[Lazarus] How to PostMessage to object?

[Michael Schnell]

On 06/09/2011 12:12 PM, Henry Vermaak wrote:
>
> Do you propose that QueueAsyncCall throws an exception if it's used 
> from outside the main thread? 
The purpose of QueueAsyncCall() is to use it in worker threads to notify 
the main thread of something that happens in the thread (without the 
worker thread needing to wait that the main thread was able to handle 
the event). But it's not forbidden to call QueueAsyncCall() in the main 
thread.
> Otherwise adding a critical section to all the async queue methods is 
> in order.
>
IMOH protecting a call to QueueAsyncCall() (in user code or <IMHO 
better> in the LCL itself) by a semaphore should not harm anyway in most 
cases, as there would be no waiting on anything else in that critical 
section. If you assign different priorities to the threads there of 
course is the usual problem of priority inversion.

-Michael