Once more forgot to post to list- thanks Jerry. Hi Jerry, Jerry Haltom wrote:
Anybody interested in this at all?
Yes :-) Sorry, I am currently away and have on sporadic and short access to my email.
On Sun, 2005-04-03 at 11:12 -0500, Jerry Haltom wrote:We need a standard, nice, easy to extend way for binary wrappers in /usr/bin and/or startup scripts to locate their VM. There are a few requirements that I had: 1) Whatever we do should be GUI configurable. I want to write a "System VM Selection" control panel of some sort allowing the user to choose which VM is used system-wide and also program specific.
That would be nice - especially as users are should be allowed to override the vm. But I think we should put the scripts first in java-common - to have something to test etc. - and then at a later stage put the GUI stuff in place. Just to ensure that the feature doesn't need to wait till a working GUI is written. BTW, should the GUI be in Java ?
2) It would be nice if a user (or us, as maintainers) could set the system up so that a certain VM is used by default for a certain program. There is a very obvious use case for wanting to run something like Eclipse on Sun's VM, yet everything else on GCJ (at least until we are feature complete with Sun!) 3) It should be overridable per user. If only one user wants to run Eclipse on Sun, he should be able to.
No comment - just fine.
So the obvious way to implement this is to write a shell script fragment which queries a number of files and returns a valid path to a JAVA_HOME. We then include this fragment at the top of existing wrappers, or such as in the case of Ant, just replace the wrapper (the Ant wrapper sucks really badly.) Here's my idea. A JVM selection file is just a file listing JAVA_HOME paths in order of preference. We put the default system one here: /etc/jvm Additionally, we create a directory to hold per program files. /etc/jvm.d A file in here would be for example named 'ant'. I'd like to talk about this naming convention for these files. I'm thinking we'd use the same stuff as like, /usr/share/$prog, not the specific package name. The script would test for /etc/jvm.d/prog, test each JAVA_HOME listed within, then, if it hasn't found a jvm yet, proceed with /etc/jvm. We could also have it check ~/.jvm.d and ~/.jvm in the same manor. Because I like doing things before I talk about them, I did this. This file would be cleaned up, placed in java-common, perhaps in /usr/share/java-common/jvm.sh, and jvm_find would be called in each wrapper.
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Then a wrapper just sources it, JAVA_HOME=`jvm_find myname`, and goes on.
I vote for it :-) Regards, Wolfgang PS: Some further extensions to selection per arch - or arch preferences for the free vm's come to my mind - but I have not the time currently to discuss - will come back later.