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Diffstat (limited to 'pingpong/pingpong.adb')
| -rw-r--r-- | pingpong/pingpong.adb | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/pingpong/pingpong.adb b/pingpong/pingpong.adb new file mode 100644 index 0000000..549e2e6 --- /dev/null +++ b/pingpong/pingpong.adb @@ -0,0 +1,285 @@ +with Ada.Text_IO; +with Ada.Exceptions; use Ada.Exceptions; +with GNAT.Sockets; use GNAT.Sockets; + +procedure PingPong is + + Group : constant String := "239.255.128.128"; + -- Multicast groupe: administratively scoped IP address + -- + task Pong is + entry Start; + entry Stop; + end Pong; + + task body Pong is + Address : Sock_Addr_Type; + Server : Socket_Type; + Socket : Socket_Type; + Channel : Stream_Access; + + begin + accept Start; + -- + -- Get an Internet address of a host (here the local host name). + -- Note that a host can have several addresses. Here we get + -- the first one which is supposed to be the official one. + -- + Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); + -- + -- Get a socket address that is an Internet address and a port + -- + Address.Port := 5432; + -- + -- The first step is to create a socket. Once created, this + -- socket must be associated to with an address. Usually only + -- a server (Pong here) needs to bind an address explicitly. + -- Most of the time clients can skip this step because the + -- socket routines will bind an arbitrary address to an unbound + -- socket. + -- + Create_Socket (Server); + -- + -- Allow reuse of local addresses. + -- + Set_Socket_Option + (Server, + Socket_Level, + (Reuse_Address, True)); + + Bind_Socket (Server, Address); + -- + -- A server marks a socket as willing to receive connect events. + -- + Listen_Socket (Server); + -- + -- Once a server calls Listen_Socket, incoming connects events + -- can be accepted. The returned Socket is a new socket that + -- represents the server side of the connection. Server remains + -- available to receive further connections. + -- + Accept_Socket (Server, Socket, Address); + -- + -- Return a stream associated to the connected socket. + -- + Channel := Stream (Socket); + -- + -- Force Pong to block + -- + delay 0.2; + -- + -- Receive and print message from client Ping. + -- + declare + Message : String := String'Input (Channel); + begin + Ada.Text_IO.Put_Line (Message); + -- + -- Send same message to server Pong. + -- + String'Output (Channel, Message); + end; + + Close_Socket (Server); + Close_Socket (Socket); + -- + -- Part of the multicast example + -- + -- Create a datagram socket to send connectionless, unreliable + -- messages of a fixed maximum length. + -- + Create_Socket (Socket, Family_Inet, Socket_Datagram); + -- + -- Allow reuse of local addresses. + -- + Set_Socket_Option + (Socket, + Socket_Level, + (Reuse_Address, True)); + -- + -- Join a multicast group. + -- + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); + -- + -- Controls the live time of the datagram to avoid it being + -- looped forever due to routing errors. Routers decrement + -- the TTL of every datagram as it traverses from one network + -- to another and when its value reaches 0 the packet is + -- dropped. Default is 1. + -- + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Multicast_TTL, 1)); + -- + -- Want the data you send to be looped back to your host. + -- + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Multicast_Loop, True)); + -- + -- If this socket is intended to receive messages, bind it to a + -- given socket address. + -- + Address.Addr := Any_Inet_Addr; + Address.Port := 55505; + + Bind_Socket (Socket, Address); + -- + -- If this socket is intended to send messages, provide the + -- receiver socket address. + -- + Address.Addr := Inet_Addr (Group); + Address.Port := 55506; + + Channel := Stream (Socket, Address); + -- + -- Receive and print message from client Ping. + -- + declare + Message : String := String'Input (Channel); + + begin + -- + -- Get the address of the sender. + -- + Address := Get_Address (Channel); + Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); + -- + -- Send same message to server Pong. + -- + String'Output (Channel, Message); + end; + + Close_Socket (Socket); + + accept Stop; + + exception when E : others => + Ada.Text_IO.Put_Line + (Exception_Name (E) & ": " & Exception_Message (E)); + end Pong; + + task Ping is + entry Start; + entry Stop; + end Ping; + + task body Ping is + Address : Sock_Addr_Type; + Socket : Socket_Type; + Channel : Stream_Access; + + begin + accept Start; + -- + -- See comments in Ping section for the first steps. + -- + Address.Addr := Addresses (Get_Host_By_Name (Host_Name), 1); + Address.Port := 5432; + Create_Socket (Socket); + + Set_Socket_Option + (Socket, + Socket_Level, + (Reuse_Address, True)); + -- + -- Force Pong to block + -- + delay 0.2; + -- + -- If the client's socket is not bound, Connect_Socket will + -- bind to an unused address. The client uses Connect_Socket to + -- create a logical connection between the client's socket and + -- a server's socket returned by Accept_Socket. + -- + Connect_Socket (Socket, Address); + + Channel := Stream (Socket); + -- + -- Send message to server Pong. + -- + String'Output (Channel, "Hello world"); + -- + -- Force Ping to block + -- + delay 0.2; + -- + -- Receive and print message from server Pong. + -- + Ada.Text_IO.Put_Line (String'Input (Channel)); + Close_Socket (Socket); + -- + -- Part of multicast example. Code similar to Pong's one. + -- + Create_Socket (Socket, Family_Inet, Socket_Datagram); + + Set_Socket_Option + (Socket, + Socket_Level, + (Reuse_Address, True)); + + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Add_Membership, Inet_Addr (Group), Any_Inet_Addr)); + + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Multicast_TTL, 1)); + + Set_Socket_Option + (Socket, + IP_Protocol_For_IP_Level, + (Multicast_Loop, True)); + + Address.Addr := Any_Inet_Addr; + Address.Port := 55506; + + Bind_Socket (Socket, Address); + + Address.Addr := Inet_Addr (Group); + Address.Port := 55505; + + Channel := Stream (Socket, Address); + -- + -- Send message to server Pong. + -- + String'Output (Channel, "Hello world"); + -- + -- Receive and print message from server Pong. + -- + declare + Message : String := String'Input (Channel); + + begin + Address := Get_Address (Channel); + Ada.Text_IO.Put_Line (Message & " from " & Image (Address)); + end; + + Close_Socket (Socket); + + accept Stop; + + exception when E : others => + Ada.Text_IO.Put_Line + (Exception_Name (E) & ": " & Exception_Message (E)); + end Ping; + +begin + -- Indicate whether the thread library provides process + -- blocking IO. Basically, if you are not using FSU threads + -- the default is ok. + -- + Initialize (Process_Blocking_IO => False); + Ping.Start; + Pong.Start; + Ping.Stop; + Pong.Stop; + Finalize; +end PingPong; |