nuttx/libs/libnx/nxmu/nx_connect.c

198 lines
5.8 KiB
C
Raw Normal View History

/****************************************************************************
* libs/libnx/nxmu/nx_connect.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 <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/signal.h>
#include <nuttx/mqueue.h>
#include <nuttx/nx/nx.h>
#include <nuttx/nx/nxmu.h>
#include "nxcontext.h"
/****************************************************************************
* Private Data
****************************************************************************/
/* Each client is assigned a unique ID using the g_nxcid counter. That
* counter increments as each new counter is created and is protected for
* thread safety with g_nxlibsem. Note that these are the only global values
* in the NX implementation. This is because the client ID must be unique
* even across all server instances.
*
* NOTE: that client ID 0 is reserved for the server(s) themselves
*/
static sem_t g_nxlibsem = SEM_INITIALIZER(1);
static uint32_t g_nxcid = 1;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nx_connectinstance
*
* Description:
* Open a connection from a client to the NX server. One one client
* connection is normally needed per thread as each connection can host
* multiple windows.
*
* NOTES:
* - This function returns before the connection is fully instantiated.
* it is necessary to wait for the connection event before using the
* returned handle.
* - Multiple instances of the NX server may run at the same time,
* each with different message queue names.
*
* Input Parameters:
* svrmqname - The name for the server incoming message queue
*
* Returned Value:
* Success: A non-NULL handle used with subsequent NX accesses
* Failure: NULL is returned and errno is set appropriately
*
****************************************************************************/
NXHANDLE nx_connectinstance(FAR const char *svrmqname)
{
FAR struct nxmu_conn_s *conn;
struct nxsvrmsg_s outmsg;
char climqname[NX_CLIENT_MXNAMELEN];
struct mq_attr attr;
int ret;
/* Sanity checking */
#ifdef CONFIG_DEBUG_FEATURES
if (!svrmqname)
{
set_errno(EINVAL);
return NULL;
}
#endif
/* Allocate the NX client structure */
conn = (FAR struct nxmu_conn_s *)lib_uzalloc(sizeof(struct nxmu_conn_s));
if (!conn)
{
set_errno(ENOMEM);
goto errout;
}
/* Create the client MQ name */
nxmu_semtake(&g_nxlibsem);
conn->cid = g_nxcid++;
nxmu_semgive(&g_nxlibsem);
sprintf(climqname, NX_CLIENT_MQNAMEFMT, conn->cid);
/* Open the client MQ for reading */
attr.mq_maxmsg = CONFIG_NX_MXCLIENTMSGS;
attr.mq_msgsize = NX_MXCLIMSGLEN;
attr.mq_flags = 0;
#ifdef CONFIG_NX_BLOCKING
conn->crdmq = _MQ_OPEN(climqname, O_RDONLY | O_CREAT, 0666, &attr);
#else
conn->crdmq = _MQ_OPEN(climqname, O_RDONLY | O_CREAT | O_NONBLOCK,
0666, &attr);
#endif
if (conn->crdmq < 0)
{
_NX_SETERRNO(conn->crdmq);
gerr("ERROR: _MQ_OPEN(%s) failed: %d\n", climqname,
_NX_GETERRNO(conn->crdmq));
goto errout_with_conn;
}
/* Open the server MQ for writing */
attr.mq_maxmsg = CONFIG_NX_MXSERVERMSGS;
attr.mq_msgsize = NX_MXSVRMSGLEN;
attr.mq_flags = 0;
conn->cwrmq = _MQ_OPEN(svrmqname, O_WRONLY | O_CREAT, 0666, &attr);
if (conn->cwrmq < 0)
{
_NX_SETERRNO(conn->cwrmq);
gerr("ERROR: _MQ_OPEN(%s) failed: %d\n", svrmqname,
_NX_GETERRNO(conn->crdmq));
goto errout_with_rmq;
}
/* Inform the server that this client exists */
outmsg.msgid = NX_SVRMSG_CONNECT;
outmsg.conn = conn;
ret = nxmu_sendserver(conn, &outmsg, sizeof(struct nxsvrmsg_s));
if (ret < 0)
{
gerr("ERROR: nxmu_sendserver failed: %d\n", errno);
goto errout_with_wmq;
}
#if 0
/* Now read until we get a response to this message. The server will
* respond with either (1) NX_CLIMSG_CONNECTED, in which case the state
* will change to NX_CLISTATE_CONNECTED, or (2) NX_CLIMSG_DISCONNECTED
* in which case, nx_message will fail with errno = EHOSTDOWN.
*/
do
{
ret = nx_eventhandler((NXHANDLE)conn);
if (ret < 0)
{
gerr("ERROR: nx_message failed: %d\n", errno);
goto errout_with_wmq;
}
_SIG_USLEEP(300000);
}
while (conn->state != NX_CLISTATE_CONNECTED);
#endif
return (NXHANDLE)conn;
errout_with_wmq:
_MQ_CLOSE(conn->cwrmq);
errout_with_rmq:
_MQ_CLOSE(conn->crdmq);
errout_with_conn:
lib_ufree(conn);
errout:
return NULL;
}