Mercurial > sdl-ios-xcode

view docs/html/sdlcreatemutex.html @ 1542:a8bf1aa21020

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fixed bug #15 SDL_blit_A.mmx-speed.patch.txt -- Speed improvements and a bugfix for the current GCC inline mmx asm code: - Changed some ops and removed some resulting useless ones. - Added some instruction parallelism (some gain) The resulting speed on my Xeon improved upto 35% depending on the function (measured in fps). - Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was setting the alpha component on the destination surfaces (to opaque-alpha) even when the surface had none. SDL_blit_A.mmx-msvc.patch.txt -- MSVC mmx intrinsics version of the same GCC asm code. MSVC compiler tries to parallelize the code and to avoid register stalls, but does not always do a very good job. Per-surface blending MSVC functions run quite a bit faster than their pure-asm counterparts (upto 55% faster for 16bit ones), but the per-pixel blending runs somewhat slower than asm. - BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all variants) can now also handle formats other than (A)RGB8888. Formats like RGBA8888 and some quite exotic ones are allowed -- like RAGB8888, or actually anything having channels aligned on 8bit boundary and full 8bit alpha (for per-pixel alpha blending). The performance cost of this change is virtually 0 for per-surface alpha blending (no extra ops inside the loop) and a single non-MMX op inside the loop for per-pixel blending. In testing, the per-pixel alpha blending takes a ~2% performance hit, but it still runs much faster than the current code in CVS. If necessary, a separate function with this functionality can be made. This code requires Processor Pack for VC6.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:39:29 +0000
parents 355632dca928
children
line wrap: on
line source

<HTML
><HEAD
><TITLE
>SDL_CreateMutex</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_KillThread"
HREF="sdlkillthread.html"><LINK
REL="NEXT"
TITLE="SDL_DestroyMutex"
HREF="sdldestroymutex.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="sdlkillthread.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdldestroymutex.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLCREATEMUTEX"
></A
>SDL_CreateMutex</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7820"
></A
><H2
>Name</H2
>SDL_CreateMutex&nbsp;--&nbsp;Create a mutex</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7823"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN7824"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"
#include "SDL_thread.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_mutex *<B
CLASS="FSFUNC"
>SDL_CreateMutex</B
></CODE
>(void);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7830"
></A
><H2
>Description</H2
><P
>Create a new, unlocked mutex.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7833"
></A
><H2
>Examples</H2
><PRE
CLASS="PROGRAMLISTING"
>SDL_mutex *mut;

mut=SDL_CreateMutex();
.
.
if(SDL_mutexP(mut)==-1){
  fprintf(stderr, "Couldn't lock mutex\n");
  exit(-1);
}
.
/* Do stuff while mutex is locked */
.
.
if(SDL_mutexV(mut)==-1){
  fprintf(stderr, "Couldn't unlock mutex\n");
  exit(-1);
}

SDL_DestroyMutex(mut);&#13;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7836"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlmutexp.html"
><TT
CLASS="FUNCTION"
>SDL_mutexP</TT
></A
>,
<A
HREF="sdlmutexv.html"
><TT
CLASS="FUNCTION"
>SDL_mutexV</TT
></A
>,
<A
HREF="sdldestroymutex.html"
><TT
CLASS="FUNCTION"
>SDL_DestroyMutex</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="sdlkillthread.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="sdldestroymutex.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_KillThread</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_DestroyMutex</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>