The deadlock caused by inconsistent thread ident (RLock of logging handlers)

logging-and-gevent.py

import logging
import itertools
import gevent.monkey


class SlowHandler(logging.Handler):
    def emit(self, record):
        gevent.sleep(1)


logging.basicConfig()
logger = logging.getLogger(__name__)
# gevent.monkey.patch_all()
logger.addHandler(SlowHandler())
gevent.monkey.patch_all()


def dump_sth(name):
    for idx in itertools.count():
        logger.warning('=> %s %s' % (name, idx))
        gevent.sleep(0)


gevent.spawn(dump_sth, 'foo')
gevent.spawn(dump_sth, 'bar')
gevent.wait()