Is SoapHttpClientProtocol thread safe?

问题:

I created a Web Service proxy with the "add web reference" feature of VS 2008 (c#).

The generated class derives from SoapHttpClientProtocol

Can I store only one instance of my proxy in a singleton? Is it thread safe? Is there state between calls that would prevent me from doing this?

回答1:

No. It is not thread safe. the client must be in the Open state to enable calls. A simple scenario where one thread does client.Close() while another tries to call a method will fail.

回答2:

MSDN says that SoapHttpClientProtocol is thread safe:

Thread Safety

This type is thread safe.

For another class like System.Windows.Forms which isn't thread-safe, MSDN says,

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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Here is a Microsoft/MSDN employee saying (though without guarantee) that it is thread-safe:

Hi Max,

For the webservice proxy, I think it should be thread-safe as the .NET generated proxy class is derived from the "SoapHttpClientProtocol" class which is marked as thread-safe in document:

SoapHttpClientProtocol Class

http://msdn.microsoft.com/en-us/library/system.web.services.protocols.soaphttpclientprotocol(VS.71).aspx

therefore, it should be safe to use it in multi-thread context as long as you haven't manually add any context-sensitive member in the derived proxy class. Do you think so?

Sincerely,

Steven Cheng

Microsoft MSDN Online Support Lead

This posting is provided "AS IS" with no warranties, and confers no rights.

回答3:

Per this link: http://msdn.microsoft.com/en-us/library/system.web.services.protocols.soaphttpclientprotocol.aspx

at the bottom under 'thread safety' it says this type is thread safe. I do however not know that using it as a Singleton will be Thread safe.

回答4:

MSDN makes no mention that it's thread safe:

Thread Safety

This type is thread safe.

The class is safe, no mention of the object.

But it is safe to say that that it's not thread safe - no object in the .NET library is thread safe.

(At least i've never seen one)