gevent：调试旋转线程？

Question

在我基于gevent的程序中，我在某处有一个线程，该线程陷入了类似循环的状态：

while True:
    gevent.sleep(0)

如何确定这是哪个线程？是否可以列出（并获得堆栈跟踪）正在运行的线程？

Answer 1

方法1.超时

我在我的代码中使用它来跟踪可能被阻止的greenlet。发生这种情况时会引发NodeTaskTimeout。只需将您的作业包装在超时中或为它们提供一个超时对象即可。

 with Timeout(90, False):
        task_jobs.join()

    if task_jobs:
        print 'task jobs killed', task_jobs
        task_jobs.kill()
        if settings.DEBUG:
            raise NodeTaskTimeout

如果此打印件挂起/挡住/占用时间过长，则表示此任务已完成。那些相互依赖并导致僵局的工作尤其令人讨厌作业1 /线程->作业2 /线程2->作业3 /线程3和作业/线程3仅在作业1完成时才完成，因为作业2未完成而作业2由于作业3未完成而没有完成..你明白了; ）

Mehtod 2 Settrace

http://www.rfk.id.au/blog/entry/detect-gevent-blocking-with-greenlet-settrace/

但您还需要将怀疑“旋转”的代码放在with块中。

Answer 2

[有一个官方的API用于检查块，它将查明导致该块的确切行，请参见下面的代码示例：

# gevent        1.3.7
# greenlet      0.4.15
# zope.event    4.4
import gevent
from gevent import config, get_hub
from gevent.events import IEventLoopBlocked
import logging
from pprint import pformat
import time
import zope.event

# initial logging
logging.basicConfig(level=logging.INFO)
log = logging.getLogger(__name__)

# setup gevent config
# enable the monitor thread
config.monitor_thread = True
config.max_blocking_time = 4

# start the monitor thread
hub = get_hub()
monitor = hub.start_periodic_monitoring_thread()

# register the event to logging system
def g(event):
    log.error('Greenlet: {}, exceed the max blocking time: {}'.format(event.greenlet, event.blocking_time))
    log.error(pformat(event.info))
event = IEventLoopBlocked()
zope.event.subscribers.append(g)

# you can also create you own monitoring function
# def check(hub):
#     print('< periodic check in monitoring thread >')
#
# monitor.add_monitoring_function(check, 1)

def gl1():
    # use time.sleep to trigger block
    log.info('block at gl1 for 2 seconds')
    time.sleep(2)
    log.info('leave gl1 now')

def gl2():
    # use time.sleep to trigger block
    log.info('block at gl2 for 6 seconds should be detected')
    time.sleep(6)
    log.info('leave gl2 now')

def gl3():
    # gevent.sleep will not block
    log.info('gl3 will not block since it use gevent.sleep')
    gevent.sleep(8)
    log.info('leave gl3 now')


gevent.joinall([
    gevent.spawn(gl3),
    gevent.spawn(gl1),
    gevent.spawn(gl2),
])

希望对您有所帮助！