view src/video/photon/SDL_ph_modes.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 d910939febfa
children e49147870aac c121d94672cb 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"

#include "SDL_ph_modes_c.h"

static PgVideoModeInfo_t mode_info;
static PgVideoModes_t mode_list;

/* The current list of available video modes */
SDL_Rect  SDL_modelist[PH_MAX_VIDEOMODES];
SDL_Rect* SDL_modearray[PH_MAX_VIDEOMODES];

static int compare_modes_by_res(const void* mode1, const void* mode2)
{
    PgVideoModeInfo_t mode1_info;
    PgVideoModeInfo_t mode2_info;

    if (PgGetVideoModeInfo(*(unsigned short*)mode1, &mode1_info) < 0)
    {
        return 0;
    }

    if (PgGetVideoModeInfo(*(unsigned short*)mode2, &mode2_info) < 0)
    {
        return 0;
    }

    if (mode1_info.width == mode2_info.width)
    {
        return mode2_info.height - mode1_info.height;
    }
    else
    {
        return mode2_info.width - mode1_info.width;
    }
}

SDL_Rect **ph_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags)
{
    int i = 0;
    int j = 0;
    SDL_Rect Amodelist[PH_MAX_VIDEOMODES];

    for (i=0; i<PH_MAX_VIDEOMODES; i++)
    {
        SDL_modearray[i]=&SDL_modelist[i];
    }

    if (PgGetVideoModeList(&mode_list) < 0)
    {
       SDL_SetError("ph_ListModes(): PgGetVideoModeList() function failed !\n");
       return NULL;
    }

    mode_info.bits_per_pixel = 0;

    for (i=0; i < mode_list.num_modes; i++) 
    {
        if (PgGetVideoModeInfo(mode_list.modes[i], &mode_info) < 0)
        {
            SDL_SetError("ph_ListModes(): PgGetVideoModeInfo() function failed on mode: 0x%X.\n", mode_list.modes[i]);
            return NULL;
        }
        if(mode_info.bits_per_pixel == format->BitsPerPixel)
        {
            Amodelist[j].w = mode_info.width;
            Amodelist[j].h = mode_info.height;
            Amodelist[j].x = 0;
            Amodelist[j].y = 0;
            j++;	
        }
    }
	
    /* reorder biggest for smallest, assume width dominates */

    for(i=0; i<j; i++)
    {
        SDL_modelist[i].w = Amodelist[j - i - 1].w;
        SDL_modelist[i].h = Amodelist[j - i - 1].h;
        SDL_modelist[i].x = Amodelist[j - i - 1].x;
        SDL_modelist[i].y = Amodelist[j - i - 1].y;
    }
    SDL_modearray[j]=NULL;
	
    return SDL_modearray;
}

void ph_FreeVideoModes(_THIS)
{
   return;
}

/* return the mode associated with width, height and bpp */
/* if there is no mode then zero is returned             */
int ph_GetVideoMode(int width, int height, int bpp)
{
    int i;
    int modestage=0;
    int closestmode=0;

    if (PgGetVideoModeList(&mode_list) < 0)
    {
        return -1;
    }

    /* special case for the double-sized 320x200 mode */
    if ((width==640) && (height==400))
    {
       modestage=1;
    }

    /* search list for exact match */
    for (i=0; i<mode_list.num_modes; i++)
    {
        if (PgGetVideoModeInfo(mode_list.modes[i], &mode_info) < 0)
        {
            return 0;
        }

        if ((mode_info.width == width) && (mode_info.height == height) && 
            (mode_info.bits_per_pixel == bpp))
        {
            return mode_list.modes[i];
        }
        else
        {
           if ((modestage) && (mode_info.width == width) && (mode_info.height == height+80) && 
               (mode_info.bits_per_pixel == bpp))
           {
              modestage=2;
              closestmode=mode_list.modes[i];
           }
        }
    }

    /* if we are here, then no 640x400xbpp mode found and we'll emulate it via 640x480xbpp mode */
    if (modestage==2)
    {
       return closestmode;
    }

    return (i == mode_list.num_modes) ? 0 : mode_list.modes[i];
}

/* return the mode associated with width, height and bpp               */
/* if requested bpp is not found the mode with closest bpp is returned */
int get_mode_any_format(int width, int height, int bpp)
{
    int i, closest, delta, min_delta;

    if (PgGetVideoModeList(&mode_list) < 0)
    {
        return -1;
    }

    SDL_qsort(mode_list.modes, mode_list.num_modes, sizeof(unsigned short), compare_modes_by_res);

    for(i=0;i<mode_list.num_modes;i++)
    {
        if (PgGetVideoModeInfo(mode_list.modes[i], &mode_info) < 0)
        {
            return 0;
        }
        if ((mode_info.width == width) && (mode_info.height == height))
        {
           break;
        }
    }

    if (i<mode_list.num_modes)
    {
        /* get closest bpp */
        closest = i++;
        if (mode_info.bits_per_pixel == bpp)
        {
            return mode_list.modes[closest];
        }

        min_delta = abs(mode_info.bits_per_pixel - bpp);

        while(1)
        {
            if (PgGetVideoModeInfo(mode_list.modes[i], &mode_info) < 0)
            {
                return 0;
            }

            if ((mode_info.width != width) || (mode_info.height != height))
            {
                break;
            }
            else
            {
                if (mode_info.bits_per_pixel == bpp)
                {
                    closest = i;
                    break;
                }
                else
                {
                    delta = abs(mode_info.bits_per_pixel - bpp);
                    if (delta < min_delta)
                    {
                        closest = i;
                        min_delta = delta;
                    }
                    i++;
                }
            }
        }
        return mode_list.modes[closest];
    }

    return 0;
}

int ph_ToggleFullScreen(_THIS, int on)
{
    return -1;
}

int ph_EnterFullScreen(_THIS, SDL_Surface* screen, int fmode)
{
    PgDisplaySettings_t settings;
    int mode;
    char* refreshrate;
    int refreshratenum;

    if (!currently_fullscreen)
    {
        /* Get the video mode and set it */
        if (screen->flags & SDL_ANYFORMAT)
        {
            if ((mode = get_mode_any_format(screen->w, screen->h, screen->format->BitsPerPixel)) == 0)
            {
                SDL_SetError("ph_EnterFullScreen(): can't find appropriate video mode !\n");
                return 0;
            }
        }
        else
        {
            if ((mode = ph_GetVideoMode(screen->w, screen->h, screen->format->BitsPerPixel)) == 0)
            {
                SDL_SetError("ph_EnterFullScreen(): can't find appropriate video mode !\n");
                return 0;
            }
            if (PgGetVideoModeInfo(mode, &mode_info) < 0)
            {
                SDL_SetError("ph_EnterFullScreen(): can't get video mode capabilities !\n");
                return 0;
            }
            if (mode_info.height != screen->h)
            {
               if ((mode_info.height==480) && (screen->h==400))
               {
                  videomode_emulatemode=1;
               }
            }
            else
            {
               videomode_emulatemode=0;
            }
        }

        /* save old video mode caps */
        PgGetVideoMode(&settings);
        old_video_mode=settings.mode;
        old_refresh_rate=settings.refresh;

        /* setup new video mode */
        settings.mode = mode;
        settings.refresh = 0;
        settings.flags = 0;

        refreshrate=SDL_getenv("SDL_PHOTON_FULLSCREEN_REFRESH");
        if (refreshrate!=NULL)
        {
           if (SDL_sscanf(refreshrate, "%d", &refreshratenum)==1)
           {
               settings.refresh = refreshratenum;
           }
        }

        if (PgSetVideoMode(&settings) < 0)
        {
            SDL_SetError("ph_EnterFullScreen(): PgSetVideoMode() call failed !\n");
            return 0;
        }

        if (this->screen)
        {
            if ((this->screen->flags & SDL_OPENGL)==SDL_OPENGL)
            {
#if !SDL_VIDEO_OPENGL || (_NTO_VERSION < 630)
                return 0; /* 6.3.0 */
#endif
            }
        }

        if (fmode==0)
        {
            if (OCImage.direct_context==NULL)
            {
                OCImage.direct_context=(PdDirectContext_t*)PdCreateDirectContext();
                if (!OCImage.direct_context)
                {
                    SDL_SetError("ph_EnterFullScreen(): Can't create direct context !\n");
                    ph_LeaveFullScreen(this);
                    return 0;
                }
            }
            OCImage.oldDC=PdDirectStart(OCImage.direct_context);
        }

        currently_fullscreen = 1;
    }
    PgFlush();

    return 1;
}

int ph_LeaveFullScreen(_THIS)
{
    PgDisplaySettings_t oldmode_settings;
       
    if (currently_fullscreen)
    {
        if ((this->screen) && ((this->screen->flags & SDL_OPENGL)==SDL_OPENGL))
        {
#if !SDL_VIDEO_OPENGL || (_NTO_VERSION < 630)
            return 0;
#endif
        }

        /* release routines starts here */
        {
            if (OCImage.direct_context)
            {
                PdDirectStop(OCImage.direct_context);
                PdReleaseDirectContext(OCImage.direct_context);
                OCImage.direct_context=NULL;
            }
            if (OCImage.oldDC)
            {
                PhDCSetCurrent(OCImage.oldDC);
                OCImage.oldDC=NULL;
            }

            currently_fullscreen=0;

            /* Restore old video mode */
            if (old_video_mode != -1)
            {
                oldmode_settings.mode = (unsigned short) old_video_mode;
                oldmode_settings.refresh = (unsigned short) old_refresh_rate;
                oldmode_settings.flags = 0;
                
                if (PgSetVideoMode(&oldmode_settings) < 0)
                {
                    SDL_SetError("Ph_LeaveFullScreen(): PgSetVideoMode() function failed !\n");
                    return 0;
                }
            }

            old_video_mode=-1;
            old_refresh_rate=-1;
        }
    }
    return 1;
}