from __future__ import print_function
import gevent
import gevent.core
import time
try:
    import thread
except ImportError:
    import _thread as thread


hub = gevent.get_hub()
watcher = hub.loop.async_()

# BWC for <3.7: This should still be an attribute
assert hasattr(hub.loop, 'async')

gevent.spawn_later(0.1, thread.start_new_thread, watcher.send, ())

start = time.time()

with gevent.Timeout(1.0): # Large timeout for appveyor
    hub.wait(watcher)

print('Watcher %r reacted after %.6f seconds' % (watcher, time.time() - start - 0.1))