[8u] Request for enhancement backport approval for 8059038: Create new launcher for SA tools

[Severin Gehwolf]

Hi Kevin,

On Wed, 2018-11-28 at 13:18 +0000, Kevin Walls wrote:
> Hi,
> 
> OK maybe I misread your intent.  I though  "adds launchers for CLHSDB 
> and HSDB" meant standalone launchers like jstack and friends, because 
> that's how we do this (how we have done done this) in jdk8.
> 
> JDK-8059038 exists because of removal of -F ("SA options") from jstack 
> etc., so it's not so relevant in 8?

The intent is to have *some* way to launch the SA (CLI or GUI). Whether
it's going to be via direct launchers (e.g. clhsdb and hsdb) or via
'jhsdb <foo>' seems debatable. Either way works for me.

> I didn't imagine you'd propose the new jhsdb command in jdk8u, but I see 
> in the hotspot repo change you are bringing back SALauncher.java.  
> You're proposing a stripped-down version of SALauncher.java for those 
> two commands, but it won't launch jstack, jmap, jinfo, ... as it would 
> in later versions.
> 
> That might be confusing

Thinking about it that way it might be confusing. On the other hand, it
could be confusing to have them available via launchers directly in JDK
8, but JDK 9+ would use jhsdb <foo> instead. Yet again, the same is
true for jstack and friends, so...

> I would have thought a standalone launcher for 
> clhsdb and hsdb made sense?

If that's the preferred way to get an SA launcher done for JDK 8,
that's fine with me. I can revise the patch if you think that it would
then make it more likely to get approved.

Thanks,
Severin

> Thanks
> Kevin
> 
> 
> On 28/11/2018 12:32, Severin Gehwolf wrote:
> > Hi Kevin,
> > 
> > On Wed, 2018-11-28 at 12:18 +0000, Kevin Walls wrote:
> > > Hi Severin,
> > > 
> > > I would be in favour of things that make the SA tools more visible. 8-)
> > > 
> > > Did you mean to create a clhsdb launcher as well as the jhsdb one I can
> > > see here?
> > 
> > Not sure what you mean by this.
> > 
> > In JDK 9+ clhsdb is being launched with jhsdb, is it not? In particular
> > this: "bin/jhsdb clhsdb". The gui would be "bin/jhsdb hsdb". After this
> > patch JDK 8 will have jhsdb which will be able to launch 'hsdb' or
> > 'clhsdb' in the same way as JDK 9+ does (modulo different switches like
> > --pid, etc.)
> > 
> > > The alternative would be backporting the jhsdb command itself, but we
> > > don't want to take _out_ any existing launchers, and having both would
> > > be odd, so I'd vote for what you're proposing here.
> > 
> > Maybe I'm wrong, but the proposed patch adds the jhsdb command into bin
> > for JDK 8. Thanks for your input!
> > 
> > Cheers,
> > Severin
> > 
> > > Thanks
> > > Kevin
> > > 
> > > 
> > > On 20/11/2018 17:29, Severin Gehwolf wrote:
> > > > Hi,
> > > > 
> > > > Please approve this enhancement backport request which adds launchers
> > > > for CLHSDB and HSDB (part of the sa-jdi.jar) currently not present in
> > > > JDK 8u. JDK 9+ has 'jshsdb clhsdb' (CLI) and 'jhsdb hsdb' (GUI) for the
> > > > serviceability agent. This patch would make those available in JDK 8u
> > > > too.
> > > > 
> > > > The risk of making them available is none. It's not possible to use
> > > > them this way right now. The commands don't exist. Except for a new
> > > > launcher no new code has been added. The launcher delegates to existing
> > > > CLHSDB and HSDB classes.
> > > > 
> > > > Testing: New basic test, manual testing that launchers work.
> > > > 
> > > > webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8059038/01/
> > > > Bug: https://bugs.openjdk.java.net/browse/JDK-8059038
> > > > 
> > > > Thoughts?
> > > > 
> > > > Thanks,
> > > > Severin
> > > > 
> 
>