1 files changed, 170 insertions, 0 deletions
diff --git a/eti_tcp.py b/eti_tcp.py
new file mode 100755
index 0000000..9cb9a22
--- /dev/null
+++ b/eti_tcp.py
@@ -0,0 +1,170 @@
+#!/usr/bin/env python2
+#
+# A small program that transmits stdin to several TCP connections
+#
+# Known to work with TM 2. Be careful when using TM 1 or 4: modulator might
+# lose frame phase synchronisation when frames are dropped. Setting
+# PACKET_SIZE to 4*6144 should avoid this problem.
+#
+# 2012, mpb
+
+from socket import *
+import threading
+import Queue
+import sys
+import os
+import time
+
+PACKET_SIZE=6144
+QUEUE_PACKET_CAPACITY=100 # represents 2.4 seconds of ETI data
+
+class Connection(object):
+    def __init__(self, conn, addr):
+        print("Got new connection from {0}".format(addr))
+        self.addr = addr
+        self.q = Queue.Queue(PACKET_SIZE*QUEUE_PACKET_CAPACITY)
+        self.ch = ConnectionHandler(conn, self.q)
+        self.ch.start()
+
+    def send(self, data):
+        if self.ch.running:
+            try:
+                self.q.put_nowait(data)
+            except Queue.Full:
+                pass
+            return True
+        else:
+            return False
+
+    def join(self):
+        self.ch.join()
+
+    def terminate(self):
+        self.ch.running = False
+        self.ch.close()
+     
+class ConnectionHandler(threading.Thread):
+    def __init__(self, sock, queue):
+        self.sock = sock
+        self.queue = queue
+        self.running = True
+        threading.Thread.__init__(self)
+
+    def run(self):
+        print("Server for {0} created".format(self.sock.getpeername()))
+
+        # Disable Nagle's algorithm, s.t. the TCP stack does not
+        # put together small send()s
+        self.sock.setsockopt(IPPROTO_TCP, TCP_NODELAY, 1)
+
+        while self.running:
+            data = self.queue.get()
+            try:
+                self.sock.sendall(data)
+            except:
+                self.running = False
+
+        self.sock.close()
+
+    def close(self):
+        self.sock.close()
+
+import fcntl
+class DataSender(threading.Thread):
+
+    def __init__(self, connections):
+        print("DS starting.")
+
+        if True:
+            # make stdin a non-blocking file
+            fd = sys.stdin.fileno()
+            fl = fcntl.fcntl(fd, fcntl.F_GETFL)
+            fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+
+        self.running = True
+        self.connections = connections
+        threading.Thread.__init__(self)
+
+    def run(self):
+        while self.running:
+            try:
+                data = sys.stdin.read(PACKET_SIZE)
+            except KeyboardInterrupt:
+                break
+            except:
+                time.sleep(0.005)
+                continue
+
+            removeconns = []
+
+            for c in self.connections:
+                if not c.send(data):
+                    removeconns.append(c)
+            #print("DS: Put {0} bytes into {1} connections".format(len(data), len(self.connections)))
+
+            for c in removeconns:
+                c.terminate()
+                self.connections.remove(c)
+            if len(removeconns) != 0:
+                print("DS: Removed {0} connections".format(len(removeconns)))
+            del removeconns
+
+        print("DS: Bye")
+
+def listener(port):
+    print("eti_tcp.py [{0}] starting...".format(os.getpid()))
+    ADDR = ("", port)
+     
+    serv = socket(AF_INET, SOCK_STREAM)    
+
+    # Can reuse a socket that is in TIME_WAIT
+    serv.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
+     
+    serv.bind((ADDR))
+    serv.listen(3)
+
+    connections = []
+
+    ds = DataSender(connections)
+    ds.start()
+
+    while True:
+        try:
+            print("Main: accepting on port {0}...".format(port))
+            sock, addr = serv.accept()
+            connections.append(Connection(sock, addr))
+        except KeyboardInterrupt:
+            print("Interrupted")
+            break
+
+    print("Terminating {0} connections".format(len(connections)))
+    for c in connections:
+        c.terminate()
+
+    print("Joining connections")
+    for c in connections:
+        c.join()
+
+    print("Send Ctrl-D to close stdin")
+
+    ds.running = False
+    ds.join()
+
+def usage():
+    print("""Usage:
+    {0} port
+
+    port: specifies on which TCP port to listen for incoming connections""".format(sys.argv[0]))
+
+if len(sys.argv) != 2:
+    usage()
+    sys.exit(1)
+else:
+    port = 0
+    try:
+        port = int(sys.argv[1])
+    except:
+        usage()
+        sys.exit(1)
+
+    listener(port)