management: add sync_struct

artiq/management/network.py

@@ -0,0 +1,55 @@
+import asyncio
+from copy import copy
+
+
+class AsyncioServer:
+    """Generic TCP server based on asyncio.
+
+    Users of this class must derive from it and define the
+    ``_handle_connection_cr`` method and coroutine.
+
+    """
+    def __init__(self):
+        self._client_tasks = set()
+
+    @asyncio.coroutine
+    def start(self, host, port):
+        """Starts the server.
+
+        The user must call ``stop`` to free resources properly after this
+        method completes successfully.
+
+        This method is a `coroutine`.
+
+        :param host: Bind address of the server (see ``asyncio.start_server``
+            from the Python standard library).
+        :param port: TCP port to bind to.
+
+        """
+        self.server = yield from asyncio.start_server(self._handle_connection,
+                                                      host, port)
+
+    @asyncio.coroutine
+    def stop(self):
+        """Stops the server.
+
+        """
+        wait_for = copy(self._client_tasks)
+        for task in self._client_tasks:
+            task.cancel()
+        for task in wait_for:
+            try:
+                yield from asyncio.wait_for(task, None)
+            except asyncio.CancelledError:
+                pass
+        self.server.close()
+        yield from self.server.wait_closed()
+        del self.server
+
+    def _client_done(self, task):
+        self._client_tasks.remove(task)
+
+    def _handle_connection(self, reader, writer):
+        task = asyncio.Task(self._handle_connection_cr(reader, writer))
+        self._client_tasks.add(task)
+        task.add_done_callback(self._client_done)

artiq/management/pc_rpc.py

@@ -17,6 +17,7 @@ import asyncio
 import traceback
 
 from artiq.management import pyon
+from artiq.management.network import AsyncioServer
 
 
 class RemoteError(Exception):
@@ -123,7 +124,7 @@ class Client:
         return proxy
 
 
-class Server:
+class Server(AsyncioServer):
     """This class creates a TCP server that handles requests coming from
     ``Client`` objects.
 
@@ -142,49 +143,13 @@ class Server:
 
     """
     def __init__(self, target, id_type, id_parameters=None):
+        AsyncioServer.__init__(self)
         self.target = target
         self.id_type = id_type
         self.id_parameters = id_parameters
-        self._client_tasks = set()
 
     @asyncio.coroutine
-    def start(self, host, port):
-        """Starts the server.
-
-        The user must call ``stop`` to free resources properly after this
-        method completes successfully.
-
-        This method is a `coroutine`.
-
-        :param host: Bind address of the server (see ``asyncio.start_server``
-            from the Python standard library).
-        :param port: TCP port to bind to.
-
-        """
-        self.server = yield from asyncio.start_server(self._handle_connection,
-                                                      host, port)
-
-    @asyncio.coroutine
-    def stop(self):
-        """Stops the server.
-
-        """
-        for task in self._client_tasks:
-            task.cancel()
-        self.server.close()
-        yield from self.server.wait_closed()
-        del self.server
-
-    def _client_done(self, task):
-        self._client_tasks.remove(task)
-
-    def _handle_connection(self, reader, writer):
-        task = asyncio.Task(self._handle_connection_task(reader, writer))
-        self._client_tasks.add(task)
-        task.add_done_callback(self._client_done)
-
-    @asyncio.coroutine
-    def _handle_connection_task(self, reader, writer):
+    def _handle_connection_cr(self, reader, writer):
         try:
             line = yield from reader.readline()
             if line != _init_string:

artiq/management/sync_struct.py

@@ -0,0 +1,119 @@
+import asyncio
+
+from artiq.management import pyon
+from artiq.management.network import AsyncioServer
+
+
+_init_string = b"ARTIQ sync_struct\n"
+
+
+class Subscriber:
+    def __init__(self, target_builder, error_cb, notify_cb=None):
+        self.target_builder = target_builder
+        self.error_cb = error_cb
+        self.notify_cb = notify_cb
+
+    @asyncio.coroutine
+    def connect(self, host, port):
+        self._reader, self._writer = \
+            yield from asyncio.open_connection(host, port)
+        try:
+            self._writer.write(_init_string)
+            self._receive_task = asyncio.Task(self._receive_cr())
+        except:
+            self._writer.close()
+            del self._reader
+            del self._writer
+            raise
+
+    @asyncio.coroutine
+    def close(self):
+        try:
+            self._receive_task.cancel()
+            try:
+                yield from asyncio.wait_for(self._receive_task, None)
+            except asyncio.CancelledError:
+                pass
+        finally:
+            self._writer.close()
+            del self._reader
+            del self._writer
+
+    @asyncio.coroutine
+    def _receive_cr(self):
+        try:
+            target = None
+            while True:
+                line = yield from self._reader.readline()
+                obj = pyon.decode(line.decode())
+                action = obj["action"]
+
+                if action == "init":
+                    target = self.target_builder(obj["struct"])
+                elif action == "append":
+                    target.append(obj["x"])
+                elif action == "pop":
+                    target.pop(obj["i"])
+                elif action == "delitem":
+                    target.__delitem__(obj["key"])
+                if self.notify_cb is not None:
+                    self.notify_cb()
+        except:
+            self.error_cb()
+            raise
+
+
+class Publisher(AsyncioServer):
+    def __init__(self, backing_struct):
+        AsyncioServer.__init__(self)
+        self.backing_struct = backing_struct
+        self._recipients = set()
+
+    @asyncio.coroutine
+    def _handle_connection_cr(self, reader, writer):
+        try:
+            line = yield from reader.readline()
+            if line != _init_string:
+                return
+
+            obj = {"action": "init", "struct": self.backing_struct}
+            line = pyon.encode(obj) + "\n"
+            writer.write(line.encode())
+
+            queue = asyncio.Queue()
+            self._recipients.add(queue)
+            try:
+                while True:
+                    line = yield from queue.get()
+                    writer.write(line)
+                    # raise exception on connection error
+                    yield from writer.drain()
+            finally:
+                self._recipients.remove(queue)
+        except ConnectionResetError:
+            # subscribers disconnecting are a normal occurence
+            pass
+        finally:
+            writer.close()
+
+    def _publish(self, obj):
+        line = pyon.encode(obj) + "\n"
+        line = line.encode()
+        for recipient in self._recipients:
+            recipient.put_nowait(line)
+
+    # Backing struct modification methods.
+    # All modifications must go through them!
+
+    def append(self, x):
+        self.backing_struct.append(x)
+        self._publish({"action": "append", "x": x})
+
+    def pop(self, i=-1):
+        r = self.backing_struct.pop(i)
+        self._publish({"action": "pop", "i": i})
+        return r
+
+    def __delitem__(self, key):
+        self.backing_struct.__delitem__(key)
+        self._publish({"action": "delitem", "key": key})

doc/manual/management_reference.rst

@@ -7,8 +7,21 @@ Management reference
 .. automodule:: artiq.management.pyon
     :members:
 
+:mod:`artiq.management.network` module
+-------------------------------------
+
+.. automodule:: artiq.management.network
+    :members:
+
+
 :mod:`artiq.management.pc_rpc` module
 -------------------------------------
 
 .. automodule:: artiq.management.pc_rpc
     :members:
+
+:mod:`artiq.management.sync_struct` module
+-------------------------------------
+
+.. automodule:: artiq.management.sync_struct
+    :members: