The existing TclBlend (1.2.6) code doesn't quite work. If one tries to do a
"new tcl.lang.Interp()" in the JVM before Tclblend_Init() is called, an
access violation happens in Java_tcl_lang_Interp_create():
jlong JNICALL
Java_tcl_lang_Interp_create(
JNIEnv *env, /* Java environment. */
jobject interpObj) /* Handle to Interp object. */
{
jlong lvalue;
Tcl_Interp *interp;
JNIEnv *oldEnv;
JAVA_LOCK(); /* !!!!!!! this line triggers an access violation
!!!!!! */
/* ... stuff to create the native TCL interpreter ... */
JAVA_UNLOCK();
return lvalue;
}
JAVA_LOCK macro tries to access the global java.NativeLock, which is not set
up if Tclblend_Init is not called. I will open a bug and supply a patch to
fix this initialization problem.
As to using multiple native TCL interpreters in multiple Java threads, it
probably requires a bit more work in the TclBlend code. The main issue
seems to be with the use of a single global Notifier object. Even if one
creates more than one Interp object, all Interp objects are using the same
global Notifier object. That doesn't seem right. If I have more time, I
may look into fixing this issue. Using multiple interpreters in my server
may be beneficial.
-- Jiang Wu
[EMAIL PROTECTED]
-----Original Message-----
From: Mo DeJong [mailto:[EMAIL PROTECTED]]
Sent: Thursday, March 02, 2000 3:41 PM
To: [EMAIL PROTECTED]
Subject: [Tcl Java] Re: [Tcl Java] Using native TCL in JVM
Here is a note from the original author of Tcl Blend on this subject.
Mo Dejong
Red Hat Inc.
Jiang Wu said:
> Then there is TclBlend, which does a nice job of linking a native TCL
> interpreter with JVM. But TclBlend assumes that the TCL interpreter
starts
> first, then it creates a JVM to run the Java code. That is the reverse
of
> my setup, in which the JVM starts first, then loads the TCL
interpreter.
TclBlend can also be used from inside a preexisting JVM. TclBlend should
only create a new JVM if it can't find one already running. You can use
the tcl.lang.Interp class to create a new Tcl interpreter and then
evaluate scripts in it. Your sample code seemed correct without any
modifications to blend. The initialization code in Tclblend_Init is only
needed if you are loading the package from C initially. It mostly just
creates a new Interp object to wrap the already existing C interpreter.
If you are creating the initial interpreter from Java, then it doesn't
need to do this.
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