This looks good - and thanks for the detailed description! My only comment is that you chose to ignore the error in only some of the methods - I assume these were the methods where you have encountered a problem in. Should we write a comment about that, or should we ignore the error in all methods?
/Staffan On 29 okt 2014, at 02:11, serguei.spit...@oracle.com wrote: > Please, review the fix for: > https://bugs.openjdk.java.net/browse/JDK-6988950 > > > Open webrev: > http://cr.openjdk.java.net/~sspitsyn/webrevs/2014/jdk/6988950-JDWP-wrong-phase.1/ > > > Summary: > > The failing scenario: > The debugger and the debuggee are well aware a VM shutdown has been > started in the target process. > The debugger at this point is not expected to send any commands to the > JDWP agent. > However, the JDI layer (debugger side) and the jdwp agent (debuggee side) > are not in sync with the consumer layers. > > One reason is because the test debugger does not invoke the JDI method > VirtualMachine.dispose(). > Another reason is that the Debugger and the debuggee processes are uneasy > to sync in general. > > As a result the following steps are possible: > - The test debugger sends a 'quit' command to the test debuggee > - The debuggee is normally exiting > - The jdwp backend reports (over the jdwp protocol) an anonymous class > unload event > - The JDI InternalEventHandler thread handles the ClassUnloadEvent event > - The InternalEventHandler wants to uncache the matching reference type. > If there is more than one class with the same host class signature, > it can't distinguish them, > and so, deletes all references and re-retrieves them again (see > tracing below): > MY_TRACE: JDI: VirtualMachineImpl.retrieveClassesBySignature: > sig=Ljava/lang/invoke/LambdaForm$DMH; > - The jdwp backend debugLoop_run() gets the command from JDI and calls > the functions > classesForSignature() and classStatus() recursively. > - The classStatus() makes a call to the JVMTI GetClassStatus() and gets > the JVMTI_ERROR_WRONG_PHASE > - As a result the jdwp backend reports the JVMTI error to the JDI, and > so, the test fails > > For details, see the analysis in bug report closed as a dup of the bug > 6988950: > https://bugs.openjdk.java.net/browse/JDK-8024865 > > Some similar cases can be found in the two bug reports (6988950 and > 8024865) describing this issue. > > The fix is to skip reporting the JVMTI_ERROR_WRONG_PHASE error as it is > normal at the VM shutdown. > The original jdwp backend implementation had a similar approach for the > raw monitor functions. > Threy use the ignore_vm_death() to workaround the JVMTI_ERROR_WRONG_PHASE > errors. > For reference, please, see the file: src/share/back/util.c > > > Testing: > Run nsk.jdi.testlist, nsk.jdwp.testlist and JTREG com/sun/jdi tests > > > Thanks, > Serguei >
