Include class relationship diagrams in network stack documentation.

net/docs/pools.dot

Index: net/docs/pools.dot
diff --git a/net/docs/pools.dot b/net/docs/pools.dot
new file mode 100644
index 0000000000000000000000000000000000000000..271d98de138f6f4c21f838ee5d8546bdc8e348aa
--- /dev/null
+++ b/net/docs/pools.dot
@@ -0,0 +1,101 @@
+digraph SocketPools {
+    subgraph cluster_legend {
+	label="Legend";
+
+	## The following legend is an attempt to match UML notation,
+	## except for template_class and Factory->object, which are
+	## invented for this diagram.
+	BaseClass;
+	SubClass [label="Derived Class"];
+	Whole;
+	Part;
+	A;
+	B;
+	Interface [label="Interface / ABC", style=dashed];
+	template_class [shape=diamond]; # Link will name parameter(s)
+
+	SubClass -> BaseClass [arrowhead="empty"];
+	SubClass -> Interface [arrowhead="empty", style=dashed];
+	Part -> Whole [arrowhead="diamond", label="ownership"];
+	Part -> Whole [arrowhead="odiamond", label="pointer"];
+	RefCountedPart -> Whole [arrowhead="diamond", color=red,
+		                 label="partial\nownership"];
+	A -> B [arrowhead="none", headlabel="?..?", taillabel="?..?",
+		label="association"];
+	// Often a "subgraph { rank=same; .. }" is used to wrap the
+	// below to make the generative relationship distinctive
+	// from the other class relationships.
+	Factory -> object [arrowhead=veevee];
+    };
+
+    ClientSocketPoolBase [shape=diamond];
+    ClientSocketPoolBaseHelper;
+
+    ClientSocketPoolBaseHelper_ConnectJobFactory
+        [style=dotted, label="ClientSocketPoolBaseHelper::\nConnectJobFactory"];
+    ClientSocketPoolBase_ConnectJobFactory
+        [style=dotted, shape=diamond,
+	 label="ClientSocketPoolBase::\nConnectJobFactory"];
+    ClientSocketPoolBase_ConnectJobFactoryAdaptor
+        [shape=diamond,
+	 label="ClientSocketPoolBase::\nConnectJobFactoryAdaptor"];
+
+    HigherLayeredPool [style=dotted];
+    LowerLayeredPool [style=dotted];
+    ClientSocketPool [style=dotted];
+
+    ConnectJob [style=dashed];
+    ConnectJob_Delegate [style=dotted, label="ConnectJob::Delegate"];
+
+    ClientSocketFactory [style=dotted];
+    DefaultClientSocketFactory;
+    TCPClientSocket;
+    StreamSocket [style=dotted]
+    Socket;
+
+    TransportSocketParams;
+    TransportConnectJobHelper;
+    TransportConnectJobFactory;
+    TransportConnectJob;
+
+    TransportClientSocketPool -> ClientSocketPool [arrowhead=empty];
+    ClientSocketPool -> LowerLayeredPool [arrowhead=empty];
+    ClientSocketPoolBaseHelper -> ConnectJob_Delegate [arrowhead=empty];
+    TransportConnectJobFactory -> ClientSocketPoolBase_ConnectJobFactory
+        [arrowhead=empty, label="TransportSocketParams"];
+    ClientSocketPoolBase_ConnectJobFactoryAdaptor ->
+        ClientSocketPoolBaseHelper_ConnectJobFactory
+ 	    [arrowhead=empty, arrowtail=none];
+    TransportConnectJob -> ConnectJob [arrowhead=empty];
+    DefaultClientSocketFactory -> ClientSocketFactory [arrowhead=empty];
+    StreamSocket -> Socket [arrowhead=empty]
+    TCPClientSocket -> StreamSocket [arrowhead=empty]
+
+    ClientSocketPoolBaseHelper -> ClientSocketPoolBase [arrowhead=diamond];
+    ClientSocketPoolBase -> TransportClientSocketPool
+        [arrowhead=diamond, label="TransportSocketParams"];
+    ClientSocketPoolBase_ConnectJobFactory ->
+        ClientSocketPoolBase_ConnectJobFactoryAdaptor [arrowhead=diamond];
+    ClientSocketPoolBaseHelper_ConnectJobFactory -> 
+        ClientSocketPoolBaseHelper [arrowhead=diamond];
+    TransportConnectJobHelper -> TransportConnectJob [arrowhead=diamond];
+    TransportSocketParams -> TransportConnectJobHelper
+        [arrowhead=diamond, color=red];
+
+    ConnectJob -> ConnectJob_Delegate
+        [dir=back, arrowhead=none, arrowtail=odiamond];
+    HigherLayeredPool -> ClientSocketPoolBaseHelper
+        [arrowhead=odiamond, taillabel="*"];
+    LowerLayeredPool -> ClientSocketPoolBaseHelper
+        [arrowhead=odiamond, taillabel="*"];
+    ClientSocketFactory -> ClientSocketPoolBaseHelper [arrowhead=odiamond];
+
+    subgraph {
+        rank=same;
+        ClientSocketPoolBaseHelper_ConnectJobFactory -> ConnectJob
+            [arrowhead=veevee];
+    }
+    ClientSocketPoolBase_ConnectJobFactory -> ConnectJob [arrowhead=veevee];
+    ClientSocketFactory -> TCPClientSocket [arrowhead=veevee]
+}
+