JDK-8219143: jdb should support breakpoint thread filters

[Alex Menkov]

Hi Chris,

- New threadid param breaks at/in clause - this doesn't look good.
Maybe it would be better to put threadid before in/at:
stop [go|thread] [threadid <thread_id>] <at|in> <location>
This also would make commandStop/parseBreakpointSpec logic more clear:
commandStop handles go/thread/threadid, parseBreakpointSpec handles 
position (part starting from in/at);

- do you think BreakpointSpec toString should contain info about the 
thread (i.e. to specified in the breakpoint list)?;

- it would be nice to add a test for the new threadid functionality.

--alex

On 02/19/2019 21:57, Chris Plummer wrote:
> Hello,
> 
> Please review the following:
> 
> http://cr.openjdk.java.net/~cjplummer/8219143/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8219143
> 
> Normally when a breakpoint is set in jdb, it is set globally (all 
> threads). JDI supports the ability to have the breakpoint be 
> automatically filtered so it will only be delivered on a specified 
> thread and ignored on all other threads. This change allows making use 
> of that JDI feature from jdb. So instead of something like:
> 
>    stop at Foo:23
> 
> You can now do:
> 
>    stop at threadid 7 Foo:23
> 
> Where 7 is the threadID for the thread as seen in the output of the 
> "threads" command. The format of the stop command is now:
> 
>     stop [go|thread] <at|in> [threadid <thread_id>] <location>
> 
> It is still fully backwards compatible.
> 
> As part of this change I also cleaned up the "stop" command parsing and 
> error handling. It was kind of a mess, and was near impossible to add 
> the "threadid" option until after I did much of the cleanup. I've also 
> cleaned up the help output a lot, and added help for the "go" and 
> "thread" options. One last change was to remove the distinction between 
> "stop at" and "stop in", which was suggested already in a comment. They 
> can be used interchangeably now. The changes in Commands.java are pretty 
> much all just the above cleanup, except for the one short section with 
> the 'Handle "threadid" modifier' comment.
> 
> thanks,
> 
> Chris
>