Codereview request: 8007710 runtime/7158988/FieldMonitor.java fails with com.sun.jdi.VMDisconnectedException: Connection closed (original) (raw)

shanliang shanliang.jiang at oracle.com
Tue Feb 11 07:31:26 PST 2014

Staffan Larsen wrote:

Hi Shanliang,

I can’t quite see how the test can fail in this way. When the ClassPrepareEvent happens, the debuggee will be suspended. So when addFieldWatch() is called, the debuggee should not have moved. I am not expert of jdi so I may miss something here. I checked the failure trace and saw the report exception happen when FieldMonitor received ClassPrepareEvent and was doing addFieldWatch. FieldMonitor did call "vm.resume()" before treating events.

I reproduced the bug by add sleep(1000) after vm.resume() but before calling eventQueue.remove();

Thanks, Shanliang

One problem I do see with the test is that it does not wait for a VMStartEvent before setting up requests. I’m not sure if that could cause the failure in the bug report, though.

/Staffan On 11 feb 2014, at 15:13, shanliang <shanliang.jiang at oracle.com> wrote:

Hi , The problem could be that FieldMonitor did not have enough time to "addFieldWatch" but the vm to monitor (TestPostFieldModification) was already ended. So we should make sure that TestPostFieldModification exits after FieldMonitor has done necessary. The solution proposed here is that FieldMonitor creates a file after adding field watching, and TestPostFieldModification quits only after finding the file. web: http://icncweb.fr.oracle.com/~shjiang/webrev/8007710/00/ bug: https://bugs.openjdk.java.net/browse/JDK-8007710 Thanks, Shanliang

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