Worker coordination with file locks

tests/test_worker_coordination.py

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+#!/usr/bin/env python3
+"""Test script to verify worker coordination with file locking.
+
+This simulates multiple workers trying to acquire the primary worker lock.
+"""
+
+import multiprocessing
+import time
+from pathlib import Path
+
+from src.alpine_bits_python.worker_coordination import WorkerLock
+
+
+def worker_process(worker_id: int, lock_file: str):
+    """Simulate a worker process trying to acquire the lock."""
+    print(f"Worker {worker_id} (PID {multiprocessing.current_process().pid}): Starting")
+
+    lock = WorkerLock(lock_file)
+    is_primary = lock.acquire()
+
+    if is_primary:
+        print(f"Worker {worker_id} (PID {multiprocessing.current_process().pid}): ✓ I am PRIMARY")
+        # Simulate running singleton services
+        time.sleep(3)
+        print(f"Worker {worker_id} (PID {multiprocessing.current_process().pid}): Releasing lock")
+        lock.release()
+    else:
+        print(f"Worker {worker_id} (PID {multiprocessing.current_process().pid}): ✗ I am SECONDARY")
+        # Simulate regular worker work
+        time.sleep(3)
+
+    print(f"Worker {worker_id} (PID {multiprocessing.current_process().pid}): Exiting")
+
+
+if __name__ == "__main__":
+    # Use a test lock file
+    lock_file = "/tmp/test_alpinebits_worker.lock"
+
+    # Clean up any existing lock file
+    Path(lock_file).unlink(missing_ok=True)
+
+    print("Starting 4 worker processes (simulating uvicorn --workers 4)")
+    print("=" * 70)
+
+    # Start multiple workers
+    processes = []
+    for i in range(4):
+        p = multiprocessing.Process(target=worker_process, args=(i, lock_file))
+        p.start()
+        processes.append(p)
+        # Small delay to make output clearer
+        time.sleep(0.1)
+
+    # Wait for all workers to complete
+    for p in processes:
+        p.join()
+
+    print("=" * 70)
+    print("✓ Test complete: Only ONE worker should have been PRIMARY")
+
+    # Clean up
+    Path(lock_file).unlink(missing_ok=True)