A way to avoid that ?

Dan Rathbun

Yes - as long as the operations a kept small it'll prevent whiteout.

"whiteout" = "ghost window"

(http://msdn.microsoft.com/en-us/library/ms644943(v)":2x9onnad]If a top-level window stops responding to messages for more than several seconds, the system considers the window to be not responding and replaces it with a ghost window that has the same z-order, location, size, and visual attributes. This allows the user to move it, resize it, or even close the application. However, these are the only actions available because the application is actually not responding. When an application is being debugged, the system does not generate a ghost window.

When Sketchup goes into "ghost mode", you will see it listed as "Skethcup (not responding)" in the Task Manager.

First of all, changing the interval that Windows uses to determine when a process is "not responding", although possible, causes other major headaches systemwide. Also, I think that it requires a registry change and reboot (if memory serves me,) so is not a serious option for us.

I would attempt to force a [PeekMessage](http://msdn.microsoft.com/en-us/library/ms644943(v) system call, for Sketchup's thread, within the "responding inteval" (can't remember offhand what it is.)

So any way it's not your add entities block that needs to go inside a UI.start_timer proc, ... it's a API call to PeekMessage, like:

begin
  peek = UI.start_timer(interval, true) {
   peek_window_msg()
  }
  do_create_lots_of_model_entities()
  UI.stop_timer(peek)
end

where, peek_window_msg() would be a method that sets up and makes the proper API call. (It should NOT delete any messages from the queue, basically it is just acknowledging to the system that Sketchup knows that messages are pending to be processed.)

It would be better (for us,) if something like this was built into the main() loop (prodived C++ has something like a start_timer function.) Perhaps John Hauswirth might know if it's possible.

Dan Rathbun

The other option, would be to "fool" the system into thinking that Sketchup was being debugged, during the long add entities block.

thomthom

Have you used that PeekMessage thing?

Jim

That would be awesome if it works.

Dan Rathbun

@dan rathbun said:

A debugger object needs to be created and attached to the Sketchup process, etc.

I am wary of releasing anything that does something this drastic.. and because BugSplat! is also likely a (post-mortem) debugger implementation... the last thing I want to do is break the BugSplat! functionality.

Dan Rathbun

@thomthom said:

Have you used that PeekMessage thing?

I haven't had time yet myself, (as I have not yet written any code that creates a long Ruby processing delay.)

Also.. it has been a few months since I read that MSDN page, and just noticed the last item about debug mode. (A quick look into this, seems much more complex. A debugger object needs to be created and attached to the Sketchup process, etc.)

thomthom

Haaaaaaah!!!!!

Just made a really quick and dirty hack - calling PeekMessage at the inner most loop:

<span class="syntaxdefault"><br />&nbsp;&nbsp;PeekMessage&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">TT</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Win32</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">API</span><span class="syntaxkeyword">.new(</span><span class="syntaxstring">'PeekMessage'&nbsp;</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxstring">'PLIII'</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxstring">'I'</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxstring">'user32'</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;</span><span class="syntaxdefault">def&nbsp;self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">refresh<br />&nbsp;&nbsp;&nbsp;&nbsp;msg&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxstring">'&nbsp;'&nbsp;</span><span class="syntaxkeyword">*&nbsp;</span><span class="syntaxdefault">2048<br />&nbsp;&nbsp;&nbsp;&nbsp;r&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">PeekMessage</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">call</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">msg</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;</span><span class="syntaxdefault">end<br /></span>

worked perfectly!!!!

Though I think one might want to time the peek after a given short enough time. (And msg needs to be of correct size...)

thomthom

tried using a timer to sending PeekMessage - while the inner loop did its thing.
didn't work. the inner loop blocked it. So the inner loops need to call this. which means that when SU's methods are processing they will probably block the UI . like intersecting many entities.

But in many cases this can really help.

of course - OSX users are out of luck....

Jim

Oh, that's interesting.

Couple a thoughts - terminate the message with a c language null: '\0' (just in case?) The size should still be 2048 including the null.

More obviously, you don't need to peek every loop iteration - so something like:

refresh if (loop_counter % 500 == 0)

thomthom

@jim said:

Couple a thoughts - terminate the message with a c language null: '\0' (just in case?)

Isn't that just for strings?
The string I pass is just a data buffer that will be filled with binary data - which one has to extract.

@jim said:

More obviously, you don't need to peek every loop iteration - so something like:
refresh if (loop_counter % 500 == 0)

Yes - more pragmatic than calculating time. I like it, it's KISS.

Jim

@thomthom said:

Isn't that just for strings?

Yeah, I made an assumption the message was a c character array.

thomthom

@jim said:

@thomthom said:

Isn't that just for strings?

Yeah, I made an assumption the message was a c character array.

No, it's a MSG structure. Just didn't bother to work out exactly how large it is. (probably will be making a wrapper for this.) So I just make a large buffer while I quickly tested it.
...if I don't need the returned message, would it be ok to just send an empty buffer?

Dan Rathbun

@dan rathbun said:

@thomthom said:

Yes - as long as the operations a kept small it'll prevent whiteout.

"whiteout" = "ghost window"

...[snip]...

I would attempt to force a [PeekMessage](http://msdn.microsoft.com/en-us/library/ms644943(v) system call, for Sketchup's thread, within the "responding inteval" (can't remember offhand what it is.)

So any way it's not your add entities block that needs to go inside a UI.start_timer proc, ... it's a API call to PeekMessage, like:

begin
>   peek = UI.start_timer(interval, true) {
>    peek_window_msg()
>   }
>   do_create_lots_of_model_entities()
>   UI.stop_timer(peek)
> end

where, peek_window_msg() would be a method that sets up and makes the proper API call.

@ThomThom & friends, ... I stumbled across where I saw the 'whiteout' interval.
It's specified on the [IsHungAppWindow](http://msdn.microsoft.com/en-us/library/ms633526(v) Function reference page.
Says 5 seconds.

So perhaps:

begin
  interval =( Sketchup.version.to_i<8 ? 4 ; 4.9 )
  peek = UI.start_timer(interval, true) {
   peek_window_msg()
  }
  do_create_lots_of_model_entities()
  UI.stop_timer(peek)
end

thomthom

Interesting - from that article.

@unknownuser said:

An application is considered to be not responding if it is not waiting for input, is not in startup processing, and has not called PeekMessage within the internal timeout period of 5 seconds.

Though, it seems one can't reply on that time.

@unknownuser said:

The Windows timeout criteria of 5 seconds is subject to change.

I have set the interval to a handful of times per second because I use it to force SU to update its statusbar.

Dan Rathbun

I still wonder if a peek message loop could be written into the commit_operation API method.

Dan Rathbun

And there is another 'nutty' thing that happens. When the ghost window is created, it has a different handle then the "real" application window. There are a couple functions that return the other handle, depending on which window handle you grab. (Strange that the IsHungAppWindow function is "not for general use.")

thomthom

@dan rathbun said:

I still wonder if a peek message loop could be written into the commit_operation API method.

I made a wrapper iterator that will take an enumerator objects and wrap it in between start and commit operation while updating the progress in the statusbar, kept alive by PeekMessage limited to a certain interval. Works really well for simple one-iteration operations.

nikusknx

Update for Sketchup 2014 :


require "Win32API.rb
msg = "\000" * 36
peekMessage = Win32API.new('user32','PeekMessage' , 'PLIII', 'I')
peekMessage.call( msg, 0, 0, 0, 0x0000 ) != 0