view src/video/xbios/SDL_xbios_sb3.h @ 4158:96ce26f24b01 SDL-1.2

Date: Sun, 7 Sep 2008 15:17:00 +0200 From: c2woody@gmx.net Subject: [SDL] SDL 1.2 doube free/pointer zeroing missing Hello, this is about a crash/debug breakage for the current SDL 1.2 source tree (today's svn checkout, same problem in 1.2.13 and before as far as relevant). In some places memory is free()d but the associated pointer is not zeroed, leading to for example double free()s. For me this happened because SDL_StopEventThread() was executed twice (during restart of the subsystems), once for the close down in SDL_VideoQuit() and once at the startup, right at the beginning of SDL_StartEventLoop(). Thus the code SDL_DestroyMutex(SDL_EventQ.lock); (see SDL_events.c) was called twice and executed the SDL_free(mutex); twice as well, leading to a crash (msvc 64bit for which it was noticed). I've tried to check all other occurrences of SDL_free and similar code in msvc, see the attached patch (udiff against revision 4082). Non-windows only codepaths have neither been checked nor touched. Comments/ideas welcome. Attached patch: NULLifies some pointers after they have been free()d.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 12 Nov 2008 17:23:40 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
	ScreenBlaster 3 definitions

	Patrice Mandin
*/

#ifndef _SDL_xbios_sb3_h_
#define _SDL_xbios_sb3_h_

/*--- Defines ---*/

#ifndef C_SCPN
#define C_SCPN 0x5343504EL
#endif

#define SCPN_DEV_1BPP	0
#define SCPN_DEV_2BPP	1
#define SCPN_DEV_4BPP	2
#define SCPN_DEV_8BPP	3
#define SCPN_DEV_16BPP	4

extern const int SDL_XBIOS_scpn_planes_device[];

/*--- Types ---*/

typedef struct {
	unsigned short	virtual_width;	/* Virtual screen width */
	unsigned short	virtual_height;	/* Virtual screen height */
	unsigned short	visible_width;	/* Visible width */
	unsigned short	visible_height;	/* Visible height */
	unsigned short	h_pos;	/* Horizontal position in virtual screen */
	unsigned short	v_pos;	/* Vertical position in virtual screen */
	unsigned short	dummy;
	unsigned long	size;	/* Size of screen in bytes */
	unsigned short	device;	/* Device number to find planes = getRez() */
							/* = Index in scpn_planes_device[] */
} __attribute__((packed)) scpn_screeninfo_t;

typedef struct {
	unsigned long	magic;	/* just a BRA assembler jump */
	unsigned short	version;
	void			*dummy1;
	unsigned short	ptsout0_1;
	unsigned short	ptsout0_2;
	unsigned short	dummy3;
	unsigned char	date[8];	/* Date of program build */
	unsigned char	asm_string[30];	/* 10 times the 'ASM' string */
	unsigned short	dummy4;
	scpn_screeninfo_t	*screen_info;
	unsigned short	dummy6;
} __attribute__((packed)) scpn_cookie_t;

/*--- Function prototypes ---*/

int SDL_XBIOS_SB3Usable(scpn_cookie_t *cookie_scpn);

void SDL_XBIOS_SB3Init(_THIS, scpn_cookie_t *cookie_scpn);

#endif /* _SDL_xbios_sb3_h_ */