-- C954021.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 within a protected entry to an entry in a -- different protected object is queued correctly. -- -- TEST DESCRIPTION: -- One transaction is sent through to check the paths. After processing -- this the Credit task sets the "overloaded" indicator. Once this -- indicator is set the Distributor (a protected object) queues low -- priority transactions on a Wait_for_Underload queue in another -- protected object using a requeue. The Distributor still delivers high -- priority transactions. After two high priority transactions have been -- processed by the Credit task it clears the overload condition. The -- low priority transactions should now be delivered. -- -- 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 -- 26 Nov 95 SAIC Fixed shared global variable for ACVC 2.0.1 -- --! with Report; with ImpDef; procedure C954021 is -- Arbitrary test values Credit_Return : constant := 1; Debit_Return : constant := 2; -- Mechanism to count the number of Credit Message tasks completed protected TC_Tasks_Completed is procedure Increment; function Count return integer; private Number_Complete : integer := 0; end TC_Tasks_Completed; TC_Credit_Messages_Expected : constant integer := 5; protected TC_Handshake is procedure Set; function First_Message_Arrived return Boolean; private Arrived_Flag : Boolean := false; end TC_Handshake; -- Handshaking mechanism between the Line Driver and the Credit task -- protected body TC_Handshake is -- procedure Set is begin Arrived_Flag := true; end Set; -- function First_Message_Arrived return Boolean is begin return Arrived_Flag; end First_Message_Arrived; -- end TC_Handshake; 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); type Transaction_Code is (Credit, Debit); type Transaction_Priority is (High, Low); type Transaction_Record; type acc_Transaction_Record is access Transaction_Record; type Transaction_Record is record ID : integer := 0; Code : Transaction_Code := Debit; Priority : Transaction_Priority := High; Account_Number : integer := 0; Stock_Number : integer := 0; Quantity : integer := 0; Return_Value : integer := 0; TC_Message_Count : integer := 0; TC_Thru_Dist : Boolean := false; 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; protected Distributor is procedure Set_Credit_Overloaded; procedure Clear_Credit_Overloaded; function Credit_is_Overloaded return Boolean; entry Input (Transaction : acc_Transaction_Record); private Credit_Overloaded : Boolean := false; end Distributor; protected Hold is procedure Underloaded; entry Wait_for_Underload (Transaction : acc_Transaction_Record); private Release_All : Boolean := false; end Hold; 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; -- -- Dispose each input Transaction_Record to the appropriate -- computation tasks -- protected body Distributor is procedure Set_Credit_Overloaded is begin Credit_Overloaded := true; end Set_Credit_Overloaded; procedure Clear_Credit_Overloaded is begin Credit_Overloaded := false; Hold.Underloaded; -- Release all held messages end Clear_Credit_Overloaded; function Credit_is_Overloaded return Boolean is begin return Credit_Overloaded; end Credit_is_Overloaded; entry Input (Transaction : acc_Transaction_Record) when true is -- barrier is always open begin -- Test Control: Set the indicator in the message to show it has -- passed through the Distributor object Transaction.TC_thru_Dist := true; -- Pass this transaction on to the appropriate computation -- task but temporarily hold low-priority transactions under -- overload conditions case Transaction.Code is when Credit => if Credit_Overloaded and Transaction.Priority = Low then requeue Hold.Wait_for_Underload with abort; else requeue Credit_Computation.Input with abort; end if; when Debit => requeue Debit_Computation.Input with abort; end case; end Input; end Distributor; -- Low priority Message tasks are held on the Wait_for_Underload queue -- while the Credit computation system is overloaded. Once the Credit -- system reached underload send all queued messages immediately -- protected body Hold is -- Once this is executed the barrier condition for the entry is -- evaluated procedure Underloaded is begin Release_All := true; end Underloaded; entry Wait_for_Underload (Transaction : acc_Transaction_Record) when Release_All is begin requeue Credit_Computation.Input with abort; if Wait_for_Underload'count = 0 then -- Queue is purged. Set up to hold next batch Release_All := false; end if; end Wait_for_Underload; end Hold; -- Mechanism to count the number of Message tasks completed (Credit) protected body TC_Tasks_Completed is procedure Increment is begin Number_Complete := Number_Complete + 1; end Increment; function Count return integer is begin return Number_Complete; end Count; end TC_Tasks_Completed; -- 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. -- The Line Driver task would normally be designed to loop continuously -- creating the messages as input is received. Simulate this -- but limit it to the required number of dummy messages needed for -- this test and allow it to terminate at that point. Artificially -- alternate High and Low priority Credit transactions for this test. -- task body Line_Driver is Current_ID : integer := 1; Current_Priority : Transaction_Priority := High; -- Artificial: number of messages required for this test type TC_Trans_Range is range 1..6; 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.Priority := Current_Priority; 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 Transaction_Numb in TC_Trans_Range loop -- TC: limit the loop 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 Transaction_Numb = TC_Trans_Range'first then -- Send the first Credit message Build_Credit_Record ( Next_Transaction ); Next_Message_Task.Accept_Transaction ( Next_Transaction ); -- TC: Wait until the first message has been received by the -- Credit task and it has set the Overload indicator for the -- Distributor while not TC_Handshake.First_Message_Arrived loop delay ImpDef.Minimum_Task_Switch; end loop; elsif Transaction_Numb = TC_Trans_Range'last then -- For this test send the last transaction to the Debit task -- to improve the mix Build_Debit_Record( Next_Transaction ); Next_Message_Task.Accept_Transaction ( Next_Transaction ); else -- TC: Alternate high and low priority transactions if Current_Priority = High then Current_Priority := Low; else Current_Priority := High; end if; Build_Credit_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 if This_Transaction.Return_Value /= Credit_Return or not This_Transaction.TC_thru_Dist then Report.Failed ("Expected path not traversed - Credit"); end if; TC_Tasks_Completed.Increment; else if This_Transaction.Return_Value /= Debit_Return or This_Transaction.TC_Message_Count /= 1 or not This_Transaction.TC_thru_Dist then Report.Failed ("Expected path not traversed - Debit"); end if; TC_Debit_Message_Complete.Set_True; end if; exception when others => Report.Failed ("Unexpected exception in Message_Task"); end Message_Task; -- Computation task. After the computation is performed 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 if Distributor.Credit_is_Overloaded and Transaction.Priority = Low then -- We should not be getting any Low Priority messages. They -- should be waiting on the Hold.Wait_for_Underload -- queue Report.Failed ("Credit Task: Low priority transaction during overload"); end if; -- Perform the computations required for this transaction null; -- stub -- For the test: if not Transaction.TC_thru_Dist 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; -- The following is all Test Control code: Transaction.Return_Value := Credit_Return; Message_Count := Message_Count + 1; -- -- Now take special action depending on which Message if Message_Count = 1 then -- After the first message : Distributor.Set_Credit_Overloaded; -- Now flag the Line_Driver that the second and subsequent -- messages may now be sent TC_Handshake.Set; end if; if Message_Count = 3 then -- The two high priority transactions created subsequent -- to the overload have now been processed Distributor.Clear_Credit_Overloaded; end if; end Input; or terminate; end select; end loop; exception when others => Report.Failed ("Unexpected exception in Credit_Computation"); end Credit_Computation; -- Computation task. After the computation is performed 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 -- For the test: if not Transaction.TC_thru_Dist 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 Report.Test ("C954021", "Requeue from one entry body to an entry in" & " another protected object"); Line_Driver.Start; -- Start the test -- Ensure that the message tasks have completed before reporting result while (TC_Tasks_Completed.Count < TC_Credit_Messages_Expected) and not TC_Debit_Message_Complete.Value loop delay ImpDef.Minimum_Task_Switch; end loop; Report.Result; end C954021;