SocketManager

SocketManager manages multiple Wayland sockets concurrently using DashMap.

Overview

In a multi-output Wayland compositor, each output may have its own socket. SocketManager provides a concurrent registry for named sockets, allowing the compositor to:

• Register sockets by name ("default", "hdmi-1", etc.)
• Retrieve sockets when spawning compositor clients
• Share socket references across threads via Arc

The DashMap backend allows concurrent reads and writes without a single Mutex lock - multiple threads can register and retrieve sockets simultaneously.

register() uses the DashMap entry API for atomic check-and-insert, preventing TOCTOU race conditions when multiple threads register sockets concurrently.

API

Concurrency Model

graph TD
    classDef default fill: #1e1e1e, stroke: #333333, stroke-width: 1px, color: #ffffff
    classDef thread fill: #00a1e4, stroke: #ffffff, stroke-width: 2px, color: #ffffff
    classDef map fill: #f5b700, stroke: #333333, stroke-width: 2px, color: #000000
    classDef socket fill: #89fc00, stroke: #333333, stroke-width: 1px, color: #000

    A["Thread 1<br/>Compositor main"] --> B["SocketManager<br/><small>DashMap&lt;String, Socket&gt;</small>"]
    C["Thread 2<br/>Client spawner"] --> B
    D["Thread 3<br/>Output handler"] --> B
    B --> E["register('default', socket)"]
    B --> F["get('hdmi-1')"]
    B --> G["remove('old-output')"]

    class A thread
    class C thread
    class D thread
    class B map
    class E socket
    class F socket
    class G socket

Usage

Basic

#![allow(unused)]
fn main() {
use process_manager_socket::{SocketBuilder, SocketManager};

let manager = SocketManager::new();
let socket = SocketBuilder::build(&None)?;
manager.register("default", socket)?;

let socket = manager.get("default");
assert!(socket.is_some());
}

Multi-output with Arc

#![allow(unused)]
fn main() {
use process_manager_socket::{SocketBuilder, SocketManager};
use std::sync::Arc;

let manager = Arc::new(SocketManager::new());

// Register sockets for each output
manager.register("default", SocketBuilder::build(&Some("wayland-0".to_string()))?)?;
manager.register("hdmi-1", SocketBuilder::build(&Some("wayland-1".to_string()))?)?;

// Share across threads
let manager_clone = Arc::clone(&manager);
std::thread::spawn(move || {
    let socket = manager_clone.get("hdmi-1").unwrap();
    // Use socket for spawning a client on hdmi-1
});

// List all sockets
let names = manager.names();
assert_eq!(names.len(), 2);
}

Errors