How to use the execnet.makegateway function in execnet

# -*- coding: utf-8 -*-
import execnet


def multiplier(channel, factor):
    while not channel.isclosed():
        param = channel.receive()
        channel.send(param * factor)


gw = execnet.makegateway()
channel = gw.remote_exec(multiplier, factor=10)

for i in range(5):
    channel.send(i)
    result = channel.receive()
    assert result == i * 10

gw.exit()

def test_hrsync_one_host(self, mysetup):
        source, dest = mysetup.source, mysetup.dest
        gw = execnet.makegateway("popen//chdir=%s" % dest)
        finished = []
        rsync = HostRSync(source)
        rsync.add_target_host(gw, finished=lambda: finished.append(1))
        source.join("hello.py").write("world")
        rsync.send()
        gw.exit()
        assert dest.join(source.basename, "hello.py").check()
        assert len(finished) == 1

def test_hrsync_one_host(self, mysetup):
        source, dest = mysetup.source, mysetup.dest
        gw = execnet.makegateway("popen//chdir=%s" % dest)
        finished = []
        rsync = HostRSync(source)
        rsync.add_target_host(gw, finished=lambda: finished.append(1))
        source.join("hello.py").write("world")
        rsync.send()
        gw.exit()
        assert dest.join(source.basename, "hello.py").check()
        assert len(finished) == 1

def getgateway(host, configfile=None):
    xspec = "ssh=%s" % host
    if configfile is not None:
        xspec += "//ssh_config=%s" % configfile
    return execnet.makegateway(xspec)

# -*- coding: utf-8 -*-
"""
example

reading results from possibly blocking code running in sub processes.
"""
from __future__ import print_function

import execnet

NUM_PROCESSES = 5

channels = []
for i in range(NUM_PROCESSES):
    gw = execnet.makegateway()  # or use SSH or socket gateways
    channel = gw.remote_exec(
        """
        import time
        secs = channel.receive()
        time.sleep(secs)
        channel.send("waited %d secs" % secs)
    """
    )
    channels.append(channel)
    print("*** instantiated subprocess", gw)

mc = execnet.MultiChannel(channels)
queue = mc.make_receive_queue()

print("*** verifying that timeout on receiving results from blocked subprocesses works")
try:

def setup(self,):
        self.testdir.chdir()
        # import os ; os.environ['EXECNET_DEBUG'] = "2"
        self.gateway = execnet.makegateway()
        self.config = config = self.testdir.parseconfigure()
        putevent = self.use_callback and self.events.put or None

        class DummyMananger:
            testrunuid = uuid.uuid4().hex
            specs = [0, 1]

        self.slp = WorkerController(DummyMananger, self.gateway, config, putevent)
        self.request.addfinalizer(self.slp.ensure_teardown)
        self.slp.setup()

# -*- coding: utf-8 -*-
import execnet

gw = execnet.makegateway("popen//python=python2")
channel = gw.remote_exec(
    """
    import numpy
    array = numpy.array([1,2,3])
    while 1:
        x = channel.receive()
        if x is None:
            break
        array = numpy.append(array, x)
    channel.send(repr(array))
"""
)
for x in range(10):
    channel.send(x)
channel.send(None)
print(channel.receive())

def initgateway(self):
        return execnet.makegateway("popen")

def test_2_to_3_bridge_can_send_binary_files(self, tmpdir):
        python = _find_version('3')
        gw = execnet.makegateway('popen//python=%s'%(python,))
        source = tmpdir.ensure('source', dir=1)
        for i, content in enumerate('foo bar baz \x10foo'):
            source.join(str(i)).write(content)
        rsync = RSync(source)

        target = tmpdir.join('target')
        rsync.add_target(gw, target)
        rsync.send()

def ff(*args):
    """
    function_name: str=args[0]
    Code adapted from https://stackoverflow.com/a/44965570
    """
    gw = execnet.makegateway("popen//python=" + FF_PYTHON)
    channel = gw.remote_exec("""
        from {} import {} as the_function
        channel.send(the_function(*channel.receive()))
    """.format(MODULE, args[0]))
    channel.send(args[1:])
    return channel.receive()