dtringfifo

Lock-free byte ring buffer for Single Producer Single Consumer use

This group of functions provides byte-oriented FIFO buffering for a single producer and a single consumer. It implements for low-level data transfer between concurrent contexts without external locking. The implementation uses simple memcpy-based transfers.

Mini-guide

• Configure the ring over caller-provided storage by requiring explicit initialization and configuration.
• Use exactly one producer and one consumer to preserve the lock-free concurrency model.
• If necessary to reset the ring, do it only when no concurrent access is happening by enforcing external synchronization.

Example

uint8_t storage[128];
dtringfifo_t fifo;
dtringfifo_config_t cfg = {
    .buffer = storage,
    .capacity = sizeof(storage),
};

dtringfifo_init(&fifo);
dtringfifo_configure(&fifo, &cfg);

dtringfifo_push(&fifo, data, data_len);
count = dtringfifo_pop(&fifo, out, out_len);

Data structures

dtringfifo_config_t

Describes caller-provided storage used to configure a ring.

Members:

uint8_t* buffer Pointer to caller-owned storage backing the ring.
int32_t capacity Total number of bytes in the storage buffer.

dtringfifo_t

Holds ring state and indices for single-producer single-consumer access.

Members:

uint8_t* buffer Pointer to caller-owned storage backing the ring.
int32_t capacity Total number of bytes in the storage buffer.
_Atomic int32_t head Index of the next write position.
_Atomic int32_t tail Index of the next read position.

Functions

dtringfifo_configure

Associates the ring with caller-provided storage and initializes indices.

Params:

dtringfifo_t* self Ring instance to configure.
const dtringfifo_config_t* cfg Configuration describing storage and capacity.

Return: dterr_t* Error object on failure, or NULL on success.

dtringfifo_init

Initializes the ring structure to a known empty state.

Params:

dtringfifo_t* self Ring instance to initialize.

Return: dterr_t* Error object on failure, or NULL on success.

dtringfifo_pop

Copies available bytes from the ring into the destination buffer.

Params:

dtringfifo_t* self Ring instance to read from.
uint8_t* dest Destination buffer to receive data.
int32_t dest_len Maximum number of bytes to copy.

Return: int32_t Number of bytes actually copied.

dtringfifo_push

Copies bytes from the source buffer into the ring until full.

Params:

dtringfifo_t* self Ring instance to write to.
const uint8_t* src Source buffer providing data.
int32_t src_len Number of bytes available in the source buffer.

Return: int32_t Number of bytes actually stored.

dtringfifo_reset

Resets read and write indices while preserving configured storage.

Params:

dtringfifo_t* self Ring instance to reset.

Return: void No return value.