U++ forum: Welcome to the forum

Re: ArrayCtrl: GPF when thread Add(), PopUpEx, and Scroll collide [message #40227 is a reply to message #40223]

Sat, 06 July 2013 20:54

mirek
Messages: 14267
Registered: November 2005

Ultimate Member

kropniczki wrote on Sat, 06 July 2013 11:39

Tks for the prompt response.

Quote:

The root of problem is stupid M$ decision that binds windows and event loops to threads. That makes practically only possible to create windows and run event loops in the main thread.

I thought it was something rather OS-independent, since the issue apparently occurs under Linux too, according to Alendar's posting in this topic.

Well, the decision then requires all that main-thread GUI stuff, so other platforms have to follow if we want to be crossplatform compatible...

Quote:

Anyway, I wonder, would it be worth to ask how M$ does it? In other words, how a pure M$ app is supposed to be developed so that it does what I want without crashing? I mean, is there some M$ recipe for creating new windows not in main thread and still be able to run event loops in it without crashing? I don't know, maybe such an investigation could bring up new insights on which course to take to fix the problem, for I guess purely M$-based progs must end up having to do it one way or another.

Well, I guess it is not really that much needed.... I mean, opening windows in non-main threads is not really that much useful.

Quote:

Alternatively, I am starting to thing that perhaps easiest is to ban creation of windows in non-main thread (Prompts could perhaps be supported as exception, DisplayPopup::Sync would have to be rewritten).

If you decide to do so, does it mean we will no longer be able do stuff like adding Ctrls in a background thread dynamically, while 'simultaneously' enabling user interaction with GUI, or would new DisplayPopup::Sync code otherwise still make it possible?

It will be OK. (Actually it IS OK, as changes are commit). Only thing you cannot do easily anymore is to directly open window from another thread or run message loop. But even for that you have still easy workaround, just use Call to have Callback performed on the main thread. You just have to consider that Call unlocks GuiLock...

You can check updated GuiLock example... (Even if actually it would work without change, as Prompts are "fixed" to run from non-main thread).

Mirek
Mirek

Report message to a moderator