pc_rpc: factor out asyncio server code

artiq/devices/pdq2/pdq2-controller

@@ -10,7 +10,7 @@ import asyncio
 from scipy import interpolate
 import numpy as np
 
-from artiq.management.pc_rpc import Server
+from artiq.management.pc_rpc import simple_server_loop
 
 
 logger = logging.getLogger("Pdq2")
@@ -355,16 +355,7 @@ def main():
 
     dev = Pdq2(serial=args.serial)
     try:
-        loop = asyncio.get_event_loop()
-        try:
-            server = Server(dev)
-            loop.run_until_complete(server.start(args.bind, args.port))
-            try:
-                loop.run_forever()
-            finally:
-                loop.run_until_complete(server.stop())
-        finally:
-            loop.close()
+        simple_server_loop(dev, args.bind, args.port)
     finally:
         dev.close()
 

artiq/management/pc_rpc.py

@@ -158,3 +158,24 @@ class Server:
                     writer.write(line.encode())
         finally:
             writer.close()
+
+
+def simple_server_loop(target, host, port):
+    """Runs a server until an exception is raised (e.g. the user hits Ctrl-C).
+
+    :param target: Object providing the RPC methods to be exposed to the
+        client.
+    :param host: Bind address of the server.
+    :param port: TCP port to bind to.
+
+    """
+    loop = asyncio.get_event_loop()
+    try:
+        server = Server(target)
+        loop.run_until_complete(server.start(host, port))
+        try:
+            loop.run_forever()
+        finally:
+            loop.run_until_complete(server.stop())
+    finally:
+        loop.close()