c-queues

c-queues is a small C queue library with a common API and multiple implementations:

• mutex_queue for a simple mutex-protected ring buffer
• lf_spsc for single-producer/single-consumer use
• lf_spmc for single-producer/multi-consumer use
• lf_mpsc for multi-producer/single-consumer use
• lf_mpmc for multi-producer/multi-consumer use

All queues store int values and use a fixed capacity. Capacities must be a power of two.

Build

The project uses CMake.

cmake -S . -B build
cmake --build build

This builds the library code plus two executables:

• tests
• benchmarks

Run Tests

The test binary accepts one or more queue-type flags:

./build/tests/tests --spsc
./build/tests/tests --spmc
./build/tests/tests --mpsc
./build/tests/tests --mpmc
./build/tests/tests --spsc --spmc --mpsc --mpmc

Run Benchmarks

The benchmark binary accepts one or more benchmark flags:

./build/benchmarks/benchmarks --mutex
./build/benchmarks/benchmarks --spsc
./build/benchmarks/benchmarks --spmc
./build/benchmarks/benchmarks --mpsc
./build/benchmarks/benchmarks --mpmc
./build/benchmarks/benchmarks --mutex --spsc --spmc --mpsc --mpmc

API

Each queue implementation exposes create, push, pop, and destroy functions. The generic wrapper in include/queue.h provides queue_enqueue, queue_dequeue, and queue_destroy.

Example:

#include "lf_spsc.h"
#include "queue.h"

int main(void) {
  queue_t *q = lf_spsc_create(1024);
  if (!q) {
    return 1;
  }

  queue_enqueue(q, 42);

  int value = 0;
  if (queue_dequeue(q, &value) == 0) {
    /* value == 42 */
  }

  queue_destroy(q);
  return 0;
}

Notes

• Queue capacity must be non-zero and a power of two.
• The current API stores int values.
• queue_destroy and the type-specific destroy functions free the queue instance and its storage; callers must ensure no other threads are still using the queue.