From: Takashi Iwai <tiwai@suse.de>
Date: Fri, 17 Feb 2006 20:51:12 +0000 (+0000)
Subject: Add description about non-blocking behavior
X-Git-Tag: v1.0.11rc4~30
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=37aa30ddc374b0078860c7f67b3a309aff3bb435;p=alsa-lib.git

Add description about non-blocking behavior

Add description about the default non-blocking behavior.
---

diff --git a/NOTES b/NOTES
index 5c0e0103..eb745c6b 100644
--- a/NOTES
+++ b/NOTES
@@ -32,3 +32,22 @@ assert() to catch with a debugger, in addition to parameter debugging.
 
 This feature is disabled when --with-debug=no is passed to configure,
 i.e. no strict checking is done in alsa-lib.
+
+
+Blocking Open Mode
+==================
+
+The default behavior of blocking at snd_pcm_open is changed to
+non-blocking since version 1.0.11.  That is, snd_pcm_open() returns
+-EAGAIN immediately when the device is in use and cannot be opened,
+while the function was blocked in the former version.  This influences
+only on the opening behavior.  The behavior of the further access,
+read/write, poll or commit, are not changed.  They follow the extra
+flag argument of snd_pcm_open() as well as the former version.
+
+For taking back the compatible behavior of open blocking mode, set
+
+	defaults.pcm.nonblock 0
+
+in /etc/asound.conf or ~/.asoundrc file.
+