-- C954014.A -- -- Grant of Unlimited Rights -- -- 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. -- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making -- this public release, the Government intends to confer upon all -- 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 delay ImpDef.Minimum_Task_Switch; end loop; -- Indicate to the Main program that this section is complete TC_Handshake_F.Set_True; else -- The main part of the test is complete. Send one Debit message -- as further exercise of the Distributor to ensure it has not -- been affected by the abort of the requeue; Build_Debit_Record ( Next_Transaction ); Next_Message_Task.Accept_Transaction ( Next_Transaction ); end if; end; -- declare end loop; exception when others => Report.Failed ("Unexpected exception in Line_Driver"); end Line_Driver; task body Message_Task is TC_Original_Transaction_Code : Transaction_Code; This_Transaction : acc_Transaction_Record := new Transaction_Record; begin accept Accept_Transaction (In_Transaction : acc_Transaction_Record) do This_Transaction.all := In_Transaction.all; end Accept_Transaction; -- Note the original code to ensure correct return TC_Original_Transaction_Code := This_Transaction.Code; -- Queue up on Distributor's Input queue Distributor.Input ( This_Transaction ); -- This task will now wait for the requeued rendezvous -- to complete before proceeding -- After the required computations have been performed -- return the Transaction_Record appropriately (probably to an output -- line driver) null; -- stub -- For the test check that the return values are as expected if TC_Original_Transaction_Code /= This_Transaction.Code then -- Incorrect rendezvous Report.Failed ("Message Task: Incorrect code returned"); end if; if This_Transaction.Code = Credit then -- The only Credit message was the one that should have been aborted Report.Failed ("Abort was not effective"); else if This_Transaction.Return_Value /= Debit_Return or This_Transaction.TC_Message_Count /= 1 or not This_Transaction.TC_Thru_Distrib then Report.Failed ("Expected path not traversed"); end if; TC_Debit_Message_Complete.Set_True; end if; exception when others => Report.Failed ("Unexpected exception in Message_Task"); end Message_Task; -- Dispose each input Transaction_Record to the appropriate -- computation tasks -- task body Distributor is begin loop select accept Input (Transaction : acc_Transaction_Record) do -- Indicate that the message did pass through the -- Distributor Task Transaction.TC_Thru_Distrib := true; -- Pass this transaction on the appropriate computation -- task case Transaction.Code is when Credit => requeue Credit_Computation.Input; -- without abort when Debit => requeue Debit_Computation.Input; -- without abort end case; end Input; or terminate; end select; end loop; exception when others => Report.Failed ("Unexpected exception in Distributor"); end Distributor; -- Computation task. -- Note: After the computation is performed in this task and the -- accept body is completed the rendezvous in the original -- message task is completed. task body Credit_Computation is Message_Count : integer := 0; begin loop select accept Input ( Transaction : acc_Transaction_Record) do -- Perform the computations required for this transaction -- null; -- stub -- The rest of this code is for Test Control -- if not Transaction.TC_Thru_Distrib then Report.Failed ("Credit Task: Wrong queue, Distributor bypassed"); end if; if Transaction.code /= Credit then Report.Failed ("Credit Task: Requeue delivered to the wrong queue"); end if; -- for the test plug a known value and count Transaction.Return_Value := Credit_Return; -- one, and only one message should pass through if Message_Count /= 0 then Report.Failed ("Aborted Requeue was not canceled -1"); end if; Message_Count := Message_Count + 1; Transaction.TC_Message_Count := Message_Count; -- Having done the basic housekeeping we now need to signal -- that we are in the accept body of the credit task. The -- message has arrived and the Line Driver may now abort the -- calling task TC_Handshake_A.Set_True; -- Now wait for the Line Driver to inform us the calling -- task has been aborted while not TC_Handshake_B.Value loop delay ImpDef.Minimum_Task_Switch; end loop; -- The abort has taken place -- Inform the Line Driver that we are still running in the -- accept body TC_Handshake_C.Set_True; -- Now wait for the Line Driver to digest this information while not TC_Handshake_D.Value loop delay ImpDef.Minimum_Task_Switch; end loop; -- The Line driver has checked that the caller is not terminated -- We can now complete the accept end Input; -- We are out of the accept TC_Handshake_E.Set_True; or terminate; end select; end loop; exception when others => Report.Failed ("Unexpected exception in Credit_Computation"); end Credit_Computation; -- Computation task. -- Note: After the computation is performed in this task and the -- accept body is completed the rendezvous in the original -- message task is completed. task body Debit_Computation is Message_Count : integer := 0; begin loop select accept Input (Transaction : acc_Transaction_Record) do -- Perform the computations required for this message -- null; -- stub -- The rest of this code is for Test Control -- if not Transaction.TC_Thru_Distrib then Report.Failed ("Debit Task: Wrong queue, Distributor bypassed"); end if; if Transaction.code /= Debit then Report.Failed ("Debit Task: Requeue delivered to the wrong queue"); end if; -- for the test plug a known value and count Transaction.Return_Value := Debit_Return; -- one, and only one, message should pass through Message_Count := Message_Count + 1; Transaction.TC_Message_Count := Message_Count; end Input; or terminate; end select; end loop; exception when others => Report.Failed ("Unexpected exception in Debit_Computation"); end Debit_Computation; begin -- c954014 Report.Test ("C954014", "Abort a task that has a call" & " requeued_without_abort"); Line_Driver.Start; -- Start the test -- Wait for the message tasks to complete before reporting the result -- while not (TC_Handshake_F.Value -- abort not effective? and TC_Debit_Message_Complete.Value -- Distributor affected? and TC_Handshake_E.Value ) loop -- accept not completed? delay ImpDef.Minimum_Task_Switch; end loop; Report.Result; end C954014;