一、协程
1.理论知识
协程,又称伪线程,是一种用户态的轻量级线程。
协程拥有自己的寄存器上下文和栈,协程调度切换时,将寄存器上下文和栈保存到其他地方,在切回来的时候,恢复先前保存的寄存器上下文和栈。因此:协程能保留上一次调用时的状态(即所有局部状态的一个特定组合),每次过程重入时,就相当于进入上一次调用的状态,换种说法:进入上一次离开时所处逻辑流的位置。
优点:
- 无需线程上下文切换的开销
- 无需原子操作锁定及同步的开销
- "原子操作(atomic operation)是不需要synchronized",所谓原子操作是指不会被线程调度机制打断的操作;这种操作一旦开始,就一直运行到结束,中间不会有任何 context switch (切换到另一个线程)。原子操作可以是一个步骤,也可以是多个操作步骤,但是其顺序是不可以被打乱,或者切割掉只执行部分。视作整体是原子性的核心。
- 方便切换控制流,简化编程模型
- 高并发+高扩展性+低成本:一个CPU支持上万的协程都不是问题。所以很适合用于高并发处理。
缺点:
- 无法利用多核资源:协程的本质是个单线程,它不能同时将 单个CPU 的多个核用上,协程需要和进程配合才能运行在多CPU上.当然我们日常所编写的绝大部分应用都没有这个必要,除非是cpu密集型应用。
- 进行阻塞(Blocking)操作(如IO时)会阻塞掉整个程序
协程满足条件:
- 必须在只有一个单线程里实现并发
- 修改共享数据不需加锁
- 用户程序里自己保存多个控制流的上下文栈
- 一个协程遇到IO操作自动切换到其它协程
2.代码实例
Gevent 是一个第三方库,可以轻松通过gevent实现并发同步或异步编程,在gevent中用到的主要模式是Greenlet, 它是以C扩展模块形式接入Python的轻量级协程。 Greenlet全部运行在主程序操作系统进程的内部,但它们被协作式地调度。
1 import gevent
2 def func1():
3 print('\033[31;1m李闯在跟海涛搞...\033[0m')
4 gevent.sleep(2)
5 print('\033[31;1m李闯又回去跟继续跟海涛搞...\033[0m')
6
7
8 def func2():
9 print('\033[32;1m李闯切换到了跟海龙搞...\033[0m')
10 gevent.sleep(1)
11 print('\033[32;1m李闯搞完了海涛,回来继续跟海龙搞...\033[0m')
12
13 def func3():
14 print("33333")
15 gevent.sleep(1)
16 print("4444")
17
18 gevent.joinall([
19 gevent.spawn(func1),
20 gevent.spawn(func2),
21 gevent.spawn(func3),
22 ])
输出结果:
李闯在跟海涛搞...
李闯切换到了跟海龙搞...
33333
李闯搞完了海涛,回来继续跟海龙搞...
4444
李闯又回去跟继续跟海涛搞...
3.同步与异步的性能区别
import gevent
def task(pid):
"""
Some non-deterministic task
"""
gevent.sleep(0.5)
print('Task %s done' % pid)
def synchronous():
for i in range(1,10):
task(i)
def asynchronous():
threads = [gevent.spawn(task, i) for i in range(10)]
gevent.joinall(threads)
print('Synchronous:')
synchronous()
print('Asynchronous:')
asynchronous()
4.遇到IO阻塞自动切换任务(爬虫实例)
1 import gevent
2 from gevent import monkey
3 monkey.patch_all()
4 from urllib.request import urlopen
5 import time
6
7 def pa_web_page(url):
8 print("GET url",url)
9 req = urlopen(url)
10 data =req.read()
11 print(data)
12 print('%d bytes received from %s.' % (len(data), url))
13
14 t_start = time.time()
15 pa_web_page("http://www.autohome.com.cn/beijing/")
16 pa_web_page("http://www.xiaohuar.com/")
17 print("time cost:",time.time()-t_start)
18
19 t2_start = time.time()
20 gevent.joinall([
21 #gevent.spawn(pa_web_page, 'https://www.python.org/'),
22 gevent.spawn(pa_web_page, 'http://www.autohome.com.cn/beijing/'),
23 gevent.spawn(pa_web_page, 'http://www.xiaohuar.com/'),
24 #gevent.spawn(pa_web_page, 'https://github.com/'),
25 ])
26 print("time cost t2:",time.time()-t2_start)
二、事件驱动与异步IO
事件驱动编程是一种编程范式,这里程序的执行流由外部事件来决定。它的特点是包含一个事件循环,当外部事件发生时使用回调机制来触发相应的处理。另外两种常见的编程范式是(单线程)同步以及多线程编程。
在单线程同步模型中,任务按照顺序执行。如果某个任务因为I/O而阻塞,其他所有的任务都必须等待,直到它完成之后它们才能依次执行。这种明确的执行顺序和串行化处理的行为是很容易推断得出的。如果任务之间并没有互相依赖的关系,但仍然需要互相等待的话这就使得程序不必要的降低了运行速度。
在多线程版本中,这3个任务分别在独立的线程中执行。这些线程由操作系统来管理,在多处理器系统上可以并行处理,或者在单处理器系统上交错执行。这使得当某个线程阻塞在某个资源的同时其他线程得以继续执行。与完成类似功能的同步程序相比,这种方式更有效率,但程序员必须写代码来保护共享资源,防止其被多个线程同时访问。多线程程序更加难以推断,因为这类程序不得不通过线程同步机制如锁、可重入函数、线程局部存储或者其他机制来处理线程安全问题,如果实现不当就会导致出现微妙且令人痛不欲生的bug。
在事件驱动版本的程序中,3个任务交错执行,但仍然在一个单独的线程控制中。当处理I/O或者其他昂贵的操作时,注册一个回调到事件循环中,然后当I/O操作完成时继续执行。回调描述了该如何处理某个事件。事件循环轮询所有的事件,当事件到来时将它们分配给等待处理事件的回调函数。这种方式让程序尽可能的得以执行而不需要用到额外的线程。事件驱动型程序比多线程程序更容易推断出行为,因为程序员不需要关心线程安全问题。
当我们面对如下的环境时,事件驱动模型通常是一个好的选择:
- 程序中有许多任务,而且…
- 任务之间高度独立(因此它们不需要互相通信,或者等待彼此)而且…
- 在等待事件到来时,某些任务会阻塞。
当应用程序需要在任务间共享可变的数据时,这也是一个不错的选择,因为这里不需要采用同步处理。
网络应用程序通常都有上述这些特点,这使得它们能够很好的契合事件驱动编程模型。
1.select多并发socket例子
1 #_*_coding:utf-8_*_
2 __author__ = 'Alex Li'
3
4 import select
5 import socket
6 import sys
7 import queue
8
9
10 server = socket.socket()
11 server.setblocking(0)
12
13 server_addr = ('localhost',10000)
14
15 print('starting up on %s port %s' % server_addr)
16 server.bind(server_addr)
17
18 server.listen(5)
19
20
21 inputs = [server, ] #自己也要监测呀,因为server本身也是个fd
22 outputs = []
23
24 message_queues = {}
25
26 while True:
27 print("waiting for next event...")
28
29 readable, writeable, exeptional = select.select(inputs,outputs,inputs) #如果没有任何fd就绪,那程序就会一直阻塞在这里
30
31 for s in readable: #每个s就是一个socket
32
33 if s is server: #别忘记,上面我们server自己也当做一个fd放在了inputs列表里,传给了select,如果这个s是server,代表server这个fd就绪了,
34 #就是有活动了, 什么情况下它才有活动? 当然 是有新连接进来的时候 呀
35 #新连接进来了,接受这个连接
36 conn, client_addr = s.accept()
37 print("new connection from",client_addr)
38 conn.setblocking(0)
39 inputs.append(conn) #为了不阻塞整个程序,我们不会立刻在这里开始接收客户端发来的数据, 把它放到inputs里, 下一次loop时,这个新连接
40 #就会被交给select去监听,如果这个连接的客户端发来了数据 ,那这个连接的fd在server端就会变成就续的,select就会把这个连接返回,返回到
41 #readable 列表里,然后你就可以loop readable列表,取出这个连接,开始接收数据了, 下面就是这么干 的
42
43 message_queues[conn] = queue.Queue() #接收到客户端的数据后,不立刻返回 ,暂存在队列里,以后发送
44
45 else: #s不是server的话,那就只能是一个 与客户端建立的连接的fd了
46 #客户端的数据过来了,在这接收
47 data = s.recv(1024)
48 if data:
49 print("收到来自[%s]的数据:" % s.getpeername()[0], data)
50 message_queues[s].put(data) #收到的数据先放到queue里,一会返回给客户端
51 if s not in outputs:
52 outputs.append(s) #为了不影响处理与其它客户端的连接 , 这里不立刻返回数据给客户端
53
54
55 else:#如果收不到data代表什么呢? 代表客户端断开了呀
56 print("客户端断开了",s)
57
58 if s in outputs:
59 outputs.remove(s) #清理已断开的连接
60
61 inputs.remove(s) #清理已断开的连接
62
63 del message_queues[s] ##清理已断开的连接
64
65
66 for s in writeable:
67 try :
68 next_msg = message_queues[s].get_nowait()
69
70 except queue.Empty:
71 print("client [%s]" %s.getpeername()[0], "queue is empty..")
72 outputs.remove(s)
73
74 else:
75 print("sending msg to [%s]"%s.getpeername()[0], next_msg)
76 s.send(next_msg.upper())
77
78
79 for s in exeptional:
80 print("handling exception for ",s.getpeername())
81 inputs.remove(s)
82 if s in outputs:
83 outputs.remove(s)
84 s.close()
85
86 del message_queues[s]
1 import socket
2 import sys
3
4 messages = [ b'This is the message. ',
5 b'It will be sent ',
6 b'in parts.',
7 ]
8 server_address = ('localhost', 10000)
9
10 # Create a TCP/IP socket
11 socks = [ socket.socket(socket.AF_INET, socket.SOCK_STREAM),
12 socket.socket(socket.AF_INET, socket.SOCK_STREAM),
13 ]
14
15 # Connect the socket to the port where the server is listening
16 print('connecting to %s port %s' % server_address)
17 for s in socks:
18 s.connect(server_address)
19
20 for message in messages:
21
22 # Send messages on both sockets
23 for s in socks:
24 print('%s: sending "%s"' % (s.getsockname(), message) )
25 s.send(message)
26
27 # Read responses on both sockets
28 for s in socks:
29 data = s.recv(1024)
30 print( '%s: received "%s"' % (s.getsockname(), data) )
31 if not data:
32 print(sys.stderr, 'closing socket', s.getsockname() )
33
34 select socket client
2.selectors模块
1 import selectors
2 import socket
3
4 def accept(sock, mask):
5 conn, addr = sock.accept() # Should be ready
6 print('accepted', conn, 'from', addr)
7 conn.setblocking(False)#非阻塞,或者设置为0
8 sel.register(conn, selectors.EVENT_READ, read)
9 def read(conn, mask):
10 try:
11 data = conn.recv(1000) # Should be ready
12 if data:
13 print('echoing', repr(data), 'to', conn)
14 conn.send(data) # Hope it won't block
15 else:
16 print('closing', conn)
17 sel.unregister(conn)
18 conn.close()
19 except ConnectionResetError as e:
20 sel.unregister(conn)
21 sock = socket.socket()
22 sock.bind(('localhost', 10000))
23 sock.listen(100)
24 sock.setblocking(False)
25
26 sel = selectors.DefaultSelector()#生成实例
27 sel.register(sock, selectors.EVENT_READ, accept)#注册sock连接,读事件,如果有请求调用accept
28 #select.select(inputs,outputs...)
29 while True:
30 events = sel.select() #如果没有事件,一直等待,返回列表
31 for key, mask in events: #有事件,循环events列表
32 callback = key.data #accept内存地址,发送数据后变成read内存地址
33 print("--->",key,mask)
34 callback(key.fileobj, mask)#fileobj是conn,
35 #fileobj=<socket.socket fd=220, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 10000)>,
三、RabbitMQ队列
1.安装
安装python rabbitMQ module
pip install pika
or
easy_install pika
or
源码
https://pypi.python.org/pypi/pika
2.最简单的通讯队列
send端
1 #!/usr/bin/env python
2 import pika
3
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 'localhost'))
6 channel = connection.channel()
7
8 #声明queue
9 channel.queue_declare(queue='hello')
10
11 #n RabbitMQ a message can never be sent directly to the queue, it always needs to go through an exchange.
12 channel.basic_publish(exchange='',
13 routing_key='hello',
14 body='Hello World!')
15 print(" [x] Sent 'Hello World!'")
16 connection.close()
receive端
1 #_*_coding:utf-8_*_
2 __author__ = 'Alex Li'
3 import pika
4
5 connection = pika.BlockingConnection(pika.ConnectionParameters(
6 'localhost'))
7 channel = connection.channel()
8
9
10 #You may ask why we declare the queue again ‒ we have already declared it in our previous code.
11 # We could avoid that if we were sure that the queue already exists. For example if send.py program
12 #was run before. But we're not yet sure which program to run first. In such cases it's a good
13 # practice to repeat declaring the queue in both programs.
14 channel.queue_declare(queue='hello')
15
16 def callback(ch, method, properties, body):
17 print(" [x] Received %r" % body)
18
19 channel.basic_consume(callback,
20 queue='hello',
21 no_ack=True)#这种情况下一旦被deliver出去,就已经被确认了,在consumer异常时会导致消息丢失。
22 23 print(' [*] Waiting for messages. To exit press CTRL+C') 24 channel.start_consuming()
3.Work Queues模式
这种模式下,RabbitMQ会默认把消息依次分发给各个消费者,跟负载均衡差不多。
消息提供着代码(send):
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 # Author:Liumj
4 import pika
5 import time
6 import sys
7 connection = pika.BlockingConnection(pika.ConnectionParameters('127.0.0.1')) #建立socket连接
8 channel = connection.channel() #打开一个通道
9 channel.queue_declare(queue='hello') #声明queue,名称是hello
10 message = ' '.join(sys.argv[1:]) or "Hello World! %s" % time.time()
11 channel.basic_publish(exchange = '',
12 routing_key='hello', #queue名
13 body = message, #消息内容
14 properties=pika.BasicProperties(
15 delivery_mode=2
16 ) #basic_publist发消息
17 )
18
19 connection.close()
View Code
消费者代码(recv):
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 # Author:Liumj
4 import pika,time
5 connection = pika.BlockingConnection(pika.ConnectionParameters('127.0.0.1')) #建立连接
6 channel = connection.channel() #建立通道
7 channel.queue_declare(queue='hello') #如果确定hello存在,该条可以不写
8 def callback(ch,method,properties,body): #channel对象,属性信息
9 print("[x] Received %r" % body)
10 #time.sleep(20)
11 print("[x] Done")
12 print("method.delivery_tag",method.delivery_tag)
13 ch.basic_ack(delivery_tag=method.delivery_tag)
14 channel.basic_consume(callback, #从hello里面收消息,收到之后调用callback函数
15 queue='hello',
16 no_ack=True)
17 print('[*] waiting for message. To exit press CTRL+C')
18 channel.start_consuming()
View Code
消息会自动依次分配到各个消费者身上。
4.消息持久化和公平分发
为防止消息发送过程中出现异常需要将消息持久化,这样重启服务消息不会丢失。
消息公平分发:根据每个机器配置不同,处理的任务不同,配置perfetch = 1,告诉RabbitMQ,在这个消费者当前消息没有处理完之前,不要发送新的消息。
完整代码如下:
生产者(send):
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 # Author:Liumj
4 # !/usr/bin/env python
5 import pika
6 import sys
7 connection = pika.BlockingConnection(pika.ConnectionParameters(
8 host='127.0.0.1')) #建立连接
9 channel = connection.channel() #打开通道
10 channel.queue_declare(queue='task_queue', durable=True) #声明queue、队列持久化
11 message = ' '.join(sys.argv[1:]) or "Hello World!"#消息内容
12 channel.basic_publish(exchange='',
13 routing_key='task_queue',
14 body=message,
15 properties=pika.BasicProperties(
16 delivery_mode=2, # make message persistent
17 ))
18 print(" [x] Sent %r" % message)
19 connection.close()
消费者(recv):
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 # Author:Liumj
4 import pika
5 import time
6 connection = pika.BlockingConnection(pika.ConnectionParameters(
7 host='127.0.0.1'))
8 channel = connection.channel()
9 channel.queue_declare(queue='task_queue', durable=True)
10 print(' [*] Waiting for messages. To exit press CTRL+C')
11 def callback(ch, method, properties, body):
12 print(" [x] Received %r" % body)
13 time.sleep(body.count(b'.'))
14 print(" [x] Done")
15 ch.basic_ack(delivery_tag=method.delivery_tag)
16 channel.basic_qos(prefetch_count=1) #公平分发
17 channel.basic_consume(callback,
18 queue='task_queue') #从task_queue里面接收消息后调用callback函数
19 channel.start_consuming()
5.Publish\Subscribe(消息发布\订阅)
类似于广播,只要符合条件都可以接收消息
fanout:所有bind到此exchange的queue都可以接收消息
direct:通过routingKey和exchange决定哪一个唯一的queue可以接收消息,队列绑定关键字,发送者讲根据数据关键字发送到消息exchange,exchange根据关键字判定应该将数据发送制定队列。
topic:所有符合routingKey所bind的queue可以接收消息
publisher_fanout:
1 import pika
2 import sys
3 #credentials = pika.PlainCredentials('alex', 'alex3714')
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 host='127.0.0.1'))
6 channel = connection.channel()
7 channel.exchange_declare(exchange='logs', type='fanout')
8 message = ' '.join(sys.argv[1:]) or "info: Hello World!"
9 channel.basic_publish(exchange='logs',
10 routing_key='',
11 body=message)
12 print(" [x] Sent %r" % message)
13 connection.close()
View Code
subscriber_fanout:
1 import pika
2 #credentials = pika.PlainCredentials('alex', 'alex3714')
3 connection = pika.BlockingConnection(pika.ConnectionParameters(
4 host='127.0.0.1'))
5 channel = connection.channel()
6 channel.exchange_declare(exchange='logs',type='fanout')
7 result = channel.queue_declare(exclusive=True) # 不指定queue名字,rabbit会随机分配一个名字,exclusive=True会在使用此queue的消费者断开后,自动将queue删除
8 queue_name = result.method.queue
9 channel.queue_bind(exchange='logs',queue=queue_name)
10 print(' [*] Waiting for logs. To exit press CTRL+C')
11 def callback(ch, method, properties, body):
12 print(" [x] %r" % body)
13 channel.basic_consume(callback,
14 queue=queue_name,
15 )
16 channel.start_consuming()
View Code
publisher_direct:
1 import pika
2 import sys
3
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 host='127.0.0.1'))
6 channel = connection.channel()
7
8 channel.exchange_declare(exchange='direct_logs',
9 type='direct')
10
11 severity = sys.argv[1] if len(sys.argv) > 1 else 'info'
12 message = ' '.join(sys.argv[2:]) or 'Hello World!'
13 channel.basic_publish(exchange='direct_logs',
14 routing_key=severity,
15 body=message)
16 print(" [x] Sent %r:%r" % (severity, message))
17 connection.close()
View Code
subscriber_direct:
1 import pika
2 import sys
3
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 host='127.0.0.1'))
6 channel = connection.channel()
7
8 channel.exchange_declare(exchange='direct_logs',
9 type='direct')
10
11 result = channel.queue_declare(exclusive=True)
12 queue_name = result.method.queue
13
14 severities = sys.argv[1:]
15 if not severities:
16 sys.stderr.write("Usage: %s [info] [warning] [error]\n" % sys.argv[0])
17 sys.exit(1)
18
19 for severity in severities:
20 channel.queue_bind(exchange='direct_logs',
21 queue=queue_name,
22 routing_key=severity)
23
24 print(' [*] Waiting for logs. To exit press CTRL+C')
25
26 def callback(ch, method, properties, body):
27 print(" [x] %r:%r" % (method.routing_key, body))
28
29 channel.basic_consume(callback,
30 queue=queue_name,
31 no_ack=True)
32
33 channel.start_consuming()
View Code
publisher_topic:
1 import pika
2 import sys
3
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 host='127.0.0.1'))
6 channel = connection.channel()
7
8 channel.exchange_declare(exchange='topic_logs',
9 type='topic')
10
11 routing_key = sys.argv[1] if len(sys.argv) > 1 else 'anonymous.info'
12 message = ' '.join(sys.argv[2:]) or 'Hello World!'
13 channel.basic_publish(exchange='topic_logs',
14 routing_key=routing_key,
15 body=message)
16 print(" [x] Sent %r:%r" % (routing_key, message))
17 connection.close()
View Code
subscriber_topic:
1 import pika
2 import sys
3
4 connection = pika.BlockingConnection(pika.ConnectionParameters(
5 host='127.0.0.1'))
6 channel = connection.channel()
7
8 channel.exchange_declare(exchange='topic_logs',
9 type='topic')
10
11 result = channel.queue_declare(exclusive=True)
12 queue_name = result.method.queue
13
14 binding_keys = sys.argv[1:]
15 if not binding_keys:
16 sys.stderr.write("Usage: %s [binding_key]...\n" % sys.argv[0])
17 sys.exit(1)
18
19 for binding_key in binding_keys:
20 channel.queue_bind(exchange='topic_logs',
21 queue=queue_name,
22 routing_key=binding_key)
23
24 print(' [*] Waiting for logs. To exit press CTRL+C')
25
26 def callback(ch, method, properties, body):
27 print(" [x] %r:%r" % (method.routing_key, body))
28
29 channel.basic_consume(callback,
30 queue=queue_name,
31 no_ack=True)
32
33 channel.start_consuming()
View Code
6.RPC
RabbitMQ_RPC_send:
1 import pika
2 import uuid
3 class SSHRpcClient(object):
4 def __init__(self):
5 # credentials = pika.PlainCredentials('alex', 'alex3714')
6 self.connection = pika.BlockingConnection(pika.ConnectionParameters(
7 host='127.0.0.1'))
8 self.channel = self.connection.channel()
9 result = self.channel.queue_declare(exclusive=True) # 客户端的结果必须要返回到这个queue
10 self.callback_queue = result.method.queue
11 self.channel.basic_consume(self.on_response,queue=self.callback_queue) #声明从这个queue里收结果
12 def on_response(self, ch, method, props, body):
13 if self.corr_id == props.correlation_id: #任务标识符
14 self.response = body
15 print(body)
16 def call(self, n):
17 self.response = None
18 self.corr_id = str(uuid.uuid4()) #唯一标识符
19 self.channel.basic_publish(exchange='',
20 routing_key='rpc_queue3',
21 properties=pika.BasicProperties(
22 reply_to=self.callback_queue,
23 correlation_id=self.corr_id,
24 ),
25 body=str(n))
26 print("start waiting for cmd result ")
27 #self.channel.start_consuming()
28 count = 0
29 while self.response is None: #如果命令没返回结果
30 print("loop ",count)
31 count +=1
32 self.connection.process_data_events() #以不阻塞的形式去检测有没有新事件
33 #如果没事件,那就什么也不做, 如果有事件,就触发on_response事件
34 return self.response
35 ssh_rpc = SSHRpcClient()
36 print(" [x] sending cmd")
37 response = ssh_rpc.call("ipconfig")
38
39
40 print(" [.] Got result ")
41 print(response.decode("gbk"))
View Code
RabbitMQ_RPC_recv:
1 import pika
2 import time
3 import subprocess
4 #credentials = pika.PlainCredentials('alex', 'alex3714')
5 connection = pika.BlockingConnection(pika.ConnectionParameters(
6 host='127.0.0.1'))
7 channel = connection.channel()
8 channel.queue_declare(queue='rpc_queue3')
9 def SSHRPCServer(cmd):
10 # if n == 0:
11 # return 0
12 # elif n == 1:
13 # return 1
14 # else:
15 # return fib(n - 1) + fib(n - 2)
16 print("recv cmd:",cmd)
17 cmd_obj = subprocess.Popen(cmd.decode(),shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
18 result = cmd_obj.stdout.read() or cmd_obj.stderr.read()
19 return result
20 def on_request(ch, method, props, body):
21 #n = int(body)
22 print(" [.] fib(%s)" % body)
23 response = SSHRPCServer(body)
24 ch.basic_publish(exchange='',
25 routing_key=props.reply_to,
26 properties=pika.BasicProperties(correlation_id= \
27 props.correlation_id),
28 body=response)
29 channel.basic_consume(on_request, queue='rpc_queue3')
30 print(" [x] Awaiting RPC requests")
31 channel.start_consuming()
View Code