forking server example with oberon; -- noch.

Former-commit-id: 48041fee19

src/test/server/s.Mod

@@ -0,0 +1,102 @@
+MODULE s;
+
+IMPORT sockets, types, Out := Console, Unix, S := SYSTEM;
+
+TYPE Int32 = types.Int32;
+     Int16 = types.Int16;
+     String = types.String;
+
+PROCEDURE DoSmth(sock : Int32);
+VAR str, aff : String;
+    n, s : LONGINT;
+BEGIN
+   s := SIZE(String);
+   aff := "Affirmative, Dave";
+   n := Unix.Read(sock, S.ADR(str), s);
+
+   IF n < 0 THEN
+      Out.String("error reading from socket"); Out.Ln;
+   END;
+   Out.String("message is "); Out.String(str); Out.Ln;
+   s := 17;
+   n := Unix.Write(sock, S.ADR(aff), s);
+   IF n < 2 THEN
+      Out.String("error writing to socket"); Out.Ln
+   END;
+      
+END DoSmth;
+
+
+PROCEDURE serve;
+VAR sockfd, newsockfd, portno, clilen, pid: sockets.Int32;
+    ServAddr, CliAddr: sockets.SockAddrIn;
+    Null : Int32;
+    Port, maxQueue, res : Int32;
+    afinet, port: Int16;
+BEGIN
+   Port := 2055;
+   maxQueue := 5;
+   Null := 0;
+   sockfd := sockets.Socket(S.VAL(Int32, sockets.AfInet), S.VAL(Int32, sockets.SockStream), Null);
+   IF sockfd < 0 THEN
+      Out.String("error opening socket")
+   ELSE
+      Out.String("socket created.")
+   END;
+   Out.Ln;
+   
+   types.IntegerToInt16(sockets.AfInet, afinet);
+   types.IntegerToInt16(Port, port);
+   ServAddr.SinFamily := afinet;
+   ServAddr.SinPort := port;
+   Out.String("listening on port ");Out.Int(S.VAL(INTEGER, ServAddr.SinPort), 0); Out.Ln;
+   ServAddr.SinAddr.SAddr := 0(*sockets.InAddrAny*);
+   
+   res := sockets.Bind(sockfd, S.VAL(sockets.SockAddr, ServAddr), (SIZE(sockets.SockAddrIn)));
+   IF res < 0 THEN
+      Out.String("error on binding")
+   ELSE
+      Out.String("binding completed.")
+   END;
+   Out.Ln;
+    
+   res := sockets.Listen(sockfd, maxQueue);
+   
+   IF res # 0 THEN
+      Out.String("listen() failed");
+   ELSE
+      Out.String("listen okay");
+   END;
+   Out.Ln;
+   clilen := SIZE(sockets.SockAddrIn);
+   LOOP
+      newsockfd := sockets.Accept(sockfd, S.VAL(sockets.SockAddr, ServAddr), clilen);
+      IF newsockfd < 0 THEN
+         Out.String("error on accept")
+      ELSE
+         Out.String("accept okay")
+      END;
+      Out.Ln;
+
+      pid := Unix.Fork();
+      IF pid < 0 THEN
+         Out.String("error on fork")
+      ELSIF pid = 0 THEN
+         Out.String("forked okay"); Out.Ln;
+         res := Unix.Close(sockfd);
+	 DoSmth(newsockfd);
+	 EXIT
+      ELSE
+         res := Unix.Close(newsockfd);
+      END;
+   END;
+
+
+END serve;
+
+
+BEGIN
+
+serve;
+
+END s.