C++ SOCKBUF_UNLOCK函数代码示例

/*
 * Socket buffer (struct sockbuf) utility routines.
 *
 * Each socket contains two socket buffers: one for sending data and one for
 * receiving data.  Each buffer contains a queue of mbufs, information about
 * the number of mbufs and amount of data in the queue, and other fields
 * allowing select() statements and notification on data availability to be
 * implemented.
 *
 * Data stored in a socket buffer is maintained as a list of records.  Each
 * record is a list of mbufs chained together with the m_next field.  Records
 * are chained together with the m_nextpkt field. The upper level routine
 * soreceive() expects the following conventions to be observed when placing
 * information in the receive buffer:
 *
 * 1. If the protocol requires each message be preceded by the sender's name,
 *    then a record containing that name must be present before any
 *    associated data (mbuf's must be of type MT_SONAME).
 * 2. If the protocol supports the exchange of ``access rights'' (really just
 *    additional data associated with the message), and there are ``rights''
 *    to be received, then a record containing this data should be present
 *    (mbuf's must be of type MT_RIGHTS).
 * 3. If a name or rights record exists, then it must be followed by a data
 *    record, perhaps of zero length.
 *
 * Before using a new socket structure it is first necessary to reserve
 * buffer space to the socket, by calling sbreserve().  This should commit
 * some of the available buffer space in the system buffer pool for the
 * socket (currently, it does nothing but enforce limits).  The space should
 * be released by calling sbrelease() when the socket is destroyed.
 */
int
soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
{
	struct thread *td = NULL;//curthread;

	SOCKBUF_LOCK(&so->so_snd);
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
		goto bad;
	if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
		goto bad2;
	if (so->so_rcv.sb_lowat == 0)
		so->so_rcv.sb_lowat = 1;// 0x8000;
	if (so->so_snd.sb_lowat == 0)
		so->so_snd.sb_lowat = MCLBYTES;
	if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
		so->so_snd.sb_lowat = so->so_snd.sb_hiwat;

	so->so_snd.sb_cc_cond = host_pthread_cond_init();
	so->so_snd.sb_timeo_cond= host_pthread_cond_init();
	so->so_rcv.sb_cc_cond = host_pthread_cond_init();
	so->so_rcv.sb_timeo_cond= host_pthread_cond_init();
	
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (0);
bad2:
	sbrelease_locked(&so->so_snd, so);
bad:
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (ENOBUFS);
}

void
t4_rcvd(struct toedev *tod, struct tcpcb *tp)
{
	struct adapter *sc = tod->tod_softc;
	struct inpcb *inp = tp->t_inpcb;
	struct socket *so = inp->inp_socket;
	struct sockbuf *sb = &so->so_rcv;
	struct toepcb *toep = tp->t_toe;
	int credits;

	INP_WLOCK_ASSERT(inp);

	SOCKBUF_LOCK(sb);
	KASSERT(toep->sb_cc >= sb->sb_cc,
	    ("%s: sb %p has more data (%d) than last time (%d).",
	    __func__, sb, sb->sb_cc, toep->sb_cc));
	toep->rx_credits += toep->sb_cc - sb->sb_cc;
	toep->sb_cc = sb->sb_cc;
	credits = toep->rx_credits;
	SOCKBUF_UNLOCK(sb);

	if (credits > 0 &&
	    (credits + 16384 >= tp->rcv_wnd || credits >= 15 * 1024)) {

		credits = send_rx_credits(sc, toep, credits);
		SOCKBUF_LOCK(sb);
		toep->rx_credits -= credits;
		SOCKBUF_UNLOCK(sb);
		tp->rcv_wnd += credits;
		tp->rcv_adv += credits;
	}
}

/* This is _not_ the normal way to "unoffload" a socket. */
void
undo_offload_socket(struct socket *so)
{
	struct inpcb *inp = sotoinpcb(so);
	struct tcpcb *tp = intotcpcb(inp);
	struct toepcb *toep = tp->t_toe;
	struct tom_data *td = toep->td;
	struct sockbuf *sb;

	INP_WLOCK_ASSERT(inp);

	sb = &so->so_snd;
	SOCKBUF_LOCK(sb);
	sb->sb_flags &= ~SB_NOCOALESCE;
	SOCKBUF_UNLOCK(sb);
	sb = &so->so_rcv;
	SOCKBUF_LOCK(sb);
	sb->sb_flags &= ~SB_NOCOALESCE;
	SOCKBUF_UNLOCK(sb);

	tp->tod = NULL;
	tp->t_toe = NULL;
	tp->t_flags &= ~TF_TOE;

	toep->inp = NULL;
	toep->flags &= ~TPF_ATTACHED;
	if (in_pcbrele_wlocked(inp))
		panic("%s: inp freed.", __func__);

	mtx_lock(&td->toep_list_lock);
	TAILQ_REMOVE(&td->toep_list, toep, link);
	mtx_unlock(&td->toep_list_lock);
}

/*
 * Socket buffer (struct sockbuf) utility routines.
 *
 * Each socket contains two socket buffers: one for sending data and one for
 * receiving data.  Each buffer contains a queue of mbufs, information about
 * the number of mbufs and amount of data in the queue, and other fields
 * allowing select() statements and notification on data availability to be
 * implemented.
 *
 * Data stored in a socket buffer is maintained as a list of records.  Each
 * record is a list of mbufs chained together with the m_next field.  Records
 * are chained together with the m_nextpkt field. The upper level routine
 * ofp_soreceive() expects the following conventions to be observed when placing
 * information in the receive buffer:
 *
 * 1. If the protocol requires each message be preceded by the sender's name,
 *    then a record containing that name must be present before any
 *    associated data (mbuf's must be of type MT_SONAME).
 * 2. If the protocol supports the exchange of ``access rights'' (really just
 *    additional data associated with the message), and there are ``rights''
 *    to be received, then a record containing this data should be present
 *    (mbuf's must be of type MT_RIGHTS).
 * 3. If a name or rights record exists, then it must be followed by a data
 *    record, perhaps of zero length.
 *
 * Before using a new socket structure it is first necessary to reserve
 * buffer space to the socket, by calling ofp_sbreserve().  This should commit
 * some of the available buffer space in the system buffer pool for the
 * socket (currently, it does nothing but enforce limits).  The space should
 * be released by calling ofp_sbrelease() when the socket is destroyed.
 */
int
ofp_soreserve(struct socket *so, uint64_t sndcc, uint64_t rcvcc)
{
	struct thread *td = NULL /* HJo curthread*/;

	SOCKBUF_LOCK(&so->so_snd);
	SOCKBUF_LOCK(&so->so_rcv);
	if (ofp_sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
		goto bad;
	if (ofp_sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
		goto bad2;
	if (so->so_rcv.sb_lowat == 0)
		so->so_rcv.sb_lowat = 1;
	if (so->so_snd.sb_lowat == 0)
		so->so_snd.sb_lowat = global_param->pkt_pool.buffer_size;
	if (so->so_snd.sb_lowat > (int)so->so_snd.sb_hiwat)
		so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (0);
bad2:
	ofp_sbrelease_locked(&so->so_snd, so);
bad:
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (OFP_ENOBUFS);
}

/*
 * Socket buffer (struct sockbuf) utility routines.
 *
 * Each socket contains two socket buffers: one for sending data and one for
 * receiving data.  Each buffer contains a queue of mbufs, information about
 * the number of mbufs and amount of data in the queue, and other fields
 * allowing select() statements and notification on data availability to be
 * implemented.
 *
 * Data stored in a socket buffer is maintained as a list of records.  Each
 * record is a list of mbufs chained together with the m_next field.  Records
 * are chained together with the m_nextpkt field. The upper level routine
 * soreceive() expects the following conventions to be observed when placing
 * information in the receive buffer:
 *
 * 1. If the protocol requires each message be preceded by the sender's name,
 *    then a record containing that name must be present before any
 *    associated data (mbuf's must be of type MT_SONAME).
 * 2. If the protocol supports the exchange of ``access rights'' (really just
 *    additional data associated with the message), and there are ``rights''
 *    to be received, then a record containing this data should be present
 *    (mbuf's must be of type MT_RIGHTS).
 * 3. If a name or rights record exists, then it must be followed by a data
 *    record, perhaps of zero length.
 *
 * Before using a new socket structure it is first necessary to reserve
 * buffer space to the socket, by calling sbreserve().  This should commit
 * some of the available buffer space in the system buffer pool for the
 * socket (currently, it does nothing but enforce limits).  The space should
 * be released by calling sbrelease() when the socket is destroyed.
 */
int
soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
{
	struct thread *td = curthread;

	SOCKBUF_LOCK(&so->so_snd);
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
		goto bad;
	if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
		goto bad2;
	if (so->so_rcv.sb_lowat == 0)
		so->so_rcv.sb_lowat = 1;
	if (so->so_snd.sb_lowat == 0)
		so->so_snd.sb_lowat = MCLBYTES;
	if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
		so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (0);
bad2:
	sbrelease_locked(&so->so_snd, so);
bad:
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (ENOBUFS);
}

static int
ng_ksocket_connect(hook_p hook)
{
	node_p node = NG_HOOK_NODE(hook);
	const priv_p priv = NG_NODE_PRIVATE(node);
	struct socket *const so = priv->so;

	/* Add our hook for incoming data and other events */
	priv->so->so_upcallarg = (caddr_t)node;
	priv->so->so_upcall = ng_ksocket_incoming;
	SOCKBUF_LOCK(&priv->so->so_rcv);
	priv->so->so_rcv.sb_flags |= SB_UPCALL;
	SOCKBUF_UNLOCK(&priv->so->so_rcv);
	SOCKBUF_LOCK(&priv->so->so_snd);
	priv->so->so_snd.sb_flags |= SB_UPCALL;
	SOCKBUF_UNLOCK(&priv->so->so_snd);
	SOCK_LOCK(priv->so);
	sosetstate(priv->so, SS_NBIO);
	SOCK_UNLOCK(priv->so);
	/*
	 * --Original comment--
	 * On a cloned socket we may have already received one or more
	 * upcalls which we couldn't handle without a hook.  Handle
	 * those now.
	 * We cannot call the upcall function directly
	 * from here, because until this function has returned our
	 * hook isn't connected.
	 *
	 * ---meta comment for -current ---
	 * XXX This is dubius.
	 * Upcalls between the time that the hook was
	 * first created and now (on another processesor) will
	 * be earlier on the queue than the request to finalise the hook.
	 * By the time the hook is finalised,
	 * The queued upcalls will have happenned and the code
	 * will have discarded them because of a lack of a hook.
	 * (socket not open).
	 *
	 * This is a bad byproduct of the complicated way in which hooks
	 * are now created (3 daisy chained async events).
	 *
	 * Since we are a netgraph operation 
	 * We know that we hold a lock on this node. This forces the
	 * request we make below to be queued rather than implemented
	 * immediatly which will cause the upcall function to be called a bit
	 * later.
	 * However, as we will run any waiting queued operations immediatly
	 * after doing this one, if we have not finalised the other end
	 * of the hook, those queued operations will fail.
	 */
	if (priv->flags & KSF_CLONED) {
		ng_send_fn(node, NULL, &ng_ksocket_incoming2, so, M_WAITOK | M_NULLOK);
	}

	return (0);
}

/*
 * Wakeup processes waiting on a socket buffer.  Do asynchronous notification
 * via SIGIO if the socket has the SS_ASYNC flag set.
 *
 * Called with the socket buffer lock held; will release the lock by the end
 * of the function.  This allows the caller to acquire the socket buffer lock
 * while testing for the need for various sorts of wakeup and hold it through
 * to the point where it's no longer required.  We currently hold the lock
 * through calls out to other subsystems (with the exception of kqueue), and
 * then release it to avoid lock order issues.  It's not clear that's
 * correct.
 */
void
sowakeup(struct socket *so, struct sockbuf *sb)
{
	int ret = 0;

	SOCKBUF_LOCK_ASSERT(sb);

	so_wake_poll(so, sb);

	if (sb->sb_flags & SB_WAIT) {
		sb->sb_flags &= ~SB_WAIT;
		wakeup(&sb->sb_cc);
	}
	if (sb->sb_upcall != NULL) {
		ret = sb->sb_upcall(so, sb->sb_upcallarg, M_DONTWAIT);
		if (ret == SU_ISCONNECTED) {
			KASSERT(sb == &so->so_rcv,
			    ("SO_SND upcall returned SU_ISCONNECTED"));
			soupcall_clear(so, SO_RCV);
		}
	} else
		ret = SU_OK;
	SOCKBUF_UNLOCK(sb);
	if (ret == SU_ISCONNECTED)
		soisconnected(so);
	mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
}

void
ofp_sbrelease(struct sockbuf *sb, struct socket *so)
{
	SOCKBUF_LOCK(sb);
	ofp_sbrelease_locked(sb, so);
	SOCKBUF_UNLOCK(sb);
}

void
ofp_sbdrop(struct sockbuf *sb, int len)
{
	SOCKBUF_LOCK(sb);
	ofp_sbdrop_locked(sb, len);
	SOCKBUF_UNLOCK(sb);
}

/*
 * This version of sbappend() should only be used when the caller absolutely
 * knows that there will never be more than one record in the socket buffer,
 * that is, a stream protocol (such as TCP).
 */
void
ofp_sbappendstream(struct sockbuf *sb, odp_packet_t m)
{
	SOCKBUF_LOCK(sb);
	ofp_sbappendstream_locked(sb, m);
	SOCKBUF_UNLOCK(sb);
 }

static void
soo_aio_cancel(struct kaiocb *job)
{
	struct socket *so;
	struct sockbuf *sb;
	int opcode;

	so = job->fd_file->f_data;
	opcode = job->uaiocb.aio_lio_opcode;
	if (opcode == LIO_READ)
		sb = &so->so_rcv;
	else {
		MPASS(opcode == LIO_WRITE);
		sb = &so->so_snd;
	}

	SOCKBUF_LOCK(sb);
	if (!aio_cancel_cleared(job))
		TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
	if (TAILQ_EMPTY(&sb->sb_aiojobq))
		sb->sb_flags &= ~SB_AIO;
	SOCKBUF_UNLOCK(sb);

	aio_cancel(job);
}

void
t4_rcvd(struct toedev *tod, struct tcpcb *tp)
{
	struct adapter *sc = tod->tod_softc;
	struct inpcb *inp = tp->t_inpcb;
	struct socket *so = inp->inp_socket;
	struct sockbuf *sb = &so->so_rcv;
	struct toepcb *toep = tp->t_toe;
	int credits;

	INP_WLOCK_ASSERT(inp);

	SOCKBUF_LOCK(sb);
	KASSERT(toep->sb_cc >= sbused(sb),
	    ("%s: sb %p has more data (%d) than last time (%d).",
	    __func__, sb, sbused(sb), toep->sb_cc));

	toep->rx_credits += toep->sb_cc - sbused(sb);
	toep->sb_cc = sbused(sb);

	if (toep->rx_credits > 0 &&
	    (tp->rcv_wnd <= 32 * 1024 || toep->rx_credits >= 64 * 1024 ||
	    (toep->rx_credits >= 16 * 1024 && tp->rcv_wnd <= 128 * 1024) ||
	    toep->sb_cc + tp->rcv_wnd < sb->sb_lowat)) {

		credits = send_rx_credits(sc, toep, toep->rx_credits);
		toep->rx_credits -= credits;
		tp->rcv_wnd += credits;
		tp->rcv_adv += credits;
	}
	SOCKBUF_UNLOCK(sb);
}

/*
 * Wakeup processes waiting on a socket buffer.  Do asynchronous notification
 * via SIGIO if the socket has the SS_ASYNC flag set.
 *
 * Called with the socket buffer lock held; will release the lock by the end
 * of the function.  This allows the caller to acquire the socket buffer lock
 * while testing for the need for various sorts of wakeup and hold it through
 * to the point where it's no longer required.  We currently hold the lock
 * through calls out to other subsystems (with the exception of kqueue), and
 * then release it to avoid lock order issues.  It's not clear that's
 * correct.
 */
void
sowakeup(struct socket *so, struct sockbuf *sb)
{
	int ret;

	SOCKBUF_LOCK_ASSERT(sb);

	selwakeuppri(sb->sb_sel, PSOCK);
	if (!SEL_WAITING(sb->sb_sel))
		sb->sb_flags &= ~SB_SEL;
	if (sb->sb_flags & SB_WAIT) {
		sb->sb_flags &= ~SB_WAIT;
		wakeup(&sb->sb_acc);
	}
	KNOTE_LOCKED(&sb->sb_sel->si_note, 0);
	if (sb->sb_upcall != NULL) {
		ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT);
		if (ret == SU_ISCONNECTED) {
			KASSERT(sb == &so->so_rcv,
			    ("SO_SND upcall returned SU_ISCONNECTED"));
			soupcall_clear(so, SO_RCV);
		}
	} else
		ret = SU_OK;
	if (sb->sb_flags & SB_AIO)
		sowakeup_aio(so, sb);
	SOCKBUF_UNLOCK(sb);
	if (ret == SU_ISCONNECTED)
		soisconnected(so);
	if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
		pgsigio(&so->so_sigio, SIGIO, 0);
	mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
}

void
ofp_sbflush(struct sockbuf *sb)
{
	SOCKBUF_LOCK(sb);
	ofp_sbflush_locked(sb);
	SOCKBUF_UNLOCK(sb);
}

static void
soaio_process_sb(struct socket *so, struct sockbuf *sb)
{
	struct kaiocb *job;

	SOCKBUF_LOCK(sb);
	while (!TAILQ_EMPTY(&sb->sb_aiojobq) && soaio_ready(so, sb)) {
		job = TAILQ_FIRST(&sb->sb_aiojobq);
		TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
		if (!aio_clear_cancel_function(job))
			continue;

		soaio_process_job(so, sb, job);
	}

	/*
	 * If there are still pending requests, the socket must not be
	 * ready so set SB_AIO to request a wakeup when the socket
	 * becomes ready.
	 */
	if (!TAILQ_EMPTY(&sb->sb_aiojobq))
		sb->sb_flags |= SB_AIO;
	sb->sb_flags &= ~SB_AIO_RUNNING;
	SOCKBUF_UNLOCK(sb);

	ACCEPT_LOCK();
	SOCK_LOCK(so);
	sorele(so);
}