[Lazarus] App locks at startup

[SteveG]

Burkhard Carstens wrote:
> Am Sonntag, 28. Februar 2010 04:35 schrieb SteveG:
>   
>> On 28/02/10 13:18, SteveG wrote:
>>     
>>> On 28/02/10 13:08, Andrew Brunner wrote:
>>>       
>>>> I would never Process Application Messages from a timer thread.
>>>>
>>>> I suspect a threadlock going on. Does it work OK without the
>>>> application.processmessages?
>>>>
>>>> On Sat, Feb 27, 2010 at 9:02 PM, SteveG<steveg at nevets.com.au> 
>>>>         
> wrote:
>   
>>>>> I have just updated Laz (svn) and Fpc(2.4.0) and have hit a
>>>>> problem with my
>>>>> program. (worked ok with Laz 0.98 / fpc 2.?.?)
>>>>>
>>>>> I use a dyn loaded lib with my app, which seems to be relevant.
>>>>>
>>>>> If I call Application.ProcessMessages from within a
>>>>> TTimer.OnTimer event, my
>>>>> app now locks solid showing 'futex_wait_queue_me' in the process
>>>>> listing.
>>>>>
>>>>> I havent yet been able to narrow down an exact cause, as a simple
>>>>> app/lib
>>>>> test works ok.
>>>>>
>>>>> Would anybody know what would cause the above state (futex), as a
>>>>> clue to
>>>>> the change in Laz/Fpc affecting my app ?
>>>>>           
>>> It does seem to work without the App.proc call. The problem I have
>>> seems to be caused by calling App.proc once my lib is loaded. This
>>> was the closest I have been able to get in narrowing down to a
>>> small test case. I call App.procMsgs from within my lib which is
>>> where the actual problem seems to be.
>>>
>>> Is there any other way to create a 'pause' from within a
>>> library/function call (not sleep, as it 'stops' the program).
>>> My 'pause' function is works as :>
>>> StTm := NOW;
>>> while NOW < (StTm + TmOut) do begin
>>> Sleep(1);
>>> Application.ProcessMessages;
>>> end;
>>>
>>> This worked ok before the Laz/fpc update, but seems to be broken
>>> now ? This is just my 'guess' so far as where my problem lies ?
>>>       
>> After more study (read as: more google) - it may be related to the
>> kernel changes in Ubuntu 10.04 - seems to be many unrelated programs
>> suffering similar problems - will continue this story as I find more
>> :)
>>     
>
> Could you please post some of those links? Is this an Ubuntu specific 
> kernel change?
>
> Thanks, 
>  Burkhard
>   
http://ohioloco.ubuntuforums.org/showthread.php?p=8769812
http://forum.videolan.org/viewtopic.php?f=13&t=70320

These are just a quick sample of different complaints of same problem - 
I think there is still no definitive reason found.
It would appear to be kernel specific ? -
If you search google (etc) for 'futex_wait_queue_me' errors, the list is 
growing daily :)