File : src/aws-net-sets.ads


------------------------------------------------------------------------------
--                              Ada Web Server                              --
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--                            Copyright (C) 2004                            --
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--  Authors: Dmitriy Anisimkov - Pascal Obry                                --
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--  $Id: aws-net-sets.ads,v 1.3 2004/03/02 15:51:46 obry Exp $

--  Waiting on group of sockets for input/output availability.

with Ada.Finalization;

package AWS.Net.Sets is

   type Socket_Set_Type is limited private;

   type Socket_State is (None, Error, Input, Output, Both);
   --  None    no socket currently selected
   --  Error   selected socket is in error state
   --  Input   selected socket ready for input
   --  Output  selected socket ready for output
   --  Both    selected socket ready for input/output

   subtype Waiting_Mode is Socket_State range Input .. Both;

   procedure Add
     (Set    : in out Socket_Set_Type;
      Socket : in     Socket_Type'Class;
      Mode   : in     Waiting_Mode);
   --  Add socket to the set. Sockets can be retreived from the set using
   --  Get_Sockets.

   procedure Add
     (Set    : in out Socket_Set_Type;
      Socket : in     Socket_Access;
      Mode   : in     Waiting_Mode);
   --  Add socket to the set

   function Count (Set : Socket_Set_Type) return Natural;
   --  Returns the number of sockets in the Set

   procedure Wait
     (Set     : in out Socket_Set_Type;
      Timeout : in     Duration);
   --  Wait for a socket in the set to be ready for input or output operation.
   --  Raises Socket_Error if an error occurs. It selects the first socket
   --  Ready for input/output. This socket can be retreived with Get_Socket
   --  below.

   function Get_Socket_State (Set : in Socket_Set_Type) return Socket_State;
   --  Return the state of the currently selected socket ready for
   --  input/output or None if there is no more sockets available for
   --  input/output.

   function Get_Socket (Set : in Socket_Set_Type) return Socket_Type'Class;
   --  Return currently selected ready for input/output socket

   procedure Remove_Socket (Set : in out Socket_Set_Type);
   --  Delete currently selected socket from set and select the next one.
   --  Raises Constraint_Error if there is no selected socket, if
   --  Get_Socket_State returns None for example.

   procedure Next (Set : in out Socket_Set_Type);
   --  Go to the next active socket in the set. Set current state to None if
   --  there is no active socket available.

   procedure Reset (Set : in out Socket_Set_Type);
   --  Clear the set for another use

private

   type Poll_Set_Type;

   type Poll_Set_Access is access all Poll_Set_Type;

   type Socket_Record is record
      Socket    : Socket_Access;

      Allocated : Boolean;
      --  Set to True if socket was allocated internally in the set (it is the
      --  case when using the Add with Socket_Type'Class parameter).
      --  Needed to control free on delete.
   end record;

   type Socket_Array is array (Positive range <>) of Socket_Record;

   type Socket_Array_Access is access all Socket_Array;

   type Socket_Set_Type is new Ada.Finalization.Limited_Controlled with record
      Poll    : Poll_Set_Access;
      Set     : Socket_Array_Access;
      Last    : Natural  := 0;
      Current : Positive := 1;
   end record;

   procedure Finalize (Set : in out Socket_Set_Type);

end AWS.Net.Sets;