/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Socket Timer Functions
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *
 *
 * Changes:
 *       Steve Whitehouse      : Made keepalive timer part of the same
 *                               timer idea.
 *       Steve Whitehouse      : Added checks for sk->sock_readers
 *       David S. Miller       : New socket locking
 *       Steve Whitehouse      : Timer grabs socket ref.
 */
#include <linux/net.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/spinlock.h>
#include <net/sock.h>
#include <linux/atomic.h>
#include <linux/jiffies.h>
#include <net/flow.h>
#include <net/dn.h>

/*
 * Slow timer is for everything else (n * 500mS)
 */

#define SLOW_INTERVAL (HZ/2)

static void dn_slow_timer(unsigned long arg);

void dn_start_slow_timer(struct sock *sk)
{
	setup_timer(&sk->sk_timer, dn_slow_timer, (unsigned long)sk);
	sk_reset_timer(sk, &sk->sk_timer, jiffies + SLOW_INTERVAL);
}

void dn_stop_slow_timer(struct sock *sk)
{
	sk_stop_timer(sk, &sk->sk_timer);
}

static void dn_slow_timer(unsigned long arg)
{
	struct sock *sk = (struct sock *)arg;
	struct dn_scp *scp = DN_SK(sk);

	bh_lock_sock(sk);

	if (sock_owned_by_user(sk)) {
		sk_reset_timer(sk, &sk->sk_timer, jiffies + HZ / 10);
		goto out;
	}

	/*
	 * The persist timer is the standard slow timer used for retransmits
	 * in both connection establishment and disconnection as well as
	 * in the RUN state. The different states are catered for by changing
	 * the function pointer in the socket. Setting the timer to a value
	 * of zero turns it off. We allow the persist_fxn to turn the
	 * timer off in a permant way by returning non-zero, so that
	 * timer based routines may remove sockets. This is why we have a
	 * sock_hold()/sock_put() around the timer to prevent the socket
	 * going away in the middle.
	 */
	if (scp->persist && scp->persist_fxn) {
		if (scp->persist <= SLOW_INTERVAL) {
			scp->persist = 0;

			if (scp->persist_fxn(sk))
				goto out;
		} else {
			scp->persist -= SLOW_INTERVAL;
		}
	}

	/*
	 * Check for keepalive timeout. After the other timer 'cos if
	 * the previous timer caused a retransmit, we don't need to
	 * do this. scp->stamp is the last time that we sent a packet.
	 * The keepalive function sends a link service packet to the
	 * other end. If it remains unacknowledged, the standard
	 * socket timers will eventually shut the socket down. Each
	 * time we do this, scp->stamp will be updated, thus
	 * we won't try and send another until scp->keepalive has passed
	 * since the last successful transmission.
	 */
	if (scp->keepalive && scp->keepalive_fxn && (scp->state == DN_RUN)) {
		if (time_after_eq(jiffies, scp->stamp + scp->keepalive))
			scp->keepalive_fxn(sk);
	}

	sk_reset_timer(sk, &sk->sk_timer, jiffies + SLOW_INTERVAL);
out:
	bh_unlock_sock(sk);
	sock_put(sk);
}
value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-12 21:58:13 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-12 21:58:13 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Documentation/media/kapi/v4l2-mediabus.rst?id=e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba'>e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba</a> (<a href='/cgit.cgi/linux/net-next.git/patch/Documentation/media/kapi/v4l2-mediabus.rst?id=e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/'>f63906f41699c8e38af9d12b063e2ceab0286ef2</a> /<a href='/cgit.cgi/linux/net-next.git/tree/Documentation/media/kapi/v4l2-mediabus.rst'>Documentation/media/kapi/v4l2-mediabus.rst</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Documentation/media/kapi/v4l2-mediabus.rst?id=e34bac726d27056081d0250c0e173e4b155aa340'>e34bac726d27056081d0250c0e173e4b155aa340</a> (<a href='/cgit.cgi/linux/net-next.git/diff/Documentation/media/kapi/v4l2-mediabus.rst?id2=e34bac726d27056081d0250c0e173e4b155aa340'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Documentation/media/kapi/v4l2-mediabus.rst?id=868c97a846a73e937d835b09b8c885a69df50ec8'>868c97a846a73e937d835b09b8c885a69df50ec8</a> (<a href='/cgit.cgi/linux/net-next.git/diff/Documentation/media/kapi/v4l2-mediabus.rst?id2=868c97a846a73e937d835b09b8c885a69df50ec8'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'docs-4.10' of git://git.lwn.net/linux<span class='decoration'><a class='deco' href='/cgit.cgi/linux/net-next.git/commit/Documentation/media/kapi/v4l2-mediabus.rst?id=e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba'>HEAD</a><a class='branch-deco' href='/cgit.cgi/linux/net-next.git/log/Documentation/media/kapi/v4l2-mediabus.rst'>master</a></span></div><div class='commit-msg'>Pull documentation update from Jonathan Corbet:
 "These are the documentation changes for 4.10.

  It's another busy cycle for the docs tree, as the sphinx conversion
  continues. Highlights include:

   - Further work on PDF output, which remains a bit of a pain but
     should be more solid now.

   - Five more DocBook template files converted to Sphinx. Only 27 to
     go... Lots of plain-text files have also been converted and
     integrated.

   - Images in binary formats have been replaced with more
     source-friendly versions.

   - Various bits of organizational work, including the renaming of
     various files discussed at the kernel summit.

   - New documentation for the device_link mechanism.

  ... and, of course, lots of typo fixes and small updates"

* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
  dma-buf: Extract dma-buf.rst
  Update Documentation/00-INDEX
  docs: 00-INDEX: document directories/files with no docs
  docs: 00-INDEX: remove non-existing entries
  docs: 00-INDEX: add missing entries for documentation files/dirs
  docs: 00-INDEX: consolidate process/ and admin-guide/ description
  scripts: add a script to check if Documentation/00-INDEX is sane
  Docs: change sh -&gt; awk in REPORTING-BUGS
  Documentation/core-api/device_link: Add initial documentation
  core-api: remove an unexpected unident
  ppc/idle: Add documentation for powersave=off
  Doc: Correct typo, "Introdution" =&gt; "Introduction"
  Documentation/atomic_ops.txt: convert to ReST markup
  Documentation/local_ops.txt: convert to ReST markup
  Documentation/assoc_array.txt: convert to ReST markup
  docs-rst: parse-headers.pl: cleanup the documentation
  docs-rst: fix media cleandocs target
  docs-rst: media/Makefile: reorganize the rules
  docs-rst: media: build SVG from graphviz files
  docs-rst: replace bayer.png by a SVG image
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/'>Diffstat</a> (limited to 'Documentation/media/kapi/v4l2-mediabus.rst')</div><table summary='diffstat' class='diffstat'>