Does this code Force Garbage Collector to Collect

[LP]

Hi,
Considering code below. Will it make GC to actually collect. One application
creates new instances of a class from 3rd party assembly in a loop (it has
to). That class doesn't have .Dispose or any similar method. I want to make
sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
called; GC will take priority it do its work, right?

GC.Collect();
GC.WaitForPendi ngFinalizers();
System.Threadin g.Thread.Sleep( 1000);

[Jay B. Harlow [MVP - Outlook]]

LP,
It does, however you may be hurting the GC's ability to "do a good job",
rather then helping it.

For details see Rule #1 at:

http://blogs.msdn.com/ricom/archive/...29/271829.aspx
http://blogs.msdn.com/ricom/archive/.../02/40780.aspx

Just remember that "the collector is self-tuning so don't mess with it"!

Hope this helps
Jay

"LP" <[e-mail]> wrote in message
news:Oq******** ******@TK2MSFTN GP09.phx.gbl... Hi,
Considering code below. Will it make GC to actually collect. One
application
creates new instances of a class from 3rd party assembly in a loop (it has
to). That class doesn't have .Dispose or any similar method. I want to
make
sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
called; GC will take priority it do its work, right?

GC.Collect();
GC.WaitForPendi ngFinalizers();
System.Threadin g.Thread.Sleep( 1000);

[Chris Lyon [MSFT]]

LP,

The GC will keep up with object allocations, and collect them when it
requires. Like Jay stated, the GC is self-tuning based on your allocation
pattern, so it will find the best time to collect by itself.

Why do you feel you need to force garbage collections?

-Chris

--------------------

|
| LP,
| It does, however you may be hurting the GC's ability to "do a good job",
| rather then helping it.
|
| For details see Rule #1 at:
|
| >> http://blogs.msdn.com/ricom/archive/...29/271829.aspx
| >> http://blogs.msdn.com/ricom/archive/.../02/40780.aspx
|
| Just remember that "the collector is self-tuning so don't mess with it"!
|
| Hope this helps
| Jay
|
| "LP" <[e-mail]> wrote in message
| news:Oq******** ******@TK2MSFTN GP09.phx.gbl...
| > Hi,
| > Considering code below. Will it make GC to actually collect. One
| > application
| > creates new instances of a class from 3rd party assembly in a loop (it
has
| > to). That class doesn't have .Dispose or any similar method. I want to
| > make
| > sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
| > called; GC will take priority it do its work, right?
| >
| > GC.Collect();
| > GC.WaitForPendi ngFinalizers();
| > System.Threadin g.Thread.Sleep( 1000);
| >
| >
| >
|
|
|

[LP]

> Why do you feel you need to force garbage collections?
As stated before there is a loop creating new instances of a 3rd party
object each instances does some processing and outputs data to a report file
in PDF format. We tried having to work with one instance in the loop, but it
just screws up the formatting of the reports, it's pretty obvious it needs a
separate instance per report file.
As of now this program creates over 100 PDFs, it's possible that eventually
there will be much more, perhaps thousands. Performance of this application
is not a critical issue, since it's a batch process style app which runs on
scheduled basis.
So, We're Just trying to avoid potential memory problems (out of Memory
exceptions); we have seen a fair share of those.
""Chris Lyon [MSFT]"" <cl***@online.m icrosoft.com> wrote in message
news:SY******** ******@TK2MSFTN GXA03.phx.gbl.. .

LP,

The GC will keep up with object allocations, and collect them when it
requires. Like Jay stated, the GC is self-tuning based on your allocation
pattern, so it will find the best time to collect by itself.

Why do you feel you need to force garbage collections?

-Chris

--------------------

|
| LP,
| It does, however you may be hurting the GC's ability to "do a good job",
| rather then helping it.
|
| For details see Rule #1 at:
|
| >> http://blogs.msdn.com/ricom/archive/...29/271829.aspx
| >> http://blogs.msdn.com/ricom/archive/.../02/40780.aspx
|
| Just remember that "the collector is self-tuning so don't mess with it"!
|
| Hope this helps
| Jay
|
| "LP" <[e-mail]> wrote in message
| news:Oq******** ******@TK2MSFTN GP09.phx.gbl...
| > Hi,
| > Considering code below. Will it make GC to actually collect. One
| > application
| > creates new instances of a class from 3rd party assembly in a loop (it
has
| > to). That class doesn't have .Dispose or any similar method. I want to
| > make
| > sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
| > called; GC will take priority it do its work, right?
| >
| > GC.Collect();
| > GC.WaitForPendi ngFinalizers();
| > System.Threadin g.Thread.Sleep( 1000);
| >
| >
| >
|
|
|

[Dan Kelley]

Is this a .Net object? If so, if it is holding on to resources, it should
expose a Dispose method. If it is a COM object, are you calling
Marshal.Release to reduce the reference count once you have finished with it?

Dan

"LP" wrote:

Why do you feel you need to force garbage collections?

As stated before there is a loop creating new instances of a 3rd party
object each instances does some processing and outputs data to a report file
in PDF format. We tried having to work with one instance in the loop, but it
just screws up the formatting of the reports, it's pretty obvious it needs a
separate instance per report file.
As of now this program creates over 100 PDFs, it's possible that eventually
there will be much more, perhaps thousands. Performance of this application
is not a critical issue, since it's a batch process style app which runs on
scheduled basis.
So, We're Just trying to avoid potential memory problems (out of Memory
exceptions); we have seen a fair share of those.
""Chris Lyon [MSFT]"" <cl***@online.m icrosoft.com> wrote in message
news:SY******** ******@TK2MSFTN GXA03.phx.gbl.. .

LP,

The GC will keep up with object allocations, and collect them when it
requires. Like Jay stated, the GC is self-tuning based on your allocation
pattern, so it will find the best time to collect by itself.

Why do you feel you need to force garbage collections?

-Chris

--------------------

|
| LP,
| It does, however you may be hurting the GC's ability to "do a good job",
| rather then helping it.
|
| For details see Rule #1 at:
|
| >> http://blogs.msdn.com/ricom/archive/...29/271829.aspx
| >> http://blogs.msdn.com/ricom/archive/.../02/40780.aspx
|
| Just remember that "the collector is self-tuning so don't mess with it"!
|
| Hope this helps
| Jay
|
| "LP" <[e-mail]> wrote in message
| news:Oq******** ******@TK2MSFTN GP09.phx.gbl...
| > Hi,
| > Considering code below. Will it make GC to actually collect. One
| > application
| > creates new instances of a class from 3rd party assembly in a loop (it
has
| > to). That class doesn't have .Dispose or any similar method. I want to
| > make
| > sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
| > called; GC will take priority it do its work, right?
| >
| > GC.Collect();
| > GC.WaitForPendi ngFinalizers();
| > System.Threadin g.Thread.Sleep( 1000);
| >
| >
| >
|
|
|

[Daniel O'Connell [C# MVP]]

> Considering code below. Will it make GC to actually collect. One

application
creates new instances of a class from 3rd party assembly in a loop (it has
to). That class doesn't have .Dispose or any similar method. I want to
make
sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00) is
called; GC will take priority it do its work, right?

GC.Collect();
GC.WaitForPendi ngFinalizers();
System.Threadin g.Thread.Sleep( 1000);

While I agree with everyone else that calling GC.Collect() isn't a good
idea, your call to Thread.Sleep isn't needed here. The GC activates on the
call to GC.Collect and WaitForPendingF inalizers() waits while finalizers are
executed and the finalizer queue cleared(however I don't know that it
ensures that those finalized object graphs are GC'd or not, that would
likely be much more important a question). By the time you are reaching the
sleep statement the garbage collection is complete.

[LP]

> Is this a .Net object? If so, if it is holding on to resources, it should

expose a Dispose method. If it is a COM object, are you calling
Marshal.Release to reduce the reference count once you have finished with it?

Yes, it's a .NET object, but no unfortunately it doesn't expose .Dispose
method .
idea, your call to Thread.Sleep isn't needed here. The GC activates on the
call to GC.Collect and WaitForPendingF inalizers() waits while finalizes are executed

I don't think it's true. GC runs on a separate thread with a priority lower
than a main thread. Calling GC.collect() doesn't guarantee that GC will
start right away, it's my understanding you're telling runtime to increase
priority of GC, but when it will actually be executed depends on what is
currently running and/or scheduled to run, after runtime executes important
tasks; then maybe GC.collect() is scheduled to execute or maybe not. Calling
GC.Collect() is like kindly suggesting to runtime, maybe you should start
thinking about garbage collection, but when it will do is unknown.
Thread.Sleep() will stop current thread and give way to other scheduled task
to execute which will hopefully be GC.collect (again it's not 100%, but much
better chances)
I've seen enough arguments that GC is optimized to do its job when needed.
So I think it makes sense to comment out GC.Collect() , and monitor memory
usage.... I hope it will become more obvious if it's needed or not over
time.

[Cor Ligthert]

LP,

Marina (regular to dotnet newsgroups) had about a year ago a problem with a
routine that had strange behaviour and memory.

Setting a "label.show " in here routine that we tried, started the GC. A kind
as if when the paint was given to the graphic adapter, the GC was doing its
job.

From that time I am not interested in it anymore because its behaviour
however have the idea that it is well done.

Cor

[Cor Ligthert]

>

From that time I am not interested in it anymore because its behaviour
however have the idea that it is well done.

From that time I am not interested anymore when it is working, because thiss
behaviour gave me the idea that it was well done.

[Chris Lyon [MSFT]]

I would recommend against early memory/perf optimizations. It's best to
measure where the bottlenecks are and address them, than trying to do early
fixes which may cause other issues. Your GC.Collect loop, for example,
will cause early promotion of objects that would otherwise be considered
garbage. This will result in less memory being freed.

Rico Mariani has a great blog about performance, and talks a lot about the
GC:
http://blogs.msdn.com/ricom

In particular, I recommend:
http://blogs.msdn.com/ricom/archive/...29/271829.aspx
http://blogs.msdn.com/ricom/archive/...29/271829.aspx
http://channel9.msdn.com/wiki/defaul...Channel9.RicoM

Hope that helps
-Chris

--------------------

|
| > Why do you feel you need to force garbage collections?
| As stated before there is a loop creating new instances of a 3rd party
| object each instances does some processing and outputs data to a report
file
| in PDF format. We tried having to work with one instance in the loop, but
it
| just screws up the formatting of the reports, it's pretty obvious it
needs a
| separate instance per report file.
| As of now this program creates over 100 PDFs, it's possible that
eventually
| there will be much more, perhaps thousands. Performance of this
application
| is not a critical issue, since it's a batch process style app which runs
on
| scheduled basis.
| So, We're Just trying to avoid potential memory problems (out of Memory
| exceptions); we have seen a fair share of those.
|
|
| ""Chris Lyon [MSFT]"" <cl***@online.m icrosoft.com> wrote in message
| news:SY******** ******@TK2MSFTN GXA03.phx.gbl.. .
| > LP,
| >
| > The GC will keep up with object allocations, and collect them when it
| > requires. Like Jay stated, the GC is self-tuning based on your
allocation
| > pattern, so it will find the best time to collect by itself.
| >
| > Why do you feel you need to force garbage collections?
| >
| > -Chris
| >
| > --------------------
| >
| > |
| > | LP,
| > | It does, however you may be hurting the GC's ability to "do a good
job",
| > | rather then helping it.
| > |
| > | For details see Rule #1 at:
| > |
| > | >> http://blogs.msdn.com/ricom/archive/...29/271829.aspx
| > | >> http://blogs.msdn.com/ricom/archive/.../02/40780.aspx
| > |
| > | Just remember that "the collector is self-tuning so don't mess with
it"!
| > |
| > | Hope this helps
| > | Jay
| > |
| > | "LP" <[e-mail]> wrote in message
| > | news:Oq******** ******@TK2MSFTN GP09.phx.gbl...
| > | > Hi,
| > | > Considering code below. Will it make GC to actually collect. One
| > | > application
| > | > creates new instances of a class from 3rd party assembly in a loop
(it
| > has
| > | > to). That class doesn't have .Dispose or any similar method. I want
to
| > | > make
| > | > sure GC keeps up with the loop. My reasoning if Thread.Sleep(10 00)
is
| > | > called; GC will take priority it do its work, right?
| > | >
| > | > GC.Collect();
| > | > GC.WaitForPendi ngFinalizers();
| > | > System.Threadin g.Thread.Sleep( 1000);
| > | >
| > | >
| > | >
| > |
| > |
| > |
| >
|
|
|