nonblocking: Add comment.

* lib/fcntl.in.h (O_NONBLOCK): Add comment.

diff --git a/ChangeLog b/ChangeLog
index d0923da..1f09ff8 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2011-04-17  Bruno Haible  <bruno@clisp.org>
 
+       nonblocking: Add comment.
+       * lib/fcntl.in.h (O_NONBLOCK): Add comment.
+
+2011-04-17  Bruno Haible  <bruno@clisp.org>
+
        nonblocking: Add tests for sockets.
        * tests/test-nonblocking-socket.sh: New file.
        * tests/test-nonblocking-socket-main.c: New file.

diff --git a/lib/fcntl.in.h b/lib/fcntl.in.h
index 971316f..ce7c8c0 100644 (file)
--- a/lib/fcntl.in.h
+++ b/lib/fcntl.in.h
@@ -218,6 +218,9 @@ _GL_WARN_ON_USE (openat, "openat is not portable - "
 # define O_NONBLOCK O_NDELAY
 #endif
 
+/* If the gnulib module 'nonblocking' is in use, guarantee a working non-zero
+   value of O_NONBLOCK.  Otherwise, O_NONBLOCK is defined (above) to O_NDELAY
+   or to 0 as fallback.  */
 #if @GNULIB_NONBLOCKING@
 # if O_NONBLOCK
 #  define GNULIB_defined_O_NONBLOCK 0