view src/video/x11/SDL_x11video.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 568c9b3c0167
children a1b03ba2fcd0
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

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

#ifndef _SDL_x11video_h
#define _SDL_x11video_h

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>

#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"

#if SDL_VIDEO_DRIVER_X11_DGAMOUSE
#include "../Xext/extensions/xf86dga.h"
#endif
#if SDL_VIDEO_DRIVER_X11_XINERAMA
#include "../Xext/extensions/Xinerama.h"
#endif 
#if SDL_VIDEO_DRIVER_X11_XRANDR
#include <X11/extensions/Xrandr.h>
#endif
#if SDL_VIDEO_DRIVER_X11_VIDMODE
#include "../Xext/extensions/xf86vmode.h"
#endif
#if SDL_VIDEO_DRIVER_X11_XME
#include "../Xext/extensions/xme.h"
#endif

#include "SDL_x11dyn.h"

/* Hidden "this" pointer for the video functions */
#define _THIS	SDL_VideoDevice *this

/* Private display data */
struct SDL_PrivateVideoData {
    int local_X11;		/* Flag: true if local display */
    Display *X11_Display;	/* Used for events and window management */
    Display *GFX_Display;	/* Used for graphics and colormap stuff */
    Visual *SDL_Visual;		/* The visual used by our window */
    Window WMwindow;		/* Input window, managed by window manager */
    Window FSwindow;		/* Fullscreen window, completely unmanaged */
    Window SDL_Window;		/* Shared by both displays (no X security?) */
    Atom WM_DELETE_WINDOW;	/* "close-window" protocol atom */
    WMcursor *BlankCursor;	/* The invisible cursor */
    XIM X11_IM;		/* Used to communicate with the input method (IM) server */
    XIC X11_IC;		/* Used for retaining the state, properties, and semantics of communication with                                                  the input method (IM) server */

    char *SDL_windowid;		/* Flag: true if we have been passed a window */

    /* Direct Graphics Access extension information */
    int using_dga;

#ifndef NO_SHARED_MEMORY
    /* MIT shared memory extension information */
    int use_mitshm;
    XShmSegmentInfo shminfo;
#endif

    /* The variables used for displaying graphics */
    XImage *Ximage;		/* The X image for our window */
    GC	gc;			/* The graphic context for drawing */

    /* The current width and height of the fullscreen mode */
    int window_w;
    int window_h;

    /* Support for internal mouse warping */
    struct {
        int x;
        int y;
    } mouse_last;
    struct {
        int numerator;
        int denominator;
        int threshold;
    } mouse_accel;
    int mouse_relative;

    /* The current list of available video modes */
    SDL_Rect **modelist;

    /* available visuals of interest to us, sorted deepest first */
    struct {
	Visual *visual;
	int depth;		/* number of significant bits/pixel */
	int bpp;		/* pixel quantum in bits */
    } visuals[2*5];		/* at most 2 entries for 8, 15, 16, 24, 32 */
    int nvisuals;

    Visual *vis;		/* current visual in use */
    int depth;			/* current visual depth (not bpp) */

    /* Variables used by the X11 video mode code */
#if SDL_VIDEO_DRIVER_X11_XINERAMA
    SDL_NAME(XineramaScreenInfo) xinerama_info;
#endif
#if SDL_VIDEO_DRIVER_X11_XRANDR
    XRRScreenConfiguration* screen_config;
    int saved_size_id;
    Rotation saved_rotation;
#endif
#if SDL_VIDEO_DRIVER_X11_VIDMODE
    SDL_NAME(XF86VidModeModeInfo) saved_mode;
    struct {
        int x, y;
    } saved_view;
#endif
#if SDL_VIDEO_DRIVER_X11_XME /* XiG XME fullscreen */
    XiGMiscResolutionInfo saved_res;
#endif

    int use_xinerama;
    int use_xrandr;
    int use_vidmode;
    int use_xme;
    int currently_fullscreen;

    /* Automatic mode switching support (entering/leaving fullscreen) */
    Uint32 switch_waiting;
    Uint32 switch_time;

    /* Prevent too many XSync() calls */
    int blit_queued;

    /* Colormap handling */
    Colormap DisplayColormap;	/* The default display colormap */
    Colormap XColorMap;		/* The current window colormap */
    int *XPixels;		/* pixels value allocation counts */
    float gamma_saved[3];	/* Saved gamma values for VidMode gamma */
    int gamma_changed;		/* flag: has VidMode gamma been modified? */

    short *iconcolors;		/* List of colors used by the icon */

    /* Screensaver settings */
    int allow_screensaver;
};

/* Old variable names */
#define local_X11		(this->hidden->local_X11)
#define SDL_Display		(this->hidden->X11_Display)
#define GFX_Display		(this->hidden->GFX_Display)
#define SDL_Screen		DefaultScreen(this->hidden->X11_Display)
#define SDL_Visual		(this->hidden->vis)
#define SDL_Root		RootWindow(SDL_Display, SDL_Screen)
#define WMwindow		(this->hidden->WMwindow)
#define FSwindow		(this->hidden->FSwindow)
#define SDL_Window		(this->hidden->SDL_Window)
#define WM_DELETE_WINDOW	(this->hidden->WM_DELETE_WINDOW)
#define SDL_BlankCursor		(this->hidden->BlankCursor)
#define SDL_IM			(this->hidden->X11_IM)
#define SDL_IC			(this->hidden->X11_IC)
#define SDL_windowid		(this->hidden->SDL_windowid)
#define using_dga		(this->hidden->using_dga)
#define use_mitshm		(this->hidden->use_mitshm)
#define shminfo			(this->hidden->shminfo)
#define SDL_Ximage		(this->hidden->Ximage)
#define SDL_GC			(this->hidden->gc)
#define window_w		(this->hidden->window_w)
#define window_h		(this->hidden->window_h)
#define mouse_last		(this->hidden->mouse_last)
#define mouse_accel		(this->hidden->mouse_accel)
#define mouse_relative		(this->hidden->mouse_relative)
#define SDL_modelist		(this->hidden->modelist)
#define xinerama_info		(this->hidden->xinerama_info)
#define saved_mode		(this->hidden->saved_mode)
#define saved_view		(this->hidden->saved_view)
#define saved_res		(this->hidden->saved_res)
#define screen_config		(this->hidden->screen_config)
#define saved_size_id		(this->hidden->saved_size_id)
#define saved_rotation		(this->hidden->saved_rotation)
#define use_xinerama		(this->hidden->use_xinerama)
#define use_vidmode		(this->hidden->use_vidmode)
#define use_xrandr		(this->hidden->use_xrandr)
#define use_xme			(this->hidden->use_xme)
#define currently_fullscreen	(this->hidden->currently_fullscreen)
#define switch_waiting		(this->hidden->switch_waiting)
#define switch_time		(this->hidden->switch_time)
#define blit_queued		(this->hidden->blit_queued)
#define SDL_DisplayColormap	(this->hidden->DisplayColormap)
#define SDL_PrivateColormap	(this->hidden->PrivateColormap)
#define SDL_XColorMap		(this->hidden->XColorMap)
#define SDL_XPixels		(this->hidden->XPixels)
#define gamma_saved		(this->hidden->gamma_saved)
#define gamma_changed		(this->hidden->gamma_changed)
#define SDL_iconcolors		(this->hidden->iconcolors)
#define allow_screensaver	(this->hidden->allow_screensaver)

/* Some versions of XFree86 have bugs - detect if this is one of them */
#define BUGGY_XFREE86(condition, buggy_version) \
((SDL_strcmp(ServerVendor(SDL_Display), "The XFree86 Project, Inc") == 0) && \
 (VendorRelease(SDL_Display) condition buggy_version))

#endif /* _SDL_x11video_h */