I have been getting some crashes in AOLserver (current cvs version).
AOLserver doesn't exit, but prints the following and stops responding:
'Tcl_SetBooleanObj called with shared object'
Here is a tcl page which exposes the behavior:
-----------
# Script to expose bug with ns_atclose/namespace commands
set store "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnop"
namespace eval ::bug { }
# Commenting out this line leads to bug: 'Tcl_SetBooleanObj called with shared
object'
#namespace eval ::bug::$store { }
proc ::bug::atClose { store } {
ns_log Debug "checking if namespace ::bug::$store exists"
if {[namespace exists ::bug::${store}]} {
ns_log Debug "Deleting namespace ::bug::$store"
namespace delete ::bug::${store}
#log Notice "Closed store (memory delete) $store"
return $store
} else {
ns_log Debug "namespace ::bug::$store does not exist"
}
}
# Comment out one of these and things work fine:
ns_atclose ::bug::atClose $store
#ns_atclose ::bug::atClose $store
ns_return 200 text/plain "ns_atclose bug"
-----------------
The bug doesn't show up under all conditions. If the namespace exists, or had
existed and was deleted, things work as expected. Also, even if the namespace
never existed, if ns_atclose is only called once, things work as expected.
However, if the namespace to be deleted never existed, and ns_atclose is
called twice with the same args, none of the ns_log Debug statements print,
and the crash occurs. (But the page is returned)
Not sure what is the cause.
tom jackson
On Friday 03 November 2006 10:31, Alex wrote:
> Oh, well
>
> so I guess it was too early to celebrate. Now I am getting the same
> crashes again, even without "exit" command in the tcl code executed in
> thread.
>
> Seems to me that the same problem now discussed in
> bug 1589968
> https://sourceforge.net/tracker/?func=detail&atid=103152&aid=1589968&group_
>id=3152
>
> and
>
> bug 1582671
> http://sourceforge.net/tracker/?func=detail&atid=110894&aid=1582671&group_i
>d=10894
>
>
> Thanks,
> ~ Alex.
>
> On 11/1/06, Alex <[EMAIL PROTECTED]> wrote:
> > Zoran, Jim
> >
> > thanks very much for suggestions!
> > I think I figured it out.
> > The code which was executing in the thread concluded with "exit" tcl
> > command. I got it replaced with "return" and it seems not to be crashing
> > anymore.
> >
> > However, it would be probably a good idea to disable/rename "exit" for
> > the code executed in threads created by ns_thread. Not sure if this
> > shall be submitted as an "enhancement"-level bug.
> >
> > Thanks,
> > ~ Alex.
> >
> > On 11/1/06, Alex <[EMAIL PROTECTED]> wrote:
> > > Jim,
> > >
> > > I tried in on the command line, seems to be my case :)
> > >
> > > However, I run aolserver on debian, via /etc/init.d/aolserver,
> > > Which basically invokes /usr/lib/aolserver4/bin/nsd.
> > > How do I make it use nstclsh instead of tclsh ?
> > > I don't see any options for that.
> > >
> > > Thanks,
> > > ~ Alex.
> > >
> > > On 11/1/06, Jim Davidson <[EMAIL PROTECTED]> wrote:
> > > > Hi,
> > > >
> > > > I think this is related to the comment I added to the RELEASE notes:
> > > >
> > > > * Loading libnsd into a tclsh and then creating new threads with
> > > > the ns_thread command will result in a crash when those threads
> > > > exit. The issues has to do with finalization of the async-cancel
> > > > context used to support the new "ns_ictl cancel" feature. This bug
> > > > is not present when using the "nstclsh" binary.
> > > >
> > > >
> > > > The issue above, where Tcl is initialized before AOLserver by loading
> > > > libnsd into tclsh, results in Tcl thread local storage being
> > > > finalized before AOLserver's context which includes a pointer to an
> > > > async handler.
> > > >
> > > > Now, that's not what you're doing here but perhaps TclX is having the
> > > > same effect. I haven't looked at TclX for sometime so I can't recall
> > > > what it would be using an async handler for -- perhaps you could dig
> > > > through the code and comment it out as the async handler stuff was
> > > > really designed for Unix signal-related things which aren't common in
> > > > multi-threaded AOLserver.
> > > >
> > > > Alternatively, Tcl could be fixed to avoid freeing itself before
> > > > AOLserver or any other extension. Unfortunately, that could be a big
> > > > job -- the Tcl core is already riddled with a lot of code to try to
> > > > manage the order of finalization.
> > > >
> > > > -Jim
> > > >
> > > > On Nov 1, 2006, at 5:35 PM, Zoran Vasiljevic wrote:
> > > > > On 01.11.2006, at 23:27, Alex wrote:
> > > > >> Hi,
> > > > >>
> > > > >> I am getting yet another crash in AOLServer 4.5.0.
> > > > >> This time it crashes after exiting from threads started with
> > > > >> "ns_thread begin" or "ns_thread begindetached".
> > > > >>
> > > > >> Any Suggestions?
> > > > >>
> > > > >> Thanks,
> > > > >> ~ Alex.
> > > > >>
> > > > >> Program received signal SIGSEGV, Segmentation fault.
> > > > >> [Switching to Thread 1086359904 (LWP 19612)]
> > > > >> 0x00002aaaaae6c2a7 in Tcl_AsyncDelete (async=0x54e6c0) at
> > > > >> /srv/DIST/tcl8.4.13/unix/../generic/tclAsync.c:297
> > > > >> 297 while (prevPtr->nextPtr != asyncPtr) {
> > > > >> (gdb) back
> > > > >> #0 0x00002aaaaae6c2a7 in Tcl_AsyncDelete (async=0x54e6c0) at
> > > > >> /srv/DIST/tcl8.4.13/unix/../generic/tclAsync.c:297
> > > > >> #1 0x00002aaaad48190e in TclX_SelectInit () from /usr/lib/
> > > > >> libtclx8.4.so.1
> > > > >
> > > > > I'm not sure TclX is thread-safe...
> > > > >
> > > > > Cheers
> > > > > Zoran
> > > > >
> > > > >
> > > > > --
> > > > > AOLserver - http://www.aolserver.com/
> > > > >
> > > > > To Remove yourself from this list, simply send an email to
> > > > > <[EMAIL PROTECTED]> with the
> > > > > body of "SIGNOFF AOLSERVER" in the email message. You can leave the
> > > > > Subject: field of your email blank.
> > > >
> > > > --
> > > > AOLserver - http://www.aolserver.com/
> > > >
> > > > To Remove yourself from this list, simply send an email to
> > > > <[EMAIL PROTECTED]> with the body of "SIGNOFF AOLSERVER" in
> > > > the email message. You can leave the Subject: field of your email
> > > > blank.
>
> --
> AOLserver - http://www.aolserver.com/
>
> To Remove yourself from this list, simply send an email to
> <[EMAIL PROTECTED]> with the body of "SIGNOFF AOLSERVER" in the
> email message. You can leave the Subject: field of your email blank.
--
AOLserver - http://www.aolserver.com/
To Remove yourself from this list, simply send an email to <[EMAIL PROTECTED]>
with the
body of "SIGNOFF AOLSERVER" in the email message. You can leave the Subject:
field of your email blank.
