Message queue

Lockless message queue implementation using C11 atomic operations. More...

Data Structures
struct	messageq_t

Macros
#define	MESSAGEQ_VAR_INIT(basep, base_len, msg_len)

Functions
void	messageq_init (messageq_t *mq, void *basep, size_t base_len, size_t msg_len)
void *	messageq_claim (messageq_t *mq)
void	messageq_send (messageq_t *mq, void *msg)
void *	messageq_receive (messageq_t *mq)
void	messageq_release (messageq_t *mq, void *msg)

Detailed Description

Lockless message queue implementation using C11 atomic operations.

This is a lightweight memory based message queue capable of passing arbitrarily sized messages providing the size can be specified up front and the memory pre-allocated.

The message queue is thread safe for one-to-one and many-to-one messaging. It cannot be used to manage multiple receiver threads without additional external locking.

Note

The message queue implementation uses a bitfield to track state. For this reasons it cannot manage queues deeper than 32 messages.

Macro Definition Documentation

#define MESSAGEQ_VAR_INIT	(		basep,
			base_len,
			msg_len
	)

Value:

{ \
                (char *) (basep), \
                (msg_len), \
                ((base_len) / (msg_len)), \
                ATOMIC_VAR_INIT(((base_len) / (msg_len))), \
                ATOMIC_VAR_INIT(0), \
                ATOMIC_VAR_INIT(0), \
                0 \
        }

Definition at line 54 of file messageq.h.

Function Documentation

void* messageq_claim

(

messageq_t *

mq

)

Definition at line 31 of file messageq.c.

void messageq_init	(	messageq_t *	mq,
		void *	basep,
		size_t	base_len,
		size_t	msg_len
	)

Definition at line 21 of file messageq.c.

void* messageq_receive

(

messageq_t *

mq

)

Definition at line 57 of file messageq.c.

void messageq_release	(	messageq_t *	mq,
		void *	msg
	)

Definition at line 73 of file messageq.c.

void messageq_send	(	messageq_t *	mq,
		void *	msg
	)

Definition at line 50 of file messageq.c.