Java Step Types with Java Virtual Machine higher than java-6u16?

Question

Documentation of Java steps says, that these steps are tested with java version 6 update 16. I am talking about the java step types that can be found in directory <TestStand Public>\TestStand 2010\Examples\Java. 
If I install another java version, e. g. java 7, step "Start JVM" will exit with an error "-4" and error message "Could not launch JVM.". While Debugging source code of JavaCall.dll, I figured the failing code line out:
"fpCreateJVM(&jvm,(void**)&env,&vm_args);" is the execution of function "JNI_CreateJavaVM" and returns error code -4.
Till now I could not find out, why the jvm does not start. I guess -4 means "Insufficient memory to create the JVM." (http://zone.ni.com/reference/en-XX/help/370052J-01/tssuppref/infotopics/java_steps_errors/)
Has anyone an advice for me?

Answer 1

This post gave me a hint: http://stackoverflow.com/questions/3400292/jni-enomem-from-jni-createjavavm-when-calling-dll-that-us...
Though my development computer has enough ram, jvm is started within the Teststand process which offers limited memory. I changed JavaCall.c and added parameter "-Xmx64m" to the jvm creation call. Now it works with jre 7.
Because memory space Teststand offers to the jvm is different on different computers, an implementation would be nice that checks how much memory is available and then passes the calculated <MEM> as parameter "-Xmx<MEM>m". Here is an example implementation: https://forums.oracle.com/forums/thread.jspa?threadID=1546540