GUI hangs on communicator shutdown

[n2503v]

Hello,
I'm running a Qt-based GUI configured with Ice::Dispatcher.
Ice::Application is configured with Ice::NoSignalHandling.
The GUI uses an IceGrid Registry.

When the user tells the GUI to Quit, all widgets close and Ice::Communicator::shutdown() is called. Most of the time, everything shuts down cleanly but sometimes the process hangs. A gdb backtrace in the hanging state is below. The registry is running just fine and, after a Ctrl-C, the same GUI comes up without a problem.

Any ideas on what's happening here? Does it have anything to do with Dispatcher?

Cheers,
Alex


Ice-3.4.0 with patches 1 & 2, Linux, gcc-4.3.2

(gdb) where
#0 0xb7fde424 in __kernel_vsyscall ()
#1 0xb543a025 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/cmov/libpthread.so.0
#2 0xb55377fd in pthread_cond_wait () from /lib/i686/cmov/libc.so.6
#3 0xb7d609ca in IceUtil::Cond::waitImpl<IceUtil::Mutex> (this=0xa20ed74, mutex=@0xa20eda4) at ../../include/IceUtil/Cond.h:215
#4 0xb7d89db8 in IceUtil::Monitor<IceUtil::Mutex>::wait (this=0xa20ed74) at ../../include/IceUtil/Monitor.h:152
#5 0xb7d85891 in IceInternal::ConnectRequestHandler::getConnection (this=0xa20ed60, waitInit=true) at ConnectRequestHandler.cpp:280
#6 0xb7d85f2b in IceInternal::ConnectRequestHandler::sendRequest (this=0xa20ed60, out=0xbfff6fd4) at ConnectRequestHandler.cpp:219
#7 0xb7e78d8f in IceInternal::Outgoing::invoke (this=0xbfff6fd4) at Outgoing.cpp:180
#8 0xb7e2cd20 in IceDelegateM::Ice::LocatorRegistry::setAdapterDire ctProxy (this=0x9f21dc0, id=@0x9f1f71c, proxy=@0xbfff76e4, __context=0x0) at Locator.cpp:1648
#9 0xb7e2fba7 in IceProxy::Ice::LocatorRegistry::setAdapterDirectPr oxy (this=0x9f21d88, id=@0x9f1f71c, proxy=@0xbfff76e4, __ctx=0x0) at Locator.cpp:1173
#10 0xb7e5f583 in IceProxy::Ice::LocatorRegistry::setAdapterDirectPr oxy (this=0x9f21d88, id=@0x9f1f71c, proxy=@0xbfff76e4) at ../../include/Ice/Locator.h:868
#11 0xb7e512d3 in Ice::ObjectAdapterI::updateLocatorRegistry (this=0x9f1f6a0, locatorInfo=@0xbfff76bc, proxy=@0xbfff76e4, registerProcess=false) at ObjectAdapterI.cpp:1311
#12 0xb7e5da78 in Ice::ObjectAdapterI::deactivate (this=0x9f1f6a0) at ObjectAdapterI.cpp:268
#13 0xb7e4db56 in IceUtilInternal::VoidMemFun<Ice::ObjectAdapter, IceUtil::Handle<Ice::ObjectAdapter> >::operator() (this=0xbfff778c, handle=
{<IceUtil::HandleBase<Ice::ObjectAdapter>> = {_ptr = 0xbfff7768}, <No data fields>}) at ../../include/IceUtil/Functional.h:65
#14 0xb7e4e2e2 in std::for_each<std::_List_iterator<IceUtil::Handle< Ice::ObjectAdapterI> >, IceUtilInternal::VoidMemFun<Ice::ObjectAdapter, IceUtil::Handle<Ice::ObjectAdapter> > > (__first={_M_node = 0xa14f650}, __last={_M_node = 0xbfff77c8}, __f=
{<std::unary_function<IceUtil::Handle<Ice::ObjectA dapter>, void>> = {<No data fields>}, _mfn = &virtual table offset 40}) at /usr/include/c++/4.3/bits/stl_algo.h:3791
#15 0xb7e4c934 in IceInternal::ObjectAdapterFactory::shutdown (this=0x9f1ca70) at ObjectAdapterFactory.cpp:51
#16 0xb7d7f431 in Ice::CommunicatorI::shutdown (this=0x9f1a110) at CommunicatorI.cpp:143
#17 0x080518bf in sysadminview::Component::start (this=0xbfff80c4) at /home/mradmin/mrsrc/shh/src/components/sysadminview/component.cpp:73
#18 0xb6eeec64 in orcaice::Application::run (this=0xbfff8118, argc=1, argv=0xbfff81f4) at /home/mradmin/mrsrc/orca/src/libs/orcaice/application.cpp:185
#19 0xb7d5b9f8 in Ice::Application::doMain (this=0xbfff8118, argc=1, argv=0xbfff81f4, initializationData=@0xbfff8034) at Application.cpp:654
#20 0xb7d5c90f in Ice::Application::main (this=0xbfff8118, argc=1, argv=0xbfff81f4, initData=@0xbfff8034) at Application.cpp:403
#21 0xb6eed3a5 in orcaice::Application::orcaMain (this=0xbfff8118, argc=1, argv=0xbfff81f4, dispatcher=0x9f19190) at /home/mradmin/mrsrc/orca/src/libs/orcaice/application.cpp:116
#22 0x080520c8 in main (argc=1, argv=0xbfff81f4) at /home/mradmin/mrsrc/shh/src/components/sysadminview/main.cpp:11

[bernard]

Hi Alex,

Your stack trace shows that your GUI is attempting to contact the IceGrid registry (Ice Locator) during the deactivation of one its object adapters (an "indirect" adapter). That's expected, although I don't know why this blocks. Is there other threads in your program at that point?

Your situation is a bit unusual: typically, a server with an indirect object adapter is started by IceGrid (an IceGrid node) and does not have a GUI.

If you don't need an indirect object adapter (i.e. a direct adapter would do as well if not better), the adapter deactivate would not call out, which would resolve this issue.

Best regards,
Bernard

[n2503v]

Hi Bernard,

to answer your question... yes, there're other threads, 6 in total. One of them is ours the others are in the Ice thread pools. Nothing interesting in the stack traces.

I followed your suggestion and disabled adapter registration for the GUI, it's true that it's not needed it in this case.

Thanks for your help,
Alex

[Maxim Pudovkin]

Hi,

I have the same problem: i using qt-gui and communicator shutdown hangs ...
It's resolved by using direct proxys but i strongly needs indirect bindings ...
Have you any another ideas around this problem ?