python - 了解 python GIL - I/O 绑定(bind)与 CPU 绑定(bind)

Question

来自 python threading文档

In CPython, due to the Global Interpreter Lock, only one thread can execute Python code at once (even though certain performance-oriented libraries might overcome this limitation). If you want your application to make better use of the computational resources of multi-core machines, you are advised to use multiprocessing. However, threading is still an appropriate model if you want to run multiple I/O-bound tasks simultaneously.

现在我有一个这样的线程 worker

def worker(queue):
    queue_full = True
    while queue_full:
        try:
            url = queue.get(False)
            w = Wappalyzer(url)
            w.analyze()
            queue.task_done()

        except Queue.Empty:
            queue_full = False

这里 w.analyze() 做了两件事

1. 使用 requests 库抓取 url
2. 使用 pyv8 javascript 库分析抓取的 html

据我所知，1 受 I/O 限制，2 受 CPU 限制。

这是否意味着，GIL 申请了 2 而我的程序将无法正常运行？

Answer 1

GIL 的描述并没有说明正确性，只说明了效率。

如果 2 受 CPU 限制，您将无法从线程中获得多核性能，但您的程序仍将正确执行。

如果您关心 CPU 并行性，您应该使用 Python 的 multiprocessing 库。