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--- tanszek:oktatas:iss_t:python_example_for_blocking_and_non-blocking_socket [2024/02/25 15:49] – létrehozva knehez
+++ tanszek:oktatas:iss_t:python_example_for_blocking_and_non-blocking_socket [2024/02/25 15:55] (current) – knehez
@@ Line 1: / Line 1: @@
+=== Blocking socket server ===
+To illustrate the difference with a blocking socket approach, we'll create a simple blocking TCP server and a corresponding client. This server will handle one connection at a time in a blocking manner, meaning it will wait (or block) on I/O operations like accepting new connections or receiving data.
+<sxh python>
+import socket
+HOST = '127.0.0.1'  # Standard loopback interface address (localhost)
+PORT = 65432        # Port to listen on (non-privileged ports are > 1023)
+# Create a socket
+with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
+    server_socket.bind((HOST, PORT))
+    server_socket.listen()
+    print(f"Server is listening on {HOST}:{PORT}")
+    while True:
+        # Accept a new connection
+        conn, addr = server_socket.accept()
+        with conn:
+            print(f"Connected by {addr}")
+            while True:
+                data = conn.recv(1024)
+                if not data:
+                    break  # No more data from client, close connection
+                print(f"Received {data.decode()} from {addr}")
+                response = "This is a response from the server.".encode()
+                conn.sendall(response)
+</sxh>
+=== Blocking client ===
+<sxh python>
+import socket
+HOST = '127.0.0.1'  # The server's hostname or IP address
+PORT = 65432        # The port used by the server
+# Create a socket
+with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+    s.connect((HOST, PORT))
+    print("Connected to the server")
+    # Send data
+    message = 'Hello, server'.encode()
+    s.sendall(message)
+    print("Message sent to the server")
+    # Wait for a response
+    data = s.recv(1024)
+    print("Received response from the server")
+print(f"Received: {data.decode()}")
+</sxh>
+----
 === Non-blocking server ===
+Creating a non-blocking TCP socket server in Python involves setting up a socket to listen for connections without blocking the main execution thread of the program. Below is a simple example of a non-blocking TCP server that accepts multiple client connections and handles them asynchronously. This server uses the select method, which is a way to check for I/O readiness on sockets, making it possible to manage multiple connections without blocking on any single one.
 <sxh python>
@@ Line 67: / Line 124: @@
             outputs.remove(s)
         s.close()
+</sxh>
+=== Non-blocking client ===
+To test the non-blocking TCP server, you can create a simple client that connects to the server, sends a message, and then waits to receive a response. Below is an example of a basic TCP client in Python that interacts with our non-blocking server.
+<sxh python>
+import socket
+HOST = '127.0.0.1'  # The server's hostname or IP address
+PORT = 65432        # The port used by the server
+# Create a socket
+with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+    # Connect to the server
+    s.connect((HOST, PORT))
+    print("Connected to server")
+    # Send data
+    message = 'Hello, server'.encode()
+    s.sendall(message)
+    print("Message sent to server")
+    # Wait for a response
+    data = s.recv(1024)
+    print("Received response from server")
+print(f"Received: {data.decode()}")
 </sxh>