gevent参考手册.pdfVIP

gevent network library Denis Bilenko Problem statement from urllib2 import urlopen response = urlopen () body = response.read () How to manage concurrent connections? Problem statement Possible answer: Async framework (Twisted, asyncore, ...) def on_response_read (response): d = response.read () d.addCallbacks (on_body_read, on_error) def on_error (error): ... def on_body_read (body): ... d = readURL (). d.addCallbacks (on_response_read, on_error) reactor.run () simplicity is lost Problem statement Possible answer: Threads from threading import Thread def read_url (url): response = urllib2.urlopen(url) body = response.read () t1=Thread(target=read_url, args=(,)) t1.start() t2=Thread(target=read_url, args=(,)) t2.start() t1.join() t2.join() resource hog Memory required for 10k connections Memory required for 10k connections threading 400 MB twisted 55 MB gevent (greenlet + libevent) from gevent import monkey; monkey.patch_all () def read_url (url): response = urllib2.urlopen(url) body = response.read () a = gevent.spawn (read_url, ) b = gevent.spawn (read_url, ) gevent.joinall ([a, b]) concurrent fetch Memory required for 10k connections Memory required for 10k connections threading 400 MB twisted gevent 70 MB 55 MB greenlet from greenlet import greenlet def myfunction (arg): ... return arg + 1 g = greenlet (myfunction) g.switch (2) 3 from greenlet import greenlet MAIN = greenlet.getcurrent () def myf