[Qt-interest] how to debug a deadlock

[alexander golks]

seeing incoming breakpoint solution while writing the same solution... ;)

i think deadlock detection is rather complex, 
and you'll not have other possibilities than logging/breakpointing locks, unlocks, etc.
however, queuing of the commands like mentionend by Atlant would avoid the dead locks.

alex

> ------------------------------
> 
> Message: 4
> Date: Wed, 14 Jul 2010 13:29:28 +0200
> From: Matthias Pospiech <matthias.pospiech at gmx.de>
> Subject: [Qt-interest] how to debug a deadlock
> To: qt-interest at trolltech.com
> Message-ID: <4C3D9F98.2060506 at gmx.de>
> Content-Type: text/plain; charset=ISO-8859-15; format=flowed
> 
> I have a dll sending commands using the serial port. The dll is from a 
> company and I can only use it the way it is.
> My problem is that this dll does not synchronise commands and replies 
> over the serial port.
> This becomes a problem if I send commands from different threads.
> 
> The simplest solution would be to ensure that all commands can only be 
> called once at the same time.
> So that the next command must wait for the previous to be finished. Here 
> however is not difference between setting and getting
> (or reading and writing), because the dll always sends and recieves for 
> a single command.
> 
> Now my idea was to use a
> QMutexLocker  locker( &mutex );
> 
> in every function sending commands with the dll.
> 
> This however leads to an immediate deadlock. QtCreator however does not 
> show where this deadlock happend.
> Now I wonder how to debug this?
> 
> Matthias
> 
> 

-- 
/*
 *  printk(KERN_ERR "BIGMAC: Would you like that for here or to go?\n");
 *    linux-2.6.19/drivers/net/sunbmac.c
 */
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