[Lazarus] blank window

[Henry Vermaak]

On 26/01/12 17:34, Henry Vermaak wrote:
> On 26/01/12 16:56, Mattias Gaertner wrote:
>>
>> Henry Vermaak <henry.vermaak at gmail.com> hat am 26. Januar 2012 um 17:21
>> geschrieben:
>> >
>> > Perhaps a thread problem?
>>
>> Maybe.
>>
>> Please add the unit cmem as first unit in ide/lazarus.pp and try again.
>
> That didn't make a difference, unfortunately.

I started looking into what changed for the "new iteration" code and 
came across gtk2msgqueue.pp.  I saw a comment that TGtkMessageQueue is 
supposed to be thread safe (presumably for PostMessage), but it appears 
that it isn't (despite the critical section in the old code, since a 
lock variable is checked first, presumably to handle nested locks).  The 
new code is even worse: g_main_context_acquire doesn't block and return 
value isn't checked, so it seems rather pointless.  Why have a "lock" 
method that doesn't actually lock?  I'd imagine the only reason that 
this doesn't break really badly is that acquiring the context seems 
unnecessary, since the help for g_main_context_acquire says:

You must be the owner of a context before you can call 
g_main_context_prepare(), g_main_context_query(), 
g_main_context_check(), g_main_context_dispatch().

But none of those functions are called anywhere.  What's going on here? 
  I can see that the message queue can get pretty screwed up when 
someone uses PostMessage.

Ludo's suggestion to remove the gdk_threads_init and the 
gdk_treads_enter/leave calls works, though.

Henry