Start work on TCP demo... wip

Author: worc3131

demos/__init__.py

@@ -4,4 +4,5 @@
 from . import demo_philosophers
 from . import demo_pi
 from . import demo_primes
-from . import demo_readers_writers
+from . import demo_readers_writers
+from . import demo_tcp

demos/demo.py

@@ -8,4 +8,5 @@
     demo_pi.main()
     demo_primes.main()
     demo_readers_writers.main()
+    demo_tcp.main()
 

demos/demo_tcp.py

@@ -0,0 +1,60 @@
+
+from cpo import *
+
+class Packet:
+    pass
+
+class SYN(Packet):
+    pass
+
+class SYNACK(Packet):
+    pass
+
+def run_demo():
+    RUNS = 1000
+    TIMEOUT = Nanoseconds.from_seconds(0.01)
+    PROB_LOSS = 0.8
+
+    DEBUGGER()
+
+    num_timeouts = 0
+    for _ in range(RUNS):
+        cl_to_sv = FaultyOneOne(prob_loss=PROB_LOSS)
+        sv_to_cl = FaultyOneOne(prob_loss=PROB_LOSS)
+        # dont return whether the send was successful we have to figure
+        # that out ourselves through ACKs etc.
+        send_sv = lambda v: sv_to_cl.write_before(TIMEOUT, v) or True
+        send_cl = lambda v: cl_to_sv.write_before(TIMEOUT, v) or True
+        recv_sv = lambda  : cl_to_sv.read_before(TIMEOUT)
+        recv_cl = lambda  : sv_to_cl.read_before(TIMEOUT)
+
+        @proc
+        def client():
+            nonlocal num_timeouts
+            send_cl(SYN())
+            p = None
+            while p is None:
+                p = recv_cl()
+                num_timeouts += p is None
+            assert isinstance(p, SYNACK)
+        @proc
+        def server():
+            nonlocal num_timeouts
+            p = None
+            while p is None:
+                p = recv_sv()
+                num_timeouts += p is None
+            assert isinstance(p, SYN)
+            send_sv(SYNACK())
+        (client | server)()
+
+    return RUNS, num_timeouts
+
+def main():
+    num_runs, num_timeouts = run_demo()
+    timeouts_per_run = num_timeouts / num_runs
+    print(f'Established {num_runs} TCP handshakes with '
+          f'{timeouts_per_run} timeouts per run')
+
+if __name__ == '__main__':
+    main()