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------------------------------------------------------------------------------

--                                                                          --

--                         GNAT COMPILER COMPONENTS                         --

--                                                                          --

--                    G N A T . S O C K E T S . T H I N                     --

--                                                                          --

--                                 B o d y                                  --

--                                                                          --

--                     Copyright (C) 2001-2009, AdaCore                     --

--                                                                          --

-- GNAT is free software;  you can  redistribute it  and/or modify it under --

-- terms of the  GNU General Public License as published  by the Free Soft- --

-- ware  Foundation;  either version 2,  or (at your option) any later ver- --

-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --

-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --

-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --

-- for  more details.  You should have  received  a copy of the GNU General --

-- Public License  distributed with GNAT;  see file COPYING.  If not, write --

-- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --

-- Boston, MA 02110-1301, USA.                                              --

--                                                                          --

-- As a special exception,  if other files  instantiate  generics from this --

-- unit, or you link  this unit with other files  to produce an executable, --

-- this  unit  does not  by itself cause  the resulting  executable  to  be --

-- covered  by the  GNU  General  Public  License.  This exception does not --

-- however invalidate  any other reasons why  the executable file  might be --

-- covered by the  GNU Public License.                                      --

--                                                                          --

-- GNAT was originally developed  by the GNAT team at  New York University. --

-- Extensive contributions were provided by Ada Core Technologies Inc.      --

--                                                                          --

------------------------------------------------------------------------------

--  This package provides a target dependent thin interface to the sockets

--  layer for use by the GNAT.Sockets package (g-socket.ads). This package

--  should not be directly with'ed by an applications program.

--  This is the default version

with GNAT.OS_Lib; use GNAT.OS_Lib;

with GNAT.Task_Lock;

with Interfaces.C; use Interfaces.C;

package body GNAT.Sockets.Thin is

   Non_Blocking_Sockets : aliased Fd_Set;

   --  When this package is initialized with Process_Blocking_IO set

   --  to True, sockets are set in non-blocking mode to avoid blocking

   --  the whole process when a thread wants to perform a blocking IO

   --  operation. But the user can also set a socket in non-blocking

   --  mode by purpose. In order to make a difference between these

   --  two situations, we track the origin of non-blocking mode in

   --  Non_Blocking_Sockets. If S is in Non_Blocking_Sockets, it has

   --  been set in non-blocking mode by the user.

   Quantum : constant Duration := 0.2;

   --  When SOSC.Thread_Blocking_IO is False, we set sockets in

   --  non-blocking mode and we spend a period of time Quantum between

   --  two attempts on a blocking operation.

   Unknown_System_Error : constant C.Strings.chars_ptr :=

                            C.Strings.New_String ("Unknown system error");

   --  Comments required for following functions ???

   function Syscall_Accept

     (S       : C.int;

      Addr    : System.Address;

      Addrlen : not null access C.int) return C.int;

   pragma Import (C, Syscall_Accept, "accept");

   function Syscall_Connect

     (S       : C.int;

      Name    : System.Address;

      Namelen : C.int) return C.int;

   pragma Import (C, Syscall_Connect, "connect");

   function Syscall_Recv

     (S     : C.int;

      Msg   : System.Address;

      Len   : C.int;

      Flags : C.int) return C.int;

   pragma Import (C, Syscall_Recv, "recv");

   function Syscall_Recvfrom

     (S       : C.int;

      Msg     : System.Address;

      Len     : C.int;

      Flags   : C.int;

      From    : System.Address;

      Fromlen : not null access C.int) return C.int;

   pragma Import (C, Syscall_Recvfrom, "recvfrom");

   function Syscall_Recvmsg

     (S     : C.int;

      Msg   : System.Address;

      Flags : C.int) return ssize_t;

   pragma Import (C, Syscall_Recvmsg, "recvmsg");

   function Syscall_Sendmsg

     (S     : C.int;

      Msg   : System.Address;

      Flags : C.int) return ssize_t;

   pragma Import (C, Syscall_Sendmsg, "sendmsg");

   function Syscall_Sendto

     (S     : C.int;

      Msg   : System.Address;

      Len   : C.int;

      Flags : C.int;

      To    : System.Address;

      Tolen : C.int) return C.int;

   pragma Import (C, Syscall_Sendto, "sendto");

   function Syscall_Socket

     (Domain   : C.int;

      Typ      : C.int;

      Protocol : C.int) return C.int;

   pragma Import (C, Syscall_Socket, "socket");

   procedure Disable_SIGPIPE (S : C.int);

   pragma Import (C, Disable_SIGPIPE, "__gnat_disable_sigpipe");

   procedure Disable_All_SIGPIPEs;

   pragma Import (C, Disable_All_SIGPIPEs, "__gnat_disable_all_sigpipes");

   --  Sets the process to ignore all SIGPIPE signals on platforms that

   --  don't support Disable_SIGPIPE for particular streams.

   function Non_Blocking_Socket (S : C.int) return Boolean;

   procedure Set_Non_Blocking_Socket (S : C.int; V : Boolean);

   --------------

   -- C_Accept --

   --------------

   function C_Accept

     (S       : C.int;

      Addr    : System.Address;

      Addrlen : not null access C.int) return C.int

   is

      R   : C.int;

      Val : aliased C.int := 1;

      Discard : C.int;

      pragma Warnings (Off, Discard);

   begin

      loop

         R := Syscall_Accept (S, Addr, Addrlen);

         exit when SOSC.Thread_Blocking_IO

           or else R /= Failure

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      if not SOSC.Thread_Blocking_IO

        and then R /= Failure

      then

         --  A socket inherits the properties ot its server especially

         --  the FIONBIO flag. Do not use Socket_Ioctl as this subprogram

         --  tracks sockets set in non-blocking mode by user.

         Set_Non_Blocking_Socket (R, Non_Blocking_Socket (S));

         Discard := C_Ioctl (R, SOSC.FIONBIO, Val'Access);

      end if;

      Disable_SIGPIPE (R);

      return R;

   end C_Accept;

   ---------------

   -- C_Connect --

   ---------------

   function C_Connect

     (S       : C.int;

      Name    : System.Address;

      Namelen : C.int) return C.int

   is

      Res : C.int;

   begin

      Res := Syscall_Connect (S, Name, Namelen);

      if SOSC.Thread_Blocking_IO

        or else Res /= Failure

        or else Non_Blocking_Socket (S)

        or else Errno /= SOSC.EINPROGRESS

      then

         return Res;

      end if;

      declare

         WSet : aliased Fd_Set;

         Now  : aliased Timeval;

      begin

         Reset_Socket_Set (WSet'Access);

         loop

            Insert_Socket_In_Set (WSet'Access, S);

            Now := Immediat;

            Res := C_Select

              (S + 1,

               No_Fd_Set_Access,

               WSet'Access,

               No_Fd_Set_Access,

               Now'Unchecked_Access);

            exit when Res > 0;

            if Res = Failure then

               return Res;

            end if;

            delay Quantum;

         end loop;

      end;

      Res := Syscall_Connect (S, Name, Namelen);

      if Res = Failure

        and then Errno = SOSC.EISCONN

      then

         return Thin_Common.Success;

      else

         return Res;

      end if;

   end C_Connect;

   ------------------

   -- Socket_Ioctl --

   ------------------

   function Socket_Ioctl

     (S   : C.int;

      Req : C.int;

      Arg : access C.int) return C.int

   is

   begin

      if not SOSC.Thread_Blocking_IO and then Req = SOSC.FIONBIO then

         if Arg.all /= 0 then

            Set_Non_Blocking_Socket (S, True);

         end if;

      end if;

      return C_Ioctl (S, Req, Arg);

   end Socket_Ioctl;

   ------------

   -- C_Recv --

   ------------

   function C_Recv

     (S     : C.int;

      Msg   : System.Address;

      Len   : C.int;

      Flags : C.int) return C.int

   is

      Res : C.int;

   begin

      loop

         Res := Syscall_Recv (S, Msg, Len, Flags);

         exit when SOSC.Thread_Blocking_IO

           or else Res /= Failure

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      return Res;

   end C_Recv;

   ----------------

   -- C_Recvfrom --

   ----------------

   function C_Recvfrom

     (S       : C.int;

      Msg     : System.Address;

      Len     : C.int;

      Flags   : C.int;

      From    : System.Address;

      Fromlen : not null access C.int) return C.int

   is

      Res : C.int;

   begin

      loop

         Res := Syscall_Recvfrom (S, Msg, Len, Flags, From, Fromlen);

         exit when SOSC.Thread_Blocking_IO

           or else Res /= Failure

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      return Res;

   end C_Recvfrom;

   ---------------

   -- C_Recvmsg --

   ---------------

   function C_Recvmsg

     (S     : C.int;

      Msg   : System.Address;

      Flags : C.int) return ssize_t

   is

      Res : ssize_t;

   begin

      loop

         Res := Syscall_Recvmsg (S, Msg, Flags);

         exit when SOSC.Thread_Blocking_IO

           or else Res /= ssize_t (Failure)

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      return Res;

   end C_Recvmsg;

   ---------------

   -- C_Sendmsg --

   ---------------

   function C_Sendmsg

     (S     : C.int;

      Msg   : System.Address;

      Flags : C.int) return ssize_t

   is

      Res : ssize_t;

   begin

      loop

         Res := Syscall_Sendmsg (S, Msg, Flags);

         exit when SOSC.Thread_Blocking_IO

           or else Res /= ssize_t (Failure)

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      return Res;

   end C_Sendmsg;

   --------------

   -- C_Sendto --

   --------------

   function C_Sendto

     (S     : C.int;

      Msg   : System.Address;

      Len   : C.int;

      Flags : C.int;

      To    : System.Address;

      Tolen : C.int) return C.int

   is

      Res : C.int;

   begin

      loop

         Res := Syscall_Sendto (S, Msg, Len, Flags, To, Tolen);

         exit when SOSC.Thread_Blocking_IO

           or else Res /= Failure

           or else Non_Blocking_Socket (S)

           or else Errno /= SOSC.EWOULDBLOCK;

         delay Quantum;

      end loop;

      return Res;

   end C_Sendto;

   --------------

   -- C_Socket --

   --------------

   function C_Socket

     (Domain   : C.int;

      Typ      : C.int;

      Protocol : C.int) return C.int

   is

      R   : C.int;

      Val : aliased C.int := 1;

      Discard : C.int;

      pragma Unreferenced (Discard);

   begin

      R := Syscall_Socket (Domain, Typ, Protocol);

      if not SOSC.Thread_Blocking_IO

        and then R /= Failure

      then

         --  Do not use Socket_Ioctl as this subprogram tracks sockets set

         --  in non-blocking mode by user.

         Discard := C_Ioctl (R, SOSC.FIONBIO, Val'Access);

         Set_Non_Blocking_Socket (R, False);

      end if;

      Disable_SIGPIPE (R);

      return R;

   end C_Socket;

   --------------

   -- Finalize --

   --------------

   procedure Finalize is

   begin

      null;

   end Finalize;

   -------------------------

   -- Host_Error_Messages --

   -------------------------

   package body Host_Error_Messages is separate;

   ----------------

   -- Initialize --

   ----------------

   procedure Initialize is

   begin

      Disable_All_SIGPIPEs;

      Reset_Socket_Set (Non_Blocking_Sockets'Access);

   end Initialize;

   -------------------------

   -- Non_Blocking_Socket --

   -------------------------

   function Non_Blocking_Socket (S : C.int) return Boolean is

      R : Boolean;

   begin

      Task_Lock.Lock;

      R := (Is_Socket_In_Set (Non_Blocking_Sockets'Access, S) /= 0);

      Task_Lock.Unlock;

      return R;

   end Non_Blocking_Socket;

   -----------------------------

   -- Set_Non_Blocking_Socket --

   -----------------------------

   procedure Set_Non_Blocking_Socket (S : C.int; V : Boolean) is

   begin

      Task_Lock.Lock;

      if V then

         Insert_Socket_In_Set (Non_Blocking_Sockets'Access, S);

      else

         Remove_Socket_From_Set (Non_Blocking_Sockets'Access, S);

      end if;

      Task_Lock.Unlock;

   end Set_Non_Blocking_Socket;

   --------------------

   -- Signalling_Fds --

   --------------------

   package body Signalling_Fds is

      --  In this default implementation, we use a C version of these

      --  subprograms provided by socket.c.

      function C_Create (Fds : not null access Fd_Pair) return C.int;

      function C_Read (Rsig : C.int) return C.int;

      function C_Write (Wsig : C.int) return C.int;

      procedure C_Close (Sig : C.int);

      pragma Import (C, C_Create, "__gnat_create_signalling_fds");

      pragma Import (C, C_Read,   "__gnat_read_signalling_fd");

      pragma Import (C, C_Write,  "__gnat_write_signalling_fd");

      pragma Import (C, C_Close,  "__gnat_close_signalling_fd");

      function Create

        (Fds : not null access Fd_Pair) return C.int renames C_Create;

      function Read (Rsig : C.int) return C.int renames C_Read;

      function Write (Wsig : C.int) return C.int renames C_Write;

      procedure Close (Sig : C.int) renames C_Close;

   end Signalling_Fds;

   --------------------------

   -- Socket_Error_Message --

   --------------------------

   function Socket_Error_Message

     (Errno : Integer) return C.Strings.chars_ptr

   is separate;

end GNAT.Sockets.Thin;