mqueue.h File Reference

#include <sys/types.h>
#include <common/list.h>

Include dependency graph for mqueue.h:

Go to the source code of this file.

Data Structures
struct	mq_attr

Typedefs
typedef uint32_t	mqd_t

Functions
int	mq_getattr (mqd_t mqdes, struct mq_attr *attr)
	Retrieve atributes of the message queue referred to by the message queue descriptor mqdes. More...
int	mq_setattr (mqd_t mqdes, const struct mq_attr *newattr, struct mq_attr *oldattr)
	Modify attributes of the message queue referred to by the message queue descriptor mqdes. More...
mqd_t	mq_open (const char *name, int oflag, struct mq_attr *attr)
	Create a new message queue or open an existing queue. More...
int	mq_close (mqd_t mqdes)
	Close the message queue descriptor. More...
int	mq_unlink (const char *name)
ssize_t	mq_receive (mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned int *msg_prio)
	Remove the oldest message with highest priority from the message queue referred to by the message queue descriptor mqdes and places it in the buffer pointed to by msg_ptr. More...
int	mq_send (mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned int msg_prio)
	Add the message pointed to by msg_ptr to the message queue referred to by the message queue descriptor mqdes. More...

Function Documentation

mq_close()

int mq_close

(

mqd_t

mqdes

)

Close the message queue descriptor.

Parameters

mqdes

The message queue descriptor to provide.

Return values

int	0 on success and nonzero error number on error.

mq_getattr()

int mq_getattr	(	mqd_t	mqdes,
		struct mq_attr *	attr
	)

Retrieve atributes of the message queue referred to by the message queue descriptor mqdes.

Parameters

mqdes	The message queue descriptor to provide.
newattr	Pointer to the new attribute.
oldattr	Pointer to the memory space for storing old attributes.

Return values

int	0 on success and nonzero error number on error.

mq_open()

mqd_t mq_open	(	const char *	name,
		int	oflag,
		struct mq_attr *	attr
	)

Create a new message queue or open an existing queue.

Parameters

name	The name of the message queue.
oflag	The flags for opening the message queue.
attr	The attribute object for setting the message queue.

Return values

mqd_t

The message queue descriptor to return.

mq_receive()

ssize_t mq_receive	(	mqd_t	mqdes,
		char *	msg_ptr,
		size_t	msg_len,
		unsigned int *	msg_prio
	)

Remove the oldest message with highest priority from the message queue referred to by the message queue descriptor mqdes and places it in the buffer pointed to by msg_ptr.

Parameters

mqdes	The message queue descriptor to provide.
msg_ptr	The buffer for storing the received message.
msg_len	The length of the buffer pointed to by msg_ptr.
msg_prio	The priority of the received message.

Return values

ssize_t

The size of the received message in bytes.

mq_send()

int mq_send	(	mqd_t	mqdes,
		const char *	msg_ptr,
		size_t	msg_len,
		unsigned int	msg_prio
	)

Add the message pointed to by msg_ptr to the message queue referred to by the message queue descriptor mqdes.

Parameters

mqdes	The message queue descriptor to provide.
msg_ptr	The message to send.
msg_len	The size of the message in bytes.
msg_prio	The priority of the message to send.

Return values

int	0 on success and nonzero error number on error.

mq_setattr()

int mq_setattr	(	mqd_t	mqdes,
		const struct mq_attr *	newattr,
		struct mq_attr *	oldattr
	)

Modify attributes of the message queue referred to by the message queue descriptor mqdes.

Parameters

mqdes	The message queue descriptor to provide.
attr	The memory space for retrieving message queue attributes.

Return values

int	0 on success and nonzero error number on error.