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Message-ID: <3FFF1AB4.4010609@nationwide.com>
Date: Fri, 09 Jan 2004 16:18:44 -0500
From: Moy Easwaran <easwarm AT nationwide DOT com>
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To: cygwin AT cygwin DOT com
Subject: Problem with JVM 1.4.2 on Cygwin 1.5.5-1 on XP and 2000
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I'm trying to run HelloWorld.java on a JVM invoked from C.  I'm using
the basic setup in David Caldwell's excellent how-to at
<http://www.inonit.com/cygwin/jni/invocationApi/> et seq.

It works fine on WinNT 4.0 and WinXP Home, but dies on WinXP Pro and
Win2000.

There's not really much of a trail I can provide.  I get a message-box
saying: "jvm.exe has encountered a problem and needs to close.  We are
sorry for the invonvenience."

It dies on JNI_CreateJavaVM with the 1.4.1 SDK.  In 1.4.2,
JNI_CreateJavaVM always returns -1 (and so FindClass can't run).

The Windows event log says:
"Faulting application jvm.exe [my executable], version 0.0.0.0,
faulting module jvm.dll, version 0.0.0.0, fault address 0x000a9d63.
Application Failure jvm.exe 0.0.0.0 in jvm.dll 0.0.0.0 at offset
000a9d63.."

Any suggestions on where to look or what to look for?  Help!

Thanks much,

Moy


My steps and files are as follows:

$ dlltool --input-def jvm.def --kill-at --dllname jvm.dll --output-lib 
libjvm.dll.a
$ gcc -Wall -mno-cygwin -o jvm.exe -I/cygdrive/c/j2sdk1.4.1_06/include 
-I/cygdrive/c/j2sdk1.4.1_06/include/win32 jvm.c -L. -ljvm
$ cat jvm.def
EXPORTS
JNI_CreateJavaVM AT 12
JNI_GetDefaultJavaVMInitArgs AT 4
JNI_GetCreatedJavaVMs AT 12

$ cat HelloWorld.java
public class HelloWorld
{
    public static void main (String args [])
    {
        System.out.println ("Hello, world!");
    }
}

$ cat jvm.c     # this is basically the invoke.c example on inonit.com
#include <stdio.h>
#include <jni.h>

JNIEnv* create_vm() {
        JavaVM* jvm;
        JNIEnv* env;
        JavaVMInitArgs args;
        JavaVMOption options[1];
    int res;

        /* There is a new JNI_VERSION_1_4, but it doesn't add anything 
for the purposes of our example. */
        args.version = JNI_VERSION_1_2;
        args.nOptions = 1;
        options[0].optionString = "-Djava.class.path=c:\\test";
        args.options = options;
        args.ignoreUnrecognized = JNI_TRUE;

    printf ("about to call CreateJavaVM.\n");
        res = JNI_CreateJavaVM(&jvm, (void **)&env, &args);
    printf ("CreateJavaVM returned [%d].\n", res);
        return env;
}

void invoke_class(JNIEnv* env) {
        jclass helloWorldClass;
        jmethodID mainMethod;
        jobjectArray applicationArgs;
        jstring applicationArg0;

    printf ("step 2...\n");
        helloWorldClass = (*env)->FindClass(env, "HelloWorld");

    printf ("step 3...\n");
        mainMethod = (*env)->GetStaticMethodID(env, helloWorldClass, 
"main", "([Ljava/lang/String;)V");

    printf ("step 4...\n");
        applicationArgs = (*env)->NewObjectArray(env, 1, 
(*env)->FindClass(env, "java/lang/String"), NULL);
        applicationArg0 = (*env)->NewStringUTF(env, "From-C-program");
        // (*env)->SetObjectArrayElement(env, applicationArgs, 0, 
applicationArg0);

    printf ("step 5...\n");
        (*env)->CallStaticVoidMethod(env, helloWorldClass, mainMethod, 
applicationArgs);
}


int main(int argc, char **argv) {
        JNIEnv* env = create_vm();
    printf ("step 1 done...\n");
        invoke_class( env );
    return 0;
}


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