SDL library memory leak

Question

I am trying to ensure that there are no memory leaks in my application. I narrowed down the leak to the following simple SDL application:

int main(int argc, char* argv[]) {

  if( SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER) != 0) {
    printf("Could not initialize SDL - %s\n", SDL_GetError());
    return -1;
  }

  int flags = SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_HWACCEL|SDL_FULLSCREEN;
  SDL_Surface* screen =  SDL_SetVideoMode(0, 0, 0, flags);

  SDL_Quit();
  return 0;
}

When I run valgrind on this application, it reports a bunch of memory leaks as listed at the end of this message.

Note that, according to the docs on SDL_SetVideoMode, the returned surface from SDL_SetVideoMode is freed by SDL_Quit and must not be freed by the caller.

http://sdl.beuc.net/sdl.wiki/SDL_SetVideoMode

I would appreciate it if someone can tell me what is it that I am missing.

Thank you in advance for your help.

    ==651== Memcheck, a memory error detector
    ==651== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
    ==651== Using Valgrind-3.6.1-Debian and LibVEX; rerun with -h for copyright info
    ==651== Command: ./main
    ==651== 
    ==651== Syscall param writev(vector[...]) points to uninitialised byte(s)
    ==651==    at 0x4F3FE05: writev (writev.c:56)
    ==651==    by 0x40004: ???
    ==651==  Address 0x5701bfb is 19 bytes inside a block of size 16,384 alloc'd
    ==651==    at 0x402732C: calloc (vg_replace_malloc.c:467)
    ==651==    by 0x5B06551: XOpenDisplay (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x4DF52DB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E00403: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED4A8: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 
    ==651== HEAP SUMMARY:
    ==651==     in use at exit: 48,065 bytes in 917 blocks
    ==651==   total heap usage: 13,115 allocs, 12,198 frees, 1,985,815 bytes allocated
    ==651== 
    ==651== 10 bytes in 2 blocks are definitely lost in loss record 9 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x4EEC010: strdup (strdup.c:43)
    ==651==    by 0xBED27FFF: ???
    ==651== 
    ==651== 12 bytes in 1 blocks are definitely lost in loss record 14 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x5C2206A: ???
    ==651==    by 0x5C21AE4: ???
    ==651==    by 0x5C21E8A: ???
    ==651==    by 0x5C22365: ???
    ==651==    by 0x5C1C8AD: ???
    ==651==    by 0x5C1CBAB: ???
    ==651==    by 0x4DF62CB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E006CF: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED4A8: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 112 (8 direct, 104 indirect) bytes in 1 blocks are definitely lost in loss record 135 of 167
    ==651==    at 0x402896C: realloc (vg_replace_malloc.c:525)
    ==651==    by 0x5B2A7B6: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2ACB2: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2C75F: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2CFEA: _XlcCreateLC (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B4BFD9: _XlcDefaultLoader (in /usr/lib/i386-linux-        gnu/libX11.so.6.3.0)
    ==651==    by 0x5B34E3B: _XOpenLC (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B34FA1: _XlcCurrentLC (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x4E005DB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED4A8: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 112 (8 direct, 104 indirect) bytes in 1 blocks are definitely lost in loss record 136 of 167
    ==651==    at 0x402896C: realloc (vg_replace_malloc.c:525)
    ==651==    by 0x5B2A7B6: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2ACB2: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2C75F: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B2CFEA: _XlcCreateLC (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B4BFD9: _XlcDefaultLoader (in /usr/lib/i386-linux-        gnu/libX11.so.6.3.0)
    ==651==    by 0x5B34E3B: _XOpenLC (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B350BA: _XrmInitParseInfo (in /usr/lib/i386-linux-        gnu/libX11.so.6.3.0)
    ==651==    by 0x5B1B6AD: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B1F294: XrmGetStringDatabase (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5AFA4DA: ??? (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5AFA6F6: XGetDefault (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651== 
    ==651== 124 bytes in 1 blocks are definitely lost in loss record 137 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x55B0747: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B0802: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B029F: xcb_connect_to_display_with_auth_info (in /usr/lib/i386- linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B045A: xcb_connect (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x5B16407: _XConnectXCB (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B0619F: XOpenDisplay (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x4DF52DB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E003DF: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED4A8: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 124 bytes in 1 blocks are definitely lost in loss record 138 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x55B0747: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B0802: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B029F: xcb_connect_to_display_with_auth_info (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B045A: xcb_connect (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x5B16407: _XConnectXCB (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B0619F: XOpenDisplay (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x4DF52DB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DFDD7B: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED574: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 124 bytes in 1 blocks are definitely lost in loss record 139 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x55B0747: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B0802: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B029F: xcb_connect_to_display_with_auth_info (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B045A: xcb_connect (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x5B16407: _XConnectXCB (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x5B0619F: XOpenDisplay (in /usr/lib/i386-linux-gnu/libX11.so.6.3.0)
    ==651==    by 0x4DF52DB: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E00403: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DED4A8: SDL_VideoInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1C79: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4E8F112: (below main) (libc-start.c:226)
    ==651== 
    ==651== 124 bytes in 1 blocks are definitely lost in loss record 140 of 167
    ==651==    at 0x4028876: malloc (vg_replace_malloc.c:236)
    ==651==    by 0x55B0747: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B0802: ??? (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B029F: xcb_connect_to_display_with_auth_info (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x55B045A: xcb_connect (in /usr/lib/i386-linux-gnu/libxcb.so.1.1.0)
    ==651==    by 0x5534050: pa_client_conf_from_x11 (in /usr/lib/i386-linux-gnu/libpulsecommon-1.0.so)
    ==651==    by 0x54172E4: pa_context_new_with_proplist (in /usr/lib/i386-linux-gnu/libpulse.so.0.13.4)
    ==651==    by 0x54173EA: pa_context_new (in /usr/lib/i386-linux-gnu/libpulse.so.0.13.4)
    ==651==    by 0x54085C5: pa_simple_new (in /usr/lib/i386-linux-gnu/libpulse-simple.so.0.0.3)
    ==651==    by 0x4DF4263: ??? (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC2B16: SDL_AudioInit (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651==    by 0x4DC1BD6: SDL_InitSubSystem (in /usr/lib/libSDL-1.2.so.0.11.3)
    ==651== 
    ==651== LEAK SUMMARY:
    ==651==    definitely lost: 534 bytes in 9 blocks
    ==651==    indirectly lost: 208 bytes in 8 blocks
    ==651==      possibly lost: 0 bytes in 0 blocks
    ==651==    still reachable: 47,323 bytes in 900 blocks
    ==651==         suppressed: 0 bytes in 0 blocks
    ==651== Reachable blocks (those to which a pointer was found) are not shown.
    ==651== To see them, rerun with: --leak-check=full --show-reachable=yes
    ==651== 
    ==651== For counts of detected and suppressed errors, rerun with: -v
    ==651== Use --track-origins=yes to see where uninitialised values come from
    ==651== ERROR SUMMARY: 10 errors from 9 contexts (suppressed: 113 from 13)

SDL version 1.2.14. Running on Ubuntu 11.10. All the latest upgrades applied. — Peter, Dec 09 '11 at 21:48
Exact duplicate of http://stackoverflow.com/questions/1997171/why-does-valgrind-say-basic-sdl-program-is-leaking-memory — Prof. Falken, Dec 09 '11 at 22:54

score 6 · Accepted Answer · answered Dec 09 '11 at 22:33

6

Unfortunately, it's not uncommon for libraries to have memory leaks. As long as it's not the ever-growing kind, it's ugly but no big deal. The OS will free the memory upon application exit. (At least operating systems such as Windows and Linux.)

answered Dec 09 '11 at 22:33

Prof. Falken

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Thank you for your help. I understand the general problem. I was looking for some confirmation that it is not something in my code that I am missing. Either that or some workaround that people have used in the past. – Peter Dec 10 '11 at 00:11

SDL library memory leak

1 Answers1