Java Doc for jvm.java in  » Database-DBMS » db-derby-10.2 » org » apache » derbyTesting » functionTests » harness » Java Source Code / Java DocumentationJava Source Code and Java Documentation

This class provides the interface and mechanism for plugging VMs into the system. Typically you only need to add a new implementation if your supported attributes or command line building are different from those that exist.

this class has fields for all options that a JDK VM can take, that is the reference point for all others. Note some VMs (like jview) don't take all options and will ignore them (like -mx). Defining the system property "verbose" to 1 will give you warnings for ignored properties in a properly implemented subclass.

here is the canonical output from java -help for options we take:

 -noasyncgc        don't allow asynchronous garbage collection
 -verbosegc        print a message when garbage collection occurs
 -noclassgc        disable class garbage collection
 -ss       set the maximum native stack size for any thread
 -oss      set the maximum Java stack size for any thread
 -ms       set the initial Java heap size
 -mx       set the maximum Java heap size
 -classpath 
 list directories in which to look for classes
 -prof[:]    output profiling data to .\java.prof or .\
 -verify           verify all classes when read in
 -noverify         do not verify any class
 -nojit            turn off the jit
 -Dprop=name       define property; can be specified more than once
 

1. If the sytem property 'jvm' use this name.
2. else if the java version starts with 1.2 use "jdk12".
3. else use "currentjvm".