Bug 26086

Summary:	dbus-c++ : hal-listen locks up on repeated plug/unplug of usb device
Product:	dbus	Reporter:	Joe Steeve <js>
Component:	core	Assignee:	Havoc Pennington <hp>
Status:	RESOLVED NOTOURBUG	QA Contact:	John (J5) Palmieri <johnp>
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	x86 (IA32)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	dbus-c++ lockup, gdb trace probable fix

Description Joe Steeve 2010-01-17 13:37:09 UTC

When an usb device is repeatedly plugged-in/plugged-out, hal-listen locks up. 

Running through gdb shows that the application is locked waiting to acquire DBus::Dispatcher::_mutex_p in DBus::Dispatcher::queue_connection (check attachment). DBus::Dispatcher::_mutex_p is already locked by the same thread earlier in the call-stack.

Should DBus::Dispatcher::_mutex_p be 'recursive' ?

Comment 1 Joe Steeve 2010-01-17 13:56:48 UTC

Created attachment 32686 [details]
dbus-c++ lockup, gdb trace

Comment 2 Joe Steeve 2010-01-17 13:59:05 UTC

Created attachment 32687 [details] [review]
probable fix

This makes DBus::Dispatcher::_mutex_p as recursive. I am not quite sure whether this will affect anything else. Someone who knows better should tell me :-S

Comment 3 Andreas Volz 2010-01-30 01:13:05 UTC

Hello John,

please attach your minimal test application which shows the crash. I'll take a look then into it.

Thanks for the patch.

regards
Andreas

Comment 4 Joe Steeve 2010-01-30 11:30:42 UTC

(In reply to comment #3)

Hello Andreas,

> please attach your minimal test application which shows the crash. I'll take a
> look then into it.

This happens with the example code (examples/hal/hal-listen) distributed along with dbus-c++.

I'm on Debian Squeeze.

Joe

Comment 5 Simon McVittie 2011-01-05 05:05:22 UTC

dbus-c++ <http://sourceforge.net/projects/dbus-cplusplus/> has its own bug
tracker and is no longer hosted here. Please open a bug over there.

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