Connection rewrite: update client and server connection logic (#49)

Drone/client.py

@@ -16,7 +16,7 @@
 parent_dir = os.path.dirname(current_dir)
 sys.path.insert(0, parent_dir) 
 
-#logging.basicConfig(level=logging.INFO)
+logging.basicConfig(level=logging.DEBUG)
 logger = logging.getLogger(__name__)
 
 import messaging_lib as messaging
@@ -103,7 +103,7 @@ def start(self):
         try:
             while True:
                 self._reconnect()
-                self._process_connections()
+                #self._process_connections()
 
         except (KeyboardInterrupt, ):
             logger.critical("Caught interrupt, exiting!")
@@ -142,7 +142,7 @@ def _reconnect(self, timeout=3.0, attempt_limit=5):
     def _connect(self):
         self.connected = True
         self.client_socket.setblocking(False)
-        events = selectors.EVENT_READ | selectors.EVENT_WRITE
+        events = selectors.EVENT_READ # | selectors.EVENT_WRITE
         self.selector.register(self.client_socket, events, data=self.server_connection)
         self.server_connection.connect(self.selector, self.client_socket, (self.server_host, self.server_port))
         self._process_connections()
@@ -187,39 +187,31 @@ def on_broadcast_bind(self):
     def _process_connections(self):
         while True:
             events = self.selector.select(timeout=1)
-            if events:
-                for key, mask in events:
-                    if key.data is None:
-                        pass
-                    else:
-                        connection = key.data
-                        try:
-                            connection.process_events(mask)
-
-                        except Exception as error:
-                            logger.error(
-                                "Exception {} occurred for {}! Resetting connection!".format(error, connection.addr)
-                            )
-                            self.server_connection.close()
-                            self.connected = False
-
-                            if isinstance(error, OSError):
-                                if error.errno == errno.EINTR:
-                                    raise KeyboardInterrupt
-            else:
-                time.sleep(0.001)
+            # logging.debug("tick")
+            for key, mask in events:  # TODO add notifier to client!
+                connection = key.data
+                if connection is None:
+                    pass
+                else:
+                    try:
+                        connection.process_events(mask)
+
+                    except Exception as error:
+                        logger.error(
+                            "Exception {} occurred for {}! Resetting connection!".format(error, connection.addr)
+                        )
+                        self.server_connection.close()
+                        self.connected = False
+
+                        if isinstance(error, OSError):
+                            if error.errno == errno.EINTR:
+                                raise KeyboardInterrupt
+
 
             if not self.selector.get_map():
                 logger.warning("No active connections left!")
                 return
 
-            time.sleep(0.001)
-
-    #def connection_processor(self):
-    #    while not self._shutdown_event.is_set():
-    #        self._running_event.wait()
-    #        self._process_connections()
-
 
 @messaging.request_callback("id")
 def _response_id():

README.md

@@ -9,7 +9,9 @@
 * [Аддон для Blender 2.8](https://github.com/artem30801/CleverSwarm/tree/master/blender-addon) для преобразования анимации полёта коптеров, созданной в Blender, в файлы полётов для каждого коптера
 * [Образ для Raspberry Pi](https://github.com/artem30801/CleverSwarm/releases/latest) для быстрого запуска ПО на коптере
 
-## Документация
+## Документация:
 Инструкция по запуску ПО находится [здесь](docs/start-tutorial.md).
 
 Подробная документация расположена в папке [docs](https://github.com/artem30801/CleverSwarm/tree/master/docs).
+
+

Server/server.py

@@ -143,20 +143,27 @@ def _client_processor(self):
         logging.info("Client processor (selector) thread started!")
         self.server_socket.listen()
         self.server_socket.setblocking(False)
-        self.sel.register(self.server_socket, selectors.EVENT_READ | selectors.EVENT_WRITE, data=None)
+        self.sel.register(self.server_socket, selectors.EVENT_READ, data=None) #| selectors.EVENT_WRITE
+
+        messaging.NotifierSock().bind((self.ip, self.port))
 
         while self.client_processor_thread_running.is_set():
             events = self.sel.select()
+            logging.error('tick')
             for key, mask in events:
-                if key.data is None:
+                # logging.error(mask)
+                # logging.error(str(key.data))
+                client = key.data
+                if client is None:
                     self._connect_client(key.fileobj)
-                else:
-                    client = key.data
+                elif isinstance(client, messaging.ConnectionManager):
                     try:
                         client.process_events(mask)
                     except Exception as error:
                         logging.error("Exception {} occurred for {}! Resetting connection!".format(error, client.addr))
                         client.close()
+                else:  # Notifier
+                    client.process_events(mask)
 
         logging.info("Client autoconnect thread stopped!")
 
@@ -165,7 +172,11 @@ def _connect_client(self, sock):
         logging.info("Got connection from: {}".format(str(addr)))
         conn.setblocking(False)
 
-        if not any([client_addr == addr[0] for client_addr in Client.clients.keys()]):
+        if addr[0] == self.ip and messaging.NotifierSock().addr is None:
+            client = messaging.NotifierSock()
+            logging.info("Notifier sock client")
+
+        elif not any([client_addr == addr[0] for client_addr in Client.clients.keys()]):
             client = Client(addr[0])
             logging.info("New client")
         else:

Server/server_qt.py

@@ -19,6 +19,7 @@
 
 import threading
 
+
 def wait(end, interrupter=threading.Event(), maxsleep=0.1):
     # Added features to interrupter sleep and set max sleeping interval
 
@@ -30,6 +31,7 @@ def wait(end, interrupter=threading.Event(), maxsleep=0.1):
         else:
             time.sleep(diff / 2)
 
+
 def confirmation_required(text="Are you sure?", label="Confirm operation?"):
     def inner(f):
 

messaging_lib.py

@@ -1,6 +1,7 @@
 import io
 import sys
 import json
+import socket
 import struct
 import random
 import logging
@@ -12,13 +13,28 @@
 except ImportError:
     import selectors2 as selectors
 
-#import logging_lib
+# import logging_lib
 
 PendingRequest = collections.namedtuple("PendingRequest", ["value", "requested_value",  # "expires_on",
                                                            "callback", "callback_args", "callback_kwargs",
                                                            ])
 logger = logging.getLogger(__name__)
-#logger = logging_lib.Logger(_logger, True)
+
+
+# logger = logging_lib.Logger(_logger, True)
+
+
+class _Singleton(type):
+    """ A metaclass that creates a Singleton base class when called. """
+    _instances = {}
+
+    def __call__(cls, *args, **kwargs):
+        if cls not in cls._instances:
+            cls._instances[cls] = super(_Singleton, cls).__call__(*args, **kwargs)
+        return cls._instances[cls]
+
+
+class Singleton(_Singleton('SingletonMeta', (object,), {})): pass
 
 
 class MessageManager:
@@ -196,14 +212,17 @@ def _set_selector_events_mask(self, mode):
             events = selectors.EVENT_READ | selectors.EVENT_WRITE
         else:
             raise ValueError("Invalid events mask mode {}.".format(mode))
-        self.selector.modify(self.socket, events, data=self)
+
+        key = self.selector.modify(self.socket, events, data=self)
+        logging.debug("Switched selector of {} to mode {}".format(self.addr, key.events))
+        return key
 
     def connect(self, client_selector, client_socket, client_addr):
         self.selector = client_selector
         self.socket = client_socket
         self.addr = client_addr
 
-        self._set_selector_events_mask('rw')
+        self._set_selector_events_mask('r')
 
     def close(self):
         logger.info("Closing connection to {}".format(self.addr))
@@ -269,7 +288,8 @@ def _read(self):
 
     def process_received(self, income_message):
         message_type = income_message.jsonheader["message-type"]
-        logger.debug("Received message! Header: {}, content: {}".format(income_message.jsonheader, income_message.content))
+        logger.debug(
+            "Received message! Header: {}, content: {}".format(income_message.jsonheader, income_message.content))
 
         if message_type == "message":
             self._process_message(income_message)
@@ -339,6 +359,8 @@ def write(self):
                 self._send_buffer += message
         if self._send_buffer:
             self._write()
+        else:
+            self._set_selector_events_mask('r')  # we're done writing
 
     def _write(self):
         try:
@@ -347,7 +369,8 @@ def _write(self):
             # Resource temporarily unavailable (errno EWOULDBLOCK)
             pass
         except Exception as error:
-            logger.warning("Attempt to send message {} to {} failed due error: {}".format(self._send_buffer, self.addr, error))
+            logger.warning(
+                "Attempt to send message {} to {} failed due error: {}".format(self._send_buffer, self.addr, error))
 
             if not self.resume_queue:
                 self._send_buffer = b''
@@ -361,6 +384,10 @@ def _send(self, data):
         with self._send_lock:
             self._send_queue.append(data)
 
+        if self.selector.get_key(self.socket).events != selectors.EVENT_WRITE:
+            self._set_selector_events_mask('w')
+            NotifierSock().notify()
+
     def get_response(self, requested_value, callback, request_args=None,  # timeout=30,
                      callback_args=(), callback_kwargs=None):
         if request_args is None:
@@ -397,3 +424,43 @@ def send_file(self, filepath, dest_filepath):  # clever_restart=False
             self._send(MessageManager.create_message(
                 data, "binary", "filetransfer", "binary", {"filepath": dest_filepath}
             ))
+
+
+class NotifierSock(Singleton):
+    def __init__(self):
+        self.receive_socket = None
+        self.addr = None
+
+        self._notify_socket = None
+        self._notify_lock = threading.Lock()
+
+    def bind(self, server_addr):
+        self._notify_socket = socket.socket()
+        self._notify_socket.connect(server_addr)
+        logger.info("Notify socket: bind")
+
+    def connect(self, _, client_socket, client_addr):
+        self.receive_socket = client_socket
+        self.addr = client_addr
+
+        logger.info("Notify socket: connected")
+
+    def notify(self):
+        with self._notify_lock:
+            if self.addr is not None:
+                self._notify_socket.sendall(bytes(1))
+                logger.debug("Notify socket: notified")
+
+    def process_events(self, mask):
+        if mask & selectors.EVENT_READ:
+            try:
+                data = self.receive_socket.recv(1024)
+            except Exception:  # TODO remove
+                pass
+            else:
+                if data:
+                    logger.debug("Notifier received {} from {}".format(data, self.addr))
+                else:
+                    self.addr = None
+                    logger.warning("Notifier: connection to {} lost!".format(self.addr))
+