How do I know when my work threads have completed their tasks?

Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal that at
the and, maybe in a finally block. If this is called from a GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <Pu***@discussi ons.microsoft.c omschrieb im Newsbeitrag
news:E8******** *************** ***********@mic rosoft.com...

Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads. How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.

Thank you Christof. These 2 threads are started within a form as worker
threads only. They are coded as 2 static method within this form. The 2
threads have no form of its own. How can I then find out when they're both
done with their tasks?
--
Thanks.
"Christof Nordiek" wrote:

Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal that at
the and, maybe in a finally block. If this is called from a GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <Pu***@discussi ons.microsoft.c omschrieb im Newsbeitrag
news:E8******** *************** ***********@mic rosoft.com...

Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads. How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.

You use the Join method on the threads. However, there's a small
problem: if you call Join in the UI thread, then you hang the UI.

The usual solution is to use one of the two threads as a "controller ",
or use a third thread. In the first case, the second thread to be
started can be handed a reference to the first thread, and do a Join
before it signals that it's finished. If the first thread isn't
finished yet, then the second thread will wait on the Join until it is.
Therefore, when the second (controller) thread is finished, you know
that they're both finishes.

If the two threads are not logically related this way, then it might be
nicer to use a third, controller thread: the UI starts the controller,
which then starts the two worker threads. The controller then does two
Joins, one on each worker thread, and when the two Joins complete, it
signals the UI that all is done. This is scalable to an arbitrary
number of worker threads.

On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:

Thank you Christof. These 2 threads are started within a form as worker
threads only. They are coded as 2 static method within this form. The 2
threads have no form of its own. How can I then find out when they're both
done with their tasks?
--
Thanks.

"Christof Nordiek" wrote:

Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal that at
the and, maybe in a finally block. If this is called from a GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
news:E8******** *************** ***********@mic rosoft.com...

Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads. How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.- Hide quoted text -- Show quoted text -

Thank you.

I now need to return SearchResultCol lection from both the thread. But I'm
getting error that my code calling the thread has the wrong return
type.ThreadPool .QueueUserWorkI tem(new WaitCallback(Po pulatAdTable));

I have declared my thread method as
static SearchResultCol lection PopulatAdTabe(o bject stateInfo)
{}

Is there something wrong with my declaration? Thanks.
--
Thanks.
"Bruce Wood" wrote:

You use the Join method on the threads. However, there's a small
problem: if you call Join in the UI thread, then you hang the UI.

The usual solution is to use one of the two threads as a "controller ",
or use a third thread. In the first case, the second thread to be
started can be handed a reference to the first thread, and do a Join
before it signals that it's finished. If the first thread isn't
finished yet, then the second thread will wait on the Join until it is.
Therefore, when the second (controller) thread is finished, you know
that they're both finishes.

If the two threads are not logically related this way, then it might be
nicer to use a third, controller thread: the UI starts the controller,
which then starts the two worker threads. The controller then does two
Joins, one on each worker thread, and when the two Joins complete, it
signals the UI that all is done. This is scalable to an arbitrary
number of worker threads.

On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:

Thank you Christof. These 2 threads are started within a form as worker
threads only. They are coded as 2 static method within this form. The 2
threads have no form of its own. How can I then find out when they're both
done with their tasks?
--
Thanks.

"Christof Nordiek" wrote:

Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal that at
the and, maybe in a finally block. If this is called from a GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
>news:E8******* *************** ************@mi crosoft.com...
Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads. How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.- Hide quoted text -- Show quoted text -

I'm using threadpool so I used AutoeventReset and it worked. Thank you very
much.
--
Thanks.
"Bruce Wood" wrote:

You use the Join method on the threads. However, there's a small
problem: if you call Join in the UI thread, then you hang the UI.

The usual solution is to use one of the two threads as a "controller ",
or use a third thread. In the first case, the second thread to be
started can be handed a reference to the first thread, and do a Join
before it signals that it's finished. If the first thread isn't
finished yet, then the second thread will wait on the Join until it is.
Therefore, when the second (controller) thread is finished, you know
that they're both finishes.

If the two threads are not logically related this way, then it might be
nicer to use a third, controller thread: the UI starts the controller,
which then starts the two worker threads. The controller then does two
Joins, one on each worker thread, and when the two Joins complete, it
signals the UI that all is done. This is scalable to an arbitrary
number of worker threads.

On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:

Thank you Christof. These 2 threads are started within a form as worker
threads only. They are coded as 2 static method within this form. The 2
threads have no form of its own. How can I then find out when they're both
done with their tasks?
--
Thanks.

"Christof Nordiek" wrote:

Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal that at
the and, maybe in a finally block. If this is called from a GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
>news:E8******* *************** ************@mi crosoft.com...
Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads. How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.- Hide quoted text -- Show quoted text -

Pucca wrote:

I'm using threadpool so I used AutoeventReset and it worked. Thank you very
much.

Be careful: many uses of AutoResetEvent have a race condition, where the
event is signaled before anything waits on it, thus causing deadlock
when threads do start waiting on it, having "missed the bus", as it
were.

-- Barry

--
http://barrkel.blogspot.com/

AutoResetEvent there is pretty scary. If your "are you done yet?" thread
isn't waiting already, then it's going to miss the fact that your work item
is complete. This means the order you do things in is very important, and
(worse) is also hard to get right.

You would be better served, I suspect, using a ManualResetEven t. This
eliminates the problem, and makes your code less likley to have race
conditions.

--
Chris Mullins, MCSD.NET, MCPD:Enterprise , MVP C#
http://www.coversant.net/blogs/cmullins

"Pucca" <Pu***@discussi ons.microsoft.c omwrote in message
news:89******** *************** ***********@mic rosoft.com...

I'm using threadpool so I used AutoeventReset and it worked. Thank you
very
much.
--
Thanks.
"Bruce Wood" wrote:

>You use the Join method on the threads. However, there's a small
problem: if you call Join in the UI thread, then you hang the UI.

The usual solution is to use one of the two threads as a "controller ",
or use a third thread. In the first case, the second thread to be
started can be handed a reference to the first thread, and do a Join
before it signals that it's finished. If the first thread isn't
finished yet, then the second thread will wait on the Join until it is.
Therefore, when the second (controller) thread is finished, you know
that they're both finishes.

If the two threads are not logically related this way, then it might be
nicer to use a third, controller thread: the UI starts the controller,
which then starts the two worker threads. The controller then does two
Joins, one on each worker thread, and when the two Joins complete, it
signals the UI that all is done. This is scalable to an arbitrary
number of worker threads.

On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:

Thank you Christof. These 2 threads are started within a form as
worker
threads only. They are coded as 2 static method within this form. The
2
threads have no form of its own. How can I then find out when they're
both
done with their tasks?
--
Thanks.

"Christof Nordiek" wrote:
Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal
that at
the and, maybe in a finally block. If this is called from a
GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
news:E8******* *************** ************@mi crosoft.com...
Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads.
How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew
WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.- Hide quoted text -- Show quoted text -

I always enjoy seeing how I might do the same thing when using my
concurrency library.
This is actually a pretty common pattern (i.e. scatter/gather). I sample
this pattern here
http://www.codeplex.com/PCR/Thread/V...?ThreadId=3459

--
William Stacey [C# MVP]
PCR concurrency library: www.codeplex.com/pcr
PSH Scripts Project www.codeplex.com/psobject
"Pucca" <Pu***@discussi ons.microsoft.c omwrote in message
news:89******** *************** ***********@mic rosoft.com...
| I'm using threadpool so I used AutoeventReset and it worked. Thank you
very
| much.
| --
| Thanks.
|
|
| "Bruce Wood" wrote:
|
| You use the Join method on the threads. However, there's a small
| problem: if you call Join in the UI thread, then you hang the UI.
| >
| The usual solution is to use one of the two threads as a "controller ",
| or use a third thread. In the first case, the second thread to be
| started can be handed a reference to the first thread, and do a Join
| before it signals that it's finished. If the first thread isn't
| finished yet, then the second thread will wait on the Join until it is.
| Therefore, when the second (controller) thread is finished, you know
| that they're both finishes.
| >
| If the two threads are not logically related this way, then it might be
| nicer to use a third, controller thread: the UI starts the controller,
| which then starts the two worker threads. The controller then does two
| Joins, one on each worker thread, and when the two Joins complete, it
| signals the UI that all is done. This is scalable to an arbitrary
| number of worker threads.
| >
| On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:
| Thank you Christof. These 2 threads are started within a form as
worker
| threads only. They are coded as 2 static method within this form.
The 2
| threads have no form of its own. How can I then find out when they're
both
| done with their tasks?
| --
| Thanks.
|
|
|
| "Christof Nordiek" wrote:
| Hi Pucca,
|
| the WaitCallBack-handler (PopulateContex tTable e.g.) should signal
that at
| the and, maybe in a finally block. If this is called from a
GUI-Thread you
| could call BeginInvoke on one of the Forms methods.
|
| Christof
|
| "Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
| >news:E8******* *************** ************@mi crosoft.com...
| Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool
threads. How
| do I
| know when they're done with their tasks? Thanks.
|
| ThreadPool.Queu eUserWorkItem(n ew
WaitCallback(Po pulateContextTa ble));
| ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
| --
| Thanks.- Hide quoted text -- Show quoted text -
| >
| >

I think the AutoResetEvent is now cuasing a problem for my code.
1. I dind't find good examples on how to code with manualResetEven t, can
you recommend a example on line?
2. Do I need to change my program.cs code's [STAThread] to something else?
Is this the Single thread meaning?
--
Thanks.
"Chris Mullins [MVP]" wrote:

AutoResetEvent there is pretty scary. If your "are you done yet?" thread
isn't waiting already, then it's going to miss the fact that your work item
is complete. This means the order you do things in is very important, and
(worse) is also hard to get right.

You would be better served, I suspect, using a ManualResetEven t. This
eliminates the problem, and makes your code less likley to have race
conditions.

--
Chris Mullins, MCSD.NET, MCPD:Enterprise , MVP C#
http://www.coversant.net/blogs/cmullins

"Pucca" <Pu***@discussi ons.microsoft.c omwrote in message
news:89******** *************** ***********@mic rosoft.com...

I'm using threadpool so I used AutoeventReset and it worked. Thank you
very
much.
--
Thanks.
"Bruce Wood" wrote:

You use the Join method on the threads. However, there's a small
problem: if you call Join in the UI thread, then you hang the UI.

The usual solution is to use one of the two threads as a "controller ",
or use a third thread. In the first case, the second thread to be
started can be handed a reference to the first thread, and do a Join
before it signals that it's finished. If the first thread isn't
finished yet, then the second thread will wait on the Join until it is.
Therefore, when the second (controller) thread is finished, you know
that they're both finishes.

If the two threads are not logically related this way, then it might be
nicer to use a third, controller thread: the UI starts the controller,
which then starts the two worker threads. The controller then does two
Joins, one on each worker thread, and when the two Joins complete, it
signals the UI that all is done. This is scalable to an arbitrary
number of worker threads.

On Jan 26, 10:35 am, Pucca <P...@discussio ns.microsoft.co mwrote:
Thank you Christof. These 2 threads are started within a form as
worker
threads only. They are coded as 2 static method within this form. The
2
threads have no form of its own. How can I then find out when they're
both
done with their tasks?
--
Thanks.

"Christof Nordiek" wrote:
Hi Pucca,

the WaitCallBack-handler (PopulateContex tTable e.g.) should signal
that at
the and, maybe in a finally block. If this is called from a
GUI-Thread you
could call BeginInvoke on one of the Forms methods.

Christof

"Pucca" <P...@discussio ns.microsoft.co mschrieb im Newsbeitrag
>news:E8******* *************** ************@mi crosoft.com...
Hi, I'm using vs2005 and .net 2.0. I started 2 threadpool threads.
How
do I
know when they're done with their tasks? Thanks.

ThreadPool.Queu eUserWorkItem(n ew
WaitCallback(Po pulateContextTa ble));
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Po pulatAdTable));
--
Thanks.- Hide quoted text -- Show quoted text -