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r25711:31eedcf7ade0 1.1 KiB text/x-c Show Annotation Show as Raw Download as Raw

Patric Stout

Fix: on startup, NewGRF scan could case race-condition (#9382)

Creating a thread was not thread-safe. The irony.

The video-driver has a function GameLoopPause() which first checks
if the thread is the game-thread or not. For this it needs access
to this->game_thread. This variable is set in StartNewThread().

However, due to timing, it is well possible GameLoopPause() is
called from the thread well before this->game_thread is assigned.

And so we have a race-condition!

Simply solve this by preventing a thread to start till we are
done with our bookkeeping.

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file null.cpp A blitter that doesn't blit. */

#include "../stdafx.h"
#include "null.hpp"

#include "../safeguards.h"

/** Instantiation of the null blitter factory. */
static FBlitter_Null iFBlitter_Null;

Sprite *Blitter_Null::Encode(const SpriteLoader::Sprite *sprite, AllocatorProc *allocator)
{
	Sprite *dest_sprite;
	dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite));

	dest_sprite->height = sprite->height;
	dest_sprite->width  = sprite->width;
	dest_sprite->x_offs = sprite->x_offs;
	dest_sprite->y_offs = sprite->y_offs;

	return dest_sprite;
}