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Bug 2746 - Render dies after SDL_SetWindowSize in other thread
Summary: Render dies after SDL_SetWindowSize in other thread
Status: RESOLVED INVALID
Alias: None
Product: SDL
Classification: Unclassified
Component: video (show other bugs)
Version: 2.0.3
Hardware: x86_64 Windows 7
: P2 critical
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-10-07 11:13 UTC by alexander
Modified: 2017-08-14 04:59 UTC (History)
1 user (show)

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Description alexander 2014-10-07 11:13:55 UTC 
Good afternoon.
I use the following code and I receive an error.

   SDL_Window * WindowTest;   
   SDL_Renderer * RenderTest;   
   SDL_Texture * TextureTest;

   void FirstThread()
   {
	WindowTest= SDL_CreateWindow(0,
					0,
					0,
					640,480,
				SDL_WINDOW_SHOWN|
                                SDL_WINDOW_FOREIGN|
                                SDL_WINDOW_BORDERLESS);
	RenderTest = SDL_CreateRenderer(WindowTest,-1,SDL_RENDERER_ACCELERATED);
	TextureTest = SDL_CreateTexture(RenderTest,
					SDL_PIXELFORMAT_IYUV,
					SDL_TEXTUREACCESS_STREAMING,
					640,480);
	SDL_SetWindowSize(WindowTest,600,400);
	if(SDL_RenderClear(RenderTest)!=0)
	{
		printf("SDL_RenderClear failed: %s\n", SDL_GetError());
		fflush(0);
	}
	// All OK!!!
	SDL_DestroyTexture(TextureTest);
	TextureTest = SDL_CreateTexture(RenderTest,
		SDL_PIXELFORMAT_IYUV,
		SDL_TEXTUREACCESS_STREAMING,
		600,400);
   }
   void SecondThread()
   {
	SDL_SetWindowSize(WindowTest,500,300);
	if(SDL_RenderClear(RenderTest)!=0)
	{
		printf("SDL_RenderClear failed: %s\n", SDL_GetError());
		fflush(0);
	}
	// ERROR!!!! INVALIDCALL!!
   }

   int main ()
   {
        boost::thread * first=new boost::thread(&FirstThread);
	first->join();
	boost::thread * second=new boost::thread(&SecondThread);
	second->join();
   }

In other thread I can't change the size. I tried the SDL 2.0.3 version.
Also I tried the version which is specified in "BUG" 1676. It doesn't work.
https://bugzilla.libsdl.org/show_bug.cgi? id=1676
Help please...
Comment 1 Alex Szpakowski 2014-10-07 21:03:24 UTC 
SDL_Render must only be used in the main thread. This isn't a bug with SDL, just limitations of the underlying GPU APIs. A comment at the top of the SDL_render.h file mentions this as well.

Similarly, I believe most of the window-related functions are not designed to be used in multiple threads either.
Comment 2 alexander 2014-10-08 06:52:55 UTC 
It's OK, thanks.
How I shall use Render if I host events from a mouse (SDL_MOUSEBUTTONDOWN) in other thread? To increase a window on mouse click... I shall create main thread and host events for processing of Render?
Comment 3 Sam Lantinga 2017-08-14 04:59:35 UTC 
Yes, that's the typical approach.

Cheers,