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8sa1-gcc/gcc/ada/s-tasren.adb
Geoffrey Keating 6cbcc54138 Delete all lines containing "$Revision:". 
* xeinfo.adb: Don't look for revision numbers.
	* xnmake.adb: Likewise.
	* xsinfo.adb: Likewise.
	* xsnames.adb: Likewise.
	* xtreeprs.adb: Likewise.

From-SVN: r50768
2002-03-14 11:00:22 +00:00

1781 lines
56 KiB
Ada
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------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . T A S K I N G . R E N D E Z V O U S --
-- --
-- B o d y --
-- --
-- --
-- Copyright (C) 1992-2001, 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 2, or (at your option) any later ver- --
-- sion. GNARL 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 GNARL; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, 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. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies, Inc. (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Ada.Exceptions;
-- Used for Exception_ID
-- Null_Id
-- Save_Occurrence
-- Raise_Exception
with System.Task_Primitives.Operations;
-- used for Get_Priority
-- Set_Priority
-- Write_Lock
-- Unlock
-- Sleep
-- Wakeup
-- Timed_Sleep
with System.Tasking.Entry_Calls;
-- Used for Wait_For_Completion
-- Wait_For_Completion_With_Timeout
-- Wait_Until_Abortable
with System.Tasking.Initialization;
-- used for Defer_Abort
-- Undefer_Abort
-- Poll_Base_Priority_Change
with System.Tasking.Queuing;
-- used for Enqueue
-- Dequeue_Head
-- Select_Task_Entry_Call
-- Count_Waiting
with System.Tasking.Utilities;
-- used for Check_Exception
-- Make_Passive
-- Wakeup_Entry_Caller
with System.Tasking.Protected_Objects.Operations;
-- used for PO_Do_Or_Queue
-- PO_Service_Entries
-- Lock_Entries
-- Unlock_Entries
with System.Tasking.Debug;
-- used for Trace
with System.Parameters;
-- used for Single_Lock
-- Runtime_Traces
with System.Traces.Tasking;
-- used for Send_Trace_Info
package body System.Tasking.Rendezvous is
package STPO renames System.Task_Primitives.Operations;
package POO renames Protected_Objects.Operations;
package POE renames Protected_Objects.Entries;
use Parameters;
use Task_Primitives.Operations;
use System.Traces;
use System.Traces.Tasking;
type Select_Treatment is (
Accept_Alternative_Selected, -- alternative with non-null body
Accept_Alternative_Completed, -- alternative with null body
Else_Selected,
Terminate_Selected,
Accept_Alternative_Open,
No_Alternative_Open);
Default_Treatment : constant array (Select_Modes) of Select_Treatment :=
(Simple_Mode => No_Alternative_Open,
Else_Mode => Else_Selected,
Terminate_Mode => Terminate_Selected,
Delay_Mode => No_Alternative_Open);
New_State : constant array (Boolean, Entry_Call_State)
of Entry_Call_State :=
(True =>
(Never_Abortable => Never_Abortable,
Not_Yet_Abortable => Now_Abortable,
Was_Abortable => Now_Abortable,
Now_Abortable => Now_Abortable,
Done => Done,
Cancelled => Cancelled),
False =>
(Never_Abortable => Never_Abortable,
Not_Yet_Abortable => Not_Yet_Abortable,
Was_Abortable => Was_Abortable,
Now_Abortable => Now_Abortable,
Done => Done,
Cancelled => Cancelled)
);
-----------------------
-- Local Subprograms --
-----------------------
procedure Local_Defer_Abort (Self_Id : Task_ID) renames
System.Tasking.Initialization.Defer_Abort_Nestable;
procedure Local_Undefer_Abort (Self_Id : Task_ID) renames
System.Tasking.Initialization.Undefer_Abort_Nestable;
-- Florist defers abort around critical sections that
-- make entry calls to the Interrupt_Manager task, which
-- violates the general rule about top-level runtime system
-- calls from abort-deferred regions. It is not that this is
-- unsafe, but when it occurs in "normal" programs it usually
-- means either the user is trying to do a potentially blocking
-- operation from within a protected object, or there is a
-- runtime system/compiler error that has failed to undefer
-- an earlier abort deferral. Thus, for debugging it may be
-- wise to modify the above renamings to the non-nestable forms.
procedure Boost_Priority (Call : Entry_Call_Link; Acceptor : Task_ID);
pragma Inline (Boost_Priority);
-- Call this only with abort deferred and holding lock of Acceptor.
procedure Call_Synchronous
(Acceptor : Task_ID;
E : Task_Entry_Index;
Uninterpreted_Data : System.Address;
Mode : Call_Modes;
Rendezvous_Successful : out Boolean);
pragma Inline (Call_Synchronous);
-- This call is used to make a simple or conditional entry call.
procedure Setup_For_Rendezvous_With_Body
(Entry_Call : Entry_Call_Link;
Acceptor : Task_ID);
pragma Inline (Setup_For_Rendezvous_With_Body);
-- Call this only with abort deferred and holding lock of Acceptor.
-- When a rendezvous selected (ready for rendezvous) we need to save
-- privious caller and adjust the priority. Also we need to make
-- this call not Abortable (Cancellable) since the rendezvous has
-- already been started.
function Is_Entry_Open (T : Task_ID; E : Task_Entry_Index) return Boolean;
pragma Inline (Is_Entry_Open);
-- Call this only with abort deferred and holding lock of T.
procedure Wait_For_Call (Self_Id : Task_ID);
pragma Inline (Wait_For_Call);
-- Call this only with abort deferred and holding lock of Self_Id.
-- An accepting task goes into Sleep by calling this routine
-- waiting for a call from the caller or waiting for an abort.
-- Make sure Self_Id is locked before calling this routine.
-----------------
-- Accept_Call --
-----------------
procedure Accept_Call
(E : Task_Entry_Index;
Uninterpreted_Data : out System.Address)
is
Self_Id : constant Task_ID := STPO.Self;
Caller : Task_ID := null;
Open_Accepts : aliased Accept_List (1 .. 1);
Entry_Call : Entry_Call_Link;
begin
Initialization.Defer_Abort (Self_Id);
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Self_Id);
if not Self_Id.Callable then
pragma Assert (Self_Id.Pending_ATC_Level = 0);
pragma Assert (Self_Id.Pending_Action);
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
-- Should never get here ???
pragma Assert (False);
raise Standard'Abort_Signal;
end if;
Queuing.Dequeue_Head (Self_Id.Entry_Queues (E), Entry_Call);
if Entry_Call /= null then
Caller := Entry_Call.Self;
Setup_For_Rendezvous_With_Body (Entry_Call, Self_Id);
Uninterpreted_Data := Entry_Call.Uninterpreted_Data;
else
-- Wait for a caller
Open_Accepts (1).Null_Body := False;
Open_Accepts (1).S := E;
Self_Id.Open_Accepts := Open_Accepts'Unrestricted_Access;
-- Wait for normal call
if Parameters.Runtime_Traces then
Send_Trace_Info (W_Accept, Self_Id, Integer (Open_Accepts'Length));
end if;
pragma Debug
(Debug.Trace (Self_Id, "Accept_Call: wait", 'R'));
Wait_For_Call (Self_Id);
pragma Assert (Self_Id.Open_Accepts = null);
if Self_Id.Common.Call /= null then
Caller := Self_Id.Common.Call.Self;
Uninterpreted_Data :=
Caller.Entry_Calls (Caller.ATC_Nesting_Level).Uninterpreted_Data;
else
-- Case of an aborted task.
Uninterpreted_Data := System.Null_Address;
end if;
end if;
-- Self_Id.Common.Call should already be updated by the Caller
-- On return, we will start the rendezvous.
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
if Parameters.Runtime_Traces then
Send_Trace_Info (M_Accept_Complete, Caller, Entry_Index (E));
end if;
end Accept_Call;
--------------------
-- Accept_Trivial --
--------------------
procedure Accept_Trivial (E : Task_Entry_Index) is
Self_Id : constant Task_ID := STPO.Self;
Caller : Task_ID := null;
Open_Accepts : aliased Accept_List (1 .. 1);
Entry_Call : Entry_Call_Link;
begin
Initialization.Defer_Abort_Nestable (Self_Id);
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Self_Id);
if not Self_Id.Callable then
pragma Assert (Self_Id.Pending_ATC_Level = 0);
pragma Assert (Self_Id.Pending_Action);
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort_Nestable (Self_Id);
-- Should never get here ???
pragma Assert (False);
raise Standard'Abort_Signal;
end if;
Queuing.Dequeue_Head (Self_Id.Entry_Queues (E), Entry_Call);
if Entry_Call = null then
-- Need to wait for entry call
Open_Accepts (1).Null_Body := True;
Open_Accepts (1).S := E;
Self_Id.Open_Accepts := Open_Accepts'Unrestricted_Access;
if Parameters.Runtime_Traces then
Send_Trace_Info (W_Accept, Self_Id, Integer (Open_Accepts'Length));
end if;
pragma Debug
(Debug.Trace (Self_Id, "Accept_Trivial: wait", 'R'));
Wait_For_Call (Self_Id);
pragma Assert (Self_Id.Open_Accepts = null);
-- No need to do anything special here for pending abort.
-- Abort_Signal will be raised by Undefer on exit.
STPO.Unlock (Self_Id);
else -- found caller already waiting
pragma Assert (Entry_Call.State < Done);
STPO.Unlock (Self_Id);
Caller := Entry_Call.Self;
STPO.Write_Lock (Caller);
Initialization.Wakeup_Entry_Caller (Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
end if;
if Parameters.Runtime_Traces then
Send_Trace_Info (M_Accept_Complete);
-- Fake one, since there is (???) no way
-- to know that the rendezvous is over
Send_Trace_Info (M_RDV_Complete);
end if;
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort_Nestable (Self_Id);
end Accept_Trivial;
--------------------
-- Boost_Priority --
--------------------
procedure Boost_Priority (Call : Entry_Call_Link; Acceptor : Task_ID) is
Caller : constant Task_ID := Call.Self;
Caller_Prio : System.Any_Priority := Get_Priority (Caller);
Acceptor_Prio : System.Any_Priority := Get_Priority (Acceptor);
begin
if Caller_Prio > Acceptor_Prio then
Call.Acceptor_Prev_Priority := Acceptor_Prio;
Set_Priority (Acceptor, Caller_Prio);
else
Call.Acceptor_Prev_Priority := Priority_Not_Boosted;
end if;
end Boost_Priority;
-----------------
-- Call_Simple --
-----------------
procedure Call_Simple
(Acceptor : Task_ID;
E : Task_Entry_Index;
Uninterpreted_Data : System.Address)
is
Rendezvous_Successful : Boolean;
begin
Call_Synchronous
(Acceptor, E, Uninterpreted_Data, Simple_Call, Rendezvous_Successful);
end Call_Simple;
----------------------
-- Call_Synchronous --
----------------------
-- Called from Call_Simple and Task_Entry_Call.
procedure Call_Synchronous
(Acceptor : Task_ID;
E : Task_Entry_Index;
Uninterpreted_Data : System.Address;
Mode : Call_Modes;
Rendezvous_Successful : out Boolean)
is
Self_Id : constant Task_ID := STPO.Self;
Level : ATC_Level;
Entry_Call : Entry_Call_Link;
begin
pragma Assert (Mode /= Asynchronous_Call);
Local_Defer_Abort (Self_Id);
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level + 1;
pragma Debug
(Debug.Trace (Self_Id, "CS: entered ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
Level := Self_Id.ATC_Nesting_Level;
Entry_Call := Self_Id.Entry_Calls (Level)'Access;
Entry_Call.Next := null;
Entry_Call.Mode := Mode;
Entry_Call.Cancellation_Attempted := False;
if Parameters.Runtime_Traces then
Send_Trace_Info (W_Call, Acceptor, Entry_Index (E));
end if;
-- If this is a call made inside of an abort deferred region,
-- the call should be never abortable.
if Self_Id.Deferral_Level > 1 then
Entry_Call.State := Never_Abortable;
else
Entry_Call.State := Now_Abortable;
end if;
Entry_Call.E := Entry_Index (E);
Entry_Call.Prio := Get_Priority (Self_Id);
Entry_Call.Uninterpreted_Data := Uninterpreted_Data;
Entry_Call.Called_Task := Acceptor;
Entry_Call.Exception_To_Raise := Ada.Exceptions.Null_Id;
-- Note: the caller will undefer abort on return (see WARNING above)
if Single_Lock then
Lock_RTS;
end if;
if not Task_Do_Or_Queue
(Self_Id, Entry_Call, With_Abort => True)
then
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level - 1;
if Single_Lock then
Unlock_RTS;
end if;
if Parameters.Runtime_Traces then
Send_Trace_Info (E_Missed, Acceptor);
end if;
Initialization.Undefer_Abort (Self_Id);
pragma Debug
(Debug.Trace (Self_Id, "CS: exited to ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
raise Tasking_Error;
end if;
STPO.Write_Lock (Self_Id);
pragma Debug
(Debug.Trace (Self_Id, "Call_Synchronous: wait", 'R'));
Entry_Calls.Wait_For_Completion (Entry_Call);
pragma Debug
(Debug.Trace (Self_Id, "Call_Synchronous: done waiting", 'R'));
Rendezvous_Successful := Entry_Call.State = Done;
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Local_Undefer_Abort (Self_Id);
Entry_Calls.Check_Exception (Self_Id, Entry_Call);
end Call_Synchronous;
--------------
-- Callable --
--------------
function Callable (T : Task_ID) return Boolean is
Result : Boolean;
Self_Id : constant Task_ID := STPO.Self;
begin
Initialization.Defer_Abort (Self_Id);
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (T);
Result := T.Callable;
STPO.Unlock (T);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
return Result;
end Callable;
----------------------------
-- Cancel_Task_Entry_Call --
----------------------------
procedure Cancel_Task_Entry_Call (Cancelled : out Boolean) is
begin
Entry_Calls.Try_To_Cancel_Entry_Call (Cancelled);
end Cancel_Task_Entry_Call;
-------------------------
-- Complete_Rendezvous --
-------------------------
procedure Complete_Rendezvous is
begin
Exceptional_Complete_Rendezvous (Ada.Exceptions.Null_Id);
end Complete_Rendezvous;
-------------------------------------
-- Exceptional_Complete_Rendezvous --
-------------------------------------
procedure Exceptional_Complete_Rendezvous
(Ex : Ada.Exceptions.Exception_Id)
is
Self_Id : constant Task_ID := STPO.Self;
Entry_Call : Entry_Call_Link := Self_Id.Common.Call;
Caller : Task_ID;
Called_PO : STPE.Protection_Entries_Access;
Exception_To_Raise : Ada.Exceptions.Exception_Id := Ex;
Ceiling_Violation : Boolean;
use type Ada.Exceptions.Exception_Id;
procedure Internal_Reraise;
pragma Import (C, Internal_Reraise, "__gnat_reraise");
use type STPE.Protection_Entries_Access;
begin
-- Consider phasing out Complete_Rendezvous in favor
-- of direct call to this with Ada.Exceptions.Null_ID.
-- See code expansion examples for Accept_Call and Selective_Wait.
-- Also consider putting an explicit re-raise after this call, in
-- the generated code. That way we could eliminate the
-- code here that reraises the exception.
-- The deferral level is critical here,
-- since we want to raise an exception or allow abort to take
-- place, if there is an exception or abort pending.
pragma Debug
(Debug.Trace (Self_Id, "Exceptional_Complete_Rendezvous", 'R'));
if Ex = Ada.Exceptions.Null_Id then
-- The call came from normal end-of-rendezvous,
-- so abort is not yet deferred.
if Parameters.Runtime_Traces then
Send_Trace_Info (M_RDV_Complete, Entry_Call.Self);
end if;
Initialization.Defer_Abort_Nestable (Self_Id);
end if;
-- We need to clean up any accepts which Self may have
-- been serving when it was aborted.
if Ex = Standard'Abort_Signal'Identity then
if Single_Lock then
Lock_RTS;
end if;
while Entry_Call /= null loop
Entry_Call.Exception_To_Raise := Tasking_Error'Identity;
-- All forms of accept make sure that the acceptor is not
-- completed, before accepting further calls, so that we
-- can be sure that no further calls are made after the
-- current calls are purged.
Caller := Entry_Call.Self;
-- Take write lock. This follows the lock precedence rule that
-- Caller may be locked while holding lock of Acceptor.
-- Complete the call abnormally, with exception.
STPO.Write_Lock (Caller);
Initialization.Wakeup_Entry_Caller (Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
Entry_Call := Entry_Call.Acceptor_Prev_Call;
end loop;
if Single_Lock then
Unlock_RTS;
end if;
else
Caller := Entry_Call.Self;
if Entry_Call.Needs_Requeue then
-- We dare not lock Self_Id at the same time as Caller,
-- for fear of deadlock.
Entry_Call.Needs_Requeue := False;
Self_Id.Common.Call := Entry_Call.Acceptor_Prev_Call;
if Entry_Call.Called_Task /= null then
-- Requeue to another task entry
if Single_Lock then
Lock_RTS;
end if;
if not Task_Do_Or_Queue
(Self_Id, Entry_Call, Entry_Call.Requeue_With_Abort)
then
if Single_Lock then
Lock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
raise Tasking_Error;
end if;
if Single_Lock then
Unlock_RTS;
end if;
else
-- Requeue to a protected entry
Called_PO := POE.To_Protection (Entry_Call.Called_PO);
STPE.Lock_Entries (Called_PO, Ceiling_Violation);
if Ceiling_Violation then
pragma Assert (Ex = Ada.Exceptions.Null_Id);
Exception_To_Raise := Program_Error'Identity;
Entry_Call.Exception_To_Raise := Exception_To_Raise;
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Caller);
Initialization.Wakeup_Entry_Caller
(Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
if Single_Lock then
Unlock_RTS;
end if;
else
POO.PO_Do_Or_Queue
(Self_Id, Called_PO, Entry_Call,
Entry_Call.Requeue_With_Abort);
POO.PO_Service_Entries (Self_Id, Called_PO);
STPE.Unlock_Entries (Called_PO);
end if;
end if;
Entry_Calls.Reset_Priority
(Self_Id, Entry_Call.Acceptor_Prev_Priority);
else
-- The call does not need to be requeued.
Self_Id.Common.Call := Entry_Call.Acceptor_Prev_Call;
Entry_Call.Exception_To_Raise := Ex;
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Caller);
-- Done with Caller locked to make sure that Wakeup is not lost.
if Ex /= Ada.Exceptions.Null_Id then
Ada.Exceptions.Save_Occurrence
(Caller.Common.Compiler_Data.Current_Excep,
Self_Id.Common.Compiler_Data.Current_Excep);
end if;
Initialization.Wakeup_Entry_Caller (Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
if Single_Lock then
Unlock_RTS;
end if;
Entry_Calls.Reset_Priority
(Self_Id, Entry_Call.Acceptor_Prev_Priority);
end if;
end if;
Initialization.Undefer_Abort (Self_Id);
if Exception_To_Raise /= Ada.Exceptions.Null_Id then
Internal_Reraise;
end if;
-- ??? Do we need to give precedence to Program_Error that might be
-- raised due to failure of finalization, over Tasking_Error from
-- failure of requeue?
end Exceptional_Complete_Rendezvous;
-------------------
-- Is_Entry_Open --
-------------------
-- Call this only with abort deferred and holding lock of T.
function Is_Entry_Open (T : Task_ID; E : Task_Entry_Index) return Boolean is
begin
pragma Assert (T.Open_Accepts /= null);
if T.Open_Accepts /= null then
for J in T.Open_Accepts'Range loop
pragma Assert (J > 0);
if E = T.Open_Accepts (J).S then
return True;
end if;
end loop;
end if;
return False;
end Is_Entry_Open;
-------------------------------------
-- Requeue_Protected_To_Task_Entry --
-------------------------------------
procedure Requeue_Protected_To_Task_Entry
(Object : STPE.Protection_Entries_Access;
Acceptor : Task_ID;
E : Task_Entry_Index;
With_Abort : Boolean)
is
Entry_Call : constant Entry_Call_Link := Object.Call_In_Progress;
begin
pragma Assert (STPO.Self.Deferral_Level > 0);
Entry_Call.E := Entry_Index (E);
Entry_Call.Called_Task := Acceptor;
Entry_Call.Called_PO := Null_Address;
Entry_Call.Requeue_With_Abort := With_Abort;
Object.Call_In_Progress := null;
end Requeue_Protected_To_Task_Entry;
------------------------
-- Requeue_Task_Entry --
------------------------
procedure Requeue_Task_Entry
(Acceptor : Task_ID;
E : Task_Entry_Index;
With_Abort : Boolean)
is
Self_Id : constant Task_ID := STPO.Self;
Entry_Call : constant Entry_Call_Link := Self_Id.Common.Call;
begin
Initialization.Defer_Abort (Self_Id);
Entry_Call.Needs_Requeue := True;
Entry_Call.Requeue_With_Abort := With_Abort;
Entry_Call.E := Entry_Index (E);
Entry_Call.Called_Task := Acceptor;
Initialization.Undefer_Abort (Self_Id);
end Requeue_Task_Entry;
--------------------
-- Selective_Wait --
--------------------
procedure Selective_Wait
(Open_Accepts : Accept_List_Access;
Select_Mode : Select_Modes;
Uninterpreted_Data : out System.Address;
Index : out Select_Index)
is
Self_Id : constant Task_ID := STPO.Self;
Entry_Call : Entry_Call_Link;
Treatment : Select_Treatment;
Caller : Task_ID;
Selection : Select_Index;
Open_Alternative : Boolean;
begin
Initialization.Defer_Abort (Self_Id);
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Self_Id);
if not Self_Id.Callable then
pragma Assert (Self_Id.Pending_ATC_Level = 0);
pragma Assert (Self_Id.Pending_Action);
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
-- ??? In some cases abort is deferred more than once. Need to
-- figure out why this happens.
Self_Id.Deferral_Level := 1;
Initialization.Undefer_Abort (Self_Id);
-- Should never get here ???
pragma Assert (False);
raise Standard'Abort_Signal;
end if;
pragma Assert (Open_Accepts /= null);
Uninterpreted_Data := Null_Address;
Queuing.Select_Task_Entry_Call
(Self_Id, Open_Accepts, Entry_Call, Selection, Open_Alternative);
-- Determine the kind and disposition of the select.
Treatment := Default_Treatment (Select_Mode);
Self_Id.Chosen_Index := No_Rendezvous;
if Open_Alternative then
if Entry_Call /= null then
if Open_Accepts (Selection).Null_Body then
Treatment := Accept_Alternative_Completed;
else
Setup_For_Rendezvous_With_Body (Entry_Call, Self_Id);
Treatment := Accept_Alternative_Selected;
end if;
Self_Id.Chosen_Index := Selection;
elsif Treatment = No_Alternative_Open then
Treatment := Accept_Alternative_Open;
end if;
end if;
-- Handle the select according to the disposition selected above.
case Treatment is
when Accept_Alternative_Selected =>
-- Ready to rendezvous
Uninterpreted_Data := Self_Id.Common.Call.Uninterpreted_Data;
-- In this case the accept body is not Null_Body. Defer abort
-- until it gets into the accept body.
pragma Assert (Self_Id.Deferral_Level = 1);
Initialization.Defer_Abort_Nestable (Self_Id);
STPO.Unlock (Self_Id);
when Accept_Alternative_Completed =>
-- Accept body is null, so rendezvous is over immediately.
if Parameters.Runtime_Traces then
Send_Trace_Info (M_RDV_Complete, Entry_Call.Self);
end if;
STPO.Unlock (Self_Id);
Caller := Entry_Call.Self;
STPO.Write_Lock (Caller);
Initialization.Wakeup_Entry_Caller (Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
when Accept_Alternative_Open =>
-- Wait for caller.
Self_Id.Open_Accepts := Open_Accepts;
pragma Debug
(Debug.Trace (Self_Id, "Selective_Wait: wait", 'R'));
if Parameters.Runtime_Traces then
Send_Trace_Info (W_Select, Self_Id,
Integer (Open_Accepts'Length));
end if;
Wait_For_Call (Self_Id);
pragma Assert (Self_Id.Open_Accepts = null);
-- Self_Id.Common.Call should already be updated by the Caller if
-- not aborted. It might also be ready to do rendezvous even if
-- this wakes up due to an abortion.
-- Therefore, if the call is not empty we need to do the
-- rendezvous if the accept body is not Null_Body.
-- Aren't the first two conditions below redundant???
if Self_Id.Chosen_Index /= No_Rendezvous
and then Self_Id.Common.Call /= null
and then not Open_Accepts (Self_Id.Chosen_Index).Null_Body
then
Uninterpreted_Data := Self_Id.Common.Call.Uninterpreted_Data;
pragma Assert (Self_Id.Deferral_Level = 1);
Initialization.Defer_Abort_Nestable (Self_Id);
-- Leave abort deferred until the accept body
end if;
STPO.Unlock (Self_Id);
when Else_Selected =>
pragma Assert (Self_Id.Open_Accepts = null);
if Parameters.Runtime_Traces then
Send_Trace_Info (M_Select_Else);
end if;
STPO.Unlock (Self_Id);
when Terminate_Selected =>
-- Terminate alternative is open
Self_Id.Open_Accepts := Open_Accepts;
Self_Id.Common.State := Acceptor_Sleep;
STPO.Unlock (Self_Id);
-- Notify ancestors that this task is on a terminate alternative.
Utilities.Make_Passive (Self_Id, Task_Completed => False);
-- Wait for normal entry call or termination
pragma Assert (Self_Id.ATC_Nesting_Level = 1);
STPO.Write_Lock (Self_Id);
loop
Initialization.Poll_Base_Priority_Change (Self_Id);
exit when Self_Id.Open_Accepts = null;
Sleep (Self_Id, Acceptor_Sleep);
end loop;
Self_Id.Common.State := Runnable;
pragma Assert (Self_Id.Open_Accepts = null);
if Self_Id.Terminate_Alternative then
-- An entry call should have reset this to False,
-- so we must be aborted.
-- We cannot be in an async. select, since that
-- is not legal, so the abort must be of the entire
-- task. Therefore, we do not need to cancel the
-- terminate alternative. The cleanup will be done
-- in Complete_Master.
pragma Assert (Self_Id.Pending_ATC_Level = 0);
pragma Assert (Self_Id.Awake_Count = 0);
-- Trust that it is OK to fall through.
null;
else
-- Self_Id.Common.Call and Self_Id.Chosen_Index
-- should already be updated by the Caller.
if Self_Id.Chosen_Index /= No_Rendezvous
and then not Open_Accepts (Self_Id.Chosen_Index).Null_Body
then
Uninterpreted_Data := Self_Id.Common.Call.Uninterpreted_Data;
pragma Assert (Self_Id.Deferral_Level = 1);
-- We need an extra defer here, to keep abort
-- deferred until we get into the accept body
Initialization.Defer_Abort_Nestable (Self_Id);
end if;
end if;
STPO.Unlock (Self_Id);
when No_Alternative_Open =>
-- In this case, Index will be No_Rendezvous on return, which
-- should cause a Program_Error if it is not a Delay_Mode.
-- If delay alternative exists (Delay_Mode) we should suspend
-- until the delay expires.
Self_Id.Open_Accepts := null;
if Select_Mode = Delay_Mode then
Self_Id.Common.State := Delay_Sleep;
loop
Initialization.Poll_Base_Priority_Change (Self_Id);
exit when
Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level;
Sleep (Self_Id, Delay_Sleep);
end loop;
Self_Id.Common.State := Runnable;
STPO.Unlock (Self_Id);
else
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
Ada.Exceptions.Raise_Exception
(Program_Error'Identity, "Entry call not a delay mode");
end if;
end case;
if Single_Lock then
Unlock_RTS;
end if;
-- Caller has been chosen.
-- Self_Id.Common.Call should already be updated by the Caller.
-- Self_Id.Chosen_Index should either be updated by the Caller
-- or by Test_Selective_Wait.
-- On return, we sill start rendezvous unless the accept body is
-- null. In the latter case, we will have already completed the RV.
Index := Self_Id.Chosen_Index;
Initialization.Undefer_Abort_Nestable (Self_Id);
end Selective_Wait;
------------------------------------
-- Setup_For_Rendezvous_With_Body --
------------------------------------
-- Call this only with abort deferred and holding lock of Acceptor.
procedure Setup_For_Rendezvous_With_Body
(Entry_Call : Entry_Call_Link;
Acceptor : Task_ID) is
begin
Entry_Call.Acceptor_Prev_Call := Acceptor.Common.Call;
Acceptor.Common.Call := Entry_Call;
if Entry_Call.State = Now_Abortable then
Entry_Call.State := Was_Abortable;
end if;
Boost_Priority (Entry_Call, Acceptor);
end Setup_For_Rendezvous_With_Body;
----------------
-- Task_Count --
----------------
function Task_Count (E : Task_Entry_Index) return Natural is
Self_Id : constant Task_ID := STPO.Self;
Return_Count : Natural;
begin
Initialization.Defer_Abort (Self_Id);
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Self_Id);
Return_Count := Queuing.Count_Waiting (Self_Id.Entry_Queues (E));
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
return Return_Count;
end Task_Count;
----------------------
-- Task_Do_Or_Queue --
----------------------
function Task_Do_Or_Queue
(Self_ID : Task_ID;
Entry_Call : Entry_Call_Link;
With_Abort : Boolean) return Boolean
is
E : constant Task_Entry_Index :=
Task_Entry_Index (Entry_Call.E);
Old_State : constant Entry_Call_State := Entry_Call.State;
Acceptor : constant Task_ID := Entry_Call.Called_Task;
Parent : constant Task_ID := Acceptor.Common.Parent;
Parent_Locked : Boolean := False;
Null_Body : Boolean;
begin
-- Find out whether Entry_Call can be accepted immediately.
-- If the Acceptor is not callable, return False.
-- If the rendezvous can start, initiate it.
-- If the accept-body is trivial, also complete the rendezvous.
-- If the acceptor is not ready, enqueue the call.
-- This should have a special case for Accept_Call and Accept_Trivial,
-- so that we don't have the loop setup overhead, below.
-- The call state Done is used here and elsewhere to include both the
-- case of normal successful completion, and the case of an exception
-- being raised. The difference is that if an exception is raised no one
-- will pay attention to the fact that State = Done. Instead the
-- exception will be raised in Undefer_Abort, and control will skip past
-- the place where we normally would resume from an entry call.
pragma Assert (not Queuing.Onqueue (Entry_Call));
-- We rely that the call is off-queue for protection, that the caller
-- will not exit the Entry_Caller_Sleep, and so will not reuse the call
-- record for another call.
-- We rely on the Caller's lock for call State mod's.
-- We can't lock Acceptor.Parent while holding Acceptor,
-- so lock it in advance if we expect to need to lock it.
if Acceptor.Terminate_Alternative then
STPO.Write_Lock (Parent);
Parent_Locked := True;
end if;
STPO.Write_Lock (Acceptor);
-- If the acceptor is not callable, abort the call and return False.
if not Acceptor.Callable then
STPO.Unlock (Acceptor);
if Parent_Locked then
STPO.Unlock (Parent);
end if;
pragma Assert (Entry_Call.State < Done);
-- In case we are not the caller, set up the caller
-- to raise Tasking_Error when it wakes up.
STPO.Write_Lock (Entry_Call.Self);
Entry_Call.Exception_To_Raise := Tasking_Error'Identity;
Initialization.Wakeup_Entry_Caller (Self_ID, Entry_Call, Done);
STPO.Unlock (Entry_Call.Self);
return False;
end if;
-- Try to serve the call immediately.
if Acceptor.Open_Accepts /= null then
for J in Acceptor.Open_Accepts'Range loop
if Entry_Call.E = Entry_Index (Acceptor.Open_Accepts (J).S) then
-- Commit acceptor to rendezvous with us.
Acceptor.Chosen_Index := J;
Null_Body := Acceptor.Open_Accepts (J).Null_Body;
Acceptor.Open_Accepts := null;
-- Prevent abort while call is being served.
if Entry_Call.State = Now_Abortable then
Entry_Call.State := Was_Abortable;
end if;
if Acceptor.Terminate_Alternative then
-- Cancel terminate alternative.
-- See matching code in Selective_Wait and
-- Vulnerable_Complete_Master.
Acceptor.Terminate_Alternative := False;
Acceptor.Awake_Count := Acceptor.Awake_Count + 1;
if Acceptor.Awake_Count = 1 then
-- Notify parent that acceptor is awake.
pragma Assert (Parent.Awake_Count > 0);
Parent.Awake_Count := Parent.Awake_Count + 1;
if Parent.Common.State = Master_Completion_Sleep
and then Acceptor.Master_of_Task = Parent.Master_Within
then
Parent.Common.Wait_Count :=
Parent.Common.Wait_Count + 1;
end if;
end if;
end if;
if Null_Body then
-- Rendezvous is over immediately.
STPO.Wakeup (Acceptor, Acceptor_Sleep);
STPO.Unlock (Acceptor);
if Parent_Locked then
STPO.Unlock (Parent);
end if;
STPO.Write_Lock (Entry_Call.Self);
Initialization.Wakeup_Entry_Caller
(Self_ID, Entry_Call, Done);
STPO.Unlock (Entry_Call.Self);
else
Setup_For_Rendezvous_With_Body (Entry_Call, Acceptor);
-- For terminate_alternative, acceptor may not be
-- asleep yet, so we skip the wakeup
if Acceptor.Common.State /= Runnable then
STPO.Wakeup (Acceptor, Acceptor_Sleep);
end if;
STPO.Unlock (Acceptor);
if Parent_Locked then
STPO.Unlock (Parent);
end if;
end if;
return True;
end if;
end loop;
-- The acceptor is accepting, but not this entry.
end if;
-- If the acceptor was ready to accept this call,
-- we would not have gotten this far, so now we should
-- (re)enqueue the call, if the mode permits that.
if Entry_Call.Mode /= Conditional_Call
or else not With_Abort
then
-- Timed_Call, Simple_Call, or Asynchronous_Call
Queuing.Enqueue (Acceptor.Entry_Queues (E), Entry_Call);
-- Update abortability of call
pragma Assert (Old_State < Done);
Entry_Call.State := New_State (With_Abort, Entry_Call.State);
STPO.Unlock (Acceptor);
if Parent_Locked then
STPO.Unlock (Parent);
end if;
if Old_State /= Entry_Call.State
and then Entry_Call.State = Now_Abortable
and then Entry_Call.Mode > Simple_Call
and then Entry_Call.Self /= Self_ID
-- Asynchronous_Call or Conditional_Call
then
-- Because of ATCB lock ordering rule
STPO.Write_Lock (Entry_Call.Self);
if Entry_Call.Self.Common.State = Async_Select_Sleep then
-- Caller may not yet have reached wait-point
STPO.Wakeup (Entry_Call.Self, Async_Select_Sleep);
end if;
STPO.Unlock (Entry_Call.Self);
end if;
else
-- Conditional_Call and With_Abort
STPO.Unlock (Acceptor);
if Parent_Locked then
STPO.Unlock (Parent);
end if;
STPO.Write_Lock (Entry_Call.Self);
pragma Assert (Entry_Call.State >= Was_Abortable);
Initialization.Wakeup_Entry_Caller (Self_ID, Entry_Call, Cancelled);
STPO.Unlock (Entry_Call.Self);
end if;
return True;
end Task_Do_Or_Queue;
---------------------
-- Task_Entry_Call --
---------------------
procedure Task_Entry_Call
(Acceptor : Task_ID;
E : Task_Entry_Index;
Uninterpreted_Data : System.Address;
Mode : Call_Modes;
Rendezvous_Successful : out Boolean)
is
Self_Id : constant Task_ID := STPO.Self;
Entry_Call : Entry_Call_Link;
begin
if Parameters.Runtime_Traces then
Send_Trace_Info (W_Call, Acceptor, Entry_Index (E));
end if;
if Mode = Simple_Call or else Mode = Conditional_Call then
Call_Synchronous
(Acceptor, E, Uninterpreted_Data, Mode, Rendezvous_Successful);
else
-- This is an asynchronous call
-- Abortion must already be deferred by the compiler-generated
-- code. Without this, an abortion that occurs between the time
-- that this call is made and the time that the abortable part's
-- cleanup handler is set up might miss the cleanup handler and
-- leave the call pending.
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level + 1;
pragma Debug
(Debug.Trace (Self_Id, "TEC: entered ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
Entry_Call := Self_Id.Entry_Calls (Self_Id.ATC_Nesting_Level)'Access;
Entry_Call.Next := null;
Entry_Call.Mode := Mode;
Entry_Call.Cancellation_Attempted := False;
Entry_Call.State := Not_Yet_Abortable;
Entry_Call.E := Entry_Index (E);
Entry_Call.Prio := Get_Priority (Self_Id);
Entry_Call.Uninterpreted_Data := Uninterpreted_Data;
Entry_Call.Called_Task := Acceptor;
Entry_Call.Called_PO := Null_Address;
Entry_Call.Exception_To_Raise := Ada.Exceptions.Null_Id;
if Single_Lock then
Lock_RTS;
end if;
if not Task_Do_Or_Queue
(Self_Id, Entry_Call, With_Abort => True)
then
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level - 1;
pragma Debug
(Debug.Trace (Self_Id, "TEC: exited to ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
if Parameters.Runtime_Traces then
Send_Trace_Info (E_Missed, Acceptor);
end if;
raise Tasking_Error;
end if;
-- The following is special for async. entry calls.
-- If the call was not queued abortably, we need to wait until
-- it is before proceeding with the abortable part.
-- Wait_Until_Abortable can be called unconditionally here,
-- but it is expensive.
if Entry_Call.State < Was_Abortable then
Entry_Calls.Wait_Until_Abortable (Self_Id, Entry_Call);
end if;
if Single_Lock then
Unlock_RTS;
end if;
-- Note: following assignment needs to be atomic.
Rendezvous_Successful := Entry_Call.State = Done;
end if;
end Task_Entry_Call;
-----------------------
-- Task_Entry_Caller --
-----------------------
function Task_Entry_Caller (D : Task_Entry_Nesting_Depth) return Task_ID is
Self_Id : constant Task_ID := STPO.Self;
Entry_Call : Entry_Call_Link;
begin
Entry_Call := Self_Id.Common.Call;
for Depth in 1 .. D loop
Entry_Call := Entry_Call.Acceptor_Prev_Call;
pragma Assert (Entry_Call /= null);
end loop;
return Entry_Call.Self;
end Task_Entry_Caller;
--------------------------
-- Timed_Selective_Wait --
--------------------------
procedure Timed_Selective_Wait
(Open_Accepts : Accept_List_Access;
Select_Mode : Select_Modes;
Uninterpreted_Data : out System.Address;
Timeout : Duration;
Mode : Delay_Modes;
Index : out Select_Index)
is
Self_Id : constant Task_ID := STPO.Self;
Treatment : Select_Treatment;
Entry_Call : Entry_Call_Link;
Caller : Task_ID;
Selection : Select_Index;
Open_Alternative : Boolean;
Timedout : Boolean := False;
Yielded : Boolean := True;
begin
pragma Assert (Select_Mode = Delay_Mode);
Initialization.Defer_Abort (Self_Id);
-- If we are aborted here, the effect will be pending
if Single_Lock then
Lock_RTS;
end if;
STPO.Write_Lock (Self_Id);
if not Self_Id.Callable then
pragma Assert (Self_Id.Pending_ATC_Level = 0);
pragma Assert (Self_Id.Pending_Action);
STPO.Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
-- Should never get here ???
pragma Assert (False);
raise Standard'Abort_Signal;
end if;
Uninterpreted_Data := Null_Address;
pragma Assert (Open_Accepts /= null);
Queuing.Select_Task_Entry_Call
(Self_Id, Open_Accepts, Entry_Call, Selection, Open_Alternative);
-- Determine the kind and disposition of the select.
Treatment := Default_Treatment (Select_Mode);
Self_Id.Chosen_Index := No_Rendezvous;
if Open_Alternative then
if Entry_Call /= null then
if Open_Accepts (Selection).Null_Body then
Treatment := Accept_Alternative_Completed;
else
Setup_For_Rendezvous_With_Body (Entry_Call, Self_Id);
Treatment := Accept_Alternative_Selected;
end if;
Self_Id.Chosen_Index := Selection;
elsif Treatment = No_Alternative_Open then
Treatment := Accept_Alternative_Open;
end if;
end if;
-- Handle the select according to the disposition selected above.
case Treatment is
when Accept_Alternative_Selected =>
-- Ready to rendezvous
-- In this case the accept body is not Null_Body. Defer abort
-- until it gets into the accept body.
Uninterpreted_Data := Self_Id.Common.Call.Uninterpreted_Data;
Initialization.Defer_Abort (Self_Id);
STPO.Unlock (Self_Id);
when Accept_Alternative_Completed =>
-- Rendezvous is over
if Parameters.Runtime_Traces then
Send_Trace_Info (M_RDV_Complete, Entry_Call.Self);
end if;
STPO.Unlock (Self_Id);
Caller := Entry_Call.Self;
STPO.Write_Lock (Caller);
Initialization.Wakeup_Entry_Caller (Self_Id, Entry_Call, Done);
STPO.Unlock (Caller);
when Accept_Alternative_Open =>
-- Wait for caller.
Self_Id.Open_Accepts := Open_Accepts;
-- Wait for a normal call and a pending action until the
-- Wakeup_Time is reached.
Self_Id.Common.State := Acceptor_Sleep;
loop
Initialization.Poll_Base_Priority_Change (Self_Id);
exit when Self_Id.Open_Accepts = null;
if Timedout then
Sleep (Self_Id, Acceptor_Sleep);
else
if Parameters.Runtime_Traces then
Send_Trace_Info (WT_Select,
Self_Id,
Integer (Open_Accepts'Length),
Timeout);
end if;
STPO.Timed_Sleep (Self_Id, Timeout, Mode,
Acceptor_Sleep, Timedout, Yielded);
end if;
if Timedout then
Self_Id.Open_Accepts := null;
if Parameters.Runtime_Traces then
Send_Trace_Info (E_Timeout);
end if;
end if;
end loop;
Self_Id.Common.State := Runnable;
-- Self_Id.Common.Call should already be updated by the Caller if
-- not aborted. It might also be ready to do rendezvous even if
-- this wakes up due to an abortion.
-- Therefore, if the call is not empty we need to do the
-- rendezvous if the accept body is not Null_Body.
if Self_Id.Chosen_Index /= No_Rendezvous
and then Self_Id.Common.Call /= null
and then not Open_Accepts (Self_Id.Chosen_Index).Null_Body
then
Uninterpreted_Data := Self_Id.Common.Call.Uninterpreted_Data;
pragma Assert (Self_Id.Deferral_Level = 1);
Initialization.Defer_Abort_Nestable (Self_Id);
-- Leave abort deferred until the accept body
end if;
STPO.Unlock (Self_Id);
when No_Alternative_Open =>
-- In this case, Index will be No_Rendezvous on return. We sleep
-- for the time we need to.
-- Wait for a signal or timeout. A wakeup can be made
-- for several reasons:
-- 1) Delay is expired
-- 2) Pending_Action needs to be checked
-- (Abortion, Priority change)
-- 3) Spurious wakeup
Self_Id.Open_Accepts := null;
Self_Id.Common.State := Acceptor_Sleep;
Initialization.Poll_Base_Priority_Change (Self_Id);
STPO.Timed_Sleep (Self_Id, Timeout, Mode, Acceptor_Sleep,
Timedout, Yielded);
Self_Id.Common.State := Runnable;
STPO.Unlock (Self_Id);
when others =>
-- Should never get here
pragma Assert (False);
null;
end case;
if Single_Lock then
Unlock_RTS;
end if;
if not Yielded then
Yield;
end if;
-- Caller has been chosen
-- Self_Id.Common.Call should already be updated by the Caller
-- Self_Id.Chosen_Index should either be updated by the Caller
-- or by Test_Selective_Wait
Index := Self_Id.Chosen_Index;
Initialization.Undefer_Abort_Nestable (Self_Id);
-- Start rendezvous, if not already completed
end Timed_Selective_Wait;
---------------------------
-- Timed_Task_Entry_Call --
---------------------------
procedure Timed_Task_Entry_Call
(Acceptor : Task_ID;
E : Task_Entry_Index;
Uninterpreted_Data : System.Address;
Timeout : Duration;
Mode : Delay_Modes;
Rendezvous_Successful : out Boolean)
is
Self_Id : constant Task_ID := STPO.Self;
Level : ATC_Level;
Entry_Call : Entry_Call_Link;
Yielded : Boolean;
begin
Initialization.Defer_Abort (Self_Id);
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level + 1;
pragma Debug
(Debug.Trace (Self_Id, "TTEC: entered ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
if Parameters.Runtime_Traces then
Send_Trace_Info (WT_Call, Acceptor,
Entry_Index (E), Timeout);
end if;
Level := Self_Id.ATC_Nesting_Level;
Entry_Call := Self_Id.Entry_Calls (Level)'Access;
Entry_Call.Next := null;
Entry_Call.Mode := Timed_Call;
Entry_Call.Cancellation_Attempted := False;
-- If this is a call made inside of an abort deferred region,
-- the call should be never abortable.
if Self_Id.Deferral_Level > 1 then
Entry_Call.State := Never_Abortable;
else
Entry_Call.State := Now_Abortable;
end if;
Entry_Call.E := Entry_Index (E);
Entry_Call.Prio := Get_Priority (Self_Id);
Entry_Call.Uninterpreted_Data := Uninterpreted_Data;
Entry_Call.Called_Task := Acceptor;
Entry_Call.Called_PO := Null_Address;
Entry_Call.Exception_To_Raise := Ada.Exceptions.Null_Id;
-- Note: the caller will undefer abortion on return (see WARNING above)
if Single_Lock then
Lock_RTS;
end if;
if not Task_Do_Or_Queue
(Self_Id, Entry_Call, With_Abort => True)
then
Self_Id.ATC_Nesting_Level := Self_Id.ATC_Nesting_Level - 1;
pragma Debug
(Debug.Trace (Self_Id, "TTEC: exited to ATC level: " &
ATC_Level'Image (Self_Id.ATC_Nesting_Level), 'A'));
if Single_Lock then
Unlock_RTS;
end if;
Initialization.Undefer_Abort (Self_Id);
if Parameters.Runtime_Traces then
Send_Trace_Info (E_Missed, Acceptor);
end if;
raise Tasking_Error;
end if;
Write_Lock (Self_Id);
Entry_Calls.Wait_For_Completion_With_Timeout
(Entry_Call, Timeout, Mode, Yielded);
Unlock (Self_Id);
if Single_Lock then
Unlock_RTS;
end if;
-- ??? Do we need to yield in case Yielded is False
Rendezvous_Successful := Entry_Call.State = Done;
Initialization.Undefer_Abort (Self_Id);
Entry_Calls.Check_Exception (Self_Id, Entry_Call);
end Timed_Task_Entry_Call;
-------------------
-- Wait_For_Call --
-------------------
-- Call this only with abort deferred and holding lock of Self_Id.
-- Wait for normal call and a pending action.
procedure Wait_For_Call (Self_Id : Task_ID) is
begin
Self_Id.Common.State := Acceptor_Sleep;
loop
Initialization.Poll_Base_Priority_Change (Self_Id);
exit when Self_Id.Open_Accepts = null;
Sleep (Self_Id, Acceptor_Sleep);
end loop;
Self_Id.Common.State := Runnable;
end Wait_For_Call;
end System.Tasking.Rendezvous;
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