CODEWITHSUNDEEP
c#asp.netweb-servicesdispose
BeaverProj
BeaverProj

Reputation: 2215

Do I need to dispose a web service reference in ASP.NET?

Does the garbage collector clean up web service references or do I need to call dispose on the service reference after I'm finished calling whatever method I call?

Upvotes: 10

Views: 16737

Answers (5)

Alec C
Alec C

Reputation: 11

I think the concerns of Seabizkit in the above answer are very legitimate. It's quoted here:

@DanHerbert what happens when two threads call the singleton.. let me explain... there is a lock on the object.. to make it thread safe. Does that mean that if theard1 call accesses webInstance, then thread2 will wait on thread1 to finish. or is the lock purely for the creatation of the instance. say you have 10 callers.... does the lock mean they are chained... or async, i think you will get what I'm asking let me know if it wasn't clear. – Seabizkit Oct 13 '16 at 10:01 <

After I've done some testing I can tell that you won't be able to get any good performance when a single 'client' object is used by multiple different threads. If ten threads are created and they all are using the same singleton 'client' then they will have to wait in line until all previous calls are done.

To see the proof for that please read and run a sample in this c-sharp corner article here: https://www.c-sharpcorner.com/article/increase-performance-with-an-object-pool-or-why-singleton-may-cause-performance/ titled "Increase Performance with an Object Pool or Why Singleton May Cause Performance Issues".

Sorry to burst the bubble of the singleton web service users. Also, you would be very hard-pressed to find Microsoft's example where the web service client is "caged" in the singleton.

Upvotes: 0

Dan Herbert
Dan Herbert

Reputation: 103447

Instead of worrying about disposing your web services, you could keep only a single instance of each web service, using a singleton pattern. Web services are stateless, so they can safely be shared between connections and threads on a web server.

Here is an example of a Web Service class you can use to hold references to your web service instances. This singleton is lazy and thread-safe. It is advised that if you make your singletons lazy, they are also kept thread safe by following the same logic. To learn more about how to do this, read the C# In Depth article on Implementing Singletons.

Also keep in mind that you may run into issues with WCF web services. I'd recommend reading up on WCF's instance management techniques article, specifically the singleton section, for more details.

public static class WS
{
    private static object sync = new object();
    private static MyWebService _MyWebServiceInstance;

    public static MyWebService MyWebServiceInstance
    {
        get
        {
            if (_MyWebServiceInstance == null) 
            {
              lock (sync)
              {
                if (_MyWebServiceInstance == null)
                {
                    _MyWebServiceInstance= new MyWebService();
                }
              }
            }
            return _MyWebServiceInstance;
        }
    }
}

And then when you need to access your web service, you can do this:

WS.MyWebServiceInstance.MyMethod(...)

or

var ws = WS.MyWebServiceInstance;
ws.MyMethod(...)

I've successfully used this pattern on several projects and it has worked well, but as tvanfosson mentions in the comments below, an even better strategy would be to use a DI framework to manage your web service instances.

Upvotes: 23

orj
orj

Reputation: 13484

Objects that implement IDispose should be disposed of manually to assist the garbage collector.

If you object is short lived use a using block. For objects that can be retained ensure that they object that retains them disposes of them when it is also disposed.

Upvotes: 1

Jobo
Jobo

Reputation: 916

what are you trying to accomplish here?

If your worried about performance, then I would worry more about the responsiveness of the server hosting the webservice and the network speed, as they can dramatically affect the length of time you have to wait for the webservice call to complete (unless its asynchronous).

The examples on MSDN dont call 'Dispose' and its quite obvious that the garbage collector will do its job, so unless your working on a realtime system that needs to process over 100,000 records in memory every second, then maybe you dont need to come up with a way to dispose resources or manage memory.

Upvotes: 0

BeaverProj
BeaverProj

Reputation: 2215

I think the DataService inherits Dispose from Component.

Upvotes: 1

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