Jimmy,Jing Lv said the following on 26.02.2008 12:15:
Hi,
2008/2/26, Ivan Popov <[EMAIL PROTECTED]>:
JDWP agent and transport implementation was developed independent on
Harmony's drlvm and classlib implementations in order to be run easily
on top on any JVM. That's why it does not use any portlib support for
platform dependent code.
I agree, however, it would be better to re-use platform dependent
support from portlib to facilitate porting jdwp code to other
platforms. The only such code is TCP/IP sockets api used in dt_socket
transport and loading transport DLL in the agent itself. All other
code is based on standard JVMTI api and thus is platform independent.
I notice the DLL loading as well. I have an idea here that shall we
start with java-level lib loading process? For Java code it may be
quite easy to do such work as:
System.loadLibrary("libname");
We can do similar things. What does native code do in this
"System.loadLibrary", does vm/classlib native code support such API
for work? If so, we may
1) directly call that API to load lib and avoid platform differences
If no, we may
2) create a java class to do the such work, reflect in the native
TransportManager. Though it may be a little strange and slower in
performance, it may also works.
Any VM guru know what's happening in the System.loadLibrary()? Would
it be used without java-level call?
I am not sure that using Java is possible here. First, agent's
initialization happens in ON_LOAD phase [1] where VM doesn't allow to
execute any Java code yet.
Second, even if you make a call to System.loadLibrary (Java or
underlying native function) you'd need the library handle to obtain
(with a platform dependent function) function pointers from it.
[1] http://java.sun.com/j2se/1.5.0/docs/guide/jvmti/jvmti.html#GetPhase
--
Gregory
