Robert Greig wrote: > Finally, there are performance issue with managed/non-managed heap > copies in Java that makes JNI unattractive (I don't know if this > applies to .NET too - although I did ask the question on this mailing > list some time ago without receiving any answer).
I'll take a stab at it now. This can be mitigated somewhat by asking the garbage collector to pin a managed memory location for a brief amount of time, but there are housekeeping costs associated with that too. In the current WCF implementation, there is a single copy between the binary message content in managed space and the individual AMQP message body frames in native space. A purely native Visual C++ application would have to make that same copy. But it would be spared the costs of the pinning and the numerous managed to native transitions used to monitor and control the Qpid objects that control connections, sessions, subscriptions etc. For very large messages, the overhead is small. For 100 byte sized ones it is certainly significant. Cliff -----Original Message----- From: Robert Greig [mailto:robert.j.gr...@gmail.com] Sent: Wednesday, January 28, 2009 12:05 PM To: dev@qpid.apache.org; cctriel...@redhat.com Subject: Re: IKVMing the Java client for .Net 2009/1/23 Carl Trieloff <cctriel...@redhat.com>: > In a discussion with the Microsoft guys, I they where thinking of using the > C++ client, with WCF on top of that. They seem to have thought about that > quite a bit, so it would be good to get those comments onto the list also > around this topic. Is this not going to suffer the same performance issues that Java has with JNI? (I ask that as a question, not an assertion, but I had always assumed this would apply across both platforms). In Java there is a non-trivial performance penalty copying data from the C heap to the Java heap and vice versa. This is one reason why some JDBC drivers built on top of native code perform and scale much worse than pure Java drivers (the example often benchmarked is the Oracle driver). RG --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:dev-subscr...@qpid.apache.org --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:dev-subscr...@qpid.apache.org
