Today i found my ktorrent freezed, no answer, dcop not responding.

Strace -p say that :

Code: Select all

futex(0x81c4fc0, FUTEX_WAIT, 1, NULL <unfinished ...>

Here is the gdb trace :

Code: Select all

#0  0xb7f4a410 in ?? ()
#1  0xbffa03e8 in ?? ()
#2  0x00000001 in ?? ()
#3  0xb685a886 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#4  0xb6d7c1f8 in QThread::start () from /usr/lib/qt3/lib/libqt-mt.so.3
#5  0xb7d4ae01 in net::SocketMonitor::add (this=0xb7e42cc0, sock=0xb39a1180) at socketmonitor.cpp:109
#6  0xb7d55fe8 in mse::StreamSocket::startMonitoring (this=0xb4492ee0, rdr=0xb44cfa68, wrt=0xb3943ac8) at streamsocket.cpp:81
#7  0xb7d9d920 in Peer (this=0xb39ec9d8, sock=0xb4492ee0, peer_id=@0xb39aecc0, num_chunks=4294967292, chunk_size=4294967292, support=0, local=false) at peer.cpp:95
#8  0xb7dad228 in bt::PeerManager::createPeer (this=0x8937c30, sock=0xb4492ee0, peer_id=@0xb39aecc0, support=0, local=false) at peermanager.cpp:257
#9  0xb7dad576 in bt::PeerManager::peerAuthenticated (this=0x8937c30, auth=0xb39aebd8, ok=true) at peermanager.cpp:252
#10 0xb7dad680 in bt::Authenticate::onFinish (this=0xb39aebd8, succes=true) at authenticate.cpp:89
#11 0xb7d91c87 in bt::Authenticate::handshakeRecieved (this=0xb39aebd8, full=true) at authenticate.cpp:134
#12 0xb7d98fd5 in bt::AuthenticateBase::onReadyRead (this=0xb39aebd8) at authenticatebase.cpp:137
#13 0xb7d7497d in bt::AuthenticationMonitor::handleData (this=0x80db0f8) at authenticationmonitor.cpp:130
#14 0xb7d74c59 in bt::AuthenticationMonitor::update (this=0x80db0f8) at authenticationmonitor.cpp:115
#15 0x0808e99d in KTorrentCore::update (this=0x83065a0) at ktorrentcore.cpp:597
#16 0x08090ac1 in KTorrentCore::qt_invoke (this=0x83065a0, _id=5, _o=0xbffa07b8) at ktorrentcore.moc:243
#17 0xb6de004d in QObject::activate_signal () from /usr/lib/qt3/lib/libqt-mt.so.3
#18 0xb6de0c5d in QObject::activate_signal () from /usr/lib/qt3/lib/libqt-mt.so.3
#19 0xb70f48f9 in QTimer::timeout () from /usr/lib/qt3/lib/libqt-mt.so.3
#20 0xb6e033cf in QTimer::event () from /usr/lib/qt3/lib/libqt-mt.so.3
#21 0xb6d83037 in QApplication::internalNotify () from /usr/lib/qt3/lib/libqt-mt.so.3
#22 0xb6d83ea9 in QApplication::notify () from /usr/lib/qt3/lib/libqt-mt.so.3
#23 0xb74aa26a in KApplication::notify () from /usr/lib/libkdecore.so.4
#24 0xb6d7822b in QEventLoop::activateTimers () from /usr/lib/qt3/lib/libqt-mt.so.3
#25 0xb6d34960 in QEventLoop::processEvents () from /usr/lib/qt3/lib/libqt-mt.so.3
#26 0xb6d98a60 in QEventLoop::enterLoop () from /usr/lib/qt3/lib/libqt-mt.so.3
#27 0xb6d98916 in QEventLoop::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#28 0xb6d829ef in QApplication::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#29 0x0809f125 in main (argc=7, argv=0xbffa0c50) at main.cpp:125
#30 0xb64e875c in __libc_start_main () from /lib/i686/libc.so.6
---Type <return> to continue, or q <return> to quit---
#31 0x08065dd1 in _start ()


It seems main thread is stuck waiting for a mutex which is already locked and that lock is not released for some reason.

The joys of multithreading