spsc.h File Reference

#include <stdint.h>
#include <stdio.h>

Include dependency graph for spsc.h:

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Data Structures
struct	spsc_ring_data
struct	spsc_ring

Macros
#define	MSG_SIZE_T   uint32_t
#define	READ_MODE   1
#define	WRITE_MODE   2

Functions
int	spsc_create_sub (spsc_ring *ring, const char *pathname, const size_t size)
int	spsc_create_pub (spsc_ring *ring, const char *pathname, const size_t size)
size_t	spsc_read (spsc_ring *ring, void *dest, const size_t n)
MSG_SIZE_T	spsc_write (spsc_ring *ring, const void *src, const MSG_SIZE_T n)
size_t	spsc_size (const spsc_ring *ring)
size_t	spsc_capacity (const spsc_ring *ring)
void	spsc_destroy (spsc_ring *ring)

Macro Definition Documentation

MSG_SIZE_T

#define MSG_SIZE_T   uint32_t

READ_MODE

#define READ_MODE   1

WRITE_MODE

#define WRITE_MODE   2

Function Documentation

spsc_capacity()

size_t spsc_capacity

(

const spsc_ring *

ring

)

Gets the maximum size of the ring.

Returns

the maximum size of the ring.

spsc_create_pub()

int spsc_create_pub	(	spsc_ring *	ring,
		const char *	pathname,
		const size_t	size
	)

Creates a publisher for a shared memory spsc ring located at the specified path. A new file is created if it doesn't exist.

Parameters

ring	pointer to a spsc_ring structure
pathname	path to the shared memory file
size	max size of the ring in bytes

Returns

0 if successful, otherwise an error code is returned.

spsc_create_sub()

int spsc_create_sub	(	spsc_ring *	ring,
		const char *	pathname,
		const size_t	size
	)

Creates a subscriber for a shared memory spsc ring located at the specified path. A new file is created if it doesn't exist.

Parameters

ring	pointer to a spsc_ring structure
pathname	path to the shared memory file
size	max size of the ring in bytes

Returns

0 if successful, otherwise an error code is returned.

spsc_destroy()

void spsc_destroy

(

spsc_ring *

ring

)

Destructor for spsc_ring.

Parameters

ring	pointer to a spsc_ring structure

spsc_read()

size_t spsc_read	(	spsc_ring *	ring,
		void *	dest,
		const size_t	n
	)

Reads the next entry from the ring into the specified location.

Parameters

ring	pointer to a spsc_ring structure
dest	pointer to a location to copy bytes to
n	number of bytes to copy, must be less than or equal to the size of dest.

Returns

the number of bytes copied, or 0 if there is nothing left to read.

spsc_size()

size_t spsc_size

(

const spsc_ring *

ring

)

Gets an approximate size of the ring. The returned number depends on whether the publishing thread or subscribing thread called the method. The behvaiour is undefined for any other calling thread.

Parameters

ring	pointer to a spsc_ring structure

Returns

an approximate size of the ring.

spsc_write()

MSG_SIZE_T spsc_write	(	spsc_ring *	ring,
		const void *	src,
		const MSG_SIZE_T	n
	)

Writes an entry into the ring, copying from the specified location.

Parameters

ring	pointer to a spsc_ring structure
src	pointer to a location to copy bytes from
n	number of bytes to copy, must be less than or equal to the size of src

Returns

the number of bytes copied, or 0 if the ring is full.