RFR(s):8252101 Add specification of expected behavior of combining "all" and "live" options of jmap(Internet mail)

[linzang(臧琳)]

After discuss with paul, it is not a good idea to combine two fix together in one webrev. I will handle them separately
Please help review the updated one. Thanks!
	Webrev: http://cr.openjdk.java.net/~lzang/8252101/webrev.01/ 
            CSR: https://bugs.openjdk.java.net/browse/JDK-8252102 
            Bug: https://bugs.openjdk.java.net/browse/JDK-8252101
 
BRs,
Lin

On 2020/8/21, 12:17 AM, "linzang(臧琳)" <linzang at tencent.com> wrote:

    Dear All, 
            May I ask your help to review this change: 
            Webrev: http://cr.openjdk.java.net/~lzang/8252101/webrev.00/ 
            CSR: https://bugs.openjdk.java.net/browse/JDK-8252102 
            Bug: https://bugs.openjdk.java.net/browse/JDK-8252101

            This change adds the description of expected behavior for jmap -hiso/-dump to use "all" and "live" at the same time. 
            With Paul's help, It also includes code refine of the dump() function in Jmap.java. which is based on Paul's change http://cr.openjdk.java.net/~phh/8251835/webrev.00/ 

    BRs,
    Lin

    On 2020/8/20, 8:18 PM, "linzang(臧琳)" <linzang at tencent.com> wrote:

        Thanks Paul!
            I have filed CSR and Bug:
            CSR: https://bugs.openjdk.java.net/browse/JDK-8252102
            Bug: https://bugs.openjdk.java.net/browse/JDK-8252101

            Patch is under testing,  will create  RFR thread when it is ready. 
        Thanks!

        Cheers,
        Lin

        On 20/08/2020 04:18, Hohensee, Paul wrote:
        > I prioritize compatibility, so would go with option 2.
        >
        > Thanks,
        > Paul
        >
        > On 8/18/20, 11:17 PM, "serviceability-dev on behalf of linzang(臧琳)" <serviceability-dev-retn at openjdk.java.net on behalf of linzang at tencent.com> wrote:
        >
        >     Dear All,
        >             May I get some suggestions?  so that I can  work out a patch
        >     base on that.
        >             Or may be it should not be treated as an issue?
        >     BRs,
        >     Lin
        >
        >     On 17/08/2020 17:17, linzang(臧琳) wrote:
        >     >  Dear all,
        >     >           we found the jmap’s histo/dump command could accept "live" and "all" options together, and the specification does not describe what is the expected behavior of it.
        >     >           I have tried that when these two options used together, the "live" takes effect, no matter what sequences are they in commandline.
        >     >           IMO, it is a little confused to use "live" and "all" together, and if it is allowed, the specification may need to be updated to state the behavior clearly.
        >     >           Therefore may I ask your suggestion on which option of the following is prefered:
        >     >           (option 1.)  disallow using these two options together, I think this is more clear, but I am not sure whether there is backward compatibility risk.
        >     >           (option 2.)  allow the combination use of "live" and "all", and update the specification to clearly describe the behavior that "live" takes effect in this case.
        >     >           What do you think?
        >     >
        >     > Thanks,
        >     > Lin
        >     >
        >     >
        >     >
        >
        >
        >