Add example for core level

docs/examples.rst

@@ -5,6 +5,13 @@ There is a list of examples from `aiozmq/examples <https://github.com/aio-libs/a
 
 Every example is a correct tiny python program.
 
+.. _aiozmq-examples-core-dealer-router:
+
+Simple DEALER-ROUTER pair implemented on Core level
+---------------------------------------------------
+
+.. literalinclude:: ../examples/core_dealer_router.py
+
 .. _aiozmq-examples-rpc-rpc:
 
 Remote Procedure Call

examples/core_dealer_router.py

@@ -0,0 +1,74 @@
+import asyncio
+import aiozmq
+import zmq
+
+
+class ZmqDealerProtocol(aiozmq.ZmqProtocol):
+
+    transport = None
+
+    def __init__(self, queue, on_close):
+        self.queue = queue
+        self.on_close = on_close
+
+    def connection_made(self, transport):
+        self.transport = transport
+
+    def msg_received(self, msg):
+        self.queue.put_nowait(msg)
+
+    def connection_lost(self, exc):
+        self.on_close.set_result(exc)
+
+
+class ZmqRouterProtocol(aiozmq.ZmqProtocol):
+
+    transport = None
+
+    def __init__(self, on_close):
+        self.on_close = on_close
+
+    def connection_made(self, transport):
+        self.transport = transport
+
+    def msg_received(self, msg):
+        self.transport.write(msg)
+
+    def connection_lost(self, exc):
+        self.on_close.set_result(exc)
+
+
+@asyncio.coroutine
+def go():
+    router_closed = asyncio.Future()
+    dealer_closed = asyncio.Future()
+    router, _ = yield from aiozmq.create_zmq_connection(
+        lambda: ZmqRouterProtocol(router_closed),
+        zmq.ROUTER,
+        bind='tcp://127.0.0.1:*')
+
+    addr = next(iter(router.bindings()))
+    queue = asyncio.Queue()
+    dealer, _ = yield from aiozmq.create_zmq_connection(
+        lambda: ZmqDealerProtocol(queue, dealer_closed),
+        zmq.DEALER,
+        connect=addr)
+
+    for i in range(10):
+        msg = (b'data', b'ask', str(i).encode('utf-8'))
+        dealer.write(msg)
+        answer = yield from queue.get()
+        print(answer)
+    dealer.close()
+    yield from dealer_closed
+    router.close()
+    yield from router_closed
+
+
+def main():
+    asyncio.get_event_loop().run_until_complete(go())
+    print("DONE")
+
+
+if __name__ == '__main__':
+    main()