CODEWITHSUNDEEP
pythoneventletgreen-threads
apporc
apporc

Reputation: 982

Does eventlet do monkey_patch for threading module?

Docs here in http://eventlet.net/doc/patching.htm says "If no arguments are specified, everything is patched." and "thread, which patches thread, threading, and Queue".

But with a simple test:

#!/bin/env python

import threading

import eventlet
eventlet.monkey_patch()

if __name__ == '__main__':
    patched = eventlet.patcher.is_monkey_patched(threading)
    print('patched : %s' % patched)

The result is: 

patched : False

It seems like threading is not patched at all. The doc is wrong?

Upvotes: 1

Views: 9458

Answers (1)

apporc
apporc

Reputation: 982

I found the doc is right. The problem is about is_monkey_patched(), it can't detect some situation like 'threading, Queue' module. Take a look at the src of this function, the behaviour is easy to understand.

def _green_thread_modules():
    from eventlet.green import Queue
    from eventlet.green import thread
    from eventlet.green import threading
    if six.PY2:
        return [('Queue', Queue), ('thread', thread), ('threading', threading)]
    if six.PY3:
        return [('queue', Queue), ('_thread', thread), ('threading', threading)]

    if on['thread'] and not already_patched.get('thread'):
        modules_to_patch += _green_thread_modules()
        already_patched['thread'] = True

def is_monkey_patched(module):
    """Returns True if the given module is monkeypatched currently, False if
    not.  *module* can be either the module itself or its name.

    Based entirely off the name of the module, so if you import a
    module some other way than with the import keyword (including
    import_patched), this might not be correct about that particular
    module."""
    return module in already_patched or \
        getattr(module, '__name__', None) in already_patched

And because the patch operation is implemented like this:

    for name, mod in modules_to_patch:
        orig_mod = sys.modules.get(name)
        if orig_mod is None:
            orig_mod = __import__(name)
        for attr_name in mod.__patched__:
            patched_attr = getattr(mod, attr_name, None)
            if patched_attr is not None:
                setattr(orig_mod, attr_name, patched_attr)

We can check whether a module like threading/Queue is patched by using:

 >>>import threading
 >>>eventlet.monkey_patch()
 >>>threading.current_thread.__module__
 >>>'eventlet.green.threading'

Upvotes: 2

Related Questions