Coming soon: second generation prototype of Hg forest consolidation

[Claes Redestad]

On 04/11/2017 11:48 AM, David Holmes wrote:
> Hi Stefan,
>
> On 11/04/2017 3:47 AM, Stefan Karlsson wrote:
>> Hi all,
>>
>> Great to see that the consolidation work is going forward!
>>
>> I have comment specific to the HotSpot code layout:
>>
>> We previously had this layout (using a small set of directories as an
>> example):
>>  hotspot/src/share/vm
>>  hotspot/src/os/linux/vm
>>  hotspot/src/os/solaris/vm
>>  hotspot/src/os/solaris/dtrace
>>  hotspot/src/os/bsd/launcher
>>  hotspot/src/share/tools/hsdis
>>
>> and this is the new layout:
>>  src/hotspot/share/vm
>>  src/hotspot/os/linux/vm
>>  src/hotspot/os/solaris/vm
>>  src/hotspot/os/solaris/dtrace
>>  src/hotspot/os/bsd/launcher
>>  src/hotspot/share/tools/hsdis
>>
>> should we consider changing the layout of the HotSpot code so that we
>> don't mix the source code for the vm, tools, launcher? For example:
>>  src/hotspot/vm/share
>>  src/hotspot/vm/os/linux
>>  src/hotspot/vm/os/solaris
>>  src/hotspot/launcher/os/bsd
>>  src/hotspot/tools/hsdis
>>  src/hotspot/dtrace/os/solaris
>>
>> I'm not sure that we would want to include such a change in the
>> consolidation effort, but we are changing all file paths so maybe it's
>> the right time to think about this.
>
> Not sure what you mean about "mix the source code" but I much prefer 
> the familiar hotspot layout:
> - share
> - os
> - os_cpu
> etc

Familiar isn't necessarily good - my outsider perspective is that the 
layout that
Stefan proposes seems the more natural grouping when exploring the code:
hotspot is built up of vm, launcher, tools, dtrace, each of which *can* 
have
shared and specialized implementations.

The current structure requires a newbie to look in four or more seemingly
unrelated trees to even start getting a grasp on where the meat is at, 
while the
proposal would make it immediately obvious that, say, hsdis is all just 
in one place,
which is a big win when on-boarding developers to a code base that is 
already
quite challenging to get familiar with.

$.02

/Claes