From: Jaroslav Kysela <perex@perex.cz>
Date: Sat, 21 Feb 2004 21:13:40 +0000 (+0000)
Subject: Initial
X-Git-Tag: v1.0.3~21
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=3190eec928093bbc71e78250b1254451d9afaae3;p=alsa-oss.git

Initial
---

diff --git a/oss-redir/README b/oss-redir/README
new file mode 100644
index 0000000..68b2465
--- /dev/null
+++ b/oss-redir/README
@@ -0,0 +1,39 @@
+Open Sound System call redirector
+=================================
+
+The purpose of this little piece of code is to redirect
+OSS (Open Sound System) calls to any shared library to avoid
+overhead caused with the LD_PRELOAD wrapper. Especially, 
+wrapping select() and poll() functions cause big overhead.
+
+In ideal world, all OSS programs will use this little code
+to allow a sound emulation for OSS based APIs without requirement
+of ugly LD_PRELOAD hacks.
+
+Usage
+=====
+
+Set environment variable OSS_REDIRECTOR to name of dynamic library
+with lib_oss_* public functions. For example (ALSA):
+
+export OSS_REDIRECTOR=libalsatoss.so
+
+If this variable is not set, or this value is "oss" or "OSS",
+the direct system calls are used.
+
+Porting OSS application to use this code
+========================================
+
+All functions have equivalent as using syscalls. Only one exception
+is select() or poll() usage. It is required to use oss_pcm_select*()
+or oss_pcm_poll*() wrappers to determine the "real" used file
+descriptors and mangle back the result.
+
+Note that the *prepare() functions returns the count of file
+descriptors allocated (poll) or the maximum used file descriptor
+(select).
+
+Porting example
+===============
+
+FIXME: Add a link to a good patch.