WMI and Quota violation exception

[Dilip]

Hi

I am using the following WMI code to watch for the termination of a
particular process. This code is running under Windows Vista.

public void WaitForDeath()
{
using (AutoResetEvent thisEvent = WatchForProcess Death())
{
WaitHandle.Wait One(thisEvent);
}
}

private AutoResetEvent WatchForProcess Death()
{
AutoResetEvent evt = new AutoResetEvent( false);
string newQry =
"select * from __InstanceDelet ionEvent within 2 where
TargetInstance ISA 'Win32_Process' and " +
"TargetInstance .Name = 'MyProcess.exe' ";
ManagementEvent Watcher mew = new ManagementEvent Watcher(@"\\.\r oot
\CIMV2", newQry);
mew.EventArrive d += delegate { evt.Set(); };
mew.Start();
return evt;
}

Our QA folks tested this functionality by calling WaitForDeath()
repeatedly in a tight loop. at some point, say after 3 hours or so,
we started getting a "Quota violation" exception of type
System.Manageme ntException on the Start() method of
ManagementEvent Watcher.

I happened upon some posts related to this on the WMI newsgroup but I
am not clear how to solve this in my case.

1) Is this happening because of the query itself? If so, why does it
happen only after 3 hours and not right away?
2) Is this happening because I am not properly disposing of the
ManagementEvent Watcher objects? In the EventArrived event I could
add:

mew.Stop();
mew.Dispose();

in addition to setting the autoreset event. I just don't know enough
about WMI to decide if it would help.

Can anyone help? (From past experience I really hope Mr. Willy
Denoyette sees this!)

[Willy Denoyette [MVP]]

"Dilip" <rd*****@lycos. comwrote in message
news:73******** *************** ***********@a23 g2000hsc.google groups.com...

Hi

I am using the following WMI code to watch for the termination of a
particular process. This code is running under Windows Vista.

public void WaitForDeath()
{
using (AutoResetEvent thisEvent = WatchForProcess Death())
{
WaitHandle.Wait One(thisEvent);
}
}

private AutoResetEvent WatchForProcess Death()
{
AutoResetEvent evt = new AutoResetEvent( false);
string newQry =
"select * from __InstanceDelet ionEvent within 2 where
TargetInstance ISA 'Win32_Process' and " +
"TargetInstance .Name = 'MyProcess.exe' ";
ManagementEvent Watcher mew = new ManagementEvent Watcher(@"\\.\r oot
\CIMV2", newQry);
mew.EventArrive d += delegate { evt.Set(); };
mew.Start();
return evt;
}

Our QA folks tested this functionality by calling WaitForDeath()
repeatedly in a tight loop. at some point, say after 3 hours or so,
we started getting a "Quota violation" exception of type
System.Manageme ntException on the Start() method of
ManagementEvent Watcher.

I happened upon some posts related to this on the WMI newsgroup but I
am not clear how to solve this in my case.

1) Is this happening because of the query itself? If so, why does it
happen only after 3 hours and not right away?
2) Is this happening because I am not properly disposing of the
ManagementEvent Watcher objects? In the EventArrived event I could
add:

mew.Stop();
mew.Dispose();

in addition to setting the autoreset event. I just don't know enough
about WMI to decide if it would help.

Can anyone help? (From past experience I really hope Mr. Willy
Denoyette sees this!)

You need to stop the ManagementEvent Watcher when done with it. The Quota
limit for *all* events that get handled on a Completion Port thread is 1000
which equals the maximum number of CP threads per process in .NET.
Why it only happens after 3 hours depends on the frequency they called the
method, call it in a tight loop and you won't have to wait longer than a
couple of seconds I guess.
Besides, it's preferable to use the Win32_ProcessSt opTrace class on Vista
and higher, this class uses ETW which is really event driven while you are
using a polling mechanism under the covers.

Willy.

[Dilip]

On Apr 11, 4:31 pm, "Willy Denoyette [MVP]"
<willy.denoye.. [e-mail] te:

"Dilip" <rdil...@lycos. comwrote in message

news:73******** *************** ***********@a23 g2000hsc.google groups.com...

Hi

I am using the following WMI code to watch for the termination of a
particular process. This code is running under Windows Vista.

public void WaitForDeath()
{
using (AutoResetEvent thisEvent = WatchForProcess Death())
{
WaitHandle.Wait One(thisEvent);
}
}

private AutoResetEvent WatchForProcess Death()
{
AutoResetEvent evt = new AutoResetEvent( false);
string newQry =
"select * from __InstanceDelet ionEvent within 2 where
TargetInstance ISA 'Win32_Process' and " +
"TargetInstance .Name = 'MyProcess.exe' ";
ManagementEvent Watcher mew = new ManagementEvent Watcher(@"\\.\r oot
\CIMV2", newQry);
mew.EventArrive d += delegate { evt.Set(); };
mew.Start();
return evt;
}

Our QA folks tested this functionality by calling WaitForDeath()
repeatedly in a tight loop. at some point, say after 3 hours or so,
we started getting a "Quota violation" exception of type
System.Manageme ntException on the Start() method of
ManagementEvent Watcher.

I happened upon some posts related to this on the WMI newsgroup but I
am not clear how to solve this in my case.

1) Is this happening because of the query itself? If so, why does it
happen only after 3 hours and not right away?
2) Is this happening because I am not properly disposing of the
ManagementEvent Watcher objects? In the EventArrived event I could
add:

mew.Stop();
mew.Dispose();

in addition to setting the autoreset event. I just don't know enough
about WMI to decide if it would help.

Can anyone help? (From past experience I really hope Mr. Willy
Denoyette sees this!)

You need to stop the ManagementEvent Watcher when done with it. The Quota
limit for *all* events that get handled on a Completion Port thread is 1000
which equals the maximum number of CP threads per process in .NET.
Why it only happens after 3 hours depends on the frequency they called the
method, call it in a tight loop and you won't have to wait longer than a
couple of seconds I guess.

Actually, as I mentioned in my original post, this problem happened
after running this code in a tight loop for 3 hours but I guess thats
besides the point when there seems to be an obvious error in my code.

Besides, it's preferable to use the Win32_ProcessSt opTrace class on Vista
and higher, this class uses ETW which is really event driven while you are
using a polling mechanism under the covers.

Thanks a ton for replying. I changed the code to call Stop() on
receiving the EventArrived event. I will have to test it on Monday.

Meanwhile, could you show me a small snippet on how to use
Win32_ProcessSt opTrace class to watch for termination of a process?
You could also point me in the right direction and that'd be fine with
me.

thanks!

[Dilip]

On Apr 11, 4:31 pm, "Willy Denoyette [MVP]"
<willy.denoye.. [e-mail] te:

"Dilip" <rdil...@lycos. comwrote in message

news:73******** *************** ***********@a23 g2000hsc.google groups.com...

Hi

I am using the following WMI code to watch for the termination of a
particular process. This code is running under Windows Vista.

public void WaitForDeath()
{
using (AutoResetEvent thisEvent = WatchForProcess Death())
{
WaitHandle.Wait One(thisEvent);
}
}

private AutoResetEvent WatchForProcess Death()
{
AutoResetEvent evt = new AutoResetEvent( false);
string newQry =
"select * from __InstanceDelet ionEvent within 2 where
TargetInstance ISA 'Win32_Process' and " +
"TargetInstance .Name = 'MyProcess.exe' ";
ManagementEvent Watcher mew = new ManagementEvent Watcher(@"\\.\r oot
\CIMV2", newQry);
mew.EventArrive d += delegate { evt.Set(); };
mew.Start();
return evt;
}

Our QA folks tested this functionality by calling WaitForDeath()
repeatedly in a tight loop. at some point, say after 3 hours or so,
we started getting a "Quota violation" exception of type
System.Manageme ntException on the Start() method of
ManagementEvent Watcher.

I happened upon some posts related to this on the WMI newsgroup but I
am not clear how to solve this in my case.

1) Is this happening because of the query itself? If so, why does it
happen only after 3 hours and not right away?
2) Is this happening because I am not properly disposing of the
ManagementEvent Watcher objects? In the EventArrived event I could
add:

mew.Stop();
mew.Dispose();

in addition to setting the autoreset event. I just don't know enough
about WMI to decide if it would help.

Can anyone help? (From past experience I really hope Mr. Willy
Denoyette sees this!)

You need to stop the ManagementEvent Watcher when done with it. The Quota
limit for *all* events that get handled on a Completion Port thread is 1000
which equals the maximum number of CP threads per process in .NET.
Why it only happens after 3 hours depends on the frequency they called the
method, call it in a tight loop and you won't have to wait longer than a
couple of seconds I guess.
Besides, it's preferable to use the Win32_ProcessSt opTrace class on Vista
and higher, this class uses ETW which is really event driven while you are
using a polling mechanism under the covers.

Willy.

Ok. It looks like all I have to do is replace my original
__InstanceDelet ionEvent query with:

Select * from Win32_ProcessSt opTrace where ProcessName='My Process.exe'

Am I right?

[Willy Denoyette [MVP]]

"Dilip" <rd*****@lycos. comwrote in message
news:a3******** *************** ***********@k13 g2000hse.google groups.com...

On Apr 11, 4:31 pm, "Willy Denoyette [MVP]"
<willy.denoye.. [e-mail] te:

>"Dilip" <rdil...@lycos. comwrote in message

news:73******* *************** ************@a2 3g2000hsc.googl egroups.com...

Hi

I am using the following WMI code to watch for the termination of a
particular process. This code is running under Windows Vista.

public void WaitForDeath()
{
using (AutoResetEvent thisEvent = WatchForProcess Death())
{
WaitHandle.Wait One(thisEvent);
}
}

private AutoResetEvent WatchForProcess Death()
{
AutoResetEvent evt = new AutoResetEvent( false);
string newQry =
"select * from __InstanceDelet ionEvent within 2 where
TargetInstance ISA 'Win32_Process' and " +
"TargetInstance .Name = 'MyProcess.exe' ";
ManagementEvent Watcher mew = new ManagementEvent Watcher(@"\\.\r oot
\CIMV2", newQry);
mew.EventArrive d += delegate { evt.Set(); };
mew.Start();
return evt;
}

Our QA folks tested this functionality by calling WaitForDeath()
repeatedly in a tight loop. at some point, say after 3 hours or so,
we started getting a "Quota violation" exception of type
System.Manageme ntException on the Start() method of
ManagementEvent Watcher.

I happened upon some posts related to this on the WMI newsgroup but I
am not clear how to solve this in my case.

1) Is this happening because of the query itself? If so, why does it
happen only after 3 hours and not right away?
2) Is this happening because I am not properly disposing of the
ManagementEvent Watcher objects? In the EventArrived event I could
add:

mew.Stop();
mew.Dispose();

in addition to setting the autoreset event. I just don't know enough
about WMI to decide if it would help.

Can anyone help? (From past experience I really hope Mr. Willy
Denoyette sees this!)

You need to stop the ManagementEvent Watcher when done with it. The Quota
limit for *all* events that get handled on a Completion Port thread is
1000
which equals the maximum number of CP threads per process in .NET.
Why it only happens after 3 hours depends on the frequency they called
the
method, call it in a tight loop and you won't have to wait longer than a
couple of seconds I guess.
Besides, it's preferable to use the Win32_ProcessSt opTrace class on Vista
and higher, this class uses ETW which is really event driven while you
are
using a polling mechanism under the covers.

Willy.

Ok. It looks like all I have to do is replace my original
__InstanceDelet ionEvent query with:

Select * from Win32_ProcessSt opTrace where ProcessName='My Process.exe'

Am I right?

No, "select" for a trace events, you need to select the property of interest
in the eventhandler, something like:

using(Managemen tEventWatcher w = new
ManagementEvent Watcher("Win32_ ProcessStopTrac e"))
{
w.EventArrived += ProcessStopped;
w.Start();
Console.ReadLin e(); // block main thread for test purposes
w.Stop();
}
}
static void ProcessStopped( object sender, EventArrivedEve ntArgs e) {

if((string)e.Ne wEvent.Properti es["processnam e"].Value ==
"notepad.ex e")
{
Console.WriteLi ne("Process: {0}, Stopped with Code: {1}",
(int)(uint)e.Ne wEvent.Properti es["ProcessId"].Value,
(int)(uint)e.Ne wEvent.Properti es["ExitStatus "].Value);
}
}
Willy.