[CFT] Update OpenJDK6 to b21

[Jung-uk Kim]

On Thursday 03 February 2011 04:24 pm, Jung-uk Kim wrote:
> On Thursday 03 February 2011 01:09 pm, Mike Jakubik wrote:
> > On Wed, 2011-02-02 at 13:54 -0500, Jung-uk Kim wrote:
> > > Yeah, I actually fixed that.  Some patches were missing in b20
> > > ports. 'jstack -m' should work, too. :-)
> > >
> > > Thanks for testing!
> >
> > Compiled OK and working with my applications OK. The jstack -m
> > option you mention however produces the following results here:
> >
> > Attaching to process ID 84046, please wait...
> > Debugger attached successfully.
> > Server compiler detected.
> > JVM version is 19.0-b09
> > sun.jvm.hotspot.debugger.DebuggerException:
> > sun.jvm.hotspot.debugger.DebuggerException: get_thread_regs
> > failed for a lwp
> > 	at sun.jvm.hotspot.debugger.bsd.BsdDebuggerLocal
> > $BsdDebuggerLocalWorkerThread.execute(BsdDebuggerLocal.java:152)
> > 	at
> > sun.jvm.hotspot.debugger.bsd.BsdDebuggerLocal.getThreadIntegerReg
> >is terSet(BsdDebuggerLocal.java:466) at
> > sun.jvm.hotspot.debugger.bsd.BsdThread.getContext(BsdThread.java:
> >65 ) at
> > sun.jvm.hotspot.runtime.bsd_amd64.BsdAMD64JavaThreadPDAccess.getC
> >ur rentFrameGuess(BsdAMD64JavaThreadPDAccess.java:92) at
> > sun.jvm.hotspot.runtime.JavaThread.getCurrentFrameGuess(JavaThrea
> >d. java:256) at
> > sun.jvm.hotspot.runtime.JavaThread.getLastJavaVFrameDbg(JavaThrea
> >d. java:218) at
> > sun.jvm.hotspot.tools.PStack.initJFrameCache(PStack.java:208) at
> > sun.jvm.hotspot.tools.PStack.run(PStack.java:66)
> > 	at sun.jvm.hotspot.tools.PStack.run(PStack.java:53)
> > 	at sun.jvm.hotspot.tools.PStack.run(PStack.java:48)
> > 	at sun.jvm.hotspot.tools.JStack.run(JStack.java:60)
> > 	at sun.jvm.hotspot.tools.Tool.start(Tool.java:221)
> > 	at sun.jvm.hotspot.tools.JStack.main(JStack.java:86)
> > 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > 	at
> > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorI
> >mp l.java:57) at
> > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> >cc essorImpl.java:43) at
> > java.lang.reflect.Method.invoke(Method.java:616)
> > 	at sun.tools.jstack.JStack.runJStackTool(JStack.java:136)
> > 	at sun.tools.jstack.JStack.main(JStack.java:102)
>
> Yeah, I noticed that, too.  It seems it's getting bogus thread IDs.
> It'll take some time for me to figure out why, though. :-(

Now I know why but it is a very complicated problem. :-(

Basically, the culprit was difference between Linux and BSD, mostly 
_thread_id and ptrace(2).  Linux has gettid(2), which returns a 
(32-bit) pid_t type, and it is used for _thread_id.  Linux code 
simply calls ptrace(PTRACE_GETREGS, ...) with it and it works fine.  
However, BSD does not have gettid(), so we used pthread_t instead.  
Alas, we copied process_get_lwp_regs() from Linux-specific file.  It 
does not work for us because _thread_id is a pthread_t type and 
ptrace() does not understand it.  Unfortunately, there is no easy way 
to map pthread_t to a lwpid_t value, either.  More worse, it gets 
truncated to 32-bit on amd64.  Grrr...

Jung-uk Kim