RFR 8010280: jvm.cfg needs updating for non-server builds

[Mike Duigou]

Looks good. It's nice to see the legacy entries finally get removed.

Mike

On Apr 26 2013, at 00:27 , David Holmes wrote:

> Here is the final form of this after CCC approval.
> 
> http://cr.openjdk.java.net/~dholmes/8010280/webrev.v3/
> 
> For the "traditional" build of client+server we continue to use the platform specific jvm.cfg files committed into the source repository. Consequently no product builds (SE or Embedded) are altered by this proposal. (Those files already contain "-minimal KNOWN" if applicable to that platform.)
> 
> Otherwise we define a jvm.cfg file where:
> - the default VM is the "dominant" VM (server > client > minimal)
> - a missing client/server is aliased to the default VM
> - the minimal VM is only present in the jvm.cfg file if it is built
> 
> Further, as a target of opportunity we stop generating, and delete from the existing jvm.cfg files the legacy entries for "hotspot", "classic", "native" and "green"
> 
> Thanks,
> David
> 
> Generated jvm.cfg contents based on selected JVM variants:
> 
> ::::::::::::::
> client
> ::::::::::::::
> -client KNOWN
> -server ALIASED_TO -client
> 
> ::::::::::::::
> minimal+client
> ::::::::::::::
> -client KNOWN
> -server ALIASED_TO -client
> -minimal KNOWN
> 
> ::::::::::::::
> minimal
> ::::::::::::::
> -minimal KNOWN
> -server ALIASED_TO -minimal
> -client ALIASED_TO -minimal
> 
> ::::::::::::::
> minimal+server
> ::::::::::::::
> -server KNOWN
> -client ALIASED_TO -server
> -minimal KNOWN
> 
> ::::::::::::::
> server
> ::::::::::::::
> -server KNOWN
> -client ALIASED_TO -server
> 
> 
> On 15/04/2013 10:18 AM, David Holmes wrote:
>> Some background.
>> 
>> The jvm.cfg file, for which there is a per-architecture committed file
>> in the repository, controls which VM's (client, server, minimal) are
>> known, which is the default, whether there are other aliases and whether
>> ergonomic selection is used.
>> 
>> Historically things were simple:
>> - 64-bit platforms had server only
>> - 32-bit platforms had client and server
>> 
>> then we acknowledged that some platforms may be client only and we added
>> some support (originally in the old build then converted to the new
>> build) for dynamically creating a jvm.cfg for the case of building
>> client only.
>> 
>> Then the minimal VM was introduced and we potentially have three VMs to
>> handle. To address this we initially added "-minimal KNOWN" to all the
>> jvm.cfg files for platforms known to support the minimal VM - this was
>> done under JDK-7198815 (and those changes are now reversed by this
>> changeset.)
>> 
>> The problem after minimal was introduced was that the logic for
>> "building client only" didn't account for building minimal (only or
>> combined with client) and we need support for not-building-server. And
>> that is what this changeset does.
>> 
>> This only affects 32-bit builds as there is no client nor minimal VM on
>> 64-bit. The basic operation is as follows:
>> 
>> - If building client+server then we use the committed jvm.cfg (which
>> handles ergonomics if applicable), adding a "-minimal KNOWN" line if
>> minimal is also selected;
>> - Otherwise we dynamically generate a jvm.cfg for the set of VMs being
>> built, using these simple rules:
>>   - if client or server are present they are default
>>   - if client and/or server is absent then the absent VM is aliased to
>> the default VM in that config
>>   - if minimal is not selected then it is absent from the jvm.cfg (we
>> do not add any aliases for minimal**).
>> 
>> ** The alias mechanism is useful for deprecating legacy VM names, and
>> has also made testing more convenient. However I think it is a flawed
>> mechanism for testing and our internal test infrastructure is moving
>> away from arbitrarily using -client/-server when actually running
>> server/client. If you ask for the minimal VM and it is not available I
>> think you should get an error not silent use of a different VM. (Note:
>> this selection doesn't affect SE Embedded as it defines jvm.cfg files
>> using it's own rules/preferences.)
>> 
>> webrev:
>> 
>> http://cr.openjdk.java.net/~dholmes/8010280/webrev/
>> 
>> Thanks,
>> David