mirror of
https://github.com/apache/nuttx.git
synced 2026-08-21 05:28:19 +00:00
N/A Signed-off-by: anjiahao <anjiahao@xiaomi.com> Change-Id: Ie777cd38af86c3f25e818a1477996a5f0c1cc195
708 lines
27 KiB
C
708 lines
27 KiB
C
/****************************************************************************
|
||
* include/nuttx/mqueue.h
|
||
*
|
||
* 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.
|
||
*
|
||
****************************************************************************/
|
||
|
||
#ifndef ___INCLUDE_NUTTX_MQUEUE_H
|
||
#define ___INCLUDE_NUTTX_MQUEUE_H
|
||
|
||
/****************************************************************************
|
||
* Included Files
|
||
****************************************************************************/
|
||
|
||
#include <nuttx/config.h>
|
||
#include <nuttx/compiler.h>
|
||
#include <nuttx/fs/fs.h>
|
||
#include <nuttx/signal.h>
|
||
|
||
#include <sys/types.h>
|
||
#include <stdint.h>
|
||
#include <stdbool.h>
|
||
#include <mqueue.h>
|
||
#include <queue.h>
|
||
#include <poll.h>
|
||
|
||
#if CONFIG_MQ_MAXMSGSIZE > 0
|
||
|
||
/****************************************************************************
|
||
* Pre-processor Definitions
|
||
****************************************************************************/
|
||
|
||
/* Most internal nxmq_* interfaces are not available in the user space in
|
||
* PROTECTED and KERNEL builds. In that context, the application message
|
||
* queue interfaces must be used. The differences between the two sets of
|
||
* interfaces are: (1) the nxmq_* interfaces do not cause cancellation
|
||
* points and (2) they do not modify the errno variable.
|
||
*
|
||
* This is only important when compiling libraries (libc or libnx) that are
|
||
* used both by the OS (libkc.a and libknx.a) or by the applications
|
||
* (libc.a and libnx.a). In that case, the correct interface must be
|
||
* used for the build context.
|
||
*
|
||
* REVISIT: In the flat build, the same functions must be used both by
|
||
* the OS and by applications. We have to use the normal user functions
|
||
* in this case or we will fail to set the errno or fail to create the
|
||
* cancellation point.
|
||
*/
|
||
|
||
#if !defined(CONFIG_BUILD_FLAT) && defined(__KERNEL__)
|
||
# define _MQ_OPEN nxmq_open
|
||
# define _MQ_CLOSE(d) nxmq_close(d)
|
||
# define _MQ_UNLINK(n) nxmq_unlink(n)
|
||
# define _MQ_SEND(d,m,l,p) nxmq_send(d,m,l,p)
|
||
# define _MQ_TIMEDSEND(d,m,l,p,t) nxmq_timedsend(d,m,l,p,t)
|
||
# define _MQ_RECEIVE(d,m,l,p) nxmq_receive(d,m,l,p)
|
||
# define _MQ_TIMEDRECEIVE(d,m,l,p,t) nxmq_timedreceive(d,m,l,p,t)
|
||
#else
|
||
# define _MQ_OPEN mq_open
|
||
# define _MQ_CLOSE(d) mq_close(d)
|
||
# define _MQ_UNLINK(n) mq_unlink(n)
|
||
# define _MQ_SEND(d,m,l,p) mq_send(d,m,l,p)
|
||
# define _MQ_TIMEDSEND(d,m,l,p,t) mq_timedsend(d,m,l,p,t)
|
||
# define _MQ_RECEIVE(d,m,l,p) mq_receive(d,m,l,p)
|
||
# define _MQ_TIMEDRECEIVE(d,m,l,p,t) mq_timedreceive(d,m,l,p,t)
|
||
#endif
|
||
|
||
/****************************************************************************
|
||
* Public Type Declarations
|
||
****************************************************************************/
|
||
|
||
/* This structure defines a message queue */
|
||
|
||
struct mqueue_inode_s
|
||
{
|
||
FAR struct inode *inode; /* Containing inode */
|
||
sq_queue_t msglist; /* Prioritized message list */
|
||
int16_t maxmsgs; /* Maximum number of messages in the queue */
|
||
int16_t nmsgs; /* Number of message in the queue */
|
||
int16_t nwaitnotfull; /* Number tasks waiting for not full */
|
||
int16_t nwaitnotempty; /* Number tasks waiting for not empty */
|
||
#if CONFIG_MQ_MAXMSGSIZE < 256
|
||
uint8_t maxmsgsize; /* Max size of message in message queue */
|
||
#else
|
||
uint16_t maxmsgsize; /* Max size of message in message queue */
|
||
#endif
|
||
pid_t ntpid; /* Notification: Receiving Task's PID */
|
||
struct sigevent ntevent; /* Notification description */
|
||
struct sigwork_s ntwork; /* Notification work */
|
||
FAR struct pollfd *fds[CONFIG_FS_MQUEUE_NPOLLWAITERS];
|
||
};
|
||
|
||
/****************************************************************************
|
||
* Public Data
|
||
****************************************************************************/
|
||
|
||
/****************************************************************************
|
||
* Public Function Prototypes
|
||
****************************************************************************/
|
||
|
||
#ifdef __cplusplus
|
||
#define EXTERN extern "C"
|
||
extern "C"
|
||
{
|
||
#else
|
||
#define EXTERN extern
|
||
#endif
|
||
|
||
struct tcb_s; /* Forward reference */
|
||
struct mq_attr; /* Forward reference */
|
||
struct timespec; /* Forward reference */
|
||
struct task_group_s; /* Forward reference */
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_open
|
||
*
|
||
* Description:
|
||
* This function establish a connection between a named message queue and
|
||
* the calling task. This is an internal OS interface. It is functionally
|
||
* equivalent to mq_open() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_open() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input 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, 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.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success, mqdes point to the new message queue descriptor.
|
||
* A negated errno value is returned on failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
mqd_t nxmq_open(FAR const char *mq_name, int oflags, ...);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_close
|
||
*
|
||
* Description:
|
||
* This is an internal OS interface. It is functionally equivalent to
|
||
* mq_close() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_close() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message queue descriptor.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int nxmq_close(mqd_t mqdes);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_unlink
|
||
*
|
||
* Description:
|
||
* This is an internal OS interface. It is functionally equivalent to
|
||
* mq_unlink() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_unlink() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq_name - Name of the message queue
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int nxmq_unlink(FAR const char *mq_name);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_send
|
||
*
|
||
* Description:
|
||
* This function adds the specified message (msg) to the message queue
|
||
* (mqdes). This is an internal OS interface. It is functionally
|
||
* equivalent to mq_send() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_send() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message queue descriptor
|
||
* msg - Message to send
|
||
* msglen - The length of the message in bytes
|
||
* prio - The priority of the message
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_send() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
int nxmq_send(mqd_t mqdes, FAR const char *msg, size_t msglen,
|
||
unsigned int prio);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_timedsend
|
||
*
|
||
* Description:
|
||
* This function adds the specified message (msg) to the message queue
|
||
* (mqdes). nxmq_timedsend() behaves just like mq_send(), except that if
|
||
* the queue is full and the O_NONBLOCK flag is not enabled for the
|
||
* message queue description, then abstime points to a structure which
|
||
* specifies a ceiling on the time for which the call will block.
|
||
*
|
||
* nxmq_timedsend() is functionally equivalent to mq_timedsend() except
|
||
* that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_timedsend() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message queue descriptor
|
||
* msg - Message to send
|
||
* msglen - The length of the message in bytes
|
||
* prio - The priority of the message
|
||
* abstime - the absolute time to wait until a timeout is decleared
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_timedsend() for the list list valid return values).
|
||
*
|
||
* EAGAIN The queue was empty, and the O_NONBLOCK flag was set for the
|
||
* message queue description referred to by mqdes.
|
||
* EINVAL Either msg or mqdes is NULL or the value of prio is invalid.
|
||
* EPERM Message queue opened not opened for writing.
|
||
* EMSGSIZE 'msglen' was greater than the maxmsgsize attribute of the
|
||
* message queue.
|
||
* EINTR The call was interrupted by a signal handler.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int nxmq_timedsend(mqd_t mqdes, FAR const char *msg, size_t msglen,
|
||
unsigned int prio, FAR const struct timespec *abstime);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_receive
|
||
*
|
||
* Description:
|
||
* This function receives the oldest of the highest priority messages
|
||
* from the message queue specified by "mqdes." This is an internal OS
|
||
* interface. It is functionally equivalent to mq_receive except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_receive() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message Queue Descriptor
|
||
* msg - Buffer to receive the message
|
||
* msglen - Size of the buffer in bytes
|
||
* prio - If not NULL, the location to store message priority.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_receive() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
ssize_t nxmq_receive(mqd_t mqdes, FAR char *msg, size_t msglen,
|
||
FAR unsigned int *prio);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_timedreceive
|
||
*
|
||
* Description:
|
||
* This function receives the oldest of the highest priority messages from
|
||
* the message queue specified by "mqdes." If the message queue is empty
|
||
* and O_NONBLOCK was not set, nxmq_timedreceive() will block until a
|
||
* message is added to the message queue (or until a timeout occurs).
|
||
*
|
||
* nxmq_timedreceive() is an internal OS interface. It is functionally
|
||
* equivalent to mq_timedreceive() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_timedreceive() for a more complete description of
|
||
* the behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message Queue Descriptor
|
||
* msg - Buffer to receive the message
|
||
* msglen - Size of the buffer in bytes
|
||
* prio - If not NULL, the location to store message priority.
|
||
* abstime - the absolute time to wait until a timeout is declared.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_timedreceive() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
ssize_t nxmq_timedreceive(mqd_t mqdes, FAR char *msg, size_t msglen,
|
||
FAR unsigned int *prio,
|
||
FAR const struct timespec *abstime);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_free_msgq
|
||
*
|
||
* Description:
|
||
* This function deallocates an initialized message queue structure.
|
||
* First, it deallocates all of the queued messages in the message
|
||
* queue. It is assumed that this message queue is fully unlinked
|
||
* and closed so that no thread will attempt to access it while it
|
||
* is being deleted.
|
||
*
|
||
* Input Parameters:
|
||
* msgq - Named message queue to be freed
|
||
*
|
||
* Returned Value:
|
||
* None
|
||
*
|
||
****************************************************************************/
|
||
|
||
void nxmq_free_msgq(FAR struct mqueue_inode_s *msgq);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_alloc_msgq
|
||
*
|
||
* Description:
|
||
* This function implements a part of the POSIX message queue open logic.
|
||
* It allocates and initializes a struct mqueue_inode_s structure.
|
||
*
|
||
* Input Parameters:
|
||
* 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.
|
||
* msgq - This parameter is a address of a pointer
|
||
*
|
||
* Returned Value:
|
||
* IF the function runs successfully,will return Zero(OK),else will
|
||
* return a error code.
|
||
*
|
||
* EINVAL attr is a null pointer and attr->mq_mqssize or attr->mq_maxmsg
|
||
* is an invalid value.
|
||
* ENOMEM No memery to alloc.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int nxmq_alloc_msgq(FAR struct mq_attr *attr,
|
||
FAR struct mqueue_inode_s **msgq);
|
||
|
||
/****************************************************************************
|
||
* Name: nxmq_pollnotify
|
||
*
|
||
* Description:
|
||
* pollnotify, used for notifying the poll
|
||
*
|
||
* Input Parameters:
|
||
* msgq - Named message queue
|
||
* eventset - evnet
|
||
*
|
||
* Returned Value:
|
||
* The allocated and initialized message queue structure or NULL in the
|
||
* event of a failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
void nxmq_pollnotify(FAR struct mqueue_inode_s *msgq, pollevent_t eventset);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_open
|
||
*
|
||
* Description:
|
||
* This function establish a connection between a named message queue and
|
||
* the calling task. This is an internal OS interface. It is functionally
|
||
* equivalent to mq_open() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_open() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input 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, 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.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* NOT NULL Message queue descriptor, NULL failed.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_open(FAR struct file *mq,
|
||
FAR const char *mq_name, int oflags, ...);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_close
|
||
*
|
||
* Description:
|
||
* This is an internal OS interface. It is functionally equivalent to
|
||
* mq_close() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_close() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message queue descriptor.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_close(FAR struct file *mq);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_unlink
|
||
*
|
||
* Description:
|
||
* This is an internal OS interface. It is functionally equivalent to
|
||
* mq_unlink() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_unlink() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq_name - Name of the message queue
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_unlink(FAR const char *mq_name);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_send
|
||
*
|
||
* Description:
|
||
* This function adds the specified message (msg) to the message queue
|
||
* (mq). This is an internal OS interface. It is functionally
|
||
* equivalent to mq_send() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_send() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message queue descriptor
|
||
* msg - Message to send
|
||
* msglen - The length of the message in bytes
|
||
* prio - The priority of the message
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_send() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_send(FAR struct file *mq, FAR const char *msg, size_t msglen,
|
||
unsigned int prio);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_timedsend
|
||
*
|
||
* Description:
|
||
* This function adds the specified message (msg) to the message queue
|
||
* (mq). file_mq_timedsend() behaves just like mq_send(), except that if
|
||
* the queue is full and the O_NONBLOCK flag is not enabled for the
|
||
* message queue description, then abstime points to a structure which
|
||
* specifies a ceiling on the time for which the call will block.
|
||
*
|
||
* file_mq_timedsend() is functionally equivalent to mq_timedsend() except
|
||
* that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_timedsend() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message queue descriptor
|
||
* msg - Message to send
|
||
* msglen - The length of the message in bytes
|
||
* prio - The priority of the message
|
||
* abstime - the absolute time to wait until a timeout is decleared
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_timedsend() for the list list valid return values).
|
||
*
|
||
* EAGAIN The queue was empty, and the O_NONBLOCK flag was set for the
|
||
* message queue description referred to by mq.
|
||
* EINVAL Either msg or mq is NULL or the value of prio is invalid.
|
||
* EPERM Message queue opened not opened for writing.
|
||
* EMSGSIZE 'msglen' was greater than the maxmsgsize attribute of the
|
||
* message queue.
|
||
* EINTR The call was interrupted by a signal handler.
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_timedsend(FAR struct file *mq, FAR const char *msg,
|
||
size_t msglen, unsigned int prio,
|
||
FAR const struct timespec *abstime);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_receive
|
||
*
|
||
* Description:
|
||
* This function receives the oldest of the highest priority messages
|
||
* from the message queue specified by "mq." This is an internal OS
|
||
* interface. It is functionally equivalent to mq_receive except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_receive() for a more complete description of the
|
||
* behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message Queue Descriptor
|
||
* msg - Buffer to receive the message
|
||
* msglen - Size of the buffer in bytes
|
||
* prio - If not NULL, the location to store message priority.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_receive() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
ssize_t file_mq_receive(FAR struct file *mq, FAR char *msg, size_t msglen,
|
||
FAR unsigned int *prio);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_timedreceive
|
||
*
|
||
* Description:
|
||
* This function receives the oldest of the highest priority messages from
|
||
* the message queue specified by "mq." If the message queue is empty
|
||
* and O_NONBLOCK was not set, file_mq_timedreceive() will block until a
|
||
* message is added to the message queue (or until a timeout occurs).
|
||
*
|
||
* file_mq_timedreceive() is an internal OS interface. It is functionally
|
||
* equivalent to mq_timedreceive() except that:
|
||
*
|
||
* - It is not a cancellation point, and
|
||
* - It does not modify the errno value.
|
||
*
|
||
* See comments with mq_timedreceive() for a more complete description of
|
||
* the behavior of this function
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message Queue Descriptor
|
||
* msg - Buffer to receive the message
|
||
* msglen - Size of the buffer in bytes
|
||
* prio - If not NULL, the location to store message priority.
|
||
* abstime - the absolute time to wait until a timeout is declared.
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
* (see mq_timedreceive() for the list list valid return values).
|
||
*
|
||
****************************************************************************/
|
||
|
||
ssize_t file_mq_timedreceive(FAR struct file *mq, FAR char *msg,
|
||
size_t msglen, FAR unsigned int *prio,
|
||
FAR const struct timespec *abstime);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_setattr
|
||
*
|
||
* Description:
|
||
* This function sets the attributes associated with the
|
||
* specified message queue "mq". Only the "O_NONBLOCK"
|
||
* bit of the "mq_flags" can be changed.
|
||
*
|
||
* If "oldstat" is non-null, mq_setattr() will store the
|
||
* previous message queue attributes at that location (just
|
||
* as would have been returned by file_mq_getattr()).
|
||
*
|
||
* Input Parameters:
|
||
* mqdes - Message queue descriptor
|
||
* mq_stat - New attributes
|
||
* oldstate - Old attributes
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
* Assumptions:
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_setattr(FAR struct file *mq, FAR const struct mq_attr *mq_stat,
|
||
FAR struct mq_attr *oldstat);
|
||
|
||
/****************************************************************************
|
||
* Name: file_mq_getattr
|
||
*
|
||
* Description:
|
||
* This functions gets status information and attributes
|
||
* associated with the specified message queue.
|
||
*
|
||
* Input Parameters:
|
||
* mq - Message queue descriptor
|
||
* mq_stat - Buffer in which to return attributes
|
||
*
|
||
* Returned Value:
|
||
* This is an internal OS interface and should not be used by applications.
|
||
* It follows the NuttX internal error return policy: Zero (OK) is
|
||
* returned on success. A negated errno value is returned on failure.
|
||
*
|
||
* Assumptions:
|
||
*
|
||
****************************************************************************/
|
||
|
||
int file_mq_getattr(FAR struct file *mq, FAR struct mq_attr *mq_stat);
|
||
|
||
#undef EXTERN
|
||
#ifdef __cplusplus
|
||
}
|
||
#endif
|
||
|
||
#endif /* CONFIG_MQ_MAXMSGSIZE > 0 */
|
||
#endif /* ___INCLUDE_NUTTX_MQUEUE_H */
|