Hi Serguei, Thanks a lot for your advice. I agree your concern and will take care of it in future.
Here is the latest webrev based on your comments: (delta is just retrieving the usage(1)) http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev14/ So may I assume that the patch is OK with you now? Hi All, In summary, Here are the status of this change at present: * Paul and Serguei have helped review the runtime/JMap part and the changes now is Okay with them. * Stefan has helped review the GC part and it is Okay with him now. So does it need more review and approval for pushing this change? BRs, Lin On 2020/8/11, 2:40 PM, "serguei.spit...@oracle.com" <serguei.spit...@oracle.com> wrote: Hi Lin, I prefer a conservative approach and do not change things without a real need. Thanks, Serguei On 8/10/20 20:23, linzang(臧琳) wrote: > Hi Serguei > I got your point, just thought usage may be a little verbosity, it prints almost my whole screen which could flush the error message. And I checked that other jcmd tools usually use System.exit() after print errors. So I made the change. > > Thanks! > Lin > >> On Aug 11, 2020, at 11:05 AM, "serguei.spit...@oracle.com" <serguei.spit...@oracle.com> wrote: >> >> Hi Lin, >> >> I've re-reviewed the JMap.java only. >> It looks good except there was no need to replace the usage(1) call with the System.exit(1). >> I did not say usage is not needed, just that it is not enough. >> >> Thanks, >> Serguei >> >> >>> On 8/10/20 19:25, linzang(臧琳) wrote: >>> Hi Serguei, >>> >> First, the CSR does not include any update for 'live' and 'all' options, does it? >>> >> If so, then I'm confused why do you need all these changes related to these two options. >>> >> Did you intend to really change anything? >>> Yes, you’re correct, CSR doesn’t mention any thing about “live” and “all”. so all those changes related become unnecessary. >>> >>> Webrev: http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_13 >>> Delta: http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_13_delta >>> >>> BTW, during refining this changeset I also found an issue that jmap -dump could accept undefined options, will setup a new issue in JBS and fix it separately soon. >>> >>> >>> BRs, >>> Lin >>> >>> From: "serguei.spit...@oracle.com" <serguei.spit...@oracle.com> >>> Date: Tuesday, August 11, 2020 at 8:40 AM >>> To: "linzang(臧琳)" <linz...@tencent.com>, "Hohensee, Paul" <hohen...@amazon.com>, Stefan Karlsson <stefan.karls...@oracle.com>, David Holmes <david.hol...@oracle.com>, serviceability-dev <serviceability-dev@openjdk.java.net>, "hotspot-gc-...@openjdk.java.net" <hotspot-gc-...@openjdk.java.net> >>> Subject: Re: RFR(L): 8215624: add parallel heap inspection support for jmap histo(G1)(Internet mail) >>> >>> Hi Lin, >>> >>> A couple of things. >>> >>> First, the CSR does not include any update for 'live' and 'all' options, does it? >>> If so, then I'm confused why do you need all these changes related to these two options. >>> Did you intend to really change anything? >>> >>> Second, new error messages do not look useful as they say nothing about what is wrong. >>> Printing usage does not help either. >>> Could these messages be more specific? >>> My suggestions are: >>> 188 if (filename == null) { >>> 189 System.err.println("Fail at processing option '" + subopt +"'"); >>> 190 usage(1); // invalid options or no filename >>> 191 } >>> System.err.println("Fail: invalid option or no file name: '" + subopt +"'"); >>> 194 if (parallel == null) { >>> 195 System.err.println("Fail at processing option '" + subopt + "'"); >>> 196 usage(1); >>> 197 } >>> System.err.println("Fail: no number provided in option: '" + subopt +"'"); >>> 198 } else { >>> 199 System.err.println("Fail at processing option '" + subopt + "'"); >>> 200 usage(1); >>> 201 } >>> System.err.println("Fail: invalid option: '" + subopt +"'"); >>> >>> >>> The default value is listed in the 'parallel' flag description: >>> parallel=<count> generate histogram using this many parallel threads, default 0 >>> It means that the flag is optionl. >>> >>> I'm okay to file a separate enhancement to add a clarification for 'live' and 'all' flags. >>> >>> Thanks, >>> Serguei >>> >>> >>> On 8/10/20 16:46, linzang(臧琳) wrote: >>> And Here is the latest refined changeset >>> Webrev: http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_12/ >>> Delta: http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_12_delta/ >>> >>> BRs, >>> Lin >>> >>> On 2020/8/11, 7:23 AM, "linzang(臧琳)" mailto:linz...@tencent.com wrote: >>> >>> Dear Serguei, >>> Here is my reply for your question about non-numeric value for “parallel” (somehow the thread of replay became out of order, not sure why). >>> >>> > >> What is going to happen if the resulting 'parallel' substring above is not a number? >>> > The error handling logic locates at http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/src/hotspot/share/services/attachListener.cpp.frames.html, (line 276-284) >>> > Generally, the result is error message will be print if “parallel” is illegal. An example output would be: >>> > ############################ >>> > $ time jmap -histo:parallel=c 26233 >>> > Exception in thread "main" com.sun.tools.attach.AttachOperationFailedException: Invalid parallel thread number: [c] >>> > at jdk.attach/sun.tools.attach.VirtualMachineImpl.execute(VirtualMachineImpl.java:227) >>> > at jdk.attach/sun.tools.attach.HotSpotVirtualMachine.executeCommand(HotSpotVirtualMachine.java:309) >>> > at jdk.jcmd/sun.tools.jmap.JMap.executeCommandForPid(JMap.java:133) >>> > at jdk.jcmd/sun.tools.jmap.JMap.histo(JMap.java:206) >>> > at jdk.jcmd/sun.tools.jmap.JMap.main(JMap.java:112) >>> > >>> > ############################ >>> > >>> > Hi Serguei, Paul and Stefan. >>> > Moreover, I will made a new changeset with following changes: >>> > * Print error message + usage when parameter check fail in Jmap.java >>> > *Retrive the histo logic that if “all” and “live” are set at same time, use “live”, rather than print error message. (not sure which one is better :P) >>> >>> My last point is to retrive the behavior for compatibility. And do you think make a separate enhancement about spec is reasonable ? >>> >>> Thanks! >>> >>> BRs, >>> Lin >>> >>> From: mailto:serguei.spit...@oracle.com mailto:serguei.spit...@oracle.com >>> Date: Tuesday, August 11, 2020 at 5:11 AM >>> To: "linzang(臧琳)" mailto:linz...@tencent.com, "Hohensee, Paul" mailto:hohen...@amazon.com, Stefan Karlsson mailto:stefan.karls...@oracle.com, David Holmes mailto:david.hol...@oracle.com, serviceability-dev mailto:serviceability-dev@openjdk.java.net, mailto:hotspot-gc-...@openjdk.java.net mailto:hotspot-gc-...@openjdk.java.net >>> Subject: Re: RFR(L): 8215624: add parallel heap inspection support for jmap histo(G1)(Internet mail) >>> >>> Hi Lin, >>> >>> >>> On 8/7/20 03:41, linzang(臧琳) wrote: >>> Dear Serguei, >>> Thanks a lot for your review! >>> >> The spec says nothing if the new option 'parallel' is mandatory or optional. >>> >> Also, (it was before your fix) the spec does not say if the options 'live' and 'all' are mutually exclusive. >>> For “parallel”, the spec adds “parallel=0” is the default behavior. So my assumption is if parallel is not used, it will be 0. Do you think it is ok ? is it necessary to obviously add comments like “if no parallel is set, use the default value 0”? >>> >>> It'd be nice to make it clear. >>> But the CSR will need to be updated. >>> In fact, I did not want you to go through this cycle again. >>> But maybe it is worth to improve the specs in this regard. >>> May be Paul has some alternative suggestions. >>> >>> >>> For “live” and “all”, before the changeset , I see the logic from the code is that both of them can be set at the same time, and the “live” will take effect. IMHO this may be a little confused. So I made the change, not sure whether I should keep the same behavior as before in this change? >>> >>> This is better to clearly specify what is allowed and what is the behavior. >>> >>> >>> And I like your idea of printing more error msg if something wrong with the options setting, but I checked that before the change, if there is not a match option, it only print usage. and not only jmap -histo but also jmap -dump has this issue, do you agree if I fix both in the changeset? >>> >>> Yes, it'd be nice to make it clear in both specs. >>> >>> >> What is going to happen if null is passed in place of parallel here? : >>> The default value 0 will be used if no “parallel” option is set. >>> >>> Okay, thanks. >>> >>> >>> >> Should the lines 193-195 be moved after the line 202? >>> I don’t think so, the logic is a little different. At line 193, the case is “parallel=<blank>”. If move them to line 203, it mean “parallel” is not optional. >>> Okay, I see what you mean. >>> The problem is that the help/spec says nothing about the flag 'parallel' as being optional. >>> >>> >>> I also asked this question: >>> Q: What is going to happen if the resulting 'parallel' sub-string above is not a number? >>> >>> >>> Thanks, >>> Serguei >>> >>> >>> >>> Thanks! >>> >>> >>> BRs, >>> Lin >>> >>> From: mailto:serguei.spit...@oracle.com mailto:serguei.spit...@oracle.com >>> Date: Friday, August 7, 2020 at 3:28 PM >>> To: "linzang(臧琳)mailto:linz...@tencent.com,Hohensee, Paulmailto:hohen...@amazon.com,StefanKarlssonmailto:stefan.karls...@oracle.com,DavidHolmesmailto:david.hol...@oracle.com,serviceability-devmailto:serviceability-dev@openjdk.java.net,mailto:hotspot-gc-...@openjdk.java.netmailto:hotspot-gc-...@openjdk.java.netSubject:Re:RFR(L):8215624:addparallelheapinspectionsupportforjmaphisto(G1)(Internetmail)HiLin,Notsure,Ifullyunderstandthespecupdateandtheoptionsprocessinginthefile:http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java.frames.htmlThespecsaysnothingifthenewoption'parallel'ismandatoryoroptional.Also,(itwasbeforeyourfix)thespecdoesnotsayiftheoptions'live'and'all'aremutuallyexclusive.TheJMap.javaimplementationjustprintusageintwocases:191}elseif(subopt.startsWith(parallel=")) { >>> 192 parallel = subopt.substring("parallel=".length()); >>> 193 if (parallel == null) { >>> 194 usage(1); >>> 195 } >>> ... >>> 200 if (set_live && set_all) { >>> 201 usage(1); >>> 202 } >>> It is not that helpful as the usage does not explain anything about these corner cases. >>> Also, it allows to pass no parallel option. >>> What is going to happen if null is passed in place of parallel here? : >>> 206 executeCommandForPid(pid, "inspectheap", liveopt, filename, parallel); >>> >>> Should the lines 193-195 be moved after the line 202? >>> >>> Thanks, >>> Serguei >>> >>> >>> On 8/5/20 18:59, linzang(臧琳) wrote: >>> Thanks Paul! >>> And I have verified this change could build success in windows. >>> >>> BRs, >>> Lin >>> >>> On 2020/8/6, 4:17 AM, "Hohensee, Paulmailto:hohensee@amazon.comwrote:Twotinynitsthatdon'tneedanewwebrev:InheapInspection.cpp,youdon'tneedtocastmissed_counttouintxinthecalltolog_info().InheapInspection.hpp,youcandeletetwoofthethreeblanklinesbefore#endif//SHARE_MEMORY_HEAPINSPECTION_HPPThanks,PaulOn8/5/20,6:46AM,linzang(臧琳)" mailto:linz...@tencent.com wrote: >>> >>> Hi Paul, Stefan and Serguei, >>> Here I uploaded a new changeset, would you like to help review again? >>> Webrev: http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/ >>> Delta (based on webrev10): http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11_delta/ >>> >>> P.S. I am in process of building it on windows environment for a double check. May update result later. Thanks! >>> >>> >>> BRs, >>> Lin >>> >>> >>> >>> >>> >>