| -- 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; |
