Re: JDK-8219143: jdb should support breakpoint thread filters

[serguei.spit...@oracle.com]

Hi Chris, Not a full review yet. Just a couple of quick mismatches. http://cr.openjdk.java.net/~cjplummer/8219143/webrev.01/src/jdk.jdi/share/classes/com/sun/tools/example/debug/tty/TTYResources.java.frames.html  Is it okay that the two fragments below describe the same differently? Do I miss anything. 250 {"printstopcommandusage", 251 "Usage: stop [go|thread] [threadid <thread_id>] <at|in> <location>\n" + 252 " If \"go\" is specified, immediately resume after stopping\n" + 253 " If \"thread\" is specified, only suspend the thread we stop in\n" + 254 " If neither \"go\" nor \"thread\" are specified, suspend all threads\n" + 255 " If [threadid <thread_id>] is specified, only stop in the specified thread" + 256 " \"at\" and \"in\" have the same meaning\n" + 257 " <location> can either be a line number or a method:\n" + 258 " <class_id>:<line_number>\n" + 259 " <class_id>.<method>[(argument_type,...)]" 260 }, 377 "stop [go|thread] [threadid <thread_id>] <at|in> <location>\n" + 378 " -- set a breakpoint\n" + 379 " -- if no options are given, the current list of breakpoints is printed\n" + 380 " -- if \"go\" is specified, immediately resume after stopping\n" + 381 " -- if \"thread\" is specified, only suspend the thread we stop in\n" + 382 " -- if neither \"go\" nor \"thread\" are specified, suspend all threads\n" + 383 " -- if [threadid <thread_id>] is specified, only stop in the specified thread\n" + 384 " -- \"at\" and \"in\" have the same meaning\n" + 385 " -- <location> can either be a line number or a method:\n" + 386 " -- <class_id>:<line_number>\n" + 387 " -- <class_id>.<method>[(argument_type,...)]\n" + http://cr.openjdk.java.net/~cjplummer/8219143/webrev.01/src/jdk.jdi/share/classes/com/sun/tools/example/debug/tty/Commands.java.frames.html 1162 * Allowed syntax: 1163 * stop [go|thread] <at|in> [threadid <thread_id>] <location> 1164 * <location> can either be a line number or a method: 1165 * - <class id>:<line> 1166 * - <class id>.<method>[(argument_type,...)] 1167 * If "go" is specified, then immediately resume after stopping. No threads are suspended. 1168 * If "thread" is specified, then only suspend the thread we stop in. 1169 * If neither "go" nor "thread" are specified, then suspend all threads. 1170 * If the optional [threadid <thread_id>] is specified, then only stop in the specified thread. 1171 * If no options are given, the current list of breakpoints is printed, 1172 */ The above is not aligned with the implementation as <at|in> has to be right before <location>. A dot is needed instead of the last comma. Should this comment to match one of the above descriptions? Thanks, Serguei On 2/20/19 19:56, Chris Plummer wrote: Please review the updated webrev: http://cr.openjdk.java.net/~cjplummer/8219143/webrev.01/ The syntax is now:     stop [go|thread] [threadid <thread_id>] <at|in> <location> I filed JDK-8219507 to cover BreakpointSpec.toString() improvements, and other possible improvements to the output when listing breakpoints. I did a minor fix in TTYResources.java to address a bug from a recent JDK-8218941 commit that added the dbgtrace command. There was missing newline. I've added a note to JDK-8218941 indicating that it is being fixed here. I've added a test. Below is a log of the debug session output that might help with reading the source of the test. The test creates 3 threads that all execute the same code, and verifies that the breakpoint set using the threadid option only stops on the one specified thread. thanks, Chris [jdb] Set uncaught java.lang.Throwable [jdb] Set deferred uncaught java.lang.Throwable [jdb] Initializing jdb ... [jdb] [jdb] VM Started: > No frames on the current call stack [jdb] [jdb] main[1] > stop in JdbStopThreadidTestTarg.brkMethod [jdb] Deferring breakpoint JdbStopThreadidTestTarg.brkMethod. [jdb] It will be set after the class is loaded. [jdb] main[1] > run [jdb] > Set deferred breakpoint JdbStopThreadidTestTarg.brkMethod [jdb] [jdb] Breakpoint hit: "thread=main", JdbStopThreadidTestTarg.brkMethod(), line=80 bci=0 [jdb] 80        } [jdb] [jdb] main[1] > threads [jdb] Group system: [jdb]   (java.lang.ref.Reference$ReferenceHandler)367 Reference Handler running [jdb]   (java.lang.ref.Finalizer$FinalizerThread)368 Finalizer         cond. waiting [jdb]   (java.lang.Thread)369                         Signal Dispatcher running [jdb] Group main: [jdb]   (java.lang.Thread)1 main              running (at breakpoint) [jdb]   (JdbStopThreadidTestTarg$MyThread)482 MYTHREAD-1        waiting in a monitor [jdb]   (JdbStopThreadidTestTarg$MyThread)483 MYTHREAD-2        waiting in a monitor [jdb]   (JdbStopThreadidTestTarg$MyThread)484 MYTHREAD-3        waiting in a monitor [jdb] Group InnocuousThreadGroup: [jdb]   (jdk.internal.misc.InnocuousThread)416 Common-Cleaner    cond. waiting [jdb] main[1] > stop threadid 483 in JdbStopThreadidTestTarg$MyThread.brkMethod [jdb] Set breakpoint JdbStopThreadidTestTarg$MyThread.brkMethod [jdb] main[1] > cont [jdb] > [jdb] Breakpoint hit: "thread=MYTHREAD-2", JdbStopThreadidTestTarg$MyThread.brkMethod(), line=101 bci=0 [jdb] 101            } [jdb] [jdb] MYTHREAD-2[1] > cont [jdb] > [jdb] The application exited [jdb] On 2/20/19 2:23 PM, Chris Plummer wrote: On 2/20/19 2:00 PM, Alex Menkov wrote: 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> Ok. I'll try moving it. 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)?; I had added this at one point, alone with also adding the suspend policy. You then see both of these when you use "stop in/at" or "clear" without any arguments (it lists the breakpoints in this case). I was a little worried that the extra text might break something, so I left it out. Note also that currently the text given when you list breakpoints is exactly the text you need to enter when using the clear command, so that would no longer be true if I added any more text. However, I did envision a better version of this that not only include the suspend policy and threadid, but also a breakpoint index, allowing you to more easily clear one after listing it. Maybe I could add an RFE for this. - it would be nice to add a test for the new threadid functionality. I've been working on one today. It's near completion. Chris --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