We've been diagnosing a performance issue and isolated it to receiving on a datagram socket where we are seeing a significant step down in performance, and increase in allocation, when more than one source is sending.
https://github.com/frohoff/jdk8u-jdk/blob/master/src/windows/native/sun/nio/ch/DatagramChannelImpl.c#L138 When receiving from two or more sources we get InetAddress and InetSocketAddress objects allocated and they are set via multiple up calls from the JNI code into Java. A much more efficient implementation would be one that passes down two ByteBuffers. One to be filled in for the payload and one for the header. Allocation on a per packet receive is not a useful design for a network API. A read operation is not a valid alternative as we need the sender address. Regards, Martin...
