apr_file_open() and non blocking IO

[Graham Leggett]

Hi all,

I am trying to open a fifo on disk with the O_NONBLOCK flag set, and I  
notice that apr's apr_file_open() cannot do this.

As a result, if nobody else is already reading from the fifo,  
apr_file_open blocks, and this is the behaviour I want to avoid.

Does anyone know of any reason why this wouldn't work?

Index: include/apr_file_io.h
===================================================================
--- include/apr_file_io.h       (revision 916953)
+++ include/apr_file_io.h       (working copy)
@@ -81,6 +81,8 @@
 #define APR_FOPEN_SPARSE      0x08000 /**< Platform dependent flag  
to enable
                                        * sparse file support, see  
WARNING below
                                        */
+#define APR_FOPEN_NONBLOCK    0x10000 /**< Platform dependent flag to  
enable
+                                       * non blocking file io */

 #define APR_FOPEN_ROTATING  0x10000 /**< Do file file rotation  
checking */

@@ -102,6 +104,7 @@
 #define APR_FILE_NOCLEANUP   APR_FOPEN_NOCLEANUP  /**< @deprecated  
@see APR_FOPEN_NOCLEANUP */
 #define APR_SENDFILE_ENABLED APR_FOPEN_SENDFILE_ENABLED /**<  
@deprecated @see APR_FOPEN_SENDFILE_ENABLED */
 #define APR_LARGEFILE        APR_FOPEN_LARGEFILE  /**< @deprecated  
@see APR_FOPEN_LARGEFILE */
+#define APR_NONBLOCK         APR_FOPEN_NONBLOCK   /**< @deprecated  
@see APR_FOPEN_NONBLOCK */

 /** @warning APR_FOPEN_LARGEFILE flag only has effect on some
  * platforms where sizeof(apr_off_t) == 4.  Where implemented, it
Index: file_io/unix/open.c
===================================================================
--- file_io/unix/open.c (revision 916953)
+++ file_io/unix/open.c (working copy)
@@ -136,6 +136,12 @@
     }
 #endif

+#ifdef O_NONBLOCK
+    if (flag & APR_NONBLOCK) {
+        oflags |= O_NONBLOCK;
+    }
+#endif
+
 #ifdef O_CLOEXEC
     /* Introduced in Linux 2.6.23. Silently ignored on earlier Linux  
kernels.
      */

Regards,
Graham
--