Quite useful, I was missing this corner..
Below is quote from documentation as it is provided by code author.
// This method DOES NOT DO ANYTHING in and of itself. It's used to // prevent a finalizable object from losing any outstanding references // a touch too early. The JIT is very aggressive about keeping an // object's lifetime to as small a window as possible, to the point // where a 'this' pointer isn't considered live in an instance method // unless you read a value from the instance. So for finalizable // objects that store a handle or pointer and provide a finalizer that // cleans them up, this can cause subtle ----s with the finalizer // thread. This isn't just about handles - it can happen with just // about any finalizable resource. // // Users should insert a call to this method near the end of a // method where they must keep an object alive for the duration of that // method, up until this method is called. Here is an example: // // "...all you really need is one object with a Finalize method, and a // second object with a Close/Dispose/Done method. Such as the following // contrived example: // // class Foo { // Stream stream = ...; // protected void Finalize() { stream.Close(); } // void Problem() { stream.MethodThatSpansGCs(); } // static void Main() { new Foo().Problem(); } // } // // // In this code, Foo will be finalized in the middle of // stream.MethodThatSpansGCs, thus closing a stream still in use." // // If we insert a call to GC.KeepAlive(this) at the end of Problem(), then // Foo doesn't get finalized and the stream says open. [MethodImplAttribute(MethodImplOptions.InternalCall)] [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)] public static extern void KeepAlive(Object obj); |
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