CODEWITHSUNDEEP
c#.netwcftimerthreadpool
user1845394
user1845394

Reputation: 65

System.Timer elapsed in separate thread and keeping the thread limit

I want to limit my number of threads in my multi-threaded WCF service. So, I use ThreadPool.SetMaxThread function. Now, I want to use System.Timers to generate events at given intervals.

But, my service receives at the meantime many actions to execute in the thread pool. When my timer is elapsed, the action is queued in the ThreadPool (I've sometimes 100,000 tasks in expectations) and therefore slow to execute.

Is there a way to execute my elapsed event before? For example, by setting priority task queued on the threadpool? Or Elapsed the event outside of the threadpool?

I want to keep my global limit of thread in my service.

Upvotes: 4

Views: 455

Answers (3)

ErnieL
ErnieL

Reputation: 5801

This .NET Matters MSDN article ThreadPoolPriority, and MethodImplAttribute is a bit old but I think the approach is still valid. His solution is to create a ThreadPriorityPool that defines what the next available thread from the managed pool should execute.

Another option is to try the Smart Thread Pool on CodeProject. It explicitly supports ordering work items by priority.

Upvotes: 0

user1693593
user1693593

Reputation:

You could, if an option, convert your code to support a producer-consumer pattern by using the Taskfactory combined with a blocking collection.

The collection allow you to set a max limit.

From the link below:

- An implementation of the Producer-Consumer pattern.

- Concurrent adding and taking of items from multiple threads.

> - Optional maximum capacity.

- Insertion and removal operations that block when collection is empty or 
  full.

- Insertion and removal "try" operations that do not block or that block
  up to a specified period of time.

- Encapsulates any collection type that implements
  IProducerConsumerCollection(Of T)

- Cancellation with cancellation tokens.

- Two kinds of enumeration with foreach (For Each in Visual Basic):

    - Read-only enumeration.

    - Enumeration that removes items as they are enumerated.

Here are some resources worth to check out:

blocking-collection-and-the-producer-consumer-problem
http://msdn.microsoft.com/en-us/library/dd997371.aspx
http://msdn.microsoft.com/en-us/library/dd267312.aspx

Upvotes: 1

Alexander Stepaniuk
Alexander Stepaniuk

Reputation: 6418

If you need to limit threads number only to protect denial of service attacks then better option here is to limit maxConcurrentCalls property for ServiceThrottlingBehavior. see details at http://msdn.microsoft.com/en-us/library/system.servicemodel.description.servicethrottlingbehavior.maxconcurrentcalls.aspx

By default this parameter is 16 times the processor count.

If so then you can avoid to limit max threads number for thread pool.

Then your WCF service will be safe from multiple concurrent calls point of view and at the same time timer events will be processed witn no delay.

Upvotes: 1

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