upstream/ipython Files · docs/examples/parallel/demo/noncopying.py

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      """non-copying sends"""

      import zmq

      import numpy

      n = 10

      iface = 'inproc://pub'

      ctx = zmq.Context()

      p = ctx.socket(zmq.PUB)

      p.bind(iface)

      # connect 2 subs

      s1 = ctx.socket(zmq.SUB)

      s1.connect(iface)

      s1.setsockopt(zmq.SUBSCRIBE, '')

      s2 = ctx.socket(zmq.SUB)

      s2.connect(iface)

      s2.setsockopt(zmq.SUBSCRIBE, '')

      A = numpy.random.random((1024,1024))

      # send

      p.send(A, copy=False)

      # recv on 1 non-copy

      msg1 = s1.recv(copy=False)

      B1 = numpy.frombuffer(msg1.buffer, dtype=A.dtype).reshape(A.shape)

      # recv on 2 copy

      msg2 = s2.recv(copy=False)

      B2 = numpy.frombuffer(buffer(msg2.bytes), dtype=A.dtype).reshape(A.shape)

      print (B1==B2).all()

      print (B1==A).all()

      A[0][0] += 10

      print "~"

      # after changing A in-place, B1 changes too, proving non-copying sends

      print (B1==A).all()

      # but B2 is fixed, since it called the msg.bytes attr, which copies

      print (B1==B2).all()

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				"""non-copying sends"""
				import zmq
				import numpy

				n = 10
				iface = 'inproc://pub'

				ctx = zmq.Context()

				p = ctx.socket(zmq.PUB)
				p.bind(iface)

				# connect 2 subs
				s1 = ctx.socket(zmq.SUB)
				s1.connect(iface)
				s1.setsockopt(zmq.SUBSCRIBE, '')

				s2 = ctx.socket(zmq.SUB)
				s2.connect(iface)
				s2.setsockopt(zmq.SUBSCRIBE, '')

				A = numpy.random.random((1024,1024))

				# send
				p.send(A, copy=False)
				# recv on 1 non-copy
				msg1 = s1.recv(copy=False)
				B1 = numpy.frombuffer(msg1.buffer, dtype=A.dtype).reshape(A.shape)
				# recv on 2 copy
				msg2 = s2.recv(copy=False)
				B2 = numpy.frombuffer(buffer(msg2.bytes), dtype=A.dtype).reshape(A.shape)

				print (B1==B2).all()
				print (B1==A).all()
				A[0][0] += 10
				print "~"
				# after changing A in-place, B1 changes too, proving non-copying sends
				print (B1==A).all()
				# but B2 is fixed, since it called the msg.bytes attr, which copies
				print (B1==B2).all()