CODEWITHSUNDEEP
csdl
zufall
zufall

Reputation: 69

SDL_Quit() causes SIGBUS error

The following basic SDL2 code taken from a tutorial website is causing some strange trouble :

#include <SDL2/SDL.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define SCREENH 768
#define SCREENW 1366

SDL_Window *window = NULL;
SDL_Surface *screenSurface = NULL;
SDL_Surface *windowSurface = NULL;

int init_SDL() {
    int success = 0;
    if(SDL_Init(SDL_INIT_VIDEO) < 0) {
       printf("SDL could not initialize! ");
       printf("SDL_Error: %s\n",SDL_GetError());
       success = -1;
    }
    else {
       window = SDL_CreateWindow("SDL2_Tutorial02",SDL_WINDOWPOS_UNDEFINED,SDL_WINDOWPOS_UNDEFINED,SCREENW,SCREENH,SDL_WINDOW_SHOWN);
      if(window == NULL) {
          printf("Window could not be created! ");
          printf("SDL Error: %s\n",SDL_GetError());
      }
      else {
          screenSurface = SDL_GetWindowSurface(window);
      }
    }
    return success;
}

int loadMedia() {
    int success = 0;
    windowSurface = SDL_LoadBMP("Images/Hallo.bmp");
    if(windowSurface == NULL) {
    printf("Unable to load image! ");
    printf("SDL Error: %s\n",SDL_GetError());
    success = -1;
    }
    return success;
}

void close() {
    SDL_FreeSurface(windowSurface);
    windowSurface = NULL;
    SDL_DestroyWindow(window);
    window = NULL;
    SDL_Quit();
}

int main(int argc,char *argv[]) {
    assert(init_SDL() == 0);
    assert(loadMedia() == 0);
    SDL_BlitSurface(windowSurface,NULL,screenSurface,NULL);
    SDL_UpdateWindowSurface(window);
    SDL_Delay(3000);
    close();
    exit(EXIT_SUCCESS);
}

As soon as SDL_Quit(), placed in close(), is invoked I receive a memory access error. Using GDB the following is revealed:

49      SDL_Quit();
(gdb) n

Program received signal SIGBUS, Bus error.
0x00007ffff68a5895 in ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6
(gdb)

The strange about that is when I place SDL_Quit() outside of close() like this:

void close() {
    SDL_FreeSurface(windowSurface);
    windowSurface = NULL;
    SDL_DestroyWindow(window);
    window = NULL;
}

int main(int argc,char *argv[]) {
    assert(init_SDL() == 0);
    assert(loadMedia() == 0);
    SDL_BlitSurface(windowSurface,NULL,screenSurface,NULL);
    SDL_UpdateWindowSurface(window);
    SDL_Delay(3000);
    close();
    SDL_Quit();
    exit(EXIT_SUCCESS);
}

all things are fine. SDL_Quit() works without error. Why does it cause a SIGBUS Error when I invoke SDL_Quit() in another function ?

EDIT: This code was compiled on ubuntu 14.04 with gcc and the following compile command

gcc -g3 -o tutorial tutorial.c `sdl2-config --cflags --libs`

Upvotes: 3

Views: 224

Answers (1)

blakelead
blakelead

Reputation: 1890

Your function close() is in conflict with an internal SDL function with the same name causing weird behavior (actually, it is the libc standard close() syscall called by SDL).

Rename your function and it should be fine.

Upvotes: 4

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