python asyncio run forever and inter-process communication
<p>What is the most efficient way to achieve the following goal: main process is collecting and distributing events (event loop run_forever) to subprocessess. These subprocesses stay alive and collect signals from outer world or consume signals and perform cpu-bound operations. So far, I came up with something like this:</p>

<pre><code>import os
import time
import signal
import asyncio
from asyncio import PriorityQueue
from multiprocessing import Process, Pipe

class Event(object):
    __slots__ = ['type','priority','payload','timestamp']   
    def __init__(self, _type = None, _priority = None, _payload = None):
        self.type, self.priority, self.payload, self.timestamp = _type, _priority, _payload, time.time()
    def __str__(self):
        return "%s(%s,%s,%s)" % (self.__class__.__name__, self.type, self.priority, self.payload)
    def __lt__(self, other):
        return (self.priority, self.timestamp) &gt; (other.priority, other.timestamp)

class EventQueue(PriorityQueue):
    def _put(self, event):
        super()._put( (event.priority, event) ) 

@asyncio.coroutine
def consumeAnyEvent(eq, acon_write_p = None): ## more args with write_conn pipes 
    while True:
        priority, event = yield from eq.get()
        print("consumed",event)
        if event.type == 'sig_a':
            acon_write_p.send(event)
        if event.type == 'sig_b':
            pass
        if event.type == 'sig_c':
            pass
        ## and so on - broadcast events to relevant sub-processes
        yield from asyncio.sleep(0)

@asyncio.coroutine
def produceSignalA(eq,read_p):
    while True:
        yield from asyncio.sleep(0)
        row = read_p.recv()
        if row:
            yield from eq.put( Event( 'sig_a', payload = row ) )

class someSource(object):
    """db, http, file watch or other io"""
    def fetch(self):
        pass

def someSlowMethod(a=None):
    """cpu-bound operations"""
    pass

def signalAPublisher(pipe):
    read_p, write_p = pipe
    read_p.close() 
    s = someSource()
    while True:
        result = s.fetch()
        if result:
            write_p.send(result)

def signalAConsumer(pipe):
    read_p, write_p = pipe
    while True:
        inp = read_p.recv()        
        if inp:
            result = someSlowMethod(inp)
            write_p.send(result)

def main():
    ## main process is responsible for handling events: 
    ## colllecting from all signal publisher subprocessses 
    ## and broadcasting to all interested consumer subprocesses
    eventQueue = EventQueue()    
    apub_read_p, apub_write_p = Pipe()
    acon_read_p, acon_write_p = Pipe()
    ## more pipes for Signal B, ... Signal Z
    signalAPublisher_p = Process(target=signalAPublisher, args=((apub_read_p, apub_write_p),))    
    signalAConsumer_p = Process(target=signalAPublisher, args=((acon_read_p, acon_write_p),))
    signalAPublisher_p.start()
    signalAConsumer_p.start()
    ## and so on for Signal B, Signal C, ... Signal Z
    loop = asyncio.get_event_loop()
    try:
        tasks = asyncio.gather(
            loop.create_task(produceSignalA(eventQueue,apub_read_p)),
            loop.create_task(consumeAnyEvent(eventQueue,acon_write_p))    
        )
        loop.run_forever()
    except KeyboardInterrupt:
        print("Caught keyboard interrupt. Canceling tasks...")
        tasks.cancel()
    finally:
        loop.close()
        os.kill(signalAPublisher_p.pid, signal.SIGTERM) 
        os.kill(signalAConsumer_p.pid, signal.SIGTERM)
        ## kill for Signal B, ... Signal Z

if __name__ == '__main__':
    main()
</code></pre>

<p>However I have a feeling that the above is not efficient / elegant enough and i'm missing something. Any ideas, suggestions?</p>