Files
deb-python-eventlet/eventlet/coropool.py

66 lines
1.9 KiB
Python

# replacement of CoroutinePool implemented with proc module
from eventlet import coros, proc, api
class Pool(object):
def __init__(self, min_size=0, max_size=4, track_events=False):
if min_size > max_size:
raise ValueError('min_size cannot be bigger than max_size')
self.sem = coros.Semaphore(max_size)
for _ in xrange(min_size):
self.sem.acquire()
self.procs = proc.RunningProcSet()
if track_events:
self.results = coros.queue()
else:
self.results = None
def free(self):
return self.sem.counter
def execute(self, func, *args, **kwargs):
"""Execute func in one of the coroutines maintained
by the pool, when one is free.
Immediately returns a Proc object which can be queried
for the func's result.
>>> pool = Pool()
>>> task = pool.execute(lambda a: ('foo', a), 1)
>>> task.wait()
('foo', 1)
"""
# if reentering an empty pool, don't try to wait on a coroutine freeing
# itself -- instead, just execute in the current coroutine
if self.sem.locked() and api.getcurrent() in self.procs:
p = proc.spawn(func, *args, **kwargs)
try:
p.wait()
except:
pass
else:
self.sem.acquire()
p = self.procs.spawn(func, *args, **kwargs)
# assuming the above line cannot raise
p.link(lambda p: self.sem.release())
if self.results is not None:
p.link(self.results)
return p
execute_async = execute
def waitall(self):
return self.procs.waitall()
wait_all = waitall
def wait(self):
"""Wait for the next execute in the pool to complete,
and return the result."""
return self.results.wait()
def killall(self):
return self.procs.killall()