mcmpq.h

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MCMPQ(3) Library Functions Manual MCMPQ(3)

NAME mcmpq.h - Multi-Consumer Multi-Producer Queue (MCMPQ) library

DESCRIPTION mcmpq.h provides a simple, cache-friendly, lock-free multi-consumer multi-producer queue implementation in C11.

This library is designed for high-performance concurrent
programming where multiple threads may simultaneously
enqueue and dequeue items without requiring mutexes.

The queue is based on atomic operations and is optimized
for minimal contention between threads.

It allows the following:

    Enqueueing items to the queue,
    Dequeueing items from the queue,
    Checking the size of the queue,
    Checking if the queue is empty.

SYNOPSIS #include "mcmpq.h"

typedef struct {
    _Atomic size_t turn;
    unsigned char storage[ITEM_SIZE];
} slot_t;

typedef struct {
    slot_t slots[QUEUE_SIZE];
    _Atomic size_t head;
    _Atomic size_t tail;
} MPMCQueue;

void enqueue(MPMCQueue *queue, const void *item);
bool try_enqueue(MPMCQueue *queue, const void *item);
void dequeue(MPMCQueue *queue, void *item);
bool try_dequeue(MPMCQueue *queue, void *item);
size_t queue_size(MPMCQueue *queue);
bool queue_empty(MPMCQueue *queue);

FUNCTIONS void enqueue(MPMCQueue *queue, const void *item) Enqueues an item to the queue. This function will busy-wait if the queue is full.

bool try_enqueue(MPMCQueue *queue, const void *item)
    Attempts to enqueue an item to the queue without
    busy-waiting. Returns true on success or false if
    the queue is full.

void dequeue(MPMCQueue *queue, void *item)
    Dequeues an item from the queue. This function
    will busy-wait if the queue is empty.

bool try_dequeue(MPMCQueue *queue, void *item)
    Attempts to dequeue an item from the queue without
    busy-waiting. Returns true on success or false if
    the queue is empty.

size_t queue_size(MPMCQueue *queue)
    Returns the current number of items in the queue.

bool queue_empty(MPMCQueue *queue)
    Checks if the queue is empty. Returns true if the
    queue is empty, false otherwise.

CONSTANTS QUEUE_SIZE Number of slots in the queue (10).

ITEM_SIZE
    Size of each item in the queue (56). (^on x86-64)

CACHE_LINE_SIZE
    Cache line size for alignment (64 bytes).

AUTHOR 173duprot https://github.com/173duprot

COPYRIGHT This library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it 
will be useful, but WITHOUT ANY WARRANTY; without 
even the implied warranty of MERCHANTABILITY or 
FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
General Public License for more details.

You should have received a copy of the GNU General 
Public License along with this library. If not, 
see <https://www.gnu.org/licenses/>.

MCMPQ(3) Library Functions Manual MCMPQ(3)