def client_proc(computation, task=None):
# schedule computation with the scheduler; scheduler accepts one computation
# at a time, so if scheduler is shared, the computation is queued until it
# is done with already scheduled computations
if (yield computation.schedule()):
raise Exception('Could not schedule computation')
# in dispycos_client6.py, data is sent to each remote task; here, data
# is broadcast over channel and remote tasks subscribe to it
data_channel = pycos.Channel('data_channel')
# not necessary to register channel in this case, as it is sent to remote
# tasks; if they were to 'locate' it, it should be registered
# data_channel.register()
trend_task = pycos.Task(trend_proc)
rtask_avg = yield computation.run(rtask_avg_proc, data_channel, 0.4,
trend_task, 10)
assert isinstance(rtask_avg, pycos.Task)
rtask_save = yield computation.run(rtask_save_proc, data_channel)
assert isinstance(rtask_save, pycos.Task)
# make sure both remote tasks have subscribed to channel ('deliver'
# should return 2 if they both are)
assert (yield data_channel.deliver('start', n=2)) == 2
# if data is sent frequently (say, many times a second), enable
# streaming data to remote peer; this is more efficient as
# connections are kept open (so the cost of opening and closing
# connections is avoided), but keeping too many connections open
# consumes system resources
yield pycos.Pycos.instance().peer(rtask_avg.location, stream_send=True)
yield pycos.Pycos.instance().peer(rtask_save.location, stream_send=True)
# send 1000 items of random data to remote tasks
for i in range(1000):
n = random.uniform(-1, 1)
item = (i, n)
# data can be sent to remote tasks either with 'send' or
# 'deliver'; 'send' is more efficient but no guarantee data
# has been sent successfully whereas 'deliver' indicates
# errors right away
data_channel.send(item)
yield task.sleep(0.02)
item = (i, None)
data_channel.send(item)
yield computation.close()
data_channel.close()
def client_proc(task=None):
# create channel
channel = pycos.Channel('sum_prod')
# create tasks to compute sum and product of numbers sent
sum_task = pycos.Task(seqsum)
prod_task = pycos.Task(seqprod)
# subscribe tasks to channel so they receive messages
yield channel.subscribe(sum_task)
yield channel.subscribe(prod_task)
# send 4 numbers to channel
for _ in range(4):
r = random.uniform(0.5, 3)
channel.send(r)
print('sent %f' % r)
# send None to indicate end of data
channel.send(None)
yield channel.unsubscribe(sum_task)
yield channel.unsubscribe(prod_task)
def server_proc(task=None):
# to illustrate 'transform' function of channel, messages are modified
def txfm_msgs(name, msg_cid):
msg, client_id = msg_cid
# assert name == 'chat_channel'
# e.g., drop shoutings
if msg.isupper():
return None
if msg == 'joined':
msg += ' :-)'
elif msg == 'bye':
msg = 'left :-('
else:
msg = 'says: %s' % msg
return (msg, client_id)
channel = pycos.Channel('chat_channel', transform=txfm_msgs)
channel.register()
task.set_daemon()
task.register('chat_server')
client_id = 1
while True:
# each message is a 2-tuple
cmd, who = yield task.receive()
# join/quit messages can be sent by clients themselves, but
# for illustration server sends them instead
if cmd == 'join':
channel.send(('joined', client_id))
who.send(client_id)
client_id += 1
elif cmd == 'quit':
channel.send(('bye', who))
elif cmd == 'terminate':
break
channel.unregister()
task.unregister()
task.set_daemon()
# until subscribed, client's deliver will block
yield task.sleep(5)
# subscribe to channel to get messages
yield channel.subscribe(task)
print(' receiver subscribed')
while True:
msg = yield task.receive()
if msg:
print('Received "%s" from %s at %s' %
(msg['msg'], msg['sender'].name, msg['sender'].location))
if __name__ == '__main__':
# pycos.logger.setLevel(pycos.logger.DEBUG)
channel = pycos.Channel('2clients')
# register channel so client can get a reference to it
channel.register()
recv = pycos.Task(receiver_proc)
if sys.version_info.major > 2:
read_input = input
else:
read_input = raw_input
while True:
try:
cmd = read_input('Enter "quit" or "exit" to terminate: ').strip().lower()
if cmd in ('quit', 'exit'):
break
except:
