jake -> jdk9/dev

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jake -> jdk9/dev

Alan Bateman
We have again accumulated quite a few changes in the jake forest and I'd
like to bring to jdk9/dev next week. It's all small changes this time,
JDK-8178380 [1] has the summary.

-Alan

[1] https://bugs.openjdk.java.net/browse/JDK-8178380

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RE: jake -> jdk9/dev

Stephen Felts
I think that there is one large item in that change that should not be included.
The requirement for using -Djdk.attach.allowAttachSelf=true is in Jake but not jdk9/dev.
I think that the Java community made it clear that this feature should not be included in JDK9, including going to the effort of writing a paper to that effect at
https://docs.google.com/document/d/19H1iGUnyI4Y40U5sNVAmH0uLxcpNfYSjPIW3s0Rv5Ss/edit?usp=sharing
The revised proposal doesn't fix the problem that this JDK 9 command line property will be needed in many cases.
This "feature" takes away an API that was introduced publically in JDK 6 and obviously popular in usage.




-----Original Message-----
From: Alan Bateman
Sent: Saturday, April 29, 2017 3:45 AM
To: jigsaw-dev
Subject: jake -> jdk9/dev

We have again accumulated quite a few changes in the jake forest and I'd like to bring to jdk9/dev next week. It's all small changes this time,
JDK-8178380 [1] has the summary.

-Alan

[1] https://bugs.openjdk.java.net/browse/JDK-8178380

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Re: jake -> jdk9/dev

Alan Bateman
On 29/04/2017 11:04, Stephen Felts wrote:

> I think that the Java community made it clear that this feature should not be included in JDK9, including going to the effort of writing a paper to that effect at
> https://docs.google.com/document/d/19H1iGUnyI4Y40U5sNVAmH0uLxcpNfYSjPIW3s0Rv5Ss/edit?usp=sharing
>
This is the proposal for the EnableDynamicAgentLoading option. The
default is true so that tools can load agents into target VMs as before.
The proposal is that some future version disable this, maybe in
conjunction with a signing solution. Details TBD as it's not JDK 9.

-Alan
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RE: jake -> jdk9/dev

Stephen Felts
The default is currently false in Jake (at least it's failing for me).
Is this going to be reversed in Jake so that Jake and JDK9 match behavior?


-----Original Message-----
From: Alan Bateman
Sent: Saturday, April 29, 2017 7:46 AM
To: Stephen Felts; jigsaw-dev
Subject: Re: jake -> jdk9/dev

On 29/04/2017 11:04, Stephen Felts wrote:

> I think that the Java community made it clear that this feature should
> not be included in JDK9, including going to the effort of writing a
> paper to that effect at
> https://docs.google.com/document/d/19H1iGUnyI4Y40U5sNVAmH0uLxcpNfYSjPI
> W3s0Rv5Ss/edit?usp=sharing
>
This is the proposal for the EnableDynamicAgentLoading option. The default is true so that tools can load agents into target VMs as before.
The proposal is that some future version disable this, maybe in conjunction with a signing solution. Details TBD as it's not JDK 9.

-Alan
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RE: jake -> jdk9/dev

Stephen Felts
In reply to this post by Alan Bateman
I think this statement is very misleading.
As part of this "small changes", jdk.attach.allowAttachSelf will be set to false and everyone that has self-attaching agents will start failing.
So to repeat myself, I think that the Java community made it clear that this feature should not be included in JDK9.

-----Original Message-----
From: Alan Bateman
Sent: Saturday, April 29, 2017 7:46 AM
To: Stephen Felts; jigsaw-dev
Subject: Re: jake -> jdk9/dev

On 29/04/2017 11:04, Stephen Felts wrote:

> I think that the Java community made it clear that this feature should
> not be included in JDK9, including going to the effort of writing a
> paper to that effect at
> https://docs.google.com/document/d/19H1iGUnyI4Y40U5sNVAmH0uLxcpNfYSjPI
> W3s0Rv5Ss/edit?usp=sharing
>
This is the proposal for the EnableDynamicAgentLoading option. The default is true so that tools can load agents into target VMs as before.
The proposal is that some future version disable this, maybe in conjunction with a signing solution. Details TBD as it's not JDK 9.

-Alan
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Re: jake -> jdk9/dev

Alan Bateman
On 01/05/2017 12:48, Stephen Felts wrote:

> I think this statement is very misleading.
> As part of this "small changes", jdk.attach.allowAttachSelf will be set to false and everyone that has self-attaching agents will start failing.
>
This is part of the revised proposal that Mark sent to the list a few
weeks ago [1]

-Alan

[1] http://mail.openjdk.java.net/pipermail/jigsaw-dev/2017-April/012040.html
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Re: jake -> jdk9/dev

Andrew Dinn
In reply to this post by Stephen Felts
On 01/05/17 12:48, Stephen Felts wrote:
> I think this statement is very misleading. As part of this "small
> changes", jdk.attach.allowAttachSelf will be set to false and
> everyone that has self-attaching agents will start failing. So to
> repeat myself, I think that the Java community made it clear that
> this feature should not be included in JDK9.

Well, not exactly 'the Java community'. Quite a few people did object to
the EnableDynamicAgentLoading switch being introduced and defaulting to
false and as a result setting of that default was delayed until JDK10 to
ease the transition (so that the switch could be added to scripts in
advance of any need to move backwards and forwards between jdk9 and jdk10).

Now, there was also some discussion of the agent self-hoist restriction
on list but, to my recall, it was not universally addressed or
discredited as you claim. Most of the discussion was concerned with how
the process restrictions would apply. Anyway, at the very least, if you
are going to arrogate any rights on behalf of your conception of who is
'the Java community' then, as Sam Goldwyn said, please "Include me out".

I'm personally less concerned about this change of behaviour than the
EnableDynamicAgentLoading change because retaining the old behaviour
only requires a system property setting to be added to the command line.
Since that setting will be innocuous if you move back to an older
version my view is that coping with this change doesn't cause any major
transition problem.

I can understand the concern to avoid an /irremediable/ transition where
existing, important behaviour is removed. Indeed, I can easily stretch
such concern to cover an /awkward/ transition where straightforward
switching between releases is prejudiced. However, to object to a change
to new behaviour in circumstances where retaining the old behaviour
requires a relatively innocuous change seems to me to be a much less
reasonable approach. If followed repeatedly that sort of behaviour will
paint Java into a corner where we can never achieve important changes in
the JVM and JDK.

regards,


Andrew Dinn
-----------
Senior Principal Software Engineer
Red Hat UK Ltd
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