Re: RFR(S): 8247533: SA stack walking sometimes fails with sun.jvm.hotspot.debugger.DebuggerException: get_thread_regs failed for a lwp

[Daniil Titov]

Hi Chris,

The fix looks good to me.

Best regards,
Daniil


    On 6/25/20 13:29, Chris Plummer wrote:
    > Ping. I still need one more review for this. There was one updated 
    > webev. I list it below so you don't need to dig it up in the long 
    > email thread:
    >> I've  updated with webrev based on the new finding that a JavaThread 
    >> cannot be on the ThreadList after its OS thread has been destroyed 
    >> since the JavaThread removes itself from the ThreadList, and 
    >> therefore must be running on its OS thread. The logic of the fix is 
    >> unchanged from the first webrev, but I updated the comments to better 
    >> reflect what is going on. I also updated the CR:
    >>
    >> https://bugs.openjdk.java.net/browse/JDK-8247533
    >> http://cr.openjdk.java.net/~cjplummer/8247533/webrev.01/index.html
    >
    > thanks,
    >
    > Chris
    >
    > On 6/17/20 1:34 PM, 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:
    >>
    >> 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
    >
    >