view src/video/bwindow/SDL_sysmouse.cc @ 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 4e29535b821b
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"

#include <AppKit.h>
#include <GameKit.h>

#include "SDL_BWin.h"

extern "C" {
#include "../SDL_cursor_c.h"
#include "SDL_sysmouse_c.h"

/* Convert bits to padded bytes */
#define PADDED_BITS(bits)  ((bits+7)/8)

/* The implementation dependent data for the window manager cursor */
struct WMcursor {
	char *bits;
};

/* Can this be done in the BeOS? */
WMcursor *BE_CreateWMCursor(_THIS,
		Uint8 *data, Uint8 *mask, int w, int h, int hot_x, int hot_y)
{
	WMcursor *cursor;
	int allowed_x;
	int allowed_y;
	int run, pad, i;
	char *cptr;

	allowed_x = 16;	/* BeOS limitation */
	allowed_y = 16;	/* BeOS limitation */
	if ( (w > allowed_x) || (h > allowed_y) ) {
		SDL_SetError("Only cursors of dimension (%dx%d) are allowed",
							allowed_x, allowed_y);
		return(NULL);
	}

	/* Allocate the cursor */
	cursor = (WMcursor *)SDL_malloc(sizeof(WMcursor));
	if ( cursor == NULL ) {
		SDL_OutOfMemory();
		return(NULL);
	}
	cursor->bits = (char *)SDL_malloc(4+2*((allowed_x/8)*allowed_y));
	if ( cursor->bits == NULL ) {
		SDL_free(cursor);
		SDL_OutOfMemory();
		return(NULL);
	}
	cursor->bits[0] = allowed_y;		/* Size of the cursor */
	cursor->bits[1] = 1;			/* Bit depth of cursor */
	cursor->bits[2] = hot_y;
	cursor->bits[3] = hot_x;
	cptr = &cursor->bits[4];

	/* Pad out to the normal cursor size */
	run = PADDED_BITS(w);
	pad = PADDED_BITS(allowed_x)-run;
	for ( i=0; i<h; ++i ) {
		SDL_memcpy(cptr, data, run);
		SDL_memset(cptr+run, 0, pad);
		data += run;
		cptr += (run+pad);
	}
	for ( ; i<allowed_y; ++i ) {
		SDL_memset(cptr, 0, run+pad);
		cptr += (run+pad);
	}
	for ( i=0; i<h; ++i ) {
		/* FIXME: The mask should be OR'd with the data to turn 
		   inverted color pixels black, since inverted color pixels
		   aren't supported under BeOS.
		 */
		SDL_memcpy(cptr, mask, run);
		SDL_memset(cptr+run, 0, pad);
		mask += run;
		cptr += (run+pad);
	}
	for ( ; i<allowed_y; ++i ) {
		SDL_memset(cptr, 0, run+pad);
		cptr += (run+pad);
	}
	return(cursor);
}

int BE_ShowWMCursor(_THIS, WMcursor *cursor)
{
	if ( be_app->Lock() ) {
		if ( cursor == NULL ) {
			if ( SDL_BlankCursor != NULL ) {
				be_app->SetCursor(SDL_BlankCursor->bits);
			}
		} else {
			be_app->SetCursor(cursor->bits);
		}
		be_app->Unlock();
	}
	return(1);
}

void BE_FreeWMCursor(_THIS, WMcursor *cursor)
{
	SDL_free(cursor->bits);
	SDL_free(cursor);
}

/* Implementation by Christian Bauer <cbauer@student.physik.uni-mainz.de> */
void BE_WarpWMCursor(_THIS, Uint16 x, Uint16 y)
{
	BPoint pt;
	SDL_Win->GetXYOffset(pt.x, pt.y);
	pt.x += x;
	pt.y += y;
	SDL_Win->Lock();
	SDL_Win->ConvertToScreen(&pt);
	SDL_Win->Unlock();
	set_mouse_position((int32)pt.x, (int32)pt.y);
}

/* Check to see if we need to enter or leave mouse relative mode */
void BE_CheckMouseMode(_THIS)
{
        /* If the mouse is hidden and input is grabbed, we use relative mode */
        if ( !(SDL_cursorstate & CURSOR_VISIBLE) &&
             (_this->input_grab != SDL_GRAB_OFF) ) {
                mouse_relative = 1;
        } else {
                mouse_relative = 0;
        }
}

}; /* Extern C */