Great questions! Let's break these down clearly:

1. 多进程是否支持命名管道（FIFO）？ #

Absolutely yes. 命名管道（FIFO）是操作系统层面的进程间通信（IPC）机制，它本质是文件系统中的一个特殊节点。只要是同一主机上的进程（无论是否有亲缘关系，只要拥有对应文件权限），都可以通过打开这个特殊文件完成读写通信。它遵循先进先出的规则，和匿名管道不同的是，FIFO可以用于完全独立的进程之间，不需要依赖父子进程的创建关联。

2. Python的multiprocessing模块是否提供命名管道（FIFO）？ #

The short answer is: No, the multiprocessing module doesn't include a dedicated wrapper for FIFO. As you mentioned, its built-in Pipe() and Queue are implemented based on anonymous pipes, which only work for related processes (like parent-child or sibling processes spawned via the module).

But you can absolutely use FIFO in Python multi-process scenarios—you just need to use the lower-level os module to create and interact with FIFO directly. Here's a practical example to demonstrate this:

Example: Python Multi-Process FIFO Communication #

import os
import multiprocessing
import time

# 定义FIFO的临时路径（通常放在/tmp目录下）
FIFO_PATH = "/tmp/python_fifo_demo"

def fifo_writer():
    # 检查FIFO是否存在，不存在则创建
    if not os.path.exists(FIFO_PATH):
        os.mkfifo(FIFO_PATH)
    
    # 打开FIFO写模式（默认阻塞，直到有进程打开读端）
    with open(FIFO_PATH, 'w') as fifo:
        for idx in range(5):
            msg = f"Process Writer: Message {idx + 1}"
            fifo.write(f"{msg}\n")
            fifo.flush()  # 强制刷新缓冲区，确保读进程及时获取数据
            print(f"Writer sent: {msg}")
            time.sleep(1)
    
    # 通信完成后删除FIFO（可选，根据需求决定是否保留）
    os.unlink(FIFO_PATH)

def fifo_reader():
    # 等待FIFO被创建
    while not os.path.exists(FIFO_PATH):
        time.sleep(0.2)
    
    # 打开FIFO读模式
    with open(FIFO_PATH, 'r') as fifo:
        while True:
            line = fifo.readline()
            if not line:
                # 写进程关闭FIFO后，读端会收到空行，退出循环
                break
            print(f"Reader received: {line.strip()}")

if __name__ == "__main__":
    # 创建并启动读写进程
    reader_process = multiprocessing.Process(target=fifo_reader)
    writer_process = multiprocessing.Process(target=fifo_writer)
    
    reader_process.start()
    writer_process.start()
    
    # 等待进程执行完毕
    writer_process.join()
    reader_process.join()

Important Notes for Using FIFO in Python: #

• Blocking Behavior: By default, opening a FIFO will block until the corresponding end (read or write) is opened by another process. For non-blocking behavior, use os.open() with the os.O_NONBLOCK flag, then wrap the file descriptor with os.fdopen().
• Multi-Writer Safety: If multiple processes write to the same FIFO, use synchronization tools like multiprocessing.Lock to avoid interleaved, corrupted data.
• Bidirectional Communication: FIFO is unidirectional. For two-way communication, create two separate FIFO pipes (one for each direction).

内容的提问来源于stack exchange，提问作者QuantumEnergy