Gregory Shimansky wrote:
On 8 января 2008 Jimmy,Jing Lv wrote:
Hi All,
I've done some study on the Harmony JDWP. The current JDWP is of
high quality and well-tested (really good job! :)).
However compared with RI's implementation, I find RI has a
shared-memory transport (startup like "java
-agentlib:jdwp=transport=dt_shmem"). As Harmony's target is compatible
with RI, we may implement a shared-memory transport as well as RI
does. Do some one already has such plan? Or I'd like to implement in
the near future.
A further study in windows API shows we may not use shared memory
directly, windows pipe api (pipe is also a kind of "shared memory", is
it?) may be a good alternative. In all we need to implement
open/read/write/select/close operations with pipe/shared-memory and
implement agent-load/unload shared-memory agent and error-handling
like socket-transport do.
I think we should need the same method that the client (eclipse or whatever
IDE or debugger) use for connecting to the agent. Since clients are usually
written in Java the method should be done in the same way it is done in Java
API. I am not aware of however with a way for a Java application to use
shared memory or windows pipe API. Do you know some client debugger or
profiler that uses dt_shmem method and API that it uses for connection to the
debuggee?
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.
Anyone recall seeing a spec for it or is it non-standard?
And I also notice that there' s some updates on JDWP-protocol in
java6, e.g, some new commands on
VirtualMachine/ReferenceType/ObjectReference/ThreadReference/CapabilitiesNe
w Command Set, which is necessary for Java6 implemetation. We may also
implement them in a tools Java6 branch (currently only classlib has Java6
branch, we may also build a repository for others? ) I'm not sure DRLVM has
a plan to update vmi/jvmti to java6 level, however I think update JDWP
first will do no harm.
Well, eventually we'll have to have a version of DRLVM for Java6 (whether it
is going to be a branch, compile time define or some other way is a subject
for a separate discussion). In any case, JDWP agent should be working with
RI, so it is possible to add updates for new JDWP protocol functionality and
test it with RI for now. Again, maybe it will require a separate branch for
jdktools or build time define flag.
Any suggestion/comments? I may start further study/plan and
implementation for this if no objection.
I think it would be great to start supporting Java6 features not only in class
library!
+1
Regards,
Tim
