Issue2880

classification
Title: JVM hangs on PyType.createType method
Type: Severity: major
Components: Core Versions: Jython 2.7
Milestone:
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: jeff.allen, stefan.richthofer, zsultan
Priority: normal Keywords:

Created on 2020-04-21.19:54:40 by zsultan, last changed 2020-04-26.16:25:22 by jeff.allen.

Files
File name Uploaded Description Edit Remove
stackTrace.txt zsultan, 2020-04-21.19:54:39
Messages
msg13032 (view) Author: Zaid Sultan (zsultan) Date: 2020-04-21.19:54:39
Runnable thread hangs forever on java.lang.Class.forName0(Native Method) which is called from PyType.fromClass method which is static synchronized, which in turn blocks all other threads that are trying to obtain the lock on this class. Do you think this is a JVM issue or a Jython issue? Attached the whole stack trace.

The issue happens sporadically. 
My JVM version is:
Java HotSpot(TM) 64-Bit Server VM version 25.66-b18 (Java version 1.8.0_66-b18)

My OS is:
Windows Server 2012 R2 6.3
msg13034 (view) Author: Stefan Richthofer (stefan.richthofer) Date: 2020-04-22.10:51:01
From the stackTrace it is evident that you are using Jython 2.7.0. There was significant work on fixing these types of synchronization issues since then. Please try again with the recent Jython release 2.7.2 and reprot back if the problem persists.
msg13046 (view) Author: Jeff Allen (jeff.allen) Date: 2020-04-26.16:25:22
I'm *so* relieved this is against 2.7.0, thanks for spotting that Stefan.

Actually, it would be good to hear back if the problem has been gone in 2.7.2, not only if it hasn't.

It was specifically the type system where we worked on concurrency. It was more a problem of not waiting at all, rather than hanging.
History
Date User Action Args
2020-04-26 16:25:22jeff.allensetpriority: normal
nosy: + jeff.allen
messages: + msg13046
2020-04-22 10:51:01stefan.richthofersetnosy: + stefan.richthofer
messages: + msg13034
2020-04-21 19:54:40zsultancreate