X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fio%2Fsg_socket.hxx;h=4e1d9e0513e683025692ffc019c3cb7b3519c35e;hb=761b7b93543ad2e8dfd307ee3679b3a2a7082ddc;hp=0d393f4f1b4e897320f722f5da7c6b09f50e41d8;hpb=9af5f9f094706685bae09a885fb6adf6394124c2;p=simgear.git

diff --git a/simgear/io/sg_socket.hxx b/simgear/io/sg_socket.hxx
index 0d393f4f..4e1d9e05 100644
--- a/simgear/io/sg_socket.hxx
+++ b/simgear/io/sg_socket.hxx
@@ -1,5 +1,8 @@
-// sg_socket.hxx -- Socket I/O routines
-//
+/**
+ * \file sg_socket.hxx
+ * Socket I/O routines.
+ */
+
 // Written by Curtis Olson, started November 1999.
 //
 // Copyright (C) 1999  Curtis L. Olson - curt@flightgear.org
@@ -36,24 +39,18 @@
 #include <simgear/math/sg_types.hxx>
 #include <simgear/io/iochannel.hxx>
 
-FG_USING_STD(string);
+#include <plib/netSocket.h>
 
-#if defined(_MSC_VER)
-#  include <winsock.h>
-#endif
+SG_USING_STD(string);
 
 #define SG_MAX_SOCKET_QUEUE 32
 
 
+/**
+ * A socket I/O class based on SGIOChannel.
+ */
 class SGSocket : public SGIOChannel {
 public:
-#if defined(_MSC_VER)
-    typedef SOCKET SocketType;
-#else
-    typedef int SocketType;
-#   define INVALID_SOCKET (-1)
-#endif
-
 private:
     string hostname;
     string port_str;
@@ -61,35 +58,76 @@ private:
     char save_buf[ 2 * SG_IO_MAX_MSG_SIZE ];
     int save_len;
 
-    SocketType sock;
-    SocketType msgsock;
-    short unsigned int port;
-    int sock_style;			// SOCK_STREAM or SOCK_DGRAM
-
+    netSocket sock;
+    netSocket* client;
+    unsigned short port;
+    bool is_tcp;
+    bool is_server;
     bool first_read;
 
+    static bool init;
+
     // make a server (master listening) socket
-    SocketType make_server_socket();
+    bool make_server_socket();
 
     // make a client socket
-    SocketType make_client_socket();
+    bool  make_client_socket();
 
-    // wrapper functions
-    size_t readsocket( int fd, void *buf, size_t count );
-    size_t writesocket( int fd, const void *buf, size_t count );
-#if !defined(_MSC_VER)
-    int closesocket(int fd);
-#endif
-
-#if defined(_MSC_VER)
-    // Ensure winsock has been initialised.
-    static bool wsock_init;
-    static bool wsastartup();
-#endif
+    // Poll for new connections or data to read.
+    int poll();
 
 public:
 
+    /**
+     * Create an instance of SGSocket.
+     *
+     * When calling the constructor you need to provide a host name, a
+     * port number, and a socket style. The convention used by the
+     * SGSocket class is that the server side listens and the client
+     * side sends. For a server socket, the host name should be
+     * empty. For a server, the port number is optional, if you do not
+     * specify a port, the system will assign one. For a client
+     * socket, you need to specify both a destination host and
+     * destination port. For both client and server sockets you must
+     * specify the socket type. Type must be either udp or tcp. Here's
+     * a quick breakdown of the major differences between UDP and TCP
+     * type sockets.
+     *
+     * TCP sockets are the type where you establish a connection and
+     * then can read and write to the socket from both ends. If one
+     * end of TCP socket connect quits, the other end will likely
+     * segfault if it doesn't take special precautions.  But, the nice
+     * thing about TCP connections is that the underlying protocol
+     * guarantees that your message will get through. This imposes a
+     * certain performance overhead though on the communication
+     * because the protocol must resend failed messages. TCP sockets
+     * are good for sending periodic command/response type messages
+     * where performance isn't a big issues, but reliability is.
+     *
+     * UDP sockets on the other hand are a lower level protocol and
+     * don't have the same sort of connection as TCP sockets. With UDP
+     * sockets, the server end just sits and listens for incoming
+     * packets from anywhere. The client end sends it's message and
+     * forgets about it. It doesn't care if there isn't even a server
+     * out there listening and all the packets are getting
+     * lost. Although systems/networks usually do a pretty good job
+     * (statistically) of getting your UDP packets to their
+     * destination, there is no guarantee that any particular packet
+     * will make it. But, because of this low level implementation and
+     * lack of error checking, UDP packets are much faster and
+     * efficient. UDP packets are good for sending positional
+     * information to synchronize two applications. In this case, you
+     * want the information to arrive as quickly as possible, and if
+     * you lose a packet, you'd rather get new updated information
+     * rather than have the system waste time resending a packet that
+     * is becoming older and older with every retry.
+     * @param host name of host if direction is SG_IO_OUT or SG_IO_BI
+     * @param port port number if we care to choose one.
+     * @param style specify "udp" or "tcp"
+     */
     SGSocket( const string& host, const string& port, const string& style );
+
+    /** Destructor */
     ~SGSocket();
 
     // If specified as a server (in direction for now) open the master
@@ -112,14 +150,18 @@ public:
     // close file
     bool close();
 
-    // Enable non-blocking mode.
+    /**
+     * Enable non-blocking mode.
+     * @return success/failure
+     */
     bool nonblock();
 
+    /** @return the remote host name */
     inline string get_hostname() const { return hostname; }
+
+    /** @return the port number (in string form) */
     inline string get_port_str() const { return port_str; }
 };
 
 
 #endif // _SG_SOCKET_HXX
-
-