The [STAThread] attribute is probably a strong contender for 'most misunderstood feature of a typical .NET project'. It doesn't do what you think it does.
If you aren't using COM interop for anything, then this attribute is irrelevant. It only comes into play the first time your thread needs to do something with COM - it will determine whether your thread joins an STA or the MTA. (I.e. will it call OleInitialize[1] or CoInitializeEx(NULL, COINIT_MULTITHREADED)?) This attribute has no bearing on whether your component is 'single threaded' or 'multi-threaded'. If some piece of code gets hold of a reference to one of your components objects and they start calling into it from multiple threads, then it had better be multithreaded - unlike in COM, the .NET runtime will offer no automatic threading protection to your object. The standard approach to multithreading is to document your class's support. If you look at the .NET framework class library documentation you will see that the majority of classes are documented as being unsafe at the instance level (i.e. given a single instance of an object, clients must *not* try to use that object simultaneously from multiple threads), but safe at the class level (i.e. you can use the class simultaneously from multiple threads, just not invidivual instances). In other words, most of the FCL classes protect their static fields, but not their per-instance fields. None of this is automatic. If you want your objects to be useable in a multithreaded environment, you have to write all of the locking code yourself. But there is no declarative way of advertising this - you just have to document it. [1] I'm assuming it must call OleInitialize when in STA mode, otherwise stuff like OLE drag and drop wouldn't work with Windows Forms applications. -- Ian Griffiths DevelopMentor ----- Original Message ----- From: "David B. Bitton" <[EMAIL PROTECTED]> > I'm guessing that [STAThread] is marking to componenet as > Single Threaded Architecture. How can I make my dll > multilthreading, or free threaded/thread neutral, so I can take > advantge of MTS object pooling? You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
