c954014.a

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-- C954014.A
--
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--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained 
--     unlimited rights in the software and documentation contained herein.
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--     recipients unlimited rights  equal to those held by the Government.  
--     These rights include rights to use, duplicate, release or disclose the 
--     released technical data and computer software in whole or in part, in 
--     any manner and for any purpose whatsoever, and to have or permit others 
--     to do so.
--
--                                    DISCLAIMER
--
--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED 
--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE 
--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
--     PARTICULAR PURPOSE OF SAID MATERIAL.
--*
--
-- OBJECTIVE:
--     Check that a requeue is not canceled and that the requeueing 
--     task is unaffected when a calling task is aborted. Check that the
--     abort is deferred until the entry call is complete.
--     Specifically, check requeue to an entry in a different task,
--     requeue where the entry call has parameters, and requeue
--     without the abort option.
--
-- TEST DESCRIPTION
--     In the Driver create a task that places a call on the
--     Distributor.  In the Distributor requeue this call on the Credit task.
--     Abort the calling task when it is known to be in rendezvous with the
--     Credit task. (We arrange this by using artificial synchronization
--     points in the Driver and the accept body of the Credit task) Ensure
--     that the abort is deferred (the task is not terminated) until the
--     accept body completes.   Afterwards, send one extra message through
--     the Distributor to check that the requeueing task has not been
--     disrupted. 
--
--     This series of tests uses a simulation of a transaction driven
--     processing system.  Line Drivers accept input from an external source
--     and build them into transaction records.  These records are then
--     encapsulated in message tasks which remain extant for the life of the
--     transaction in the system.  The message tasks put themselves on the
--     input queue of a Distributor which, from information in the
--     transaction and/or system load conditions forwards them to other
--     operating tasks. These in turn might forward the transactions to yet
--     other tasks for further action.  The routing is, in real life, dynamic
--     and unpredictable at the time of message generation.  All rerouting in
--     this  model is done by means of requeues.
--
--
-- CHANGE HISTORY:
--      06 Dec 94   SAIC    ACVC 2.0
--      25 Nov 95   SAIC    Replaced global variables with protected objects
--                          for ACVC 2.0.1.
--
--!

with Report;
with ImpDef;
         
procedure C954014 is
 
   -- Arbitrary test values
   Credit_Return : constant := 1;
   Debit_Return  : constant := 2;


   protected type Shared_Boolean (Initial_Value : Boolean := False) is
      procedure Set_True;
      procedure Set_False;
      function  Value return Boolean;
   private
      Current_Value : Boolean := Initial_Value;
   end Shared_Boolean;

   protected body Shared_Boolean is
      procedure Set_True is
      begin
         Current_Value := True;
      end Set_True;

      procedure Set_False is
      begin
         Current_Value := False;
      end Set_False;

      function Value return Boolean is
      begin
         return Current_Value;
      end Value;
   end Shared_Boolean;
 

   TC_Debit_Message_Complete  : Shared_Boolean (False);
   
   -- Synchronization flags for handshaking between the Line_Driver
   -- and the Accept body in the Credit Task
   TC_Handshake_A : Shared_Boolean (False);
   TC_Handshake_B : Shared_Boolean (False);
   TC_Handshake_C : Shared_Boolean (False);
   TC_Handshake_D : Shared_Boolean (False);
   TC_Handshake_E : Shared_Boolean (False);
   TC_Handshake_F : Shared_Boolean (False);


   type Transaction_Code is (Credit, Debit);

   type Transaction_Record;
   type acc_Transaction_Record is access Transaction_Record;
   type Transaction_Record is 
      record
         ID               : integer := 0;
         Code             : Transaction_Code := Debit;
         Account_Number   : integer := 0;
         Stock_Number     : integer := 0;
         Quantity         : integer := 0;
         Return_Value     : integer := 0;
         TC_Message_Count : integer := 0; 
         TC_Thru_Distrib  : Boolean;
      end record;

   
   task type Message_Task is 
      entry Accept_Transaction (In_Transaction : acc_Transaction_Record);
   end Message_Task;
   type acc_Message_Task is access Message_Task;

   task Line_Driver is
      entry start;
   end Line_Driver;   

   task Distributor is 
      entry Input(Transaction : acc_Transaction_Record);
   end Distributor;

   task Credit_Computation is
      entry Input(Transaction : acc_Transaction_Record);
   end Credit_Computation;

   task Debit_Computation is
      entry Input(Transaction : acc_Transaction_Record);
   end Debit_Computation;


   -- Assemble messages received from an external source
   --   Creates a message task for each. The message tasks remain extant
   --   for the life of the messages in the system.
   --      TC: The Line Driver task would normally be designed to loop
   --      continuously creating the messages as input is received.  Simulate
   --      this  but limit it to two dummy messages for this test and use
   --      special artificial handshaking checks with the Credit accept body
   --      to control the test. Allow it to terminate at the end
   --
   task body Line_Driver is
      Current_ID : integer := 1;
      TC_First_message_sent: Boolean := false;

      procedure Build_Credit_Record 
                              ( Next_Transaction : acc_Transaction_Record ) is
         Dummy_Account : constant integer := 100;
      begin
            Next_Transaction.ID := Current_ID;
            Next_Transaction.Code := Credit; 

            Next_Transaction.Account_Number := Dummy_Account;
            Current_ID := Current_ID + 1;
      end Build_Credit_Record;     


      procedure Build_Debit_Record 
                              ( Next_Transaction : acc_Transaction_Record ) is
         Dummy_Account : constant integer := 200;
      begin
            Next_Transaction.ID := Current_ID;
            Next_Transaction.Code := Debit; 

            Next_Transaction.Account_Number := Dummy_Account;
            Current_ID := Current_ID + 1;
      end Build_Debit_Record;     

   begin
   
      accept Start;       -- Wait for trigger from main

      for i in 1..2 loop  -- TC: arbitrarily limit to one credit message
                          --     and one debit, then complete
         declare 
            -- Create a task for the next message
            Next_Message_Task : acc_Message_Task := new Message_Task;
            -- Create a record for it
            Next_Transaction : acc_Transaction_Record := 
                                                   new Transaction_Record;
         begin
            if not TC_First_Message_Sent then
               -- send out the first message which will be aborted
               Build_Credit_Record ( Next_Transaction );            
               Next_Message_Task.Accept_Transaction ( Next_Transaction );  
               TC_First_Message_Sent := true;

               -- Wait for Credit task to get into the accept body
               --   The call from the Message Task has been requeued by
               --   the distributor
               while not TC_Handshake_A.Value loop
                  delay ImpDef.Minimum_Task_Switch;
               end loop;

               -- Abort the calling task; the Credit task is guaranteed to 
               -- be in the accept body
               abort Next_Message_Task.all;     -- We are still in this declare
                                                -- block
              
               -- Inform the Credit task that the abort has been initiated
               TC_Handshake_B.Set_True;
               
               -- Now wait for the "acknowledgment" from the Credit task
               -- this ensures a complete task switch (at least) 
               while not TC_Handshake_C.Value loop
                  delay ImpDef.Minimum_Task_Switch;
               end loop;

               -- The aborted task must not terminate till the accept body
               -- has completed
               if Next_Message_Task'terminated then
                  Report.Failed ("The abort was not deferred");
               end if;

               -- Inform the Credit task that the termination has been checked
               TC_Handshake_D.Set_True;
               
               -- Now wait for the completion of the accept body in the 
               -- Credit task
               while not TC_Handshake_E.Value loop
                  delay ImpDef.Minimum_Task_Switch;
               end loop;
               
               while not ( Next_Message_Task'terminated ) loop