Module loop_lock 

Loop lock mechanism for preventing concurrent Ralph loops in the same workspace.

Uses flock() on .ralph/loop.lock to ensure only one primary loop runs at a time. When a second loop attempts to start, it can detect the existing lock and spawn into a git worktree instead.

Example

use ralph_core::loop_lock::{LoopLock, LockError};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    match LoopLock::try_acquire(".", "implement auth") {
        Ok(guard) => {
            // We're the primary loop - run normally
            println!("Acquired lock, running as primary loop");
            // Lock is held until guard is dropped
        }
        Err(LockError::AlreadyLocked(existing)) => {
            // Another loop is running - spawn into worktree
            println!("Lock held by PID {}, spawning worktree", existing.pid);
        }
        Err(e) => return Err(e.into()),
    }
    Ok(())
}

Structs

LockGuard

A guard that holds the loop lock. The lock is released when this is dropped.

LockMetadata

Metadata stored in the lock file, readable by other processes.

LoopLock

The loop lock mechanism.

Enums

LockError

Errors that can occur during lock operations.