You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
236 lines
8.2 KiB
236 lines
8.2 KiB
/**************************************************************************** |
|
* sched/mq_open.c |
|
* |
|
* Copyright (C) 2007-2009, 2011 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 <stdint.h> |
|
#include <stdarg.h> |
|
#include <mqueue.h> |
|
#include <fcntl.h> |
|
#include <string.h> |
|
#include <sched.h> |
|
#include <errno.h> |
|
#include <debug.h> |
|
|
|
#include <nuttx/kmalloc.h> |
|
|
|
#include "os_internal.h" |
|
#include "mq_internal.h" |
|
|
|
/**************************************************************************** |
|
* Definitions |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Private Type Declarations |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Global Variables |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Private Variables |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Private Functions |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Public Functions |
|
****************************************************************************/ |
|
|
|
/**************************************************************************** |
|
* Name: mq_open |
|
* |
|
* Description: |
|
* This function establish a connection between a named message queue and |
|
* the calling task. After a successful call of mq_open(), the task can |
|
* reference the message queue using the address returned by the call. The |
|
* message queue remains usable until it is closed by a successful call to |
|
* mq_close(). |
|
* |
|
* Parameters: |
|
* mq_name - Name of the queue to open |
|
* oflags - open flags |
|
* Optional parameters. When the O_CREAT flag is specified, two optional |
|
* parameters are expected: |
|
* |
|
* 1. mode_t mode (ignored), and |
|
* 2. struct mq_attr *attr. The mq_maxmsg attribute |
|
* is used at the time that the message queue is |
|
* created to determine the maximum number of |
|
* messages that may be placed in the message queue. |
|
* |
|
* Return Value: |
|
* A message queue descriptor or -1 (ERROR) |
|
* |
|
* Assumptions: |
|
* |
|
****************************************************************************/ |
|
|
|
mqd_t mq_open(const char *mq_name, int oflags, ...) |
|
{ |
|
FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head; |
|
FAR msgq_t *msgq; |
|
mqd_t mqdes = NULL; |
|
va_list arg; /* Points to each un-named argument */ |
|
mode_t mode; /* MQ creation mode parameter (ignored) */ |
|
struct mq_attr *attr; /* MQ creation attributes */ |
|
int namelen; /* Length of MQ name */ |
|
|
|
/* Make sure that a non-NULL name is supplied */ |
|
|
|
if (mq_name) |
|
{ |
|
sched_lock(); |
|
namelen = strlen(mq_name); |
|
if (namelen > 0) |
|
{ |
|
/* See if the message queue already exists */ |
|
|
|
msgq = mq_findnamed(mq_name); |
|
if (msgq) |
|
{ |
|
/* It does. Check if the caller wanted to create a new |
|
* message queue with this name (i.e., O_CREAT|O_EXCL) |
|
*/ |
|
|
|
if ((oflags & O_CREAT) == 0 || (oflags & O_EXCL) == 0) |
|
{ |
|
/* Create a message queue descriptor for the TCB */ |
|
|
|
mqdes = mq_descreate(rtcb, msgq, oflags); |
|
if (mqdes) |
|
{ |
|
/* Allow a new connection to the message queue */ |
|
|
|
msgq->nconnect++; |
|
} |
|
} |
|
} |
|
|
|
/* It doesn't exist. Should we create one? */ |
|
|
|
else if ((oflags & O_CREAT) != 0) |
|
{ |
|
/* Allocate memory for the new message queue. The size to |
|
* allocate is the size of the msgq_t header plus the size |
|
* of the message queue name+1. |
|
*/ |
|
|
|
msgq = (FAR msgq_t*)kzalloc(SIZEOF_MQ_HEADER + namelen + 1); |
|
if (msgq) |
|
{ |
|
/* Create a message queue descriptor for the TCB */ |
|
|
|
mqdes = mq_descreate(rtcb, msgq, oflags); |
|
if (mqdes) |
|
{ |
|
/* Set up to get the optional arguments needed to create |
|
* a message queue. |
|
*/ |
|
|
|
va_start(arg, oflags); |
|
mode = va_arg(arg, mode_t); |
|
attr = va_arg(arg, struct mq_attr*); |
|
|
|
/* Initialize the new named message queue */ |
|
|
|
sq_init(&msgq->msglist); |
|
if (attr) |
|
{ |
|
msgq->maxmsgs = (int16_t)attr->mq_maxmsg; |
|
if (attr->mq_msgsize <= MQ_MAX_BYTES) |
|
{ |
|
msgq->maxmsgsize = (int16_t)attr->mq_msgsize; |
|
} |
|
else |
|
{ |
|
msgq->maxmsgsize = MQ_MAX_BYTES; |
|
} |
|
} |
|
else |
|
{ |
|
msgq->maxmsgs = MQ_MAX_MSGS; |
|
msgq->maxmsgsize = MQ_MAX_BYTES; |
|
} |
|
|
|
msgq->nconnect = 1; |
|
#ifndef CONFIG_DISABLE_SIGNALS |
|
msgq->ntpid = INVALID_PROCESS_ID; |
|
#endif |
|
strcpy(msgq->name, mq_name); |
|
|
|
/* Add the new message queue to the list of |
|
* message queues |
|
*/ |
|
|
|
sq_addlast((FAR sq_entry_t*)msgq, &g_msgqueues); |
|
|
|
/* Clean-up variable argument stuff */ |
|
|
|
va_end(arg); |
|
} |
|
else |
|
{ |
|
/* Deallocate the msgq structure. Since it is |
|
* uninitialized, mq_deallocate() is not used. |
|
*/ |
|
|
|
sched_free(msgq); |
|
} |
|
} |
|
} |
|
} |
|
|
|
sched_unlock(); |
|
} |
|
|
|
if (mqdes == NULL) |
|
{ |
|
return (mqd_t)ERROR; |
|
} |
|
else |
|
{ |
|
return mqdes; |
|
} |
|
}
|
|
|