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Fixed bug #46
Date: Fri, 13 Jan 2006 18:09:45 -0500
From: mhall4400 vipmail kvcc edu
Subject: Possible SDL bug
Greetings
I believe Ive come across a bug in your SDL product (1.2.9), in the CD-ROM
control portion of the library.
When calling the SDL_CDPlay() function to play the last track of a CD using the
offset and length from an SDL_CD structure generated by SDL_CDOpen(), I get the
following error from a call to SDL_Error():
mciSendCommand() error: The specified parameter is out of range for the
specified command.
The code returning the error is:
SDL_CDPlay(g_playingDriveSDLCD,
g_playingDriveSDLCD->track[trackNumberInt].offset,
g_playingDriveSDLCD->track[trackNumberInt].length)
Subtracting one from the length of the provided length seems to repair the
problem:
SDL_CDPlay(g_playingDriveSDLCD,
g_playingDriveSDLCD->track[trackNumberInt].offset,
(g_playingDriveSDLCD->track[trackNumberInt].length) - 1)
Ive replicated this problem on Windows 98 SE (several months since last
patch), fully-patched Window ME, seldom-patched Windows XP SP1, and
fully-patched Windows XP SP2.
While investigating the issue, I came across a line in your librarys win32
source code in file \src\cdrom\win32\SDL_syscdrom.c (source code zip archive
from your download page), function: SDL_SYS_CDGetTOC(), line 226 where you add
1 to the value for length to fix MCI last track length bug. This may be the
source of the issue (because subtracting 1 from the length seems to resolve the
issue). Microsoft may have patched the referenced bug since you wrote that
line.
Mike Hall
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 14 Mar 2006 05:34:39 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_DestroySemaphore</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Multi-threaded Programming" HREF="thread.html"><LINK REL="PREVIOUS" TITLE="SDL_CreateSemaphore" HREF="sdlcreatesemaphore.html"><LINK REL="NEXT" TITLE="SDL_SemWait" HREF="sdlsemwait.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlcreatesemaphore.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlsemwait.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLDESTROYSEMAPHORE" ></A >SDL_DestroySemaphore</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN7982" ></A ><H2 >Name</H2 >SDL_DestroySemaphore -- Destroys a semaphore that was created by <A HREF="sdlcreatesemaphore.html" >SDL_CreateSemaphore</A >.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN7986" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN7987" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h" #include "SDL_thread.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >void <B CLASS="FSFUNC" >SDL_DestroySemaphore</B ></CODE >(SDL_sem *sem);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7993" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_DestroySemaphore</TT > destroys the semaphore pointed to by <TT CLASS="PARAMETER" ><I >sem</I ></TT > that was created by <A HREF="sdlcreatesemaphore.html" ><TT CLASS="FUNCTION" >SDL_CreateSemaphore</TT ></A >. It is not safe to destroy a semaphore if there are threads currently blocked waiting on it.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8000" ></A ><H2 >Examples</H2 ><P ><PRE CLASS="PROGRAMLISTING" >if (my_sem != NULL) { SDL_DestroySemaphore(my_sem); my_sem = NULL; }</PRE ></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8004" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcreatesemaphore.html" ><TT CLASS="FUNCTION" >SDL_CreateSemaphore</TT ></A >, <A HREF="sdlsemwait.html" ><TT CLASS="FUNCTION" >SDL_SemWait</TT ></A >, <A HREF="sdlsemtrywait.html" ><TT CLASS="FUNCTION" >SDL_SemTryWait</TT ></A >, <A HREF="sdlsemwaittimeout.html" ><TT CLASS="FUNCTION" >SDL_SemWaitTimeout</TT ></A >, <A HREF="sdlsempost.html" ><TT CLASS="FUNCTION" >SDL_SemPost</TT ></A >, <A HREF="sdlsemvalue.html" ><TT CLASS="FUNCTION" >SDL_SemValue</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlcreatesemaphore.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlsemwait.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CreateSemaphore</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="thread.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_SemWait</TD ></TR ></TABLE ></DIV ></BODY ></HTML >