Winforms and memory usage

[deerchao]

I'm developing a WinForms application. It slowly eats up memory, one
client reported that it took 200MB or more, and finnaly crashed. I
myself noticed it's common to use up 30MB memory, but if I minimize it
(all the Forms will Hide, only a NotifyIcon is shown at the System
Notification Area), the memory usage comes down to 8MB immediately.
After that, even if I show the Forms again, it uses only 8MB memory.
Do I have another way to programmly cut down the memory usage, other
than Hide/Show all the Forms manually?

Thanks!

[Chris Mullins [MVP - C#]]

It sounds like you have a legitimate memory leak. You'll need to track this
down.

It also sounds like you need to run this from time to time:
http://www.jdconley.com/blog/archive...anymemory.aspx

There's alot of debate about that 2nd one, and you should give it some
though before using it, but if your users are whining that it takes too much
memory, that'll shut them up... :)

--
Chris Mullins

"deerchao" <de******@gmail.comwrote in message
news:11**********************@z24g2000prh.googlegr oups.com...

I'm developing a WinForms application. It slowly eats up memory, one
client reported that it took 200MB or more, and finnaly crashed. I
myself noticed it's common to use up 30MB memory, but if I minimize it
(all the Forms will Hide, only a NotifyIcon is shown at the System
Notification Area), the memory usage comes down to 8MB immediately.
After that, even if I show the Forms again, it uses only 8MB memory.
Do I have another way to programmly cut down the memory usage, other
than Hide/Show all the Forms manually?

Thanks!

[Jay]

Do non-.net applications (eg VB6, MS VS6, C++ Builder, Delphi) have the same
"problem" of appearing to use a lot of memory?
"Chris Mullins [MVP - C#]" <cm******@yahoo.comwrote in message
news:OQ*************@TK2MSFTNGP02.phx.gbl...

It sounds like you have a legitimate memory leak. You'll need to track this
down.

It also sounds like you need to run this from time to time:
http://www.jdconley.com/blog/archive...anymemory.aspx

There's alot of debate about that 2nd one, and you should give it some
though before using it, but if your users are whining that it takes too much
memory, that'll shut them up... :)

[Chris Mullins [MVP - C#]]

In my experience, .Net WinForms is the worst (best?) at doing an
impersonation of a bloated sow.

In general, Winforms does quite a bit of things very well, but conservation
of desktop memory isn't on that list.

--
Chris Mullins

"Jay" <-wrote in message news:u4**************@TK2MSFTNGP06.phx.gbl...

Do non-.net applications (eg VB6, MS VS6, C++ Builder, Delphi) have the
same
"problem" of appearing to use a lot of memory?
"Chris Mullins [MVP - C#]" <cm******@yahoo.comwrote in message
news:OQ*************@TK2MSFTNGP02.phx.gbl...

It sounds like you have a legitimate memory leak. You'll need to track
this
down.

It also sounds like you need to run this from time to time:
http://www.jdconley.com/blog/archive...anymemory.aspx

There's alot of debate about that 2nd one, and you should give it some
though before using it, but if your users are whining that it takes too
much
memory, that'll shut them up... :)

[Chris Alton [MSFT]]

The best thing to do to see if you really are leaking objects is to get a
memory dump of your application at a time you think it is using an excess
of memory. Then check and see if there are a lot of objects still held
around in memory that shouldn't be there. You can use the Debugging Tools
for Windows to get that and the sos.dll extension that comes with .NET 2.0.
There are quite a few articles out on the web that can help you with this.

You can get the 32bit version from here:
http://www.microsoft.com/whdc/devtoo...nstallx86.mspx

-------------------------------------
Chris Alton, Microsoft Corp.
SQL Server Developer Support Engineer
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

From: "Chris Mullins [MVP - C#]" <cm******@yahoo.com>
References: <11**********************@z24g2000prh.googlegroups .com>

<OQ*************@TK2MSFTNGP02.phx.gbl>
<u4**************@TK2MSFTNGP06.phx.gbl>

Subject: Re: Winforms and memory usage
Date: Fri, 12 Oct 2007 13:43:36 -0700
Lines: 32

In my experience, .Net WinForms is the worst (best?) at doing an
impersonation of a bloated sow.

In general, Winforms does quite a bit of things very well, but

conservation

of desktop memory isn't on that list.

--
Chris Mullins

"Jay" <-wrote in message news:u4**************@TK2MSFTNGP06.phx.gbl...

Do non-.net applications (eg VB6, MS VS6, C++ Builder, Delphi) have the
same
"problem" of appearing to use a lot of memory?
"Chris Mullins [MVP - C#]" <cm******@yahoo.comwrote in message
news:OQ*************@TK2MSFTNGP02.phx.gbl...

It sounds like you have a legitimate memory leak. You'll need to track
this
down.

It also sounds like you need to run this from time to time:

http://www.jdconley.com/blog/archive...tothinkwedontu
seanymemory.aspx

There's alot of debate about that 2nd one, and you should give it some
though before using it, but if your users are whining that it takes too
much
memory, that'll shut them up... :)

[Chris Mullins [MVP - C#]]

Having spent far, far too much time at this, I would recommend two products
over SOS:

- SciTech Memory Profiler is excellent. They have a 14 day free trial.
- RedGate ANTS Memory Profiler is also excellent. They also have a trial.

When I do seminars or mentoring on this, I always start with these products,
and only revert to Son of Strike and WinDbg as a very last resort. The
learning curve on SOS is brutal, and most devs won't ever get through it.

The learning curve for SciTech is about a day, and it's extremely powerfull.
Amazingly so.

The learning curve for ANTS is a few hours, but it's nowhere near as
powerfull as SciTech.

--
Chris Mullins

"Chris Alton [MSFT]" <ca****@online.microsoft.comwrote in message
news:zE**************@TK2MSFTNGHUB02.phx.gbl...

The best thing to do to see if you really are leaking objects is to get a
memory dump of your application at a time you think it is using an excess
of memory. Then check and see if there are a lot of objects still held
around in memory that shouldn't be there. You can use the Debugging Tools
for Windows to get that and the sos.dll extension that comes with .NET
2.0.
There are quite a few articles out on the web that can help you with this.

You can get the 32bit version from here:
http://www.microsoft.com/whdc/devtoo...nstallx86.mspx

-------------------------------------
Chris Alton, Microsoft Corp.
SQL Server Developer Support Engineer
This posting is provided "AS IS" with no warranties, and confers no
rights.
--------------------

>From: "Chris Mullins [MVP - C#]" <cm******@yahoo.com>
References: <11**********************@z24g2000prh.googlegroups .com>

<OQ*************@TK2MSFTNGP02.phx.gbl>
<u4**************@TK2MSFTNGP06.phx.gbl>

>Subject: Re: Winforms and memory usage
Date: Fri, 12 Oct 2007 13:43:36 -0700
Lines: 32

In my experience, .Net WinForms is the worst (best?) at doing an
impersonation of a bloated sow.

In general, Winforms does quite a bit of things very well, but

conservation

>of desktop memory isn't on that list.

--
Chris Mullins

"Jay" <-wrote in message news:u4**************@TK2MSFTNGP06.phx.gbl...

Do non-.net applications (eg VB6, MS VS6, C++ Builder, Delphi) have the
same
"problem" of appearing to use a lot of memory?
"Chris Mullins [MVP - C#]" <cm******@yahoo.comwrote in message
news:OQ*************@TK2MSFTNGP02.phx.gbl...

It sounds like you have a legitimate memory leak. You'll need to track
this
down.

It also sounds like you need to run this from time to time:

http://www.jdconley.com/blog/archive...tothinkwedontu
seanymemory.aspx

>
There's alot of debate about that 2nd one, and you should give it some
though before using it, but if your users are whining that it takes too
much
memory, that'll shut them up... :)

[bob clegg]

Hi,
Just a thought when profiling, allow sufficient time for the full
behaviour to be shown.
I went chasing a 'memory leak' where the Private bytes and Working Set
usage went up for several hours for no good reason I could see.
They finally levelled out then came down again. Then went up again
etc.
Took a couple of days of this wobbling behaviour before I accepted
that there was no leak.
Bob
On Fri, 12 Oct 2007 14:21:34 -0700, "Chris Mullins [MVP - C#]"
<cm******@yahoo.comwrote:

>Having spent far, far too much time at this, I would recommend two products
over SOS:

- SciTech Memory Profiler is excellent. They have a 14 day free trial.
- RedGate ANTS Memory Profiler is also excellent. They also have a trial.

When I do seminars or mentoring on this, I always start with these products,
and only revert to Son of Strike and WinDbg as a very last resort. The
learning curve on SOS is brutal, and most devs won't ever get through it.

The learning curve for SciTech is about a day, and it's extremely powerfull.
Amazingly so.

The learning curve for ANTS is a few hours, but it's nowhere near as
powerfull as SciTech.

[Chris Alton [MSFT]]

That would be the Garbage Collector at work. The garbage collector won't
run until it deems it necessary (or you force it in your code by calling
GC.Collect). So it is possible your .NET app can use up ~300MB of RAM but
in reality that amount is much lower and the garbage collector has not run
yet. If you wait long enough the garbage collector should kick off and drop
the memory usage of your app into the normal usage range.

-------------------------------------
Chris Alton, Microsoft Corp.
SQL Server Developer Support Engineer
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

From: bob clegg <cu**********@remooove.xtra.co.nz>
Subject: Re: Winforms and memory usage
Date: Mon, 15 Oct 2007 23:13:48 +1300
Message-ID: <am********************************@4ax.com>
References: <11**********************@z24g2000prh.googlegroups .com>

<OQ*************@TK2MSFTNGP02.phx.gbl>
<u4**************@TK2MSFTNGP06.phx.gbl>
<#x**************@TK2MSFTNGP04.phx.gbl>
<zE**************@TK2MSFTNGHUB02.phx.gbl>
<Oz**************@TK2MSFTNGP03.phx.gbl>

>
Hi,
Just a thought when profiling, allow sufficient time for the full
behaviour to be shown.
I went chasing a 'memory leak' where the Private bytes and Working Set
usage went up for several hours for no good reason I could see.
They finally levelled out then came down again. Then went up again
etc.
Took a couple of days of this wobbling behaviour before I accepted
that there was no leak.
Bob
On Fri, 12 Oct 2007 14:21:34 -0700, "Chris Mullins [MVP - C#]"
<cm******@yahoo.comwrote:

Having spent far, far too much time at this, I would recommend two

products

over SOS:

- SciTech Memory Profiler is excellent. They have a 14 day free trial.
- RedGate ANTS Memory Profiler is also excellent. They also have a trial.

When I do seminars or mentoring on this, I always start with these

products,

and only revert to Son of Strike and WinDbg as a very last resort. The
learning curve on SOS is brutal, and most devs won't ever get through it.

The learning curve for SciTech is about a day, and it's extremely

powerfull.

Amazingly so.

The learning curve for ANTS is a few hours, but it's nowhere near as
powerfull as SciTech.

[Willy Denoyette [MVP]]

"Chris Alton [MSFT]" <ca****@online.microsoft.comwrote in message
news:B%******************@TK2MSFTNGHUB02.phx.gbl.. .

That would be the Garbage Collector at work. The garbage collector won't
run until it deems it necessary (or you force it in your code by calling
GC.Collect). So it is possible your .NET app can use up ~300MB of RAM but
in reality that amount is much lower and the garbage collector has not run
yet. If you wait long enough the garbage collector should kick off and
drop
the memory usage of your app into the normal usage range.

Sorry to correct you, but this is not true, the GC kicks in when the gen0
threshold has been reached, this threshold varies with the version of the
CLR ,the version of the GC (server/workstation) the size of the L2 data
cache and the allocation frequency. In general less than a few of MB but
certainly much less than ~300MB. Just write a small program that creates a
bunch of objects and watch the Gen0 collection count with perfmon while it
runs.

Willy.

[Chris Alton [MSFT]]

Please read my post carefully before jumping to conclusions.

I stated below that it is "possible" your .NET app can use up to 300MB of
RAM (as viewed in task manager) not that 300MB is the kick in point for the
Garbage Collector to run. Try loading up multiple large DataSets with
around 50,000 rows on a button click and you'll certainly see the memory
usage of the app exceed 300MB.

So it is possible your .NET app can use up ~300MB of RAM but
in reality that amount is much lower and the garbage collector has not

run

yet. If you wait long enough the garbage collector should kick off and
drop the memory usage of your app into the normal usage range.

-------------------------------------
Chris Alton, Microsoft Corp.
SQL Server Developer Support Engineer
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

From: "Willy Denoyette [MVP]" <wi*************@telenet.be>
References: <11**********************@z24g2000prh.googlegroups .com>

<OQ*************@TK2MSFTNGP02.phx.gbl>
<u4**************@TK2MSFTNGP06.phx.gbl>
<#x**************@TK2MSFTNGP04.phx.gbl>
<zE**************@TK2MSFTNGHUB02.phx.gbl>
<Oz**************@TK2MSFTNGP03.phx.gbl>
<am********************************@4ax.com>
<B#**************@TK2MSFTNGHUB02.phx.gbl>

In-Reply-To: <B#**************@TK2MSFTNGHUB02.phx.gbl>
Subject: Re: Winforms and memory usage
Date: Wed, 17 Oct 2007 21:50:27 +0200
Lines: 23
MIME-Version: 1.0
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format=flowed;
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reply-type=original
Content-Transfer-Encoding: 7bit

"Chris Alton [MSFT]" <ca****@online.microsoft.comwrote in message
news:B%******************@TK2MSFTNGHUB02.phx.gbl.. .

That would be the Garbage Collector at work. The garbage collector won't
run until it deems it necessary (or you force it in your code by calling
GC.Collect). So it is possible your .NET app can use up ~300MB of RAM

but

in reality that amount is much lower and the garbage collector has not

run

yet. If you wait long enough the garbage collector should kick off and
drop
the memory usage of your app into the normal usage range.

Sorry to correct you, but this is not true, the GC kicks in when the gen0
threshold has been reached, this threshold varies with the version of the
CLR ,the version of the GC (server/workstation) the size of the L2 data
cache and the allocation frequency. In general less than a few of MB but
certainly much less than ~300MB. Just write a small program that creates

a

bunch of objects and watch the Gen0 collection count with perfmon while

it

runs.

Willy.