incubator-nuttx/sched/mqueue/msgctl.c

127 lines
3.6 KiB
C

/****************************************************************************
* sched/mqueue/msgctl.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 "mqueue/msg.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: msgctl
*
* Description:
* System V message control operations.
* msgctl() performs the control operation specified by cmd on the
* System V message queue with identifier msqid.
*
* Input Parameters:
* msqid - System V message queue identifier
* cmd - Command operations
* msqid_ds - Defines a message queue
*
* Returned Value:
* On success, IPC_STAT, IPC_SET, and IPC_RMID return 0. A
* successful IPC_INFO or MSG_INFO operation returns the index of
* the highest used entry in the kernel's internal array recording
* information about all message queues. (This information can be
* used with repeated MSG_STAT or MSG_STAT_ANY operations to obtain
* information about all queues on the system.) A successful
* MSG_STAT or MSG_STAT_ANY operation returns the identifier of the
* queue whose index was given in msqid.
*
* On failure, -1 is returned and errno is set to indicate the error.
*
****************************************************************************/
int msgctl(int msqid, int cmd, FAR struct msqid_ds *buf)
{
FAR struct msgq_s *msgq;
irqstate_t flags;
int ret = OK;
flags = enter_critical_section();
msgq = nxmsg_lookup(msqid);
if (msgq == NULL)
{
ret = -EINVAL;
goto errout_with_critical;
}
switch (cmd)
{
case IPC_RMID:
{
nxmsg_free(msgq);
break;
}
case IPC_SET:
{
if (buf == NULL)
{
ret = -EFAULT;
break;
}
msgq->maxmsgs = buf->msg_qbytes / CONFIG_MQ_MAXMSGSIZE;
break;
}
case IPC_STAT:
{
if (buf == NULL)
{
ret = -EFAULT;
break;
}
buf->msg_qnum = list_length(&msgq->msglist);
buf->msg_cbytes = buf->msg_qnum * CONFIG_MQ_MAXMSGSIZE;
buf->msg_qbytes = msgq->maxmsgs * CONFIG_MQ_MAXMSGSIZE;
break;
}
default:
{
ret = -EINVAL;
break;
}
}
errout_with_critical:
leave_critical_section(flags);
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return ret;
}