Spsc class - spsc library

SPSC (Single-Producer Single-Consumer) channels - Efficient direct communication.

A high-performance channel type in cross_channel. Optimized for scenarios where exactly one producer communicates with exactly one consumer. Uses efficient algorithms and data structures to minimize overhead.

Performance Characteristics

Good performance: Efficient message passing, typically ~550-570ns per operation
Minimal allocations: Optimized to reduce garbage collection pressure
Efficient design: Designed to avoid contention in the hot path
Ring buffer: Uses power-of-two sized SRSW (Single-Reader Single-Writer) ring buffer

When to Use SPSC

Performance-sensitive producer-consumer scenarios
Data streaming between two components
Game logic (e.g., main thread ↔ render thread communication)
Sensor data processing
Any scenario requiring efficient 1:1 communication

Constraints

EXACTLY one producer and one consumer required

Violation leads to undefined behavior and potential data corruption
Use XChannel.mpsc for multiple producers
Use XChannel.mpmc for multiple producers and consumers

Example

import 'dart:async';

import 'package:cross_channel/spsc.dart';

Future<void> main() async {
  // 1. Create a bounded SPSC channel for 1:1 communication
  final (tx, rx) = Spsc.channel<int>(1024);

  // 2. Producer
  Future<void> produceEvents() async {
    for (int i = 0; i < 5; i++) {
      await tx.send(i);
      print('SPSC Sent: $i');
    }
    tx.close(); // Graceful shutdown
  }

  unawaited(produceEvents());

  // 3. Single Consumer
  await for (final value in rx.stream()) {
    print('SPSC Received: $value');
  }
}

Spsc class final

Performance Characteristics

When to Use SPSC

Constraints

Example

Constructors

Properties

Methods

Operators

Static Methods

spsc library