Unidirectional shared-memory multi-ring message queue. More...

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Data Structures
struct	svm_msg_q_ring_

struct	svm_msg_q_

struct	svm_msg_q_ring_cfg_

struct	svm_msg_q_cfg_

union	svm_msg_q_msg_t

Macros
#define	SVM_MQ_INVALID_MSG { .as_u64 = ~0 }

Typedefs
typedef struct svm_msg_q_ring_	svm_msg_q_ring_t

typedef struct svm_msg_q_	svm_msg_q_t

typedef struct svm_msg_q_ring_cfg_	svm_msg_q_ring_cfg_t

typedef struct svm_msg_q_cfg_	svm_msg_q_cfg_t

Functions
svm_msg_q_t *	svm_msg_q_alloc (svm_msg_q_cfg_t *cfg)
	Allocate message queue. More...

void	svm_msg_q_free (svm_msg_q_t *mq)
	Free message queue. More...

svm_msg_q_msg_t	svm_msg_q_alloc_msg (svm_msg_q_t *mq, u32 nbytes)
	Allocate message buffer. More...

svm_msg_q_msg_t	svm_msg_q_alloc_msg_w_ring (svm_msg_q_t *mq, u32 ring_index)
	Allocate message buffer on ring. More...

int	svm_msg_q_lock_and_alloc_msg_w_ring (svm_msg_q_t mq, u32 ring_index, u8 noblock, svm_msg_q_msg_t msg)
	Lock message queue and allocate message buffer on ring. More...

void	svm_msg_q_free_msg (svm_msg_q_t mq, svm_msg_q_msg_t msg)
	Free message buffer. More...

int	svm_msg_q_add (svm_msg_q_t mq, svm_msg_q_msg_t msg, int nowait)
	Producer enqueue one message to queue. More...

void	svm_msg_q_add_and_unlock (svm_msg_q_t mq, svm_msg_q_msg_t msg)
	Producer enqueue one message to queue with mutex held. More...

int	svm_msg_q_sub (svm_msg_q_t mq, svm_msg_q_msg_t msg, svm_q_conditional_wait_t cond, u32 time)
	Consumer dequeue one message from queue. More...

void	svm_msg_q_sub_w_lock (svm_msg_q_t mq, svm_msg_q_msg_t msg)
	Consumer dequeue one message from queue with mutex held. More...

void *	svm_msg_q_msg_data (svm_msg_q_t mq, svm_msg_q_msg_t msg)
	Get data for message in queue. More...

svm_msg_q_ring_t *	svm_msg_q_ring (svm_msg_q_t *mq, u32 ring_index)
	Get message queue ring. More...

void	svm_msg_q_set_consumer_eventfd (svm_msg_q_t *mq, int fd)
	Set event fd for queue consumer. More...

void	svm_msg_q_set_producer_eventfd (svm_msg_q_t *mq, int fd)
	Set event fd for queue producer. More...

int	svm_msg_q_alloc_consumer_eventfd (svm_msg_q_t *mq)
	Allocate event fd for queue consumer. More...

int	svm_msg_q_alloc_producer_eventfd (svm_msg_q_t *mq)
	Allocate event fd for queue consumer. More...

static u8	svm_msg_q_is_full (svm_msg_q_t *mq)
	Check if message queue is full. More...

static u8	svm_msg_q_ring_is_full (svm_msg_q_t *mq, u32 ring_index)

static u8	svm_msg_q_is_empty (svm_msg_q_t *mq)
	Check if message queue is empty. More...

static u32	svm_msg_q_size (svm_msg_q_t *mq)
	Check length of message queue. More...

static u8	svm_msg_q_msg_is_invalid (svm_msg_q_msg_t *msg)
	Check if message is invalid. More...

static int	svm_msg_q_try_lock (svm_msg_q_t *mq)
	Try locking message queue. More...

static int	svm_msg_q_lock (svm_msg_q_t *mq)
	Lock, or block trying, the message queue. More...

static void	svm_msg_q_unlock (svm_msg_q_t *mq)
	Unlock message queue. More...

static void	svm_msg_q_wait (svm_msg_q_t *mq)
	Wait for message queue event. More...

static int	svm_msg_q_timedwait (svm_msg_q_t *mq, double timeout)
	Timed wait for message queue event. More...

static int	svm_msg_q_get_consumer_eventfd (svm_msg_q_t *mq)

static int	svm_msg_q_get_producer_eventfd (svm_msg_q_t *mq)

Detailed Description

Unidirectional shared-memory multi-ring message queue.

Definition in file message_queue.h.

Macro Definition Documentation

#define SVM_MQ_INVALID_MSG { .as_u64 = ~0 }

Definition at line 68 of file message_queue.h.

Typedef Documentation

typedef struct svm_msg_q_cfg_ svm_msg_q_cfg_t

typedef struct svm_msg_q_ring_cfg_ svm_msg_q_ring_cfg_t

typedef struct svm_msg_q_ring_ svm_msg_q_ring_t

typedef struct svm_msg_q_ svm_msg_q_t

Function Documentation

int svm_msg_q_add	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg,
		int	nowait
	)

Producer enqueue one message to queue.

Prior to calling this, the producer should've obtained a message buffer from one of the rings by calling svm_msg_q_alloc_msg.

Parameters

mq	message queue
msg	message (pointer to ring position) to be enqueued
nowait	flag to indicate if request is blocking or not

Returns: success status

Definition at line 212 of file message_queue.c.

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void svm_msg_q_add_and_unlock	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg
	)

Producer enqueue one message to queue with mutex held.

Prior to calling this, the producer should've obtained a message buffer from one of the rings by calling svm_msg_q_alloc_msg. It assumes the queue mutex is held.

Parameters

mq	message queue
msg	message (pointer to ring position) to be enqueued

Returns: success status

Definition at line 219 of file message_queue.c.

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svm_msg_q_t* svm_msg_q_alloc ( svm_msg_q_cfg_t * cfg )

Allocate message queue.

Allocates a message queue on the heap. Based on the configuration options, apart from the message queue this also allocates (one or multiple) shared-memory rings for the messages.

Parameters

cfg	configuration options: queue len, consumer pid, ring configs

Returns: message queue

Definition at line 40 of file message_queue.c.

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int svm_msg_q_alloc_consumer_eventfd ( svm_msg_q_t * mq )

Allocate event fd for queue consumer.

Definition at line 252 of file message_queue.c.

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svm_msg_q_msg_t svm_msg_q_alloc_msg	(	svm_msg_q_t *	mq,
		u32	nbytes
	)

Allocate message buffer.

Message is allocated on the first available ring capable of holding the requested number of bytes.

Parameters

mq	message queue
nbytes	number of bytes needed for message

Returns: message structure pointing to the ring and position allocated

Definition at line 146 of file message_queue.c.

svm_msg_q_msg_t svm_msg_q_alloc_msg_w_ring	(	svm_msg_q_t *	mq,
		u32	ring_index
	)

Allocate message buffer on ring.

Message is allocated, on requested ring. The caller MUST check that the ring is not full.

Parameters

mq	message queue
ring_index	ring on which the allocation should occur

Returns: message structure pointing to the ring and position allocated

Definition at line 102 of file message_queue.c.

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int svm_msg_q_alloc_producer_eventfd ( svm_msg_q_t * mq )

Allocate event fd for queue consumer.

Definition at line 262 of file message_queue.c.

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void svm_msg_q_free ( svm_msg_q_t * mq )

Free message queue.

Parameters

mq	message queue to be freed

Definition at line 95 of file message_queue.c.

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void svm_msg_q_free_msg	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg
	)

Free message buffer.

Marks message buffer on ring as free.

Parameters

mq	message queue
msg	message to be freed

Definition at line 172 of file message_queue.c.

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static int svm_msg_q_get_consumer_eventfd ( svm_msg_q_t * mq )

inlinestatic

Definition at line 350 of file message_queue.h.

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static int svm_msg_q_get_producer_eventfd ( svm_msg_q_t * mq )

inlinestatic

Definition at line 356 of file message_queue.h.

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static u8 svm_msg_q_is_empty ( svm_msg_q_t * mq )

inlinestatic

Check if message queue is empty.

Definition at line 270 of file message_queue.h.

static u8 svm_msg_q_is_full ( svm_msg_q_t * mq )

inlinestatic

Check if message queue is full.

Definition at line 254 of file message_queue.h.

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static int svm_msg_q_lock ( svm_msg_q_t * mq )

inlinestatic

Lock, or block trying, the message queue.

Definition at line 306 of file message_queue.h.

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int svm_msg_q_lock_and_alloc_msg_w_ring	(	svm_msg_q_t *	mq,
		u32	ring_index,
		u8	noblock,
		svm_msg_q_msg_t *	msg
	)

Lock message queue and allocate message buffer on ring.

This should be used when multiple writers/readers are expected to compete for the rings/queue. Message should be enqueued by calling svm_msg_q_add_w_lock and the caller MUST unlock the queue once the message in enqueued.

Parameters

mq	message queue
ring_index	ring on which the allocation should occur
noblock	flag that indicates if request should block
msg	pointer to message to be filled in

Returns: 0 on success, negative number otherwise

Definition at line 116 of file message_queue.c.

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void* svm_msg_q_msg_data	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg
	)

Get data for message in queue.

Parameters

mq	message queue
msg	message for which the data is requested

Returns: pointer to data

Definition at line 165 of file message_queue.c.

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static u8 svm_msg_q_msg_is_invalid ( svm_msg_q_msg_t * msg )

inlinestatic

Check if message is invalid.

Definition at line 288 of file message_queue.h.

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svm_msg_q_ring_t* svm_msg_q_ring	(	svm_msg_q_t *	mq,
		u32	ring_index
	)

Get message queue ring.

Parameters

mq	message queue
ring_index	index of ring

Returns: pointer to ring

Definition at line 27 of file message_queue.c.

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static u8 svm_msg_q_ring_is_full	(	svm_msg_q_t *	mq,
		u32	ring_index
	)

inlinestatic

Definition at line 260 of file message_queue.h.

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void svm_msg_q_set_consumer_eventfd	(	svm_msg_q_t *	mq,
		int	fd
	)

Set event fd for queue consumer.

If set, queue will exclusively use eventfds for signaling. Moreover, afterwards, the queue should only be used in non-blocking mode. Waiting for events should be done externally using something like epoll.

Parameters

mq	message queue
fd	consumer eventfd

Definition at line 240 of file message_queue.c.

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void svm_msg_q_set_producer_eventfd	(	svm_msg_q_t *	mq,
		int	fd
	)

Set event fd for queue producer.

If set, queue will exclusively use eventfds for signaling. Moreover, afterwards, the queue should only be used in non-blocking mode. Waiting for events should be done externally using something like epoll.

Parameters

mq	message queue
fd	producer eventfd

Definition at line 246 of file message_queue.c.

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static u32 svm_msg_q_size ( svm_msg_q_t * mq )

inlinestatic

Check length of message queue.

Definition at line 279 of file message_queue.h.

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int svm_msg_q_sub	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg,
		svm_q_conditional_wait_t	cond,
		u32	time
	)

Consumer dequeue one message from queue.

This returns the message pointing to the data in the message rings. The consumer is expected to call svm_msg_q_free_msg once it finishes processing/copies the message data.

Parameters

mq	message queue
msg	pointer to structure where message is to be received
cond	flag that indicates if request should block or not
time	time to wait if condition it SVM_Q_TIMEDWAIT

Returns: success status

Definition at line 227 of file message_queue.c.

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void svm_msg_q_sub_w_lock	(	svm_msg_q_t *	mq,
		svm_msg_q_msg_t *	msg
	)

Consumer dequeue one message from queue with mutex held.

Returns the message pointing to the data in the message rings under the assumption that the message queue lock is already held. The consumer is expected to call svm_msg_q_free_msg once it finishes processing/copies the message data.

Parameters

mq	message queue
msg	pointer to structure where message is to be received

Returns: success status

Definition at line 234 of file message_queue.c.

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static int svm_msg_q_timedwait	(	svm_msg_q_t *	mq,
		double	timeout
	)

inlinestatic

Timed wait for message queue event.

Must be called with mutex held.

Parameters

mq	message queue
timeout	time in seconds

Definition at line 344 of file message_queue.h.

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static int svm_msg_q_try_lock ( svm_msg_q_t * mq )

inlinestatic

Try locking message queue.

Definition at line 297 of file message_queue.h.

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static void svm_msg_q_unlock ( svm_msg_q_t * mq )

inlinestatic

Unlock message queue.

Definition at line 315 of file message_queue.h.

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static void svm_msg_q_wait ( svm_msg_q_t * mq )

inlinestatic

Wait for message queue event.

Must be called with mutex held. The queue only works non-blocking with eventfds, so handle blocking calls as an exception here.

Definition at line 330 of file message_queue.h.

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Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation