On 6/17/20 7:43 PM, David Holmes wrote:
Hi Chris,
On 18/06/2020 6:34 am, Chris Plummer wrote:
Hello,
Please help review the following:
https://bugs.openjdk.java.net/browse/JDK-8247533
http://cr.openjdk.java.net/~cjplummer/8247533/webrev.00/index.html
The CR contains all the needed details. Here's a summary of changes
in each file:
The problem sounds to me like a variation of the more general problem
of not ensuring a thread is kept alive whilst acting upon it. I don't
know how the SA finds these references to the threads it is going to
stackwalk, but is it possible to fix this via appropriate uses of
ThreadsListHandle/Iterator?
It fetches ThreadsSMRSupport::_java_thread_list.
Keep in mind that once SA attaches, nothing in the VM changes. For
example, SA can't create a wrapper to a JavaThread, only to have the
JavaThread be freed later on. It's just not possible.
Chris
Cheers,
David
src/jdk.hotspot.agent/linux/native/libsaproc/LinuxDebuggerLocal.cpp
src/jdk.hotspot.agent/macosx/native/libsaproc/MacosxDebuggerLocal.m
src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp
-Instead of throwing an exception when the OS ThreadID is invalid,
print a warning.
src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c
-Improve a print_debug message
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/bsd/BsdThread.java
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/LinuxThread.java
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/amd64/WindbgAMD64Thread.java
-Deal with the array of registers read in being null due to the OS
ThreadID not being valid.
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/bsd/BsdDebuggerLocal.java
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/LinuxDebuggerLocal.java
-Fix issue with "sun.jvm.hotspot.debugger.DebuggerException"
appearing twice when printing the exception.
thanks,
Chris
