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Complete re-implementation of mq_open()

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This commit is contained in:
Gregory Nutt
2014-09-29 14:59:31 -06:00
parent 9e975a217d
commit 584d0fe4ad
7 changed files with 376 additions and 74 deletions
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190
fs/mqueue/mq_open.c
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@@ -1,7 +1,7 @@
/****************************************************************************
* sched/mqueue/mq_open.c
*
* Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
* Copyright (C) 2007-2009, 2011, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@@ -39,24 +39,36 @@
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdarg.h>
#include <stdio.h>
#include <sched.h>
#include <mqueue.h>
#include <fcntl.h>
#include <string.h>
#include <sched.h>
#include <errno.h>
#include <nuttx/mqueue.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
#include "mqueue/mqueue.h"
#if 0
#include <sys/types.h>
#include <stdint.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include "sched/sched.h"
#include "mqueue/mqueue.h"
#endif
/****************************************************************************
* Pre-procesor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_FS_MQUEUE_MPATH
# define CONFIG_FS_MQUEUE_MPATH "/var/mqueue"
#endif
/****************************************************************************
* Private Type Declarations
@@ -109,83 +121,135 @@
mqd_t mq_open(const char *mq_name, int oflags, ...)
{
FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
FAR struct inode *inode;
FAR const char *relpath = NULL;
FAR struct mqueue_inode_s *msgq;
mqd_t mqdes = NULL;
va_list arg;
char fullpath[MAX_MQUEUE_PATH];
va_list ap;
struct mq_attr *attr;
mqd_t mqdes;
mode_t mode;
int namelen;
int errcode;
int ret;
/* Make sure that a non-NULL name is supplied */
if (mq_name)
{
/* Make sure that the check for the existence of the message queue
* and the creation of the message queue are atomic with respect to
* other processes executing mq_open(). A simple sched_lock() should
* be sufficientt.
*/
sched_lock();
namelen = strlen(mq_name);
if (namelen > 0)
/* Get the full path to the message queue */
snprintf(fullpath, MAX_MQUEUE_PATH, CONFIG_FS_MQUEUE_MPATH "/%s", mq_name);
/* Get the inode for this mqueue. This should succeed if the message
* queue has already been created.
*/
inode = inode_find(fullpath, &relpath);
if (inode)
{
/* See if the message queue already exists */
/* It exists. Verify that the inode is a message queue */
msgq = mq_findnamed(mq_name);
if (msgq)
if (!INODE_IS_MQUEUE(inode))
{
/* 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++;
}
}
errcode = ENXIO;
goto errout_with_inode;
}
/* It doesn't exist. Should we create one? */
/* It exists and is a message queue. Check if the caller wanted to
* create a new mqueue with this name.
*/
else if ((oflags & O_CREAT) != 0)
if ((oflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
{
/* Yes.. Get the optional arguments needed to create a message
* queue.
*/
errcode = EEXIST;
goto errout_with_inode;
}
va_start(arg, oflags);
mode = va_arg(arg, mode_t);
attr = va_arg(arg, struct mq_attr*);
/* Create a message queue descriptor for the current thread */
/* Allocate memory for the new message queue. The size to
* allocate is the size of the struct mqueue_inode_s header
* plus the size of the message queue name+1.
*/
msgq = (FAR struct mqueue_inode_s*)mq_msgqalloc(oflags, mode, attr);
if (msgq)
{
#warning Missing logic
}
/* Clean-up variable argument stuff */
va_end(arg);
msgq = inode->u.i_mqueue;
mqdes = mq_descreate(NULL, msgq, oflags);
if (!mqdes)
{
errcode = ENOMEM;
goto errout_with_inode;
}
}
else
{
/* The mqueue does not exists. Were we asked to create it? */
sched_unlock();
if ((oflags & O_CREAT) == 0)
{
/* The mqueue does not exist and O_CREAT is not set */
errcode = ENOENT;
goto errout_with_lock;
}
/* Create the mqueue. First we have to extract the additional
* parameters from the variable argument list.
*/
va_start(ap, oflags);
mode = va_arg(ap, mode_t);
attr = va_arg(ap, FAR struct mq_attr*);
va_end(ap);
/* Create an inode in the pseudo-filesystem at this path */
inode_semtake();
ret = inode_reserve(fullpath, &inode);
inode_semgive();
if (ret < 0)
{
errcode = -ret;
goto errout_with_lock;
}
/* Allocate memory for the new message queue. */
msgq = (FAR struct mqueue_inode_s*)mq_msgqalloc(mode, attr);
if (!msgq)
{
errcode = ENOMEM;
goto errout_with_inode;
}
/* Create a message queue descriptor for the TCB */
mqdes = mq_descreate(NULL, msgq, oflags);
if (!mqdes)
{
errcode = ENOMEM;
goto errout_with_msgq;
}
/* Save the message queue in the inode structure */
inode->u.i_mqueue = msgq;
}
}
if (mqdes == NULL)
{
return (mqd_t)ERROR;
}
else
{
return mqdes;
}
sched_unlock();
return mqdes;
errout_with_msgq:
mq_msgqfree(msgq);
inode->u.i_mqueue = NULL;
errout_with_inode:
inode_release(inode);
errout_with_lock:
sched_unlock();
set_errno(errcode);
return (mqd_t)ERROR;
}