base: Tag API methods in socket.hh

Change-Id: Ifdbe1d9367df602e45fa3d39c91de9e0f8f1d87e
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33078
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/base/socket.hh b/src/base/socket.hh
index 74a379b..4b42674 100644
--- a/src/base/socket.hh
+++ b/src/base/socket.hh
@@ -32,6 +32,10 @@
 class ListenSocket
 {
   protected:
+    /**
+     * The following variables are only used by socket unit tests:
+     * listeningDisabled, anyListening, bindToLoopback.
+     */
     static bool listeningDisabled;
     static bool anyListening;
 
@@ -54,14 +58,20 @@
 
 
   public:
+    /**
+     * @ingroup api_socket
+     * @{
+     */
     ListenSocket();
     virtual ~ListenSocket();
 
     virtual int accept(bool nodelay = false);
+
     virtual bool listen(int port, bool reuse = true);
 
     int getfd() const { return fd; }
     bool islistening() const { return listening; }
+    /** @} */ // end of api_socket
 };
 
 #endif //__SOCKET_HH__