scott

We have been trying to avoid switches to unmanaged code in our development, but have recently folded in a call to CDO by using System.Web.Mail as a
quick way to send email.

Yes this is a call to unmanaged code - but does anyone have any figures for what that costs to do that switch?

How significant is a switch to unmanaged code (and back) bearing in mind
that it costs time to resolve the SMTP servers address and connecting to the SMTP server.

[Mart Rogers]

"per larsen" <perlATturbopow erDOTcom> wrote in message
news:ef******** ******@tk2msftn gp13.phx.gbl...

Mart,

In my experience, the execution overhead of an managed/unmanaged/managed
code switch by itself is only a fraction of a millisecond, so that
shouldn't cause any concern in your case. I guess if you were passing
lots of complex data (strings and such, which require special
marshaling) and did this a lot then the overhead could become
prohibitive, but it doesn't sounds like that's the case here.
Thanks for your reply.

- Per

"Mart Rogers" <ma*********@de v.null> wrote in message
news:bf******** **@sparta.btint ernet.com...

We have been trying to avoid switches to unmanaged code in our

development,

but have recently folded in a call to CDO by using System.Web.Mail as

a

quick way to send email.

Yes this is a call to unmanaged code - but does anyone have any

figures for

what that costs to do that switch?

How significant is a switch to unmanaged code (and back) bearing in

mind

that it costs time to resolve the SMTP servers address and connecting

to the

SMTP server.

Thanks in advance

Mart

[Mart Rogers]

"Andrew Downum [MSFT]" <an*****@ATmicr osoft.D0Tcom> wrote in message
news:20******** *************** *****@phx.gbl.. .

The amount of time spent in a managed/unmanaged transition
will be totally dwarfed by anything that has to make a
network call. I don't have the exact number on hand, but
a simple managed-unmanaged function call with no
parameters ends up being somewhere on the order of a dozen
machine cycles, compared to a network request which could
easily end up in the multiple-millisecond range (or even
much longer on a latent network).

My general advice would be to write your app using the
most intuitive approach without stressing the performance
of every little call, and then run through your app with a
profiler and see just where the performance hotspots are.
I can almost guarentee that you will find much more
significant places to invest your optimization efforts
than managed/unmanaged transitions.

Thank you for your reply Andrew.

~ Andrew
DISCLAIMER: This posting is provided "AS IS" with no
warranties, and confers
no rights. Use of any possible included code samples are
subject to the
terms specified at
http://www.microsoft.c om/info/cpyright.htm"

For a series of excellent articles on high perf managed
code, see
http://msdn.microsoft.com/library/?url=/library/en-
us/dndotnet/html/highperfmanaged apps.asp (specifically
the "COM Interop and Platform Invoke" section)
and the very excellent:
http://msdn.microsoft.com/library/default.asp?
url=/library/en-us/dndotnet/html/fastmanagedcode .asp
(the "resources" section at the bottom of these have lots
of good links)

-----Original Message-----
We have been trying to avoid switches to unmanaged code

in our development,

but have recently folded in a call to CDO by using

System.Web.Mail as a

quick way to send email.

Yes this is a call to unmanaged code - but does anyone

have any figures for

what that costs to do that switch?

How significant is a switch to unmanaged code (and back)

bearing in mind

that it costs time to resolve the SMTP servers address

and connecting to the

SMTP server.

Thanks in advance

Mart
.