Add exit timeout and remove socknum setter

Adds an __exit__ timeout for disconnect
removes socknum setter in favor of direct reference
Corrects documentation errors

Author: AdamCummick

adafruit_wiznet5k/adafruit_wiznet5k_socket.py

@@ -113,20 +113,17 @@ def __enter__(self):
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         self.disconnect()
+        stamp = time.monotonic()
         while self.status == adafruit_wiznet5k.SNSR_SOCK_FIN_WAIT:
-            pass
+            if time.monotonic() - stamp > 1000:
+                raise RuntimeError("Failed to disconnect socket")
         self.close()
 
     @property
     def socknum(self):
         """Returns the socket object's socket number."""
         return self._socknum
 
-    @socknum.setter
-    def socknum(self, socknum):
-        """Sets the socket object's socket number."""
-        self._socknum = socknum
-
     @property
     def status(self):
         """Returns the status of the socket"""
@@ -186,9 +183,10 @@ def listen(self, backlog=None):
         self._buffer = b""
 
     def accept(self):
-        """Mimic python socket accept for compatibility. The socket where the
-        connection originated is returned while a new socket is allocated and begins
-        listening.
+        """Accept a connection. The socket must be bound to an address and listening for
+        connections. The return value is a pair (conn, address) where conn is a new
+        socket object usable to send and receive data on the connection, and address is
+        the address bound to the socket on the other end of the connection.
         """
         stamp = time.monotonic()
         while self.status not in (
@@ -205,12 +203,12 @@ def accept(self):
         current_socknum = self.socknum
         # Create a new socket object and swap socket nums so we can continue listening
         client_sock = socket()
-        client_sock.socknum = current_socknum
-        self.socknum = new_listen_socknum
+        client_sock._socknum = current_socknum  # pylint: disable=protected-access
+        self._socknum = new_listen_socknum  # pylint: disable=protected-access
         self.bind((None, self._listen_port))
         self.listen()
         while self.status != adafruit_wiznet5k.SNSR_SOCK_LISTEN:
-            print("Waiting for socket to listen")
+            raise RuntimeError("Failed to open new listening socket")
         return client_sock, addr
 
     def connect(self, address, conntype=None):

examples/wiznet5k_simpleserver.py

@@ -0,0 +1,36 @@
+# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
+# SPDX-FileCopyrightText: 2021 Adam Cummick
+#
+# SPDX-License-Identifier: MIT
+
+import board
+import busio
+import digitalio
+from adafruit_wiznet5k.adafruit_wiznet5k import WIZNET5K
+import adafruit_wiznet5k.adafruit_wiznet5k_socket as socket
+
+print("Wiznet5k SimpleServer Test")
+
+# For Adafruit Ethernet FeatherWing
+cs = digitalio.DigitalInOut(board.D10)
+# For Particle Ethernet FeatherWing
+# cs = digitalio.DigitalInOut(board.D5)
+spi_bus = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
+
+# Initialize ethernet interface
+eth = WIZNET5K(spi_bus, cs, is_dhcp=False)
+
+# Initialize a socket for our server
+socket.set_interface(eth)
+server = socket.socket()  # Allocate socket for the server
+server_ip = "192.168.10.1"  # IP address of server
+server_port = 50007  # Port to listen on 
+server.bind((server_ip, server_port))  # Bind to IP and Port
+server.listen()  # Begin listening for incoming clients
+
+while True:
+    conn, addr = server.accept()  # Wait for a connection from a client.
+    with conn:
+        data = conn.recv()
+        print(data)
+        conn.send(data)  # Echo message back to client