Mercurial > sdl-ios-xcode

view docs/man3/SDL_CD.3 @ 4158:96ce26f24b01 SDL-1.2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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 4e3b250c950e
children 1238da4a7112
line wrap: on
line source

.TH "SDL_CD" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_CD \- CDROM Drive Information
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  int id;
  CDstatus status;
  int numtracks;
  int cur_track;
  int cur_frame;
  SDL_CDtrack track[SDL_MAX_TRACKS+1];
} SDL_CD;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBid\fR
Private drive identifier
.TP 20
\fBstatus\fR
Drive \fIstatus\fR
.TP 20
\fBnumtracks\fR
Number of tracks on the CD
.TP 20
\fBcur_track\fR
Current track
.TP 20
\fBcur_frame\fR
Current frame offset within the track
.TP 20
\fBtrack\fR[SDL_MAX_TRACKS+1]
Array of track descriptions\&. (see \fI\fBSDL_CDtrack\fR\fR)
.SH "DESCRIPTION"
.PP
An \fBSDL_CD\fR structure is returned by \fI\fBSDL_CDOpen\fP\fR\&. It represents an opened CDROM device and stores information on the layout of the tracks on the disc\&.
.PP
A frame is the base data unit of a CD\&. \fBCD_FPS\fP frames is equal to 1 second of music\&. SDL provides two macros for converting between time and frames: \fBFRAMES_TO_MSF(f, M,S,F)\fP and \fBMSF_TO_FRAMES\fP\&.
.SH "EXAMPLES"
.PP
.nf
\f(CWint min, sec, frame;
int frame_offset;

FRAMES_TO_MSF(cdrom->cur_frame, &min, &sec, &frame);
printf("Current Position: %d minutes, %d seconds, %d frames
", min, sec, frame);

frame_offset=MSF_TO_FRAMES(min, sec, frame);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_CDOpen\fP\fR, \fI\fBSDL_CDtrack\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58