sysv-ipc

import sysv_ipc import time import os # IPC_PRIVATE creates a new unique semaphore set for demonstration. # For multi-process communication, use a shared key, e.g., # key = sysv_ipc.ftok(os.getcwd(), 1) try: # Create a semaphore set with 1 semaphore, initial value 1. # IPC_CREX ensures exclusive creation, raising an error if it exists. sem = sysv_ipc.Semaphore(sysv_ipc.IPC_PRIVATE, flags=sysv_ipc.IPC_CREX, initial_value=1) print(f"Semaphore created with key: {sem.key}") print("Attempting to acquire semaphore...") sem.acquire() # Decrement semaphore value by 1 print("Semaphore acquired. Simulating work...") time.sleep(0.5) sem.release() # Increment semaphore value by 1 print("Semaphore released.") # It's crucial to remove IPC objects after use to free system resources. sem.remove() print("Semaphore removed.") except sysv_ipc.ExistentialError: print("Semaphore with this key already exists. This quickstart uses IPC_PRIVATE to avoid conflicts.") print("For multi-process, use sysv_ipc.ftok(path, id) for a shared key and omit IPC_CREX.") except sysv_ipc.Error as e: print(f"An IPC error occurred: {e}")