incubator-nuttx/net/tcp/tcp_notifier.c

328 lines
11 KiB
C

/****************************************************************************
* net/tcp/tcp_notifier.c
*
* Copyright (C) 2018-2019 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/wqueue.h>
#include <nuttx/mm/iob.h>
#include <nuttx/net/tcp.h>
#include "tcp/tcp.h"
#ifdef CONFIG_NET_TCP_NOTIFIER
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_readahead_notifier_setup
*
* Description:
* Set up to perform a callback to the worker function when an TCP data
* is added to the read-ahead buffer. The worker function will execute
* on the low priority worker thread.
*
* Input Parameters:
* worker - The worker function to execute on the low priority work
* queue when data is available in the TCP read-ahead buffer.
* conn - The TCP connection where read-ahead data is needed.
* arg - A user-defined argument that will be available to the worker
* function when it runs.
*
* Returned Value:
* > 0 - The notification is in place. The returned value is a key that
* may be used later in a call to tcp_notifier_teardown().
* == 0 - There is already buffered read-ahead data. No notification
* will be provided.
* < 0 - An unexpected error occurred and notification will ocur. The
* returned value is a negated errno value that indicates the
* nature of the failure.
*
****************************************************************************/
int tcp_readahead_notifier_setup(worker_t worker,
FAR struct tcp_conn_s *conn,
FAR void *arg)
{
struct work_notifier_s info;
DEBUGASSERT(worker != NULL);
/* If there is already buffered read-ahead data, then return zero without
* setting up the notification.
*/
if (conn->readahead.qh_head != NULL)
{
return 0;
}
/* Otherwise, this is just a simple wrapper around work_notifer_setup(). */
info.evtype = WORK_TCP_READAHEAD;
info.qid = LPWORK;
info.qualifier = conn;
info.arg = arg;
info.worker = worker;
return work_notifier_setup(&info);
}
/****************************************************************************
* Name: tcp_writebuffer_notifier_setup
*
* Description:
* Set up to perform a callback to the worker function when an TCP write
* buffer is emptied. The worker function will execute on the high
* priority worker thread.
*
* Input Parameters:
* worker - The worker function to execute on the high priority work
* queue when all buffer TX data has been sent.
* conn - The TCP connection where buffer write data is pending.
* arg - A user-defined argument that will be available to the worker
* function when it runs.
*
* Returned Value:
* > 0 - The signal notification is in place. The returned value is a
* key that may be used later in a call to
* tcp_notifier_teardown().
* == 0 - There is already buffered read-ahead data. No signal
* notification will be provided.
* < 0 - An unexpected error occurred and no signal will be sent. The
* returned value is a negated errno value that indicates the
* nature of the failure.
*
****************************************************************************/
int tcp_writebuffer_notifier_setup(worker_t worker,
FAR struct tcp_conn_s *conn,
FAR void *arg)
{
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
struct work_notifier_s info;
DEBUGASSERT(worker != NULL);
/* If the write buffers are already empty, then return zero without
* setting up the notification.
*/
if (sq_empty(&conn->write_q) && sq_empty(&conn->unacked_q))
{
return 0;
}
/* Otherwise, this is just a simple wrapper around work_notifer_setup(). */
info.evtype = WORK_TCP_WRITEBUFFER;
info.qid = LPWORK;
info.qualifier = conn;
info.arg = arg;
info.worker = worker;
return work_notifier_setup(&info);
#else
return 0;
#endif
}
/****************************************************************************
* Name: tcp_disconnect_notifier_setup
*
* Description:
* Set up to perform a callback to the worker function if the TCP
* connection is lost.
*
* Input Parameters:
* worker - The worker function to execute on the low priority work
* queue when data is available in the TCP read-ahead buffer.
* conn - The TCP connection where read-ahead data is needed.
* arg - A user-defined argument that will be available to the worker
* function when it runs.
*
* Returned Value:
* > 0 - The notification is in place. The returned value is a key that
* may be used later in a call to tcp_notifier_teardown().
* == 0 - No connection has been established.
* < 0 - An unexpected error occurred and notification will occur. The
* returned value is a negated errno value that indicates the
* nature of the failure.
*
****************************************************************************/
int tcp_disconnect_notifier_setup(worker_t worker,
FAR struct tcp_conn_s *conn,
FAR void *arg)
{
struct work_notifier_s info;
DEBUGASSERT(worker != NULL);
/* If connection has not been established, then return 0. */
if (conn->tcpstateflags != TCP_ESTABLISHED)
{
return 0;
}
/* Otherwise, this is just a simple wrapper around work_notifer_setup(). */
info.evtype = WORK_TCP_DISCONNECT;
info.qid = LPWORK;
info.qualifier = conn;
info.arg = arg;
info.worker = worker;
return work_notifier_setup(&info);
}
/****************************************************************************
* Name: tcp_notifier_teardown
*
* Description:
* Eliminate a TCP read-ahead notification previously setup by
* tcp_readahead_notifier_setup(). This function should only be called
* if the notification should be aborted prior to the notification. The
* notification will automatically be torn down after the notifcation.
*
* Input Parameters:
* key - The key value returned from a previous call to
* tcp_readahead_notifier_setup().
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
int tcp_notifier_teardown(int key)
{
/* This is just a simple wrapper around work_notifier_teardown(). */
return work_notifier_teardown(key);
}
/****************************************************************************
* Name: tcp_readahead_signal
*
* Description:
* Read-ahead data has been buffered. Signal all threads waiting for
* read-ahead data to become available.
*
* When read-ahead data becomes available, *all* of the workers waiting
* for read-ahead data will be executed. If there are multiple workers
* waiting for read-ahead data then only the first to execute will get the
* data. Others will need to call tcp_readahead_notifier_setup() once
* again.
*
* Input Parameters:
* conn - The TCP connection where read-ahead data was just buffered.
*
* Returned Value:
* None.
*
****************************************************************************/
void tcp_readahead_signal(FAR struct tcp_conn_s *conn)
{
/* This is just a simple wrapper around work_notifier_signal(). */
work_notifier_signal(WORK_TCP_READAHEAD, conn);
}
/****************************************************************************
* Name: tcp_writebuffer_signal
*
* Description:
* All buffer Tx data has been sent. Signal all threads waiting for the
* write buffers to become empty.
*
* When write buffer becomes empty, *all* of the workers waiting
* for that event data will be executed. If there are multiple workers
* waiting for read-ahead data then only the first to execute will get the
* data. Others will need to call tcp_writebuffer_notifier_setup() once
* again.
*
* Input Parameters:
* conn - The TCP connection where read-ahead data was just buffered.
*
* Returned Value:
* None.
*
****************************************************************************/
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
void tcp_writebuffer_signal(FAR struct tcp_conn_s *conn)
{
/* This is just a simple wrapper around work_notifier_signal(). */
work_notifier_signal(WORK_TCP_WRITEBUFFER, conn);
}
#endif
/****************************************************************************
* Name: tcp_disconnect_signal
*
* Description:
* The TCP connection has been lost. Signal all threads monitoring TCP
* state events.
*
* Input Parameters:
* conn - The TCP connection where read-ahead data was just buffered.
*
* Returned Value:
* None.
*
****************************************************************************/
void tcp_disconnect_signal(FAR struct tcp_conn_s *conn)
{
/* This is just a simple wrapper around work_notifier_signal(). */
work_notifier_signal(WORK_TCP_DISCONNECT, conn);
}
#endif /* CONFIG_NET_TCP_NOTIFIER */