------------------------------------------------------------------------------
--                                                                          --
--                           POLYORB COMPONENTS                             --
--                                                                          --
--                          P O L Y O R B . O R B                           --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--         Copyright (C) 2001-2012, Free Software Foundation, Inc.          --
--                                                                          --
-- This 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 3,  or (at your option) any later ver- --
-- sion.  This software is distributed in the hope  that it will be useful, --
-- but WITHOUT ANY WARRANTY;  without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public --
-- License for  more details.                                               --
--                                                                          --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception,   --
-- version 3.1, as published by the Free Software Foundation.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
--                  PolyORB is maintained by AdaCore                        --
--                     (email: sales@adacore.com)                           --
--                                                                          --
------------------------------------------------------------------------------

pragma Ada_2005;

--  The ORB core module

with Ada.Exceptions;
with Ada.Finalization;
with Ada.Tags;

with PolyORB.Any.Initialization;
with PolyORB.Binding_Data.Local;
with PolyORB.Binding_Object_QoS;
with PolyORB.Errors;
with PolyORB.Filters.Iface;
with PolyORB.Initialization;
with PolyORB.Log;
with PolyORB.ORB.Iface;
with PolyORB.Parameters.Initialization;
with PolyORB.References.Binding;
with PolyORB.Request_QoS;
with PolyORB.Servants.Iface;
with PolyORB.Setup;
with PolyORB.Smart_Pointers.Initialization;
with PolyORB.Tasking.Threads;
with PolyORB.Transport.Handlers;
with PolyORB.Utils.Strings;

--  Units included in closure for module registration purposes only

pragma Warnings (Off, PolyORB.Any.Initialization);
pragma Warnings (Off, PolyORB.Parameters.Initialization);
pragma Warnings (Off, PolyORB.Smart_Pointers.Initialization);

package body PolyORB.ORB is

   use PolyORB.Annotations;
   use PolyORB.Asynch_Ev;
   use PolyORB.Binding_Data;
   use PolyORB.Binding_Objects;
   use PolyORB.Components;
   use PolyORB.Filters;
   use PolyORB.Jobs;
   use PolyORB.Log;
   use PolyORB.ORB_Controller;
   use PolyORB.References;
   use PolyORB.Requests;
   use PolyORB.Tasking.Threads;
   use PolyORB.Transport;
   use PolyORB.Transport.Handlers;
   use Unsigned_Long_Flags;

   package L is new PolyORB.Log.Facility_Log ("polyorb.orb");
   procedure O (Message : String; Level : Log_Level := Debug)
     renames L.Output;
   function C (Level : Log_Level := Debug) return Boolean
     renames L.Enabled;

   ----------------------------------------------
   -- Management of asynchronous event sources --
   ----------------------------------------------

   procedure Insert_Source
     (ORB : access ORB_Type;
      AES : PolyORB.Asynch_Ev.Asynch_Ev_Source_Access);
   --  Insert AES in the set of asynchronous event sources monitored by ORB.
   --  The caller must not hold the ORB lock.

   procedure Delete_Source
     (ORB : access ORB_Type;
      AES : in out Asynch_Ev_Source_Access);
   --  Delete AES from the set of asynchronous event sources monitored by ORB.
   --  AES is destroyed. The caller must not hold the ORB lock.

   --------------------------------------------
   -- Annotations used by the ORB internally --
   --------------------------------------------

   --  Transport access point note

   type TAP_Note is new Note with record
      Profile_Factory : Binding_Data.Profile_Factory_Access;
      AES             : Asynch_Ev.Asynch_Ev_Source_Access;
   end record;

   --  Transport endpoint note

   type TE_Note is new Note with record
      AES : Asynch_Ev.Asynch_Ev_Source_Access;
   end record;

   ---------------------------
   -- ORB object operations --
   ---------------------------

   procedure Perform_Work
     (ORB       : access ORB_Type;
      This_Task : in out PTI.Task_Info);
   pragma Inline (Perform_Work);
   --  Perform one item of work assigned to This_Task
   --  Precondition:  Must be called from within ORB critical section.
   --  Postcondition: On exit, ORB critical section has been reasserted.
   --  Note: tasks running this function may exit ORB critical section
   --  temporarily.

   ------------
   -- Create --
   ------------

   procedure Create (ORB : in out ORB_Type) is
      pragma Unreferenced (ORB);

   begin
      --  Note: this function will be completed when implementing support for
      --  multiple ORB instances, as mandated by the CORBA personality.

      null;
   end Create;

   ----------------------------------
   -- Find_Reusable_Binding_Object --
   ----------------------------------

   function Find_Reusable_Binding_Object
     (ORB : access ORB_Type;
      Pro : Binding_Data.Profile_Access;
      QoS : PolyORB.QoS.QoS_Parameters) return Smart_Pointers.Ref
   is
      use PBOL;

      function Is_Reusable (BO_Acc : Binding_Object_Access) return Boolean;
      --  True if this BO can be reused to contact the given profile with
      --  the given QoS.

      -----------------
      -- Is_Reusable --
      -----------------

      function Is_Reusable (BO_Acc : Binding_Object_Access) return Boolean is
      begin
         if Get_Profile (BO_Acc) /= null then

            --  Until bidirectionnal BO are implemented we cannot reuse the
            --  server BOs as client BOs and inversely. So for the moment,
            --  server BOs have a null profile and are not handled here. This
            --  check shall be removed once bidirectional BO are implemented.

            return Same_Node (Pro.all, Get_Profile (BO_Acc).all)
                     and then
                   PolyORB.Binding_Object_QoS.Is_Compatible (BO_Acc, QoS);
         else
            return False;
         end if;
      end Is_Reusable;

      use BO_Ref_Lists;

      Reusable_BOs : BO_Ref_List;
      Result : Smart_Pointers.Ref;

   --  Start of processing for Find_Reusable_Binding_Object

   begin
      pragma Debug (C, O ("Find_Reusable_Binding_Object: enter"));
      pragma Debug (C, O ("#BO registered = "
        & Natural'Image (Length (ORB.Binding_Objects))));

      Reusable_BOs := Get_Binding_Objects (ORB, Is_Reusable'Access);

      if not Is_Empty (Reusable_BOs) then
         Extract_First (Reusable_BOs, Result);

         --  Get_Binding_Objects with a non-null predicate is expected to
         --  return at most one object.

         pragma Assert (Is_Empty (Reusable_BOs));
      end if;

      pragma Debug (C, O ("Find_Reusable_Binding_Object: leave"));

      --  If no reusable Binding Object has been found, Result is a nil Ref

      return Result;
   end Find_Reusable_Binding_Object;

   ------------------
   -- Perform_Work --
   ------------------

   procedure Perform_Work (ORB : access ORB_Type) is
      Job : Job_Access;
   begin
      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      Job := Get_Pending_Job (ORB.ORB_Controller);
      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      if Job /= null then
         Run (Job);
      end if;
   end Perform_Work;

   procedure Perform_Work
     (ORB       : access ORB_Type;
      This_Task : in out Task_Info.Task_Info)
   is
      use PolyORB.Task_Info;

   begin
      pragma Debug (C, O ("Perform_Work: enter " & Image (This_Task)));

      pragma Assert (Task_Info.Job (This_Task) /= null);

      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      pragma Debug (C, O ("Perform_Work: " & Image (This_Task)
                       & " working on job "
                       & Ada.Tags.External_Tag
                       (Task_Info.Job (This_Task)'Tag)));

      Run (Task_Info.Job (This_Task));

      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      pragma Debug (C, O ("Perform_Work: leave " & Image (This_Task)));

      Notify_Event (ORB.ORB_Controller, Event'(Kind => Job_Completed));
   end Perform_Work;

   -----------------------
   -- Try_Check_Sources --
   -----------------------

   procedure Try_Check_Sources
     (ORB       : access ORB_Type;
      This_Task : in out Task_Info.Task_Info);
   pragma Inline (Try_Check_Sources);
   --  Check ORB's AES attached to A_Monitor for any incoming event.
   --  Precondition:  Must be called from within ORB critical section.
   --  Postcondition: On exit, ORB critical section has been reasserted.
   --  Note: tasks running this function may exit ORB critical section
   --  temporarily.

   procedure Try_Check_Sources
     (ORB       : access ORB_Type;
      This_Task : in out Task_Info.Task_Info)
   is
      use PolyORB.Task_Info;

   begin
      --  Inside the ORB critical section

      pragma Debug (C, O ("Try_Check_Sources: task "
                       & Image (This_Task)
                       & " about to Check_Sources."));

      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      declare
         Events : constant AES_Array :=
           Check_Sources (Selector (This_Task), Task_Info.Timeout (This_Task));
         --  This_Task will block on this action until an event occurs on a
         --  source monitored by A_Monitor, or Abort_Check_Sources is called
         --  on A_Monitor.

      begin

         --  Reenter critical section to update ORB state

         Enter_ORB_Critical_Section (ORB.ORB_Controller);

         pragma Debug (C, O ("Try_Check_Sources: task "
                          & Image (This_Task)
                          & " returned from Check_Sources with"
                          & Integer'Image (Events'Length)
                          & " event(s)."));

         --  Queue events, if any

         for J in Events'Range loop
            Notify_Event
              (ORB.ORB_Controller,
               Event'(Kind      => Queue_Event_Job,
                      Event_Job => Job_Access (Handler (Events (J).all)),
                      By_Task   => Id (This_Task)));
         end loop;

         --  Notify ORB controller of completion

         Notify_Event (ORB.ORB_Controller,
                       Event'(Kind       => End_Of_Check_Sources,
                              On_Monitor => Selector (This_Task)));

         --  Inside ORB critical section

      end;
   end Try_Check_Sources;

   ---------
   -- Run --
   ---------

   --  Controlled type Task_Witness implements the Scope Lock idiom to handle
   --  exceptions and asynchronous abort while we are executing the ORB main
   --  loop.

   type Task_Witness
     (This           : access Task_Info.Task_Info;
      ORB_Controller : access POC.ORB_Controller'Class;
      TI_Reference   : access PTI.Task_Info_Access;
      Req            : access Requests.Request)
     is new Ada.Finalization.Limited_Controlled with
   record
      Normal_Exit : Boolean := False;
      --  Set True when exiting through normal completion of the protected
      --  block (as opposed to abort or exception).
   end record;

   overriding procedure Initialize (TW : in out Task_Witness);
   --  Register TW.This with OC

   overriding procedure Finalize (TW : in out Task_Witness);
   --  Unregister TW.This from OC

   ----------------
   -- Initialize --
   ----------------

   overriding procedure Initialize (TW : in out Task_Witness) is
   begin
      pragma Debug
        (O ("Initializing task witness for " & PTI.Image (TW.This.all)));
      Enter_ORB_Critical_Section (TW.ORB_Controller);

      if TW.TI_Reference /= null then
         --  This pointer must be reset to null before exiting Run so as to
         --  not leave a dangling reference.

         TW.TI_Reference.all := TW.This.all'Unchecked_Access;
      end if;

      Register_Task (TW.ORB_Controller, TW.This.all'Unchecked_Access);
   end Initialize;

   --------------
   -- Finalize --
   --------------

   overriding procedure Finalize (TW : in out Task_Witness) is
   begin
      pragma Debug
        (O ("Finalizing task witness for " & PTI.Image (TW.This.all)
            & ", Normal_Exit = " & TW.Normal_Exit'Img));

      --  Remove references to TW.This

      if TW.TI_Reference /= null then
         TW.TI_Reference.all := null;
      end if;

      if not TW.Normal_Exit then
         --  Reassert critical section to remove current task from ORB
         --  controller if terminating because of abort or exception.

         Enter_ORB_Critical_Section (TW.ORB_Controller);

         if TW.Req /= null and then TW.Req.Surrogate /= null then

            --  Notify surrogate that request was aborted

            Emit_No_Reply
              (TW.Req.Surrogate,
               Servants.Iface.Abort_Request'
                 (Req => TW.Req.all'Unchecked_Access));
         end if;

         Terminate_Task (TW.ORB_Controller, TW.This.all'Unchecked_Access);
      end if;

      Unregister_Task (TW.ORB_Controller, TW.This.all'Unchecked_Access);
      Leave_ORB_Critical_Section (TW.ORB_Controller);
   end Finalize;

   --  An ORB task is Permanent if its Request is null (case True), Transient
   --  if it is not.

   --  This is the main loop for all general-purpose ORB tasks. This subprogram
   --  must not be called recursively. Exceptions must not be propagated from
   --  within ORB critical section.

   procedure Run
     (ORB      : access ORB_Type;
      Request  : Requests.Request_Access := null;
      May_Exit : Boolean)
   is
      use PTI;

      Task_Kinds : constant array (Boolean) of Task_Kind :=
        (False => Transient, True => Permanent);
      This_Task  : aliased PTI.Task_Info (Task_Kinds (Request = null));
      TI_Ref     : access Task_Info_Access := null;
   begin
      pragma Assert (This_Task.Kind = Permanent or else May_Exit);
      --  May_Exit is expected to always be True for transient tasks

      --  Set up task information for This_Task

      Set_Id (This_Task);
      if Request /= null then
         Set_Exit_Condition (This_Task, Request.Completed'Access);
         TI_Ref := Request.Requesting_Task'Access;
      else
         Set_Exit_Condition (This_Task, null);
      end if;
      Set_May_Exit (This_Task, May_Exit);

      --  Enter critical section (scope lock using Witness)

      declare
         Witness : Task_Witness
                     (This           => This_Task'Unchecked_Access,
                      ORB_Controller => ORB.ORB_Controller,
                      TI_Reference   => TI_Ref,
                      Req            => Request);
         pragma Unreferenced (Witness);
      begin
         --  ORB Main loop

         Main_Loop :
         loop
            Schedule_Task (ORB.ORB_Controller, This_Task'Unchecked_Access);

            case State (This_Task) is
               when Running =>

                  --  This task will process one job

                  Perform_Work (ORB, This_Task);

               when Blocked =>

                  --  This task will block on event sources, waiting for events

                  Try_Check_Sources (ORB, This_Task);

               when Idle =>

                  --  This task is going idle. We are still inside the ORB
                  --  critical section at this point. The tasking policy will
                  --  release it while we are idle, and re-assert it before
                  --  returning.

                  Idle
                    (ORB.Tasking_Policy,
                     This_Task'Unchecked_Access,
                     ORB_Access (ORB));

                  --  Note: tasking policy may have decided to terminate this
                  --  task, in which case the ORB controller has already been
                  --  notified.

                  if State (This_Task) /= Terminated then
                     Notify_Event
                       (ORB.ORB_Controller,
                        Event'(Kind          => Idle_Awake,
                               Awakened_Task => This_Task'Unchecked_Access));
                  end if;

               when Terminated =>

                  --  This task has reached its exit condition: leave main loop

                  exit Main_Loop;

               when Unscheduled =>

                  --  This task is still unscheduled, this should not happen!

                  raise Program_Error;

            end case;

            --  Condition at end of loop: inside the ORB critical section

         end loop Main_Loop;

         Witness.Normal_Exit := True;

         --  Upon exiting this block, Witness is finalized, causing This_Task
         --  to be unregistered from the ORB controller.
      end;

      pragma Debug (C, O ("Run: leave."));

   exception
      when E : others =>
         O ("ORB.Run got exception:", Error);
         O (Ada.Exceptions.Exception_Information (E), Error);
         raise;
   end Run;

   ------------------
   -- Work_Pending --
   ------------------

   function Work_Pending (ORB : access ORB_Type) return Boolean is
      Result : Boolean;
   begin
      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      Result := Has_Pending_Job (ORB.ORB_Controller);
      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      return Result;
   end Work_Pending;

   --------------
   -- Shutdown --
   --------------

   procedure Shutdown
     (ORB                 : access ORB_Type;
      Wait_For_Completion : Boolean := True)
   is
   begin
      pragma Debug (C, O ("Shutdown: enter"));

      if ORB = null then
         raise Program_Error with "ORB not initialized";
      end if;

      --  Stop accepting incoming connections

      --  XXX TBD

      --  Shutdown the ORB

      Enter_ORB_Critical_Section (ORB.ORB_Controller);

      Notify_Event (ORB.ORB_Controller, Event'(Kind => ORB_Shutdown));

      --  Wait for completion of pending requests, if required

      if Wait_For_Completion then
         ORB_Controller.Wait_For_Completion (ORB.ORB_Controller);
      end if;

      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      pragma Debug (C, O ("Shutdown: leave"));
   end Shutdown;

   ------------------------
   -- Profile_Factory_Of --
   ------------------------

   function Profile_Factory_Of
     (TAP : Transport.Transport_Access_Point_Access)
     return Binding_Data.Profile_Factory_Access;
   pragma Inline (Profile_Factory_Of);

   function Profile_Factory_Of
     (TAP : Transport.Transport_Access_Point_Access)
     return Binding_Data.Profile_Factory_Access
   is
      N : TAP_Note;
   begin
      Get_Note (Notepad_Of (TAP).all, N);
      return N.Profile_Factory;
   end Profile_Factory_Of;

   ---------------------------
   -- Register_Access_Point --
   ---------------------------

   procedure Register_Access_Point
     (ORB   : access ORB_Type;
      TAP   : PT.Transport_Access_Point_Access;
      Chain : PF.Factories_Access;
      PF    : PBD.Profile_Factory_Access)
   is
      New_AES : constant Asynch_Ev_Source_Access := Create_Event_Source (TAP);
   begin
      pragma Debug (C, O ("Register_Access_Point: enter"));

      --  Set link from AES to TAP, Chain and PF

      declare
         H     : constant access AES_Event_Handler'Class :=
           Handler (New_AES.all);
         TAP_H : TAP_AES_Event_Handler renames TAP_AES_Event_Handler (H.all);
      begin
         H.AES                      := New_AES;
         TAP_H.ORB                  := ORB_Access (ORB);
         TAP_H.TAP                  := TAP;
         TAP_H.Filter_Factory_Chain := Chain;
         TAP_H.Profile_Factory      := PF;
      end;

      --  Set link from TAP to PF, and from TAP to AES

      Set_Note (Notepad_Of (TAP).all,
                TAP_Note'(Note with Profile_Factory => PF, AES => New_AES));

      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      pragma Debug (C, O ("Inserting new source: Access Point"));
      TAP_Lists.Append (ORB.Transport_Access_Points, TAP);
      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      Insert_Source (ORB, New_AES);

      pragma Debug (C, O ("Register_Access_Point: leave"));
   end Register_Access_Point;

   ----------------------
   -- Is_Profile_Local --
   ----------------------

   function Is_Profile_Local
     (ORB : access ORB_Type;
      P   : access Binding_Data.Profile_Type'Class) return Boolean
   is
   begin
      if Binding_Data.Is_Local_Profile (P.all) then
         return True;
      end if;

      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      declare
         use TAP_Lists;
         It     : Iterator := First (ORB.Transport_Access_Points);
         PF     : Profile_Factory_Access;
         Result : Boolean := False;

      begin
         All_Access_Points :
         while not Last (It) loop
            PF := Profile_Factory_Of (Value (It).all);

            if PF /= null then
               if Binding_Data.Is_Local_Profile (PF, P) then
                  Result := True;
                  exit All_Access_Points;
               end if;
            end if;

            Next (It);
         end loop All_Access_Points;
         Leave_ORB_Critical_Section (ORB.ORB_Controller);

         return Result;
      end;
   end Is_Profile_Local;

   -----------------------------
   -- Register_Binding_Object --
   -----------------------------

   procedure Register_Binding_Object
     (ORB  : access ORB_Type;
      BO   : Smart_Pointers.Ref;
      Role : Endpoint_Role)
   is
      TE         : constant Transport.Transport_Endpoint_Access :=
        Binding_Objects.Get_Endpoint (BO);
      New_AES    : constant Asynch_Ev_Source_Access :=
        Create_Event_Source (TE);
      --  New_AES is null for output-only endpoints

      ORB_Acc : constant ORB_Access := ORB_Access (ORB);
      BO_Acc  : constant Binding_Object_Access :=
        Binding_Object_Access (Smart_Pointers.Entity_Of (BO));
   begin
      pragma Debug
        (C, O ("Register_Binding_Object (" & Role'Img & "): enter"));

      --  Set ORB access in all protocol stack components

      Emit_No_Reply
        (Component_Access (TE),
         Filters.Iface.Set_Server'
           (Server         => Component_Access (ORB),
            Binding_Object => BO_Acc));

      if New_AES /= null then
         --  This is not a write only Endpoint

         declare
            H    : constant access AES_Event_Handler'Class :=
              Handler (New_AES.all);
            TE_H : TE_AES_Event_Handler renames TE_AES_Event_Handler (H.all);
         begin
            --  Register link from AES to TE

            H.AES    := New_AES;
            TE_H.ORB := ORB_Access (ORB);
            TE_H.TE  := TE;
         end;
      end if;

      --  Register link from TE to AES

      Set_Note
        (Notepad_Of (TE).all, TE_Note'(Annotations.Note with AES => New_AES));

      --  Assign execution resources to the newly-created connection

      case Role is
         when Server =>
            Handle_New_Server_Connection
              (ORB_Acc.Tasking_Policy,
               ORB_Acc,
               Active_Connection'(AES => New_AES, TE => TE));

         when Client =>
            Handle_New_Client_Connection
              (ORB_Acc.Tasking_Policy,
               ORB_Acc,
               Active_Connection'(AES => New_AES, TE => TE));
      end case;

      --  Finally register BO in the Binding_Objects list of ORB

      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      PBOL.Prepend (ORB.Binding_Objects, BO_Acc);
      Set_Referenced (BO_Acc, Referenced => True);
      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      --  From this point on, the BO must be fully initialized, as another
      --  task may reuse it through Find_Reusable_Binding_Object.

      pragma Debug (C, O ("Register_Binding_Object: leave"));
   end Register_Binding_Object;

   -------------------------------
   -- Unregister_Binding_Object --
   -------------------------------

   procedure Unregister_Binding_Object
     (ORB : access ORB_Type;
      BO  : Binding_Object_Access)
   is
      ORB_Acc : constant ORB_Access := ORB_Access (ORB);
   begin
      pragma Debug (C, O ("Unregister_Binding_Object: enter"));
      Enter_ORB_Critical_Section (ORB_Acc.ORB_Controller);

      --  If BO is still referenced, remove it now

      if Referenced (BO) then
         pragma Debug (C, O ("removing binding object"));
         Set_Referenced (BO, Referenced => False);
         PBOL.Remove_Element (ORB_Acc.Binding_Objects, BO);
      end if;

      Leave_ORB_Critical_Section (ORB_Acc.ORB_Controller);
      pragma Debug (C, O ("Unregister_Binding_Object: leave"));
   end Unregister_Binding_Object;

   ------------------------
   -- Set_Object_Adapter --
   ------------------------

   procedure Set_Object_Adapter
     (ORB : access ORB_Type;
      OA  : Obj_Adapters.Obj_Adapter_Access)
   is
      use type Obj_Adapters.Obj_Adapter_Access;

   begin
      Enter_ORB_Critical_Section (ORB.ORB_Controller);
      pragma Assert (ORB.Obj_Adapter = null);
      ORB.Obj_Adapter := OA;
      Leave_ORB_Critical_Section (ORB.ORB_Controller);
   end Set_Object_Adapter;

   --------------------
   -- Object_Adapter --
   --------------------

   function Object_Adapter (ORB : access ORB_Type)
     return Obj_Adapters.Obj_Adapter_Access is
   begin
      --  Per construction, ORB.Obj_Adapter is a read-only component.
      --  No critical section is required.

      return ORB.Obj_Adapter;
   end Object_Adapter;

   -------------------
   -- Insert_Source --
   -------------------

   procedure Insert_Source
     (ORB : access ORB_Type;
      AES : Asynch_Ev_Source_Access)
   is
   begin
      Enter_ORB_Critical_Section (ORB.ORB_Controller);

      pragma Debug (C, O ("Insert_Source: enter"));
      pragma Debug
        (C, O ("Source type: " & Ada.Tags.External_Tag (AES.all'Tag)));

      pragma Assert (AES /= null);

      declare
         Monitors : constant Monitor_Array :=
           Get_Monitors (ORB.ORB_Controller);
         AEM      : Asynch_Ev_Monitor_Access;
         RSR      : Register_Source_Result := Unknown_Source_Type;
      begin
         for J in Monitors'Range loop

            --  Try to register the source to an existing monitor

            AEM := Monitors (J);

            Disable_Polling (ORB.ORB_Controller, AEM);
            RSR := Register_Source (Monitors (J), AES);

            if RSR = Unknown_Source_Type then
               Enable_Polling (ORB.ORB_Controller, AEM);
            else
               exit;
            end if;
         end loop;

         if RSR = Unknown_Source_Type then

            --  Create a new monitor and register the source

            pragma Debug (C, O ("Creating new monitor"));

            AEM := AEM_Factory_Of (AES.all).all;

            pragma Debug (C, O ("AEM: "
                          & Ada.Tags.External_Tag (AEM.all'Tag)));
            Create (AEM.all);

            --  In this situation, no task can be polling this monitor yet,
            --  so no need to disable polling.

            RSR := Register_Source (AEM, AES);
         end if;

         pragma Assert (RSR /= Unknown_Source_Type);

         if RSR = Success then
            Notify_Event (ORB.ORB_Controller,
                          Event'(Kind           => Event_Sources_Added,
                                 Add_In_Monitor => AEM));

         else
            pragma Debug (C, O ("Insert_Source: failed to register source"));
            null;
         end if;

         Enable_Polling (ORB.ORB_Controller, AEM);
      end;

      pragma Debug (C, O ("Insert_Source: leave"));

      Leave_ORB_Critical_Section (ORB.ORB_Controller);
   end Insert_Source;

   -------------------
   -- Delete_Source --
   -------------------

   procedure Delete_Source
     (ORB : access ORB_Type;
      AES : in out Asynch_Ev_Source_Access)
   is
      Success : Boolean;
      Monitor : constant Asynch_Ev_Monitor_Access := AEM_Of (AES.all);
   begin

      Enter_ORB_Critical_Section (ORB.ORB_Controller);

      pragma Debug (C, O ("Delete_Source: enter"));

      --  Disable polling to enable safe modification of AES list

      Disable_Polling (ORB.ORB_Controller, Monitor);

      --  Remove source

      Unregister_Source (Monitor.all, AES, Success);

      if Success then
         Notify_Event
           (ORB.ORB_Controller, Event'(Kind => Event_Sources_Deleted));
      end if;

      --  Modification completed, enable polling

      Enable_Polling (ORB.ORB_Controller, Monitor);

      Leave_ORB_Critical_Section (ORB.ORB_Controller);

      --  Actually destroy AES

      Destroy (AES);

      pragma Debug (C, O ("Delete_Source: leave"));
   end Delete_Source;

   ----------------------------------
   -- Job type for object requests --
   ----------------------------------

   ---------
   -- Run --
   ---------

   overriding procedure Run (J : not null access Request_Job) is
      AJ : Job_Access := Job_Access (J);
   begin
      Run_Request (J.ORB, J.Request);
      Free (AJ);
   exception
      when E : others =>
         pragma Debug (C, O ("Run: Got exception "
                          & Ada.Exceptions.Exception_Information (E)));
         Free (AJ);
         raise;
   end Run;

   -----------------
   -- Run_Request --
   -----------------

   procedure Run_Request (ORB : access ORB_Type; Req : Request_Access) is
   begin
      pragma Debug (C, O ("Run Request_Job: enter"));
      pragma Assert (Req /= null);

      declare
         use type Task_Info.Task_Info_Access;
      begin
         pragma Debug (C, O ("Task " & Image (Current_Task)
                          & " executing: "
                          & Requests.Image (Req.all)));

         if Req.Requesting_Task /= null then
            pragma Debug
              (C, O ("... requested by "
                  & PTI.Image (Req.Requesting_Task.all)));
            null;
         end if;

         if Req.Completed then

            --  The request can be already marked as completed in the case
            --  where an error has been detected during immediate argument
            --  unmarshalling (case of a malformed SOAP argument
            --  representation, for example).

            pragma Debug (C, O ("Request completed due to early error"));

            Emit_No_Reply (Req.Requesting_Component,
                           Servants.Iface.Executed_Request'(Req => Req));
            return;

         elsif Is_Set (Sync_None, Req.Req_Flags) then

            --  At this point, the request has been queued, the Sync_None
            --  synchronisation policy has been completed.
            --  We bounce back the response to the requesting task.

            pragma Debug (C, O ("Sync_None completed"));

            Emit_No_Reply (Req.Requesting_Component,
                           Servants.Iface.Executed_Request'(Req => Req));

            Req.Completed := True;
         end if;

         --  Bind target reference to a servant if this is a local reference,
         --  or a surrogate if this is remote reference.

         declare
            use PolyORB.Errors;

            Error : Error_Container;
         begin
            References.Binding.Bind
              (Req.Target,
               ORB_Access (ORB),
               Request_QoS.Get_Request_QoS (Req.all),
               Req.Surrogate,
               Req.Profile,
               Local_Only => False,
               Error      => Error);
            --  Potential race condition, we may protect this call, TBD???

            if Found (Error) then
               pragma Debug (C, O ("Run_Request: Got an error when binding: "
                                & Error_Id'Image (Error.Kind)));

               --  Any error except ForwardLocation_E caught at this level
               --  implies a problem within the object adapter. We bounce the
               --  exception to the user for further processing.

               Set_Exception (Req.all, Error);
               Catch (Error);

               Emit_No_Reply (Req.Requesting_Component,
                              Servants.Iface.Executed_Request'(Req => Req));
               return;
            end if;
         end;

         --  At this point, the server has been contacted, a binding has been
         --  created, a servant manager has been reached. We are about to send
         --  the request to the target.

         if Is_Set (Sync_With_Server, Req.Req_Flags)
           and then Is_Profile_Local (ORB, Req.Profile)
         then
            --  We are on the server side, and use Sync_With_Server sync scope:
            --  we can send an Executed_Request message to the client prior to
            --  running the request.

            pragma Debug (C, O ("With_Server completed, sending"
                             & " Acknowledge_Request message"));

            Emit_No_Reply (Req.Requesting_Component,
                           Servants.Iface.Acknowledge_Request'(Req => Req));
         end if;

         --  Setup_Environment (Oid);
         --  XXX for 'Current' (applicative personality API for access
         --  to the oid of the current called instance, in the context
         --  of a servant handling multiple oids.)

         declare
            Result : constant Components.Message'Class :=
              Emit (Req.Surrogate,
                    Servants.Iface.Execute_Request'
                      (Req => Req, Pro => Req.Profile));
         begin
            --  Unsetup_Environment ();
            --  Unbind (J.Req.Target, J.ORB, Servant);
            --  XXX Unbind must Release_Servant.

            --  XXX Actually cannot unbind here: if the binding object is
            --    destroyed that early, we won't have the opportunity to
            --    receive a reply...
            pragma Debug (C, O ("Run_Request: got "
              & Ada.Tags.External_Tag (Result'Tag)));

            if Result in Null_Message then
               pragma Debug (C, O ("Run_Request: task " & Image (Current_Task)
                                 & " queued request for later processing"));
               null;

            else
               pragma Debug (C, O ("Run_Request: task " & Image (Current_Task)
                                 & " processed request"));
               begin
                  Emit_No_Reply (Req.Requesting_Component, Result);

                  --  XXX issue: if we are on the server side, and the
                  --  transport layer has detected a disconnection while we
                  --  were processing the request, the Requestor (Session)
                  --  object here could have become invalid. For now we hack
                  --  around this issue in an ugly fashion by catching all
                  --  exceptions.

               exception
                  when E : others =>
                     O ("Got exception sending Executed_Request:" & ASCII.LF
                        & Ada.Exceptions.Exception_Information (E), Error);
               end;
            end if;
         end;
      end;
   end Run_Request;

   ----------------------
   -- Create_Reference --
   ----------------------

   procedure Create_Reference
     (ORB : access ORB_Type;
      Oid : access Objects.Object_Id;
      Typ : String;
      Ref : out References.Ref)
   is
   begin
      pragma Debug (C, O ("Create_Reference: enter"));

      Enter_ORB_Critical_Section (ORB.ORB_Controller);

      declare
         use PolyORB.Binding_Data.Local;
         use TAP_Lists;

         It : Iterator := First (ORB.Transport_Access_Points);

         Profiles : References.Profile_Array
                      (1 .. Length (ORB.Transport_Access_Points) + 1);
         Last_Profile : Integer := Profiles'First - 1;
      begin
         while not Last (It) loop
            declare
               PF : constant Profile_Factory_Access :=
                 Profile_Factory_Of (Value (It).all);

            begin
               if PF /= null then

                  --  Null profile factories may occur for access points that
                  --  have an ad hoc protocol stack, but no binding data info.

                  declare
                     P : constant Profile_Access :=
                       Create_Profile (PF, Oid.all);
                  begin
                     if P /= null then
                        Last_Profile := Last_Profile + 1;
                        Profiles (Last_Profile) := P;
                     end if;
                  end;
               end if;
            end;
            Next (It);
         end loop;

         --  Add a local profile

         Last_Profile := Last_Profile + 1;
         Profiles (Last_Profile) := new Local_Profile_Type;
         Create_Local_Profile
           (Oid.all, Local_Profile_Type (Profiles (Last_Profile).all));

         Leave_ORB_Critical_Section (ORB.ORB_Controller);

         References.Create_Reference
           (Profiles (Profiles'First .. Last_Profile), Typ, Ref);
      end;
      pragma Debug (C, O ("Create_Reference: leave"));
   end Create_Reference;

   --------------------
   -- Handle_Message --
   --------------------

   overriding function Handle_Message
     (ORB : not null access ORB_Type;
      Msg : Components.Message'Class) return Components.Message'Class
   is
      use Servants.Iface;

      Nothing : Components.Null_Message;

   begin
      pragma Debug (C, O ("Handling message of type "
                       & Ada.Tags.External_Tag (Msg'Tag)));

      if Msg in Iface.Queue_Request then

         declare
            QR  : Iface.Queue_Request renames Iface.Queue_Request (Msg);
            Req : Requests.Request_Access renames QR.Request;
         begin
            pragma Debug (C, O ("Queue_Request: enter"));

            if QR.Requestor = null then

               --  If the request was queued directly by a client, then the
               --  ORB is responsible for setting its state to Completed upon
               --  reception of a reply.

               Req.Requesting_Component := Component_Access (ORB);
               Run_Request (ORB, Req);
            else
               Req.Requesting_Component := QR.Requestor;
               declare
                  J : constant Job_Access :=
                    new Request_Job'(Job with
                                     ORB       => ORB_Access (ORB),
                                     Request   => Req);
               begin
                  Handle_Request_Execution
                    (ORB.Tasking_Policy,
                     ORB_Access (ORB),
                     Request_Job (J.all)'Access);
               end;
            end if;
            pragma Debug (C, O ("Queue_Request: leave"));
         end;

      elsif Msg in Executed_Request then
         declare
            use PolyORB.Task_Info;

            Req : Requests.Request renames Executed_Request (Msg).Req.all;
         begin

            --  The processing of Executed_Request must be done in the ORB
            --  critical section, because it must not take place between the
            --  time an ORB task checks its exit condition and the moment the
            --  task goes idle.

            Enter_ORB_Critical_Section (ORB.ORB_Controller);

            Req.Completed := True;

            pragma Debug (C, O ("Request completed."));
            if Req.Requesting_Task /= null then

               --  Notify the requesting task

               pragma Debug
                 (C, O ("... requesting task is "
                     & Task_State'Image (State (Req.Requesting_Task.all))));

               Notify_Event (ORB.ORB_Controller,
                             Event'(Kind             => Request_Result_Ready,
                                    Requesting_Task  => Req.Requesting_Task));

            else

               --  The requesting task has already taken note of the completion
               --  of the request: nothing to do.

               null;
            end if;
            Leave_ORB_Critical_Section (ORB.ORB_Controller);
         end;

      elsif Msg in Iface.Monitor_Endpoint then
         declare
            TE : constant Transport_Endpoint_Access :=
              Iface.Monitor_Endpoint (Msg).TE;
            Note : TE_Note;
         begin
            Get_Note (Notepad_Of (TE).all, Note);

            --  Notes.AES is null for write only Endpoints; we only monitor
            --  read only and read/write Endpoints.

            if Note.AES /= null then
               pragma Debug (C, O ("Inserting source: Monitor_Endpoint"));
               Insert_Source (ORB, Note.AES);
            end if;
         end;

      elsif Msg in Iface.Monitor_Access_Point then
         declare
            TAP : constant Transport_Access_Point_Access :=
              Iface.Monitor_Access_Point (Msg).TAP;
            Note : TAP_Note;
         begin
            Get_Note (Notepad_Of (TAP).all, Note);

            pragma Debug (C, O ("Inserting source: Monitor_Access_Point"));
            Insert_Source (ORB, Note.AES);
         end;

      elsif Msg in Iface.Unregister_Endpoint then
         declare
            Note : TE_Note;
         begin
            Get_Note
              (Notepad_Of (Iface.Unregister_Endpoint (Msg).TE).all, Note);

            if Note.AES /= null then
               Delete_Source (ORB, Note.AES);
            end if;
         end;

      else
         pragma Debug
           (C, O ("ORB received unhandled message of type "
               & Ada.Tags.External_Tag (Msg'Tag)));
         raise Program_Error;
      end if;

      return Nothing;
   end Handle_Message;

   -------------------------
   -- Get_Binding_Objects --
   -------------------------

   function Get_Binding_Objects
     (ORB       : access ORB_Type;
      Predicate : access function
                           (BO_Acc : Binding_Object_Access) return Boolean
                    := null) return BO_Ref_List
   is
      use PBOL;
      use Smart_Pointers;

      It : PBOL.Iterator;
      Result : BO_Ref_List;
   begin
      Enter_ORB_Critical_Section (ORB.ORB_Controller);

      It := First (ORB.Binding_Objects);

      All_Binding_Objects :
      while not Last (It) loop
         declare
            BO_Acc : Binding_Object_Access renames Value (It);
            Ref    : Smart_Pointers.Ref;
         begin
            --  Note: the call to Valid here may cause a TE to be detected as
            --  invalid and unregistered from the ORB. The call to Unregister_
            --  Endpoint will enter the ORB critical section again.

            if not Valid (BO_Acc) then

               --  Mark binding object as not referenced anymore and purge.
               --  Note no "Next (It);" in this case, because Remove does that
               --  automatically.

               Set_Referenced (BO_Acc, Referenced => False);
               Remove (ORB.Binding_Objects, It);

            else
               if Predicate = null or else Predicate (BO_Acc) then
                  Smart_Pointers.Reuse_Entity (Ref, Entity_Ptr (Value (It)));

                  --  If binding object is being finalized, Reuse_Entity leaves
                  --  Ref unset.

                  if not Is_Nil (Ref) then
                     BO_Ref_Lists.Prepend (Result, Ref);
                  end if;

                  --  If Predicate is not null, return first matching BO only

                  exit All_Binding_Objects when Predicate /= null;
               end if;

               Next (It);
            end if;
         end;
      end loop All_Binding_Objects;

      Leave_ORB_Critical_Section (ORB.ORB_Controller);
      return Result;
   end Get_Binding_Objects;

   ----------------
   -- Notepad_Of --
   ----------------

   function Notepad_Of
     (ORB : access ORB_Type) return Annotations.Notepad_Access
   is
   begin
      return ORB.Notepad'Access;
   end Notepad_Of;

   ----------------
   -- Initialize --
   ----------------

   procedure Initialize;

   procedure Initialize is
      The_Controller : POC.ORB_Controller_Access;
   begin
      Create (The_Controller);
      Setup.The_ORB := new ORB_Type (Setup.The_Tasking_Policy, The_Controller);
      Create (Setup.The_ORB.all);
   end Initialize;

   ------------------------------
   -- Queue_Request_To_Handler --
   ------------------------------

   procedure Queue_Request_To_Handler
     (ORB : access ORB_Type;
      Msg : Message'Class)
   is
   begin
      pragma Assert (Msg in Iface.Queue_Request);
      Emit_No_Reply (Component_Access (ORB), Msg);
   end Queue_Request_To_Handler;

   ---------------------
   -- Shutdown Module --
   ---------------------

   procedure Shutdown_Module (Wait_For_Completion : Boolean);

   procedure Shutdown_Module (Wait_For_Completion : Boolean) is
   begin
      Shutdown (Setup.The_ORB, Wait_For_Completion);
   end Shutdown_Module;

   use PolyORB.Initialization;
   use PolyORB.Initialization.String_Lists;
   use PolyORB.Utils.Strings;

begin
   Register_Module
     (Module_Info'
      (Name      => +"orb",
       Conflicts => Empty,
       Depends   => +"orb.tasking_policy"
                   & "binding_data.soap?"
                   & "binding_data.srp?"
                   & "binding_data.iiop?"
                   & "orb_controller"
                   --  ??? should not have hard-coded dependencies
                   --  on specific protocols!
                   & "protocols.srp?"
                   & "protocols.giop?"
                   & "protocols.soap?"
                   & "smart_pointers"
                   & "tasking.threads",
       Provides => Empty,
       Implicit => False,
       Init     => Initialize'Access,
       Shutdown => Shutdown_Module'Access));
end PolyORB.ORB;
