view src/video/x11/SDL_x11yuv.c @ 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 12bb6311fd5d
children a1b03ba2fcd0
line wrap: on
line source

/*
    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"

/* This is the XFree86 Xv extension implementation of YUV video overlays */

#if SDL_VIDEO_DRIVER_X11_XV

#include <X11/Xlib.h>
#ifndef NO_SHARED_MEMORY
#include <sys/ipc.h>
#include <sys/shm.h>
#include <X11/extensions/XShm.h>
#endif
#include "../Xext/extensions/Xvlib.h"

#include "SDL_x11yuv_c.h"
#include "../SDL_yuvfuncs.h"

#define XFREE86_REFRESH_HACK
#ifdef XFREE86_REFRESH_HACK
#include "SDL_x11image_c.h"
#endif

/* Workaround when pitch != width */
#define PITCH_WORKAROUND

/* Workaround intel i810 video overlay waiting with failing until the
   first Xv[Shm]PutImage call <sigh> */
#define INTEL_XV_BADALLOC_WORKAROUND

/* Fix for the NVidia GeForce 2 - use the last available adaptor */
/*#define USE_LAST_ADAPTOR*/  /* Apparently the NVidia drivers are fixed */

/* The functions used to manipulate software video overlays */
static struct private_yuvhwfuncs x11_yuvfuncs = {
	X11_LockYUVOverlay,
	X11_UnlockYUVOverlay,
	X11_DisplayYUVOverlay,
	X11_FreeYUVOverlay
};

struct private_yuvhwdata {
	int port;
#ifndef NO_SHARED_MEMORY
	int yuv_use_mitshm;
	XShmSegmentInfo yuvshm;
#endif
	SDL_NAME(XvImage) *image;
};


static int (*X_handler)(Display *, XErrorEvent *) = NULL;

#ifndef NO_SHARED_MEMORY
/* Shared memory error handler routine */
static int shm_error;
static int shm_errhandler(Display *d, XErrorEvent *e)
{
        if ( e->error_code == BadAccess ) {
        	shm_error = True;
        	return(0);
        } else
		return(X_handler(d,e));
}
#endif /* !NO_SHARED_MEMORY */

static int xv_error;
static int xv_errhandler(Display *d, XErrorEvent *e)
{
        if ( e->error_code == BadMatch ) {
        	xv_error = True;
        	return(0);
        } else
		return(X_handler(d,e));
}

#ifdef INTEL_XV_BADALLOC_WORKAROUND
static int intel_errhandler(Display *d, XErrorEvent *e)
{
        if ( e->error_code == BadAlloc ) {
        	xv_error = True;
        	return(0);
        } else
		return(X_handler(d,e));
}

static void X11_ClearYUVOverlay(SDL_Overlay *overlay)
{
	int x,y;
	    
	switch (overlay->format)
	{
	case SDL_YV12_OVERLAY:
	case SDL_IYUV_OVERLAY:
		for (y = 0; y < overlay->h; y++)
			memset(overlay->pixels[0] + y * overlay->pitches[0],
				0, overlay->w);
		
		for (y = 0; y < (overlay->h / 2); y++)
		{
			memset(overlay->pixels[1] + y * overlay->pitches[1],
				-128, overlay->w / 2);
			memset(overlay->pixels[2] + y * overlay->pitches[2],
				-128, overlay->w / 2);
		}
		break;
	case SDL_YUY2_OVERLAY:
	case SDL_YVYU_OVERLAY:
		for (y = 0; y < overlay->h; y++)
		{
			for (x = 0; x < overlay->w; x += 2)
			{
				Uint8 *pixel_pair = overlay->pixels[0] +
					y * overlay->pitches[0] + x * 2;
				pixel_pair[0] = 0;
				pixel_pair[1] = -128;
				pixel_pair[2] = 0;
				pixel_pair[3] = -128;
			}
		}
		break;
	case SDL_UYVY_OVERLAY:
		for (y = 0; y < overlay->h; y++)
		{
			for (x = 0; x < overlay->w; x += 2)
			{
				Uint8 *pixel_pair = overlay->pixels[0] +
					y * overlay->pitches[0] + x * 2;
				pixel_pair[0] = -128;
				pixel_pair[1] = 0;
				pixel_pair[2] = -128;
				pixel_pair[3] = 0;
			}
		}
		break;
	}
}
#endif

SDL_Overlay *X11_CreateYUVOverlay(_THIS, int width, int height, Uint32 format, SDL_Surface *display)
{
	SDL_Overlay *overlay;
	struct private_yuvhwdata *hwdata;
	int xv_port;
	unsigned int i, j, k;
	unsigned int adaptors;
	SDL_NAME(XvAdaptorInfo) *ainfo;
	int bpp;
#ifndef NO_SHARED_MEMORY
	XShmSegmentInfo *yuvshm;
#endif
#ifdef INTEL_XV_BADALLOC_WORKAROUND
	int intel_adapter = False;
#endif

	/* Look for the XVideo extension with a valid port for this format */
	xv_port = -1;
	if ( (Success == SDL_NAME(XvQueryExtension)(GFX_Display, &j, &j, &j, &j, &j)) &&
	     (Success == SDL_NAME(XvQueryAdaptors)(GFX_Display,
	                                 RootWindow(GFX_Display, SDL_Screen),
	                                 &adaptors, &ainfo)) ) {
#ifdef USE_LAST_ADAPTOR
		for ( i=0; i < adaptors; ++i )
#else
		for ( i=0; (i < adaptors) && (xv_port == -1); ++i )
#endif /* USE_LAST_ADAPTOR */
		{
			/* Check to see if the visual can be used */
			if ( BUGGY_XFREE86(<=, 4001) ) {
				int visual_ok = 0;
				for ( j=0; j<ainfo[i].num_formats; ++j ) {
					if ( ainfo[i].formats[j].visual_id ==
							SDL_Visual->visualid ) {
						visual_ok = 1;
						break;
					}
				}
				if ( ! visual_ok ) {
					continue;
				}
			}
#ifdef INTEL_XV_BADALLOC_WORKAROUND
			if ( !strcmp(ainfo[i].name, "Intel(R) Video Overla"))
				intel_adapter = True;
			else
				intel_adapter = False;
#endif
			if ( (ainfo[i].type & XvInputMask) &&
			     (ainfo[i].type & XvImageMask) ) {
				int num_formats;
				SDL_NAME(XvImageFormatValues) *formats;
				formats = SDL_NAME(XvListImageFormats)(GFX_Display,
				              ainfo[i].base_id, &num_formats);
#ifdef USE_LAST_ADAPTOR
				for ( j=0; j < num_formats; ++j )
#else
				for ( j=0; (j < num_formats) && (xv_port == -1); ++j )
#endif /* USE_LAST_ADAPTOR */
				{
					if ( (Uint32)formats[j].id == format ) {
						for ( k=0; k < ainfo[i].num_ports; ++k ) {
							if ( Success == SDL_NAME(XvGrabPort)(GFX_Display, ainfo[i].base_id+k, CurrentTime) ) {
								xv_port = ainfo[i].base_id+k;
								break;
							}
						}
					}
				}
				if ( formats ) {
					XFree(formats);
				}
			}
		}
		SDL_NAME(XvFreeAdaptorInfo)(ainfo);
	}

	/* Precalculate the bpp for the pitch workaround below */
	switch (format) {
	    /* Add any other cases we need to support... */
	    case SDL_YUY2_OVERLAY:
	    case SDL_UYVY_OVERLAY:
	    case SDL_YVYU_OVERLAY:
		bpp = 2;
		break;
	    default:
		bpp = 1;
		break;
	}

#if 0
    /*
     * !!! FIXME:
     * "Here are some diffs for X11 and yuv.  Note that the last part 2nd
     *  diff should probably be a new call to XvQueryAdaptorFree with ainfo
     *  and the number of adaptors, instead of the loop through like I did."
     *
     *  ACHTUNG: This is broken! It looks like XvFreeAdaptorInfo does this
     *  for you, so we end up with a double-free. I need to look at this
     *  more closely...  --ryan.
     */
 	for ( i=0; i < adaptors; ++i ) {
 	  if (ainfo[i].name != NULL) Xfree(ainfo[i].name);
 	  if (ainfo[i].formats != NULL) Xfree(ainfo[i].formats);
   	}
 	Xfree(ainfo);
#endif

	if ( xv_port == -1 ) {
		SDL_SetError("No available video ports for requested format");
		return(NULL);
	}

	/* Enable auto-painting of the overlay colorkey */
	{
		static const char *attr[] = { "XV_AUTOPAINT_COLORKEY", "XV_AUTOPAINT_COLOURKEY" };
		unsigned int i;

		SDL_NAME(XvSelectPortNotify)(GFX_Display, xv_port, True);
		X_handler = XSetErrorHandler(xv_errhandler);
		for ( i=0; i < sizeof(attr)/(sizeof attr[0]); ++i ) {
			Atom a;

			xv_error = False;
			a = XInternAtom(GFX_Display, attr[i], True);
			if ( a != None ) {
     				SDL_NAME(XvSetPortAttribute)(GFX_Display, xv_port, a, 1);
				XSync(GFX_Display, True);
				if ( ! xv_error ) {
					break;
				}
			}
		}
		XSetErrorHandler(X_handler);
		SDL_NAME(XvSelectPortNotify)(GFX_Display, xv_port, False);
	}

	/* Create the overlay structure */
	overlay = (SDL_Overlay *)SDL_malloc(sizeof *overlay);
	if ( overlay == NULL ) {
		SDL_NAME(XvUngrabPort)(GFX_Display, xv_port, CurrentTime);
		SDL_OutOfMemory();
		return(NULL);
	}
	SDL_memset(overlay, 0, (sizeof *overlay));

	/* Fill in the basic members */
	overlay->format = format;
	overlay->w = width;
	overlay->h = height;

	/* Set up the YUV surface function structure */
	overlay->hwfuncs = &x11_yuvfuncs;
	overlay->hw_overlay = 1;

	/* Create the pixel data and lookup tables */
	hwdata = (struct private_yuvhwdata *)SDL_malloc(sizeof *hwdata);
	overlay->hwdata = hwdata;
	if ( hwdata == NULL ) {
		SDL_NAME(XvUngrabPort)(GFX_Display, xv_port, CurrentTime);
		SDL_OutOfMemory();
		SDL_FreeYUVOverlay(overlay);
		return(NULL);
	}
	hwdata->port = xv_port;
#ifndef NO_SHARED_MEMORY
	yuvshm = &hwdata->yuvshm;
	SDL_memset(yuvshm, 0, sizeof(*yuvshm));
	hwdata->image = SDL_NAME(XvShmCreateImage)(GFX_Display, xv_port, format,
						   0, width, height, yuvshm);
#ifdef PITCH_WORKAROUND
	if ( hwdata->image != NULL && hwdata->image->pitches[0] != (width*bpp) ) {
		/* Ajust overlay width according to pitch */ 
		XFree(hwdata->image);
		width = hwdata->image->pitches[0] / bpp;
		hwdata->image = SDL_NAME(XvShmCreateImage)(GFX_Display, xv_port, format,
							   0, width, height, yuvshm);
	}
#endif /* PITCH_WORKAROUND */
	hwdata->yuv_use_mitshm = (hwdata->image != NULL);
	if ( hwdata->yuv_use_mitshm ) {
		yuvshm->shmid = shmget(IPC_PRIVATE, hwdata->image->data_size,
				       IPC_CREAT | 0777);
		if ( yuvshm->shmid >= 0 ) {
			yuvshm->shmaddr = (char *)shmat(yuvshm->shmid, 0, 0);
			yuvshm->readOnly = False;
			if ( yuvshm->shmaddr != (char *)-1 ) {
				shm_error = False;
				X_handler = XSetErrorHandler(shm_errhandler);
				XShmAttach(GFX_Display, yuvshm);
				XSync(GFX_Display, True);
				XSetErrorHandler(X_handler);
				if ( shm_error )
					shmdt(yuvshm->shmaddr);
			} else {
				shm_error = True;
			}
			shmctl(yuvshm->shmid, IPC_RMID, NULL);
		} else {
			shm_error = True;
		}
		if ( shm_error ) {
			XFree(hwdata->image);
			hwdata->yuv_use_mitshm = 0;
		} else {
			hwdata->image->data = yuvshm->shmaddr;
		}
	}
	if ( !hwdata->yuv_use_mitshm )
#endif /* NO_SHARED_MEMORY */
	{
		hwdata->image = SDL_NAME(XvCreateImage)(GFX_Display, xv_port, format,
							0, width, height);

#ifdef PITCH_WORKAROUND
		if ( hwdata->image != NULL && hwdata->image->pitches[0] != (width*bpp) ) {
			/* Ajust overlay width according to pitch */ 
			XFree(hwdata->image);
			width = hwdata->image->pitches[0] / bpp;
			hwdata->image = SDL_NAME(XvCreateImage)(GFX_Display, xv_port, format,
								0, width, height);
		}
#endif /* PITCH_WORKAROUND */
		if ( hwdata->image == NULL ) {
			SDL_SetError("Couldn't create XVideo image");
			SDL_FreeYUVOverlay(overlay);
			return(NULL);
		}
		hwdata->image->data = SDL_malloc(hwdata->image->data_size);
		if ( hwdata->image->data == NULL ) {
			SDL_OutOfMemory();
			SDL_FreeYUVOverlay(overlay);
			return(NULL);
		}
	}

	/* Find the pitch and offset values for the overlay */
	overlay->planes = hwdata->image->num_planes;
	overlay->pitches = (Uint16 *)SDL_malloc(overlay->planes * sizeof(Uint16));
	overlay->pixels = (Uint8 **)SDL_malloc(overlay->planes * sizeof(Uint8 *));
	if ( !overlay->pitches || !overlay->pixels ) {
		SDL_OutOfMemory();
		SDL_FreeYUVOverlay(overlay);
		return(NULL);
	}
	for ( i=0; i<overlay->planes; ++i ) {
		overlay->pitches[i] = hwdata->image->pitches[i];
		overlay->pixels[i] = (Uint8 *)hwdata->image->data +
		                              hwdata->image->offsets[i];
	}

#ifdef XFREE86_REFRESH_HACK
	/* Work around an XFree86 X server bug (?)
	   We can't perform normal updates in windows that have video
	   being output to them.  See SDL_x11image.c for more details.
	 */
	X11_DisableAutoRefresh(this);
#endif

#ifdef INTEL_XV_BADALLOC_WORKAROUND
	/* HACK, GRRR sometimes (i810) creating the overlay succeeds, but the
	   first call to XvShm[Put]Image to a mapped window fails with:
	   "BadAlloc (insufficient resources for operation)". This happens with
	   certain formats when the XvImage is too large to the i810's liking.

	   We work around this by doing a test XvShm[Put]Image with a black
	   Xv image, this may cause some flashing, so only do this check if we
	   are running on an intel Xv-adapter. */
	if (intel_adapter)
	{
		xv_error = False;
		X_handler = XSetErrorHandler(intel_errhandler);
		
		X11_ClearYUVOverlay(overlay);

		/* We set the destination height and width to 1 pixel to avoid
		   putting a large black rectangle over the screen, thus
		   strongly reducing possible flashing. */
#ifndef NO_SHARED_MEMORY
		if ( hwdata->yuv_use_mitshm ) {
			SDL_NAME(XvShmPutImage)(GFX_Display, hwdata->port,
				SDL_Window, SDL_GC,
				hwdata->image,
				0, 0, overlay->w, overlay->h,
				0, 0, 1, 1, False);
		}
		else
#endif
		{
			SDL_NAME(XvPutImage)(GFX_Display, hwdata->port,
				SDL_Window, SDL_GC,
				hwdata->image,
				0, 0, overlay->w, overlay->h,
				0, 0, 1, 1);
		}
		XSync(GFX_Display, False);
		XSetErrorHandler(X_handler);

		if (xv_error)
		{
			X11_FreeYUVOverlay(this, overlay);
			return NULL;
		}
		/* Repair the (1 pixel worth of) damage we've just done */
		X11_RefreshDisplay(this);
	}
#endif

	/* We're all done.. */
	return(overlay);
}

int X11_LockYUVOverlay(_THIS, SDL_Overlay *overlay)
{
	return(0);
}

void X11_UnlockYUVOverlay(_THIS, SDL_Overlay *overlay)
{
	return;
}

int X11_DisplayYUVOverlay(_THIS, SDL_Overlay *overlay, SDL_Rect *src, SDL_Rect *dst)
{
	struct private_yuvhwdata *hwdata;

	hwdata = overlay->hwdata;

#ifndef NO_SHARED_MEMORY
	if ( hwdata->yuv_use_mitshm ) {
		SDL_NAME(XvShmPutImage)(GFX_Display, hwdata->port, SDL_Window, SDL_GC,
	              hwdata->image,
		      src->x, src->y, src->w, src->h,
		      dst->x, dst->y, dst->w, dst->h, False);
	}
	else
#endif
	{
		SDL_NAME(XvPutImage)(GFX_Display, hwdata->port, SDL_Window, SDL_GC,
				     hwdata->image,
		                     src->x, src->y, src->w, src->h,
		                     dst->x, dst->y, dst->w, dst->h);
	}
	XSync(GFX_Display, False);
	return(0);
}

void X11_FreeYUVOverlay(_THIS, SDL_Overlay *overlay)
{
	struct private_yuvhwdata *hwdata;

	hwdata = overlay->hwdata;
	if ( hwdata ) {
		SDL_NAME(XvUngrabPort)(GFX_Display, hwdata->port, CurrentTime);
#ifndef NO_SHARED_MEMORY
		if ( hwdata->yuv_use_mitshm ) {
			XShmDetach(GFX_Display, &hwdata->yuvshm);
			shmdt(hwdata->yuvshm.shmaddr);
		}
#endif
		if ( hwdata->image ) {
			XFree(hwdata->image);
		}
		SDL_free(hwdata);
	}
	if ( overlay->pitches ) {
		SDL_free(overlay->pitches);
		overlay->pitches = NULL;
	}
	if ( overlay->pixels ) {
		SDL_free(overlay->pixels);
		overlay->pixels = NULL;
	}
#ifdef XFREE86_REFRESH_HACK
	X11_EnableAutoRefresh(this);
#endif
}

#endif /* SDL_VIDEO_DRIVER_X11_XV */