Re: RFR: 8282641: Make jdb "threadgroup" command with no args reset the current threadgroup back to the default [v2]
> jdb has a probably very little used command called "threadgroup" which is
> used to set the current TheadGroup. The only purpose of the current
> ThreadGroup is as the default ThreadGroup to use for the "threads" command
> when no ThreadGroup argument is passed to it.
>
> "threads" prints out every thread in the ThreadGroup specified as the first
> argument. If none is specified, it uses the current ThreadGroup. If the
> current ThreadGroup has not yet been specified, it automatically gets set to
> the top level ThreadGroup.
>
> Once the current ThreadGroup has been set by using the threadgroup command,
> it's not that obvious how to reset it back to the default. It turns out the
> way to do this to set it to the "system" ThreadGroup, which is the top level
> ThreadGroup (and therefore the initial current ThreadGroup).
>
> With this enhancement I've made it so if you use the "threadgroup" command
> with no argument, it resets the current ThreadGroup back to the top level
> ThreadGroup ("system"). Previously with no argument it produces an error for
> not specifying the ThreadGroup argument.
Chris Plummer has updated the pull request incrementally with two additional
commits since the last revision:
- Use THREADGROUP_NAME instead of "MyThreadGroup#"
- fix minor typo in help text
-
Changes:
- all: https://git.openjdk.java.net/jdk/pull/7687/files
- new: https://git.openjdk.java.net/jdk/pull/7687/files/ad800de5..fb7ac63f
Webrevs:
- full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7687&range=01
- incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7687&range=00-01
Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
Patch: https://git.openjdk.java.net/jdk/pull/7687.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/7687/head:pull/7687
PR: https://git.openjdk.java.net/jdk/pull/7687
Re: RFR: 8282641: Make jdb "threadgroup" command with no args reset the current threadgroup back to the default [v2]
On Fri, 4 Mar 2022 07:34:35 GMT, Chris Plummer wrote:
>> jdb has a probably very little used command called "threadgroup" which is
>> used to set the current TheadGroup. The only purpose of the current
>> ThreadGroup is as the default ThreadGroup to use for the "threads" command
>> when no ThreadGroup argument is passed to it.
>>
>> "threads" prints out every thread in the ThreadGroup specified as the first
>> argument. If none is specified, it uses the current ThreadGroup. If the
>> current ThreadGroup has not yet been specified, it automatically gets set to
>> the top level ThreadGroup.
>>
>> Once the current ThreadGroup has been set by using the threadgroup command,
>> it's not that obvious how to reset it back to the default. It turns out the
>> way to do this to set it to the "system" ThreadGroup, which is the top level
>> ThreadGroup (and therefore the initial current ThreadGroup).
>>
>> With this enhancement I've made it so if you use the "threadgroup" command
>> with no argument, it resets the current ThreadGroup back to the top level
>> ThreadGroup ("system"). Previously with no argument it produces an error for
>> not specifying the ThreadGroup argument.
>
> Chris Plummer has updated the pull request incrementally with two additional
> commits since the last revision:
>
> - Use THREADGROUP_NAME instead of "MyThreadGroup#"
> - fix minor typo in help text
Looks good.
(Choosing the null or top-level thread group means to show all threads in all
thread groups, that makes sense though I didn't find if we say it anywhere. A
niche feature like you say, but good to have a way back from choosing a thread
group!)
-
Marked as reviewed by kevinw (Committer).
PR: https://git.openjdk.java.net/jdk/pull/7687
