> I believe that the Eclipse JDT debugger team wrote their own JDWP client > code, but not sure if it supports the shmem transport. I can go over > and ask.
Eclipse JDT Debugger uses its own JDI implementation (JDWP client code), which includes JDI connectors only over TCP/IP socket transport and don't support shmem transport. There is no support in Eclipse for using any other JDI connectors, even if they are provided by underlying JDK. Netbeans debugger and Sun's jdb demo use JDI connectors provided by underlying JDK, and thus may occasionally use shmem transport running with RI (they use some internal algorithm for choosing appropriate transport). I'm not sure if commercial debuggers, e.g., integrated into Idea and JBuilder environments, use JDI connectors from underlaying JDK and allow choosing particular connector. Most likely they behave the same way. > Anyone recall seeing a spec for it or is it non-standard? Any transport layer used for JDWP connection should be supported on both debugger and debuggee sides [1]. On JDWP agent's side it should follow jdwpTransport spec [2]. On debugger's side (JDI front-end) it should provide a set of JDI connectors over given JDWP transport that follow JDI Pluggable Connectors and Transports API (com.sun.jdi.connect.*, com.sun.jdi.connect.spi.* in JDI spec) [3]. The problem is that implementation of the same JDWP transport in different JDK should be compatible. Otherwise it may break interoperability between debugger and debuggee if they are started on different JDKs (e.g., debugger started on RI tries to connect to debuggee running on Harmony). Implementation of socket transport is based on well known sockets API and thus is de-facto compatible between different JDKs. For shmem transport provided by RI implementation is not evident and is not documented anywhere, so it's hard to implement it in a compatible manner even following these specifications. If someone likes to make independent implementation of shmem JDWP transport, e.g., based on pipes, he probably should give it different name - dt_pipes or so, in order to distinguish it from RI's dt_shmem implementation and avoid compatibility issues. But I doubt that any popular Java debugger will be able to use such a non-standard transport, at least without special tricks. Thanks. Ivan [1] http://java.sun.com/j2se/1.5.0/docs/guide/jpda/conninv.html [2] http://java.sun.com/j2se/1.5.0/docs/guide/jpda/jdwpTransport.html [3] http://java.sun.com/j2se/1.5.0/docs/guide/jpda/jdi/index.html
