Hi all,
I see sometimes mentioned in the Bug Parade to fix a bug
adding an .hotspot_compiler file to the VM. What does it do?
it excludes from the hotspot some methods calls? If so, does
it work recursively (for subsequent methods calls) ?
Thanks a lot
Francesco

 

 

The .hotspot_compiler file gives information to the compiler on how to compile classes.
For example, you can prevent optimization including a line like :

exclude com/foo/Bar get

that would prevent compilation of the method com.foo.Bar.get()

The file must be in the application's directory.

For what I know, this is undocummented feature and may change from one JVM release to another.

Hope this helps

 

 

You can put compilation commands on the command line instead of in the .hotspot_compiler file. This lets you invoke the VM without worrying about building a file in the current directory.

-XX:CompileCommand=exclude,my/pkg/MyClass,theMethod

The commas are interchangeable with spaces, and are more convenient than spaces on a command line, since they don't need quoting to protect them from the shell.

Also, if you have a canned list of compilation commands in a file, you don't need to name it .hotspot_compiler. Just refer to it by name this way:

-XX: CompileCommandFile=/my/canned/command/file

See also my comments here: http://forum.java.sun.com/thread.jspa?messageID=4273869