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

--                                                                          --

--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --

--                                                                          --

--         S Y S T E M . T A S K I N G . I N I T I A L I Z A T I O N        --

--                                                                          --

--                                  B o d y                                 --

--                                                                          --

--         Copyright (C) 1992-2009, Free Software Foundation, Inc.          --

--                                                                          --

-- GNARL 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.  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.                                     --

--                                                                          --

-- 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/>.                                          --

--                                                                          --

-- GNARL was developed by the GNARL team at Florida State University.       --

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

--                                                                          --

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

pragma Style_Checks (All_Checks);

--  Turn off subprogram alpha ordering check, since we group soft link bodies

--  and dummy soft link bodies together separately in this unit.

pragma Polling (Off);

--  Turn polling off for this package. We don't need polling during any of the

--  routines in this package, and more to the point, if we try to poll it can

--  cause infinite loops.

with Ada.Exceptions;

with System.Task_Primitives;

with System.Task_Primitives.Operations;

with System.Soft_Links;

with System.Soft_Links.Tasking;

with System.Tasking.Debug;

with System.Parameters;

package body System.Tasking.Initialization is

   package STPO renames System.Task_Primitives.Operations;

   package SSL  renames System.Soft_Links;

   package AE   renames Ada.Exceptions;

   use Parameters;

   use Task_Primitives.Operations;

   Global_Task_Lock : aliased System.Task_Primitives.RTS_Lock;

   --  This is a global lock; it is used to execute in mutual exclusion from

   --  all other tasks. It is only used by Task_Lock, Task_Unlock, and

   --  Final_Task_Unlock.

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

   -- Tasking versions of some services needed by non-tasking programs --

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

   procedure Abort_Defer;

   --  NON-INLINE versions without Self_ID for soft links

   procedure Abort_Undefer;

   --  NON-INLINE versions without Self_ID for soft links

   procedure Task_Lock;

   --  Locks out other tasks. Preceding a section of code by Task_Lock and

   --  following it by Task_Unlock creates a critical region. This is used

   --  for ensuring that a region of non-tasking code (such as code used to

   --  allocate memory) is tasking safe. Note that it is valid for calls to

   --  Task_Lock/Task_Unlock to be nested, and this must work properly, i.e.

   --  only the corresponding outer level Task_Unlock will actually unlock.

   procedure Task_Unlock;

   --  Releases lock previously set by call to Task_Lock. In the nested case,

   --  all nested locks must be released before other tasks competing for the

   --  tasking lock are released.

   function Get_Current_Excep return SSL.EOA;

   --  Task-safe version of SSL.Get_Current_Excep

   procedure Update_Exception

     (X : AE.Exception_Occurrence := SSL.Current_Target_Exception);

   --  Handle exception setting and check for pending actions

   function Task_Name return String;

   --  Returns current task's name

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

   --  Local Subprograms --

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

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

   -- Tasking Initialization --

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

   procedure Init_RTS;

   --  This procedure completes the initialization of the GNARL. The first part

   --  of the initialization is done in the body of System.Tasking. It consists

   --  of initializing global locks, and installing tasking versions of certain

   --  operations used by the compiler. Init_RTS is called during elaboration.

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

   -- Change_Base_Priority --

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

   --  Call only with abort deferred and holding Self_ID locked

   procedure Change_Base_Priority (T : Task_Id) is

   begin

      if T.Common.Base_Priority /= T.New_Base_Priority then

         T.Common.Base_Priority := T.New_Base_Priority;

         Set_Priority (T, T.Common.Base_Priority);

      end if;

   end Change_Base_Priority;

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

   -- Check_Abort_Status --

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

   function Check_Abort_Status return Integer is

      Self_ID : constant Task_Id := Self;

   begin

      if Self_ID /= null

        and then Self_ID.Deferral_Level = 0

        and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level

      then

         return 1;

      else

         return 0;

      end if;

   end Check_Abort_Status;

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

   -- Defer_Abort --

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

   procedure Defer_Abort (Self_ID : Task_Id) is

   begin

      if No_Abort then

         return;

      end if;

      pragma Assert (Self_ID.Deferral_Level = 0);

      --  pragma Assert

      --    (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level);

      --  The above check has been useful in detecting mismatched defer/undefer

      --  pairs. You may uncomment it when testing on systems that support

      --  preemptive abort.

      --  If the OS supports preemptive abort (e.g. pthread_kill), it should

      --  have happened already. A problem is with systems that do not support

      --  preemptive abort, and so rely on polling. On such systems we may get

      --  false failures of the assertion, since polling for pending abort does

      --  no occur until the abort undefer operation.

      --  Even on systems that only poll for abort, the assertion may be useful

      --  for catching missed abort completion polling points. The operations

      --  that undefer abort poll for pending aborts. This covers most of the

      --  places where the core Ada semantics require abort to be caught,

      --  without any special attention. However, this generally happens on

      --  exit from runtime system call, which means a pending abort will not

      --  be noticed on the way into the runtime system. We considered adding a

      --  check for pending aborts at this point, but chose not to, because of

      --  the overhead. Instead, we searched for RTS calls where abort

      --  completion is required and a task could go farther than Ada allows

      --  before undeferring abort; we then modified the code to ensure the

      --  abort would be detected.

      Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1;

   end Defer_Abort;

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

   -- Defer_Abort_Nestable --

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

   procedure Defer_Abort_Nestable (Self_ID : Task_Id) is

   begin

      if No_Abort then

         return;

      end if;

      --  The following assertion is by default disabled. See the comment in

      --  Defer_Abort on the situations in which it may be useful to uncomment

      --  this assertion and enable the test.

      --  pragma Assert

      --    (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level or else

      --     Self_ID.Deferral_Level > 0);

      Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1;

   end Defer_Abort_Nestable;

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

   -- Abort_Defer --

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

   procedure Abort_Defer is

      Self_ID : Task_Id;

   begin

      if No_Abort then

         return;

      end if;

      Self_ID := STPO.Self;

      Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1;

   end Abort_Defer;

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

   -- Get_Current_Excep --

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

   function Get_Current_Excep return SSL.EOA is

   begin

      return STPO.Self.Common.Compiler_Data.Current_Excep'Access;

   end Get_Current_Excep;

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

   -- Do_Pending_Action --

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

   --  Call only when holding no locks

   procedure Do_Pending_Action (Self_ID : Task_Id) is

      use type Ada.Exceptions.Exception_Id;

   begin

      pragma Assert (Self_ID = Self and then Self_ID.Deferral_Level = 0);

      --  Needs loop to recheck for pending action in case a new one occurred

      --  while we had abort deferred below.

      loop

         --  Temporarily defer abort so that we can lock Self_ID

         Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1;

         if Single_Lock then

            Lock_RTS;

         end if;

         Write_Lock (Self_ID);

         Self_ID.Pending_Action := False;

         Unlock (Self_ID);

         if Single_Lock then

            Unlock_RTS;

         end if;

         --  Restore the original Deferral value

         Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1;

         if not Self_ID.Pending_Action then

            if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level then

               if not Self_ID.Aborting then

                  Self_ID.Aborting := True;

                  pragma Debug

                    (Debug.Trace (Self_ID, "raise Abort_Signal", 'B'));

                  raise Standard'Abort_Signal;

                  pragma Assert (not Self_ID.ATC_Hack);

               elsif Self_ID.ATC_Hack then

                  --  The solution really belongs in the Abort_Signal handler

                  --  for async. entry calls.  The present hack is very

                  --  fragile. It relies that the very next point after

                  --  Exit_One_ATC_Level at which the task becomes abortable

                  --  will be the call to Undefer_Abort in the

                  --  Abort_Signal handler.

                  Self_ID.ATC_Hack := False;

                  pragma Debug

                    (Debug.Trace

                     (Self_ID, "raise Abort_Signal (ATC hack)", 'B'));

                  raise Standard'Abort_Signal;

               end if;

            end if;

            return;

         end if;

      end loop;

   end Do_Pending_Action;

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

   -- Final_Task_Unlock --

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

   --  This version is only for use in Terminate_Task, when the task is

   --  relinquishing further rights to its own ATCB.

   --  There is a very interesting potential race condition there, where the

   --  old task may run concurrently with a new task that is allocated the old

   --  tasks (now reused) ATCB. The critical thing here is to not make any

   --  reference to the ATCB after the lock is released. See also comments on

   --  Terminate_Task and Unlock.

   procedure Final_Task_Unlock (Self_ID : Task_Id) is

   begin

      pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting = 1);

      Unlock (Global_Task_Lock'Access, Global_Lock => True);

   end Final_Task_Unlock;

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

   -- Init_RTS --

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

   procedure Init_RTS is

      Self_Id : Task_Id;

   begin

      Tasking.Initialize;

      --  Terminate run time (regular vs restricted) specific initialization

      --  of the environment task.

      Self_Id := Environment_Task;

      Self_Id.Master_of_Task := Environment_Task_Level;

      Self_Id.Master_Within := Self_Id.Master_of_Task + 1;

      for L in Self_Id.Entry_Calls'Range loop

         Self_Id.Entry_Calls (L).Self := Self_Id;

         Self_Id.Entry_Calls (L).Level := L;

      end loop;

      Self_Id.Awake_Count := 1;

      Self_Id.Alive_Count := 1;

      --  Normally, a task starts out with internal master nesting level one

      --  larger than external master nesting level. It is incremented to one

      --  by Enter_Master, which is called in the task body only if the

      --  compiler thinks the task may have dependent tasks. There is no

      --  corresponding call to Enter_Master for the environment task, so we

      --  would need to increment it to 2 here. Instead, we set it to 3. By

      --  doing this we reserve the level 2 for server tasks of the runtime

      --  system. The environment task does not need to wait for these server

      Self_Id.Master_Within := Library_Task_Level;

      --  Initialize lock used to implement mutual exclusion between all tasks

      Initialize_Lock (Global_Task_Lock'Access, STPO.Global_Task_Level);

      --  Notify that the tasking run time has been elaborated so that

      --  the tasking version of the soft links can be used.

      if not No_Abort then

         SSL.Abort_Defer   := Abort_Defer'Access;

         SSL.Abort_Undefer := Abort_Undefer'Access;

      end if;

      SSL.Lock_Task          := Task_Lock'Access;

      SSL.Unlock_Task        := Task_Unlock'Access;

      SSL.Check_Abort_Status := Check_Abort_Status'Access;

      SSL.Task_Name          := Task_Name'Access;

      SSL.Update_Exception   := Update_Exception'Access;

      SSL.Get_Current_Excep  := Get_Current_Excep'Access;

      --  Initialize the tasking soft links (if not done yet) that are common

      --  to the full and the restricted run times.

      SSL.Tasking.Init_Tasking_Soft_Links;

      --  Abort is deferred in a new ATCB, so we need to undefer abort at this

      --  stage to make the environment task abortable.

      Undefer_Abort (Environment_Task);

   end Init_RTS;

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

   -- Locked_Abort_To_Level--

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

   --  Abort a task to the specified ATC nesting level.

   --  Call this only with T locked.

   --  An earlier version of this code contained a call to Wakeup. That should

   --  not be necessary here, if Abort_Task is implemented correctly, since

   --  Abort_Task should include the effect of Wakeup. However, the above call

   --  was in earlier versions of this file, and at least for some targets

   --  Abort_Task has not been doing Wakeup. It should not hurt to uncomment

   --  the above call, until the error is corrected for all targets.

   --  See extended comments in package body System.Tasking.Abort for the

   --  overall design of the implementation of task abort.

   --  ??? there is no such package ???

   --  If the task is sleeping it will be in an abort-deferred region, and will

   --  not have Abort_Signal raised by Abort_Task. Such an "abort deferral" is

   --  just to protect the RTS internals, and not necessarily required to

   --  enforce Ada semantics. Abort_Task should wake the task up and let it

   --  decide if it wants to complete the aborted construct immediately.

   --  Note that the effect of the low-level Abort_Task is not persistent.

   --  If the target task is not blocked, this wakeup will be missed.

   --  We don't bother calling Abort_Task if this task is aborting itself,

   --  since we are inside the RTS and have abort deferred. Similarly, We don't

   --  bother to call Abort_Task if T is terminated, since there is no need to

   --  abort a terminated task, and it could be dangerous to try if the task

   --  has stopped executing.

   --  Note that an earlier version of this code had some false reasoning about

   --  being able to reliably wake up a task that had suspended on a blocking

   --  system call that does not atomically release the task's lock (e.g., UNIX

   --  nanosleep, which we once thought could be used to implement delays).

   --  That still left the possibility of missed wakeups.

   --  We cannot safely call Vulnerable_Complete_Activation here, since that

   --  requires locking Self_ID.Parent. The anti-deadlock lock ordering rules

   --  would then require us to release the lock on Self_ID first, which would

   --  create a timing window for other tasks to lock Self_ID. This is

   --  significant for tasks that may be aborted before their execution can

   --  enter the task body, and so they do not get a chance to call

   --  Complete_Task. The actual work for this case is done in Terminate_Task.

   procedure Locked_Abort_To_Level

     (Self_ID : Task_Id;

      T       : Task_Id;

      L       : ATC_Level)

   is

   begin

      if not T.Aborting and then T /= Self_ID then

         case T.Common.State is

            when Unactivated | Terminated =>

               pragma Assert (False);

               null;

            when Activating | Runnable =>

               --  This is needed to cancel an asynchronous protected entry

               --  call during a requeue with abort.

               T.Entry_Calls

                 (T.ATC_Nesting_Level).Cancellation_Attempted := True;

            when Interrupt_Server_Blocked_On_Event_Flag =>

               null;

            when Delay_Sleep                              |

                 Async_Select_Sleep                       |

                 Interrupt_Server_Idle_Sleep              |

                 Interrupt_Server_Blocked_Interrupt_Sleep |

                 Timer_Server_Sleep                       |

                 AST_Server_Sleep                         =>

               Wakeup (T, T.Common.State);

            when Acceptor_Sleep | Acceptor_Delay_Sleep =>

               T.Open_Accepts := null;

               Wakeup (T, T.Common.State);

            when Entry_Caller_Sleep  =>

               T.Entry_Calls

                 (T.ATC_Nesting_Level).Cancellation_Attempted := True;

               Wakeup (T, T.Common.State);

            when Activator_Sleep         |

                 Master_Completion_Sleep |

                 Master_Phase_2_Sleep    |

                 Asynchronous_Hold       =>

               null;

         end case;

      end if;

      if T.Pending_ATC_Level > L then

         T.Pending_ATC_Level := L;

         T.Pending_Action := True;

         if L = 0 then

            T.Callable := False;

         end if;

         --  This prevents aborted task from accepting calls

         if T.Aborting then

            --  The test above is just a heuristic, to reduce wasteful

            --  calls to Abort_Task.  We are holding T locked, and this

            --  value will not be set to False except with T also locked,

            --  inside Exit_One_ATC_Level, so we should not miss wakeups.

            if T.Common.State = Acceptor_Sleep

                 or else

               T.Common.State = Acceptor_Delay_Sleep

            then

               T.Open_Accepts := null;

            end if;

         elsif T /= Self_ID and then

           (T.Common.State = Runnable

             or else T.Common.State = Interrupt_Server_Blocked_On_Event_Flag)

            --  The task is blocked on a system call waiting for the

            --  completion event. In this case Abort_Task may need to take

            --  special action in order to succeed. Example system: VMS.

         then

            Abort_Task (T);

         end if;

      end if;

   end Locked_Abort_To_Level;

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

   -- Remove_From_All_Tasks_List --

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

   procedure Remove_From_All_Tasks_List (T : Task_Id) is

      C        : Task_Id;

      Previous : Task_Id;

   begin

      pragma Debug

        (Debug.Trace (Self, "Remove_From_All_Tasks_List", 'C'));

      Previous := Null_Task;

      C := All_Tasks_List;

      while C /= Null_Task loop

         if C = T then

            if Previous = Null_Task then

               All_Tasks_List := All_Tasks_List.Common.All_Tasks_Link;

            else

               Previous.Common.All_Tasks_Link := C.Common.All_Tasks_Link;

            end if;

            return;

         end if;

         Previous := C;

         C := C.Common.All_Tasks_Link;

      end loop;

      pragma Assert (False);

   end Remove_From_All_Tasks_List;

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

   -- Task_Lock --

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

   procedure Task_Lock (Self_ID : Task_Id) is

   begin

      Self_ID.Common.Global_Task_Lock_Nesting :=

        Self_ID.Common.Global_Task_Lock_Nesting + 1;

      if Self_ID.Common.Global_Task_Lock_Nesting = 1 then

         Defer_Abort_Nestable (Self_ID);

         Write_Lock (Global_Task_Lock'Access, Global_Lock => True);

      end if;

   end Task_Lock;

   procedure Task_Lock is

   begin

      Task_Lock (STPO.Self);

   end Task_Lock;

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

   -- Task_Name --

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

   function Task_Name return String is

      Self_Id : constant Task_Id := STPO.Self;

   begin

      return Self_Id.Common.Task_Image (1 .. Self_Id.Common.Task_Image_Len);

   end Task_Name;

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

   -- Task_Unlock --

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

   procedure Task_Unlock (Self_ID : Task_Id) is

   begin

      pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting > 0);

      Self_ID.Common.Global_Task_Lock_Nesting :=

        Self_ID.Common.Global_Task_Lock_Nesting - 1;

      if Self_ID.Common.Global_Task_Lock_Nesting = 0 then

         Unlock (Global_Task_Lock'Access, Global_Lock => True);

         Undefer_Abort_Nestable (Self_ID);

      end if;

   end Task_Unlock;

   procedure Task_Unlock is

   begin

      Task_Unlock (STPO.Self);

   end Task_Unlock;

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

   -- Undefer_Abort --

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

   --  Precondition : Self does not hold any locks!

   --  Undefer_Abort is called on any abort completion point (aka.

   --  synchronization point). It performs the following actions if they

   --  are pending: (1) change the base priority, (2) abort the task.

   --  The priority change has to occur before abort. Otherwise, it would

   --  take effect no earlier than the next abort completion point.

   procedure Undefer_Abort (Self_ID : Task_Id) is

   begin

      if No_Abort then

         return;

      end if;

      pragma Assert (Self_ID.Deferral_Level = 1);

      Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1;

      if Self_ID.Deferral_Level = 0 then

         pragma Assert (Check_No_Locks (Self_ID));

         if Self_ID.Pending_Action then

            Do_Pending_Action (Self_ID);

         end if;

      end if;

   end Undefer_Abort;

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

   -- Undefer_Abort_Nestable --

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

   --  An earlier version would re-defer abort if an abort is in progress.

   --  Then, we modified the effect of the raise statement so that it defers

   --  abort until control reaches a handler. That was done to prevent

   --  "skipping over" a handler if another asynchronous abort occurs during

   --  the propagation of the abort to the handler.

   --  There has been talk of reversing that decision, based on a newer

   --  implementation of exception propagation. Care must be taken to evaluate

   --  how such a change would interact with the above code and all the places

   --  where abort-deferral is used to bridge over critical transitions, such

   --  as entry to the scope of a region with a finalizer and entry into the

   --  body of an accept-procedure.

   procedure Undefer_Abort_Nestable (Self_ID : Task_Id) is

   begin

      if No_Abort then

         return;

      end if;

      pragma Assert (Self_ID.Deferral_Level > 0);

      Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1;

      if Self_ID.Deferral_Level = 0 then

         pragma Assert (Check_No_Locks (Self_ID));

         if Self_ID.Pending_Action then

            Do_Pending_Action (Self_ID);

         end if;

      end if;

   end Undefer_Abort_Nestable;

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

   -- Abort_Undefer --

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

   procedure Abort_Undefer is

      Self_ID : Task_Id;

   begin

      if No_Abort then

         return;

      end if;

      Self_ID := STPO.Self;

      if Self_ID.Deferral_Level = 0 then

         --  In case there are different views on whether Abort is supported

         --  between the expander and the run time, we may end up with

         --  Self_ID.Deferral_Level being equal to zero, when called from

         --  the procedure created by the expander that corresponds to a

         --  task body.

         --  In this case, there's nothing to be done

         --  See related code in System.Tasking.Stages.Create_Task resetting

         --  Deferral_Level when System.Restrictions.Abort_Allowed is False.

         return;

      end if;

      pragma Assert (Self_ID.Deferral_Level > 0);

      Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1;

      if Self_ID.Deferral_Level = 0 then

         pragma Assert (Check_No_Locks (Self_ID));

         if Self_ID.Pending_Action then

            Do_Pending_Action (Self_ID);

         end if;

      end if;

   end Abort_Undefer;

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

   -- Update_Exception --

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

   --  Call only when holding no locks

   procedure Update_Exception

     (X : AE.Exception_Occurrence := SSL.Current_Target_Exception)

   is

      Self_Id : constant Task_Id := Self;

      use Ada.Exceptions;

   begin

      Save_Occurrence (Self_Id.Common.Compiler_Data.Current_Excep, X);

      if Self_Id.Deferral_Level = 0 then

         if Self_Id.Pending_Action then

            Self_Id.Pending_Action := False;

            Self_Id.Deferral_Level := Self_Id.Deferral_Level + 1;

            if Single_Lock then

               Lock_RTS;

            end if;

            Write_Lock (Self_Id);

            Self_Id.Pending_Action := False;

            Unlock (Self_Id);

            if Single_Lock then

               Unlock_RTS;

            end if;

            Self_Id.Deferral_Level := Self_Id.Deferral_Level - 1;

            if Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level then

               if not Self_Id.Aborting then

                  Self_Id.Aborting := True;

                  raise Standard'Abort_Signal;

               end if;

            end if;

         end if;

      end if;

   end Update_Exception;

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

   -- Wakeup_Entry_Caller --

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

   --  This is called at the end of service of an entry call, to abort the

   --  caller if he is in an abortable part, and to wake up the caller if it

   --  is on Entry_Caller_Sleep. It assumes that the call is already off-queue.

   --  (This enforces the rule that a task must be off-queue if its state is

   --  Done or Cancelled.) Call it holding the lock of Entry_Call.Self.

   --  Timed_Call or Simple_Call:

   --    The caller is waiting on Entry_Caller_Sleep, in

   --    Wait_For_Completion, or Wait_For_Completion_With_Timeout.

   --  Conditional_Call:

   --    The caller might be in Wait_For_Completion,

   --    waiting for a rendezvous (possibly requeued without abort)

   --    to complete.

   --  Asynchronous_Call:

   --    The caller may be executing in the abortable part o

   --    an async. select, or on a time delay,

   --    if Entry_Call.State >= Was_Abortable.

   procedure Wakeup_Entry_Caller

     (Self_ID    : Task_Id;

      Entry_Call : Entry_Call_Link;

      New_State  : Entry_Call_State)

   is

      Caller : constant Task_Id := Entry_Call.Self;

   begin

      pragma Debug (Debug.Trace

        (Self_ID, "Wakeup_Entry_Caller", 'E', Caller));

      pragma Assert (New_State = Done or else New_State = Cancelled);

      pragma Assert (Caller.Common.State /= Unactivated);

      Entry_Call.State := New_State;

      if Entry_Call.Mode = Asynchronous_Call then

         --  Abort the caller in his abortable part, but do so only if call has