RFR: 8262520: Add SA CommandProcessor support to connect to debug server [v3]

[Chris Plummer]

On Thu, 4 Mar 2021 01:09:40 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

>>> I think we should remove `main()` from CLHSDB/HSDB to be honest because they are called from SALauncher, and we cannot call them directly because they are not exported in module-info.
>> 
>> Yes, I'm starting to come to the same conclusion. The only code that constructs a `CLHSDB` object, and therefore triggers the potential call to `doUsage()`, is `CLHSDB.main()`, and it is only called from `SALauncher` when using `jhsdb clhsdb`. We could get rid of `main()` and have some other entrypoint that is passed the values of all the possible options, rather than having to parse them in CLHSDB.java.
>> 
>> There is one test invokes java with the `CLHSDB` class. See SABase.java. It's part of ciReplay testing. I think it would be easily modified to just run `jhsdb clhsdb`
>
>> Yes, I'm starting to come to the same conclusion. The only code that constructs a `CLHSDB` object, and therefore triggers the potential call to `doUsage()`, is `CLHSDB.main()`, and it is only called from `SALauncher` when using `jhsdb clhsdb`. We could get rid of `main()` and have some other entrypoint that is passed the values of all the possible options, rather than having to parse them in CLHSDB.java.
>> 
>> There is one test invokes java with the `CLHSDB` class. See SABase.java. It's part of ciReplay testing. I think it would be easily modified to just run `jhsdb clhsdb`
> 
> I think `debugd` and `jsnap` are also remove `main()` if they have because they do not provide commands like `jstack`.
> I will file it to JBS, and will fix them later.

BTW, referring back to the change to have attach handle pids and debug servernames, and the concern about a host having a numeric name, we already have code that assumes we don't have to deal with this in Tools.java. I just stumbled across this:

           try {
              pid = Integer.parseInt(args[0]);
              debugeeType = DEBUGEE_PID;
           } catch (NumberFormatException e) {
              // try remote server
              remoteServer = args[0];
              debugeeType  = DEBUGEE_REMOTE;
           }

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PR: https://git.openjdk.java.net/jdk/pull/2773