message_queue.c File Reference

Structures and functions for enqueueing and dequeuing general-purpose messages from a queue. More...

#include "message_queue.h"
#include "logging.h"
#include <time.h>

Go to the source code of this file.

Functions
int	enqueue_msg (struct msg_queue *q, struct dedos_msg *msg)
	Enqueues a message to be delivered as soon as possible. More...
int	schedule_msg (struct msg_queue *q, struct dedos_msg *msg, struct timespec *interval)
	Schedules a message to be delivered once interval time has passed. More...
static double	timediff_s (struct timespec *t1, struct timespec *t2)
	Returns the difference in time in seconds, t2 - t1. More...
struct dedos_msg *	dequeue_msg (struct msg_queue *q)
	Dequeues the first available message from q. More...
int	init_msg_queue (struct msg_queue *q, sem_t *sem)
	Initilializes a mesasge queue to have no messages in it, and sets up the mutex and semaphore. More...

Variables
static struct timespec	zero = {}
	Interval 0 seconds from now. More...

Detailed Description

Structures and functions for enqueueing and dequeuing general-purpose messages from a queue.

Definition in file message_queue.c.

Function Documentation

struct dedos_msg* dequeue_msg

(

struct msg_queue *

q

)

Dequeues the first available message from q.

If there are no messages, or no messages with a suitable delivery time, returns NULL.

Returns

dedos_msg dequeued, or NULL

Definition at line 87 of file message_queue.c.

int enqueue_msg	(	struct msg_queue *	q,
		struct dedos_msg *	msg
	)

Enqueues a message to be delivered as soon as possible.

Returns

0 on success, -1 on error

Definition at line 34 of file message_queue.c.

int init_msg_queue	(	struct msg_queue *	q,
		sem_t *	sem
	)

Initilializes a mesasge queue to have no messages in it, and sets up the mutex and semaphore.

Returns

0 on success, -1 on error

Definition at line 153 of file message_queue.c.

int schedule_msg	(	struct msg_queue *	q,
		struct dedos_msg *	msg,
		struct timespec *	interval
	)

Schedules a message to be delivered once interval time has passed.

Returns

0 on success, -1 on error

Definition at line 38 of file message_queue.c.

static double timediff_s ( struct timespec *  t1, struct timespec *  t2  )

static

Returns the difference in time in seconds, t2 - t1.

Definition at line 83 of file message_queue.c.

Variable Documentation

struct timespec zero = {}

static

Interval 0 seconds from now.

Definition at line 32 of file message_queue.c.