svn commit: r195134 - in head/sys: dev/ath/ath_hal/ar5416 kern sys

Poul-Henning Kamp phk at
Sun Jun 28 11:28:15 UTC 2009

Author: phk
Date: Sun Jun 28 11:28:14 2009
New Revision: 195134

  There are a number of ways an application can check if there are
  inbound data waiting on a filedescriptor, such as a pipe or a socket,
  for instance by using select(2), poll(2), kqueue(2), ioctl(FIONREAD)
  But we have no way of finding out if written data have yet to be
  disposed of, for instance, transmitted (and ack'ed!) to some remote
  host, or read by the applicantion at the far end of the pipe.
  The closest we get, is calling shutdown(2) on a TCP socket in
  non-blocking mode, but this has the undesirable sideeffect of
  preventing future communication.
  Add a complement to FIONREAD, called FIONWRITE, which returns the
  number of bytes not yet properly disposed of.  Implement it for
  all sockets.
  A HTTP server will want to time out connections, if no new request
  arrives within a certain period after the last transmitted response
  has actually been sent (and ack'ed).
  For a busy HTTP server, this timeout can be subsecond duration.
  In order to signal to a load-balancer that the connection is truly
  dead, TCP_RST will be the preferred method, as this avoids the need
  for a RTT delay for FIN handshaking, with a client which, surprisingly
  often, no longer at the remote IP number.
  If a slow, distant client is being served a response which is big
  enough to fill the window, but small enough to fit in the socket
  buffer, the write(2) call will return immediately.
  If the session timeout is armed at that time, all bytes in the
  response may not have been transmitted by the time it fires.
  FIONWRITE allows the timeout to check that no data is outstanding
  on the connection, before it TCP_RST's it.
  Input & Idea from: rwatson
  Approved by:	re (kib)


Modified: head/sys/dev/ath/ath_hal/ar5416/ar5416_reset.c
--- head/sys/dev/ath/ath_hal/ar5416/ar5416_reset.c	Sun Jun 28 10:30:53 2009	(r195133)
+++ head/sys/dev/ath/ath_hal/ar5416/ar5416_reset.c	Sun Jun 28 11:28:14 2009	(r195134)
@@ -124,7 +124,7 @@ ar5416Reset(struct ath_hal *ah, HAL_OPMO
 	if (!ar5416SetPowerMode(ah, HAL_PM_AWAKE, AH_TRUE)) {
 		HALDEBUG(ah, HAL_DEBUG_ANY, "%s: chip did not wakeup\n",
+		// FAIL(HAL_EIO);

Modified: head/sys/kern/sys_socket.c
--- head/sys/kern/sys_socket.c	Sun Jun 28 10:30:53 2009	(r195133)
+++ head/sys/kern/sys_socket.c	Sun Jun 28 11:28:14 2009	(r195134)
@@ -169,6 +169,11 @@ soo_ioctl(struct file *fp, u_long cmd, v
 		*(int *)data = so->so_rcv.sb_cc;
+		/* Unlocked read. */
+		*(int *)data = so->so_snd.sb_cc;
+		break;
 		error = fsetown(*(int *)data, &so->so_sigio);

Modified: head/sys/sys/filio.h
--- head/sys/sys/filio.h	Sun Jun 28 10:30:53 2009	(r195133)
+++ head/sys/sys/filio.h	Sun Jun 28 11:28:14 2009	(r195134)
@@ -55,6 +55,7 @@ struct fiodgname_arg {
 	void	*buf;
 #define	FIODGNAME	_IOW('f', 120, struct fiodgname_arg) /* get dev. name */
+#define	FIONWRITE	_IOR('f', 119, int)	/* get # bytes (yet) to write */
 /* Handle lseek SEEK_DATA and SEEK_HOLE for holey file knowledge. */
 #define	FIOSEEKDATA	_IOWR('f', 97, off_t)	/* SEEK_DATA */
 #define	FIOSEEKHOLE	_IOWR('f', 98, off_t)	/* SEEK_HOLE */

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