About Thread Completion Notify.

[objectref]

hi to all folks,


i want to create the following senario:
i have a T1 (Thread 1) that acts like http server that receives incoming
requests.
From that T1, i want to spawn from T1 to Tn thread jobs and beeing able to
be
notified when each of these threads finished it's job.

I would like to implement it with the functionality of the ThreadPool,
i also looked at WaitHandle, WaitAny etc etc.

I also noticed from the msdn example that if i use the AutoResetEvent. Set()
method, i just set the state of the event to signaled but i see no way of
quering this and find it's state so i can understand that it is completed
, and the WaitAll and WaitAny stuff just blocks my T1 so all or any Tn
finishes it's job.

But how i can automate this procedure and each thread notify the main T1 of
the completion of it's job ??


the following is from the msdn help:


using System;
using System.Threadin g;

public sealed class App {
// Define an array with two AutoResetEvent WaitHandles.
static WaitHandle[] waitHandles = new WaitHandle[] {
new AutoResetEvent( false),
new AutoResetEvent( false)
};

// Define a random number generator for testing.
static Random r = new Random();

static void Main() {
AutoResetEvent are = new AutoResetEvent( false);
are.Set


// Queue up two tasks on two different threads;
// wait until all tasks are completed.
DateTime dt = DateTime.Now;
Console.WriteLi ne("Main thread is waiting for BOTH tasks to complete.");
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);
WaitHandle.Wait All(waitHandles );

// The time shown below should match the longest task.
Console.WriteLi ne("Both tasks are completed (time waited={0})",
(DateTime.Now - dt).TotalMillis econds);

// Queue up two tasks on two different threads;
// wait until any tasks are completed.
dt = DateTime.Now;
Console.WriteLi ne();
Console.WriteLi ne("The main thread is waiting for either task to
complete.");
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);

int index = WaitHandle.Wait Any(waitHandles );
// The time shown below should match the shortest task.
Console.WriteLi ne("Task {0} finished first (time waited={1}).",
index + 1, (DateTime.Now - dt).TotalMillis econds);
}

static void DoTask(Object state) {
AutoResetEvent are = (AutoResetEvent ) state;
int time = 1000 * r.Next(2, 10);
Console.WriteLi ne("Performing a task for {0} milliseconds.", time);
Thread.Sleep(ti me);
are.Set();
}
}



thanks in advance fro any help

[Nicholas Paldino [.NET/C# MVP]]

Re: About Thread Completion Notify.

objectref,

Instead of using events and whatnot, why not just have the DoWork method
call a function at the end to indicate that the task is done, and then
perform whatever work you need to do at that point? Unless you have a
thread somewhere else waiting on the fact that these tasks are done (which
you probably don't since you are servicing requests in separate threads
anyways), you shouldn't have a need for waiting on events.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- mvp@spam.guard. caspershouse.co m

"objectref" <objectref@medi atrel.com> wrote in message
news:%23WQzMMOc FHA.1392@TK2MSF TNGP14.phx.gbl. ..[color=blue]
> hi to all folks,
>
>
> i want to create the following senario:
> i have a T1 (Thread 1) that acts like http server that receives incoming
> requests.
> From that T1, i want to spawn from T1 to Tn thread jobs and beeing able to
> be
> notified when each of these threads finished it's job.
>
> I would like to implement it with the functionality of the ThreadPool,
> i also looked at WaitHandle, WaitAny etc etc.
>
> I also noticed from the msdn example that if i use the
> AutoResetEvent. Set()
> method, i just set the state of the event to signaled but i see no way of
> quering this and find it's state so i can understand that it is completed
> , and the WaitAll and WaitAny stuff just blocks my T1 so all or any Tn
> finishes it's job.
>
> But how i can automate this procedure and each thread notify the main T1
> of
> the completion of it's job ??
>
>
> the following is from the msdn help:
>
>
> using System;
> using System.Threadin g;
>
> public sealed class App {
> // Define an array with two AutoResetEvent WaitHandles.
> static WaitHandle[] waitHandles = new WaitHandle[] {
> new AutoResetEvent( false),
> new AutoResetEvent( false)
> };
>
> // Define a random number generator for testing.
> static Random r = new Random();
>
> static void Main() {
> AutoResetEvent are = new AutoResetEvent( false);
> are.Set
>
>
> // Queue up two tasks on two different threads;
> // wait until all tasks are completed.
> DateTime dt = DateTime.Now;
> Console.WriteLi ne("Main thread is waiting for BOTH tasks to complete.");
> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);
> WaitHandle.Wait All(waitHandles );
>
> // The time shown below should match the longest task.
> Console.WriteLi ne("Both tasks are completed (time waited={0})",
> (DateTime.Now - dt).TotalMillis econds);
>
> // Queue up two tasks on two different threads;
> // wait until any tasks are completed.
> dt = DateTime.Now;
> Console.WriteLi ne();
> Console.WriteLi ne("The main thread is waiting for either task to
> complete.");
> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);
>
> int index = WaitHandle.Wait Any(waitHandles );
> // The time shown below should match the shortest task.
> Console.WriteLi ne("Task {0} finished first (time waited={1}).",
> index + 1, (DateTime.Now - dt).TotalMillis econds);
> }
>
> static void DoTask(Object state) {
> AutoResetEvent are = (AutoResetEvent ) state;
> int time = 1000 * r.Next(2, 10);
> Console.WriteLi ne("Performing a task for {0} milliseconds.", time);
> Thread.Sleep(ti me);
> are.Set();
> }
> }
>
>
>
> thanks in advance fro any help
>[/color]

[objectref]

Re: About Thread Completion Notify.

Nicholas,

thanks for the reply.
The reason i cannot do what you suggest me, is that i want to keep track
from the main
thread of all the threads that i spawn, so to be able to stop a thread that
it stalls.
This is a runtime system i have build and there is a possibility for a give
request to
stall, that is, come into an endless loop and the Tn will be live forever.

So, i have to keep track of them and i want to identify and stop a nasty
thread.
This is the reason that i must keep track of the threads and they have to
notify, somehow,
the T1 for their completion status.

Imagine that every thread that i spawn, belongs to an array and when
it finish it's job, i remove it from the array.
Threads that remain in the array for a specified time, are consinered
"nasty" and
will be stop and removed from there...

Any thoughts on this ?

thanks again!




"Nicholas Paldino [.NET/C# MVP]" <mvp@spam.guard .caspershouse.c om> wrote in
message news:eiHOzQPcFH A.2664@TK2MSFTN GP15.phx.gbl...[color=blue]
> objectref,
>
> Instead of using events and whatnot, why not just have the DoWork
> method call a function at the end to indicate that the task is done, and
> then perform whatever work you need to do at that point? Unless you have
> a thread somewhere else waiting on the fact that these tasks are done
> (which you probably don't since you are servicing requests in separate
> threads anyways), you shouldn't have a need for waiting on events.
>
> Hope this helps.
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - mvp@spam.guard. caspershouse.co m
>
> "objectref" <objectref@medi atrel.com> wrote in message
> news:%23WQzMMOc FHA.1392@TK2MSF TNGP14.phx.gbl. ..[color=green]
>> hi to all folks,
>>
>>
>> i want to create the following senario:
>> i have a T1 (Thread 1) that acts like http server that receives incoming
>> requests.
>> From that T1, i want to spawn from T1 to Tn thread jobs and beeing able
>> to be
>> notified when each of these threads finished it's job.
>>
>> I would like to implement it with the functionality of the ThreadPool,
>> i also looked at WaitHandle, WaitAny etc etc.
>>
>> I also noticed from the msdn example that if i use the
>> AutoResetEvent. Set()
>> method, i just set the state of the event to signaled but i see no way of
>> quering this and find it's state so i can understand that it is completed
>> , and the WaitAll and WaitAny stuff just blocks my T1 so all or any Tn
>> finishes it's job.
>>
>> But how i can automate this procedure and each thread notify the main T1
>> of
>> the completion of it's job ??
>>
>>
>> the following is from the msdn help:
>>
>>
>> using System;
>> using System.Threadin g;
>>
>> public sealed class App {
>> // Define an array with two AutoResetEvent WaitHandles.
>> static WaitHandle[] waitHandles = new WaitHandle[] {
>> new AutoResetEvent( false),
>> new AutoResetEvent( false)
>> };
>>
>> // Define a random number generator for testing.
>> static Random r = new Random();
>>
>> static void Main() {
>> AutoResetEvent are = new AutoResetEvent( false);
>> are.Set
>>
>>
>> // Queue up two tasks on two different threads;
>> // wait until all tasks are completed.
>> DateTime dt = DateTime.Now;
>> Console.WriteLi ne("Main thread is waiting for BOTH tasks to complete.");
>> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
>> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);
>> WaitHandle.Wait All(waitHandles );
>>
>> // The time shown below should match the longest task.
>> Console.WriteLi ne("Both tasks are completed (time waited={0})",
>> (DateTime.Now - dt).TotalMillis econds);
>>
>> // Queue up two tasks on two different threads;
>> // wait until any tasks are completed.
>> dt = DateTime.Now;
>> Console.WriteLi ne();
>> Console.WriteLi ne("The main thread is waiting for either task to
>> complete.");
>> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[0]);
>> ThreadPool.Queu eUserWorkItem(n ew WaitCallback(Do Task), waitHandles[1]);
>>
>> int index = WaitHandle.Wait Any(waitHandles );
>> // The time shown below should match the shortest task.
>> Console.WriteLi ne("Task {0} finished first (time waited={1}).",
>> index + 1, (DateTime.Now - dt).TotalMillis econds);
>> }
>>
>> static void DoTask(Object state) {
>> AutoResetEvent are = (AutoResetEvent ) state;
>> int time = 1000 * r.Next(2, 10);
>> Console.WriteLi ne("Performing a task for {0} milliseconds.", time);
>> Thread.Sleep(ti me);
>> are.Set();
>> }
>> }
>>
>>
>>
>> thanks in advance fro any help
>>[/color]
>
>[/color]