incubator-nuttx/net/tcp/tcp_notifier.c

312 lines
10 KiB
C

/****************************************************************************
* net/tcp/tcp_notifier.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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 occur. 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 != NULL)
{
return 0;
}
/* Otherwise, this is just a simple wrapper around work_notifier_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_notifier_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_notifier_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 notification.
*
* Input Parameters:
* key - The key value returned from a previous call to
* tcp_readahead_notifier_setup().
*
* Returned Value:
* None.
*
****************************************************************************/
void tcp_notifier_teardown(int key)
{
/* This is just a simple wrapper around work_notifier_teardown(). */
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 */