-- C954012.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 a requeue within an accept body to another entry in the same task -- Specifically, check a call with parameters and a requeue with abort. -- -- 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 queues low priority transactions -- on a Wait_for_Underload queue in the same task 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 -- 25 Nov 95 SAIC Fixed shared global variable problem for -- ACVC 2.0.1 -- 14 Mar 03 RLB Fixed a race condition and an incorrect termination -- condition in the test. --! with Report; with ImpDef; with Ada.Calendar; procedure C954012 is function "=" (X,Y: Ada.Calendar.Time) return Boolean renames Ada.Calendar."="; -- Arbitrary test values Credit_Return : constant := 1; Debit_Return : constant := 2; -- This is used as an "initializing" time for the messages as they are -- created. As they pass through the Distributor they get a time_stamp -- of the current time. An arbitrary base time is chosen. -- TC: this fact is used, incidentally, to check that the messages have, -- indeed, passed through the Distributor as expected. -- Base_Time : Ada.Calendar.Time := Ada.Calendar.Time_of(1959,3,9); -- 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; 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); -- Handshaking mechanism between the Line Driver and the Credit task TC_First_Message_Has_Arrived : Shared_Boolean (False); Credit_Overloaded : Shared_Boolean (False); TC_Credit_Messages_Expected : constant integer := 5; 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; Message_Count : integer := 0; -- for test Time_Stamp : Ada.Calendar.Time := Base_Time; 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); entry Wait_for_Underload (Transaction : acc_Transaction_Record); entry TC_Credit_OK; 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; -- 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_First_Message_Has_Arrived.Value 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; -- TC: Wait for Credit_Overloaded to be cleared, then insure that the -- Distributor has evalated all tasks. Otherwise, some tasks may never -- be evaluated. while Credit_Overloaded.Value loop delay ImpDef.Minimum_Task_Switch; end loop; Distributor.TC_Credit_OK; 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 This_Transaction.Time_Stamp = Base_Time then Report.Failed ("Expected path not traversed"); end if; TC_Tasks_Completed.Increment; else if This_Transaction.Return_Value /= Debit_Return or This_Transaction.Message_Count /= 1 or This_Transaction.Time_Stamp = Base_Time 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 -- Time_Stamp the messages with the current time -- TC: Used, incidentally, by the test to check that the -- message did pass through the Distributor Task Transaction.Time_Stamp := Ada.Calendar.Clock; -- 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.Value and Transaction.Priority = Low then requeue 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; or when not Credit_Overloaded.Value => accept Wait_for_Underload (Transaction : acc_Transaction_Record) do requeue Credit_Computation.Input with abort; end Wait_for_Underload; or accept TC_Credit_OK; -- We need this to insure that we evaluate the guards at least -- once when Credit_Overloaded is False. Otherwise, tasks -- could stay queued on Wait_for_Underload forever (starvation). or terminate; end select; end loop; exception when others => Report.Failed ("Unexpected exception in Distributor"); end Distributor; -- 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 Credit_Overloaded.Value and Transaction.Priority = Low then -- We should not be getting any Low Priority messages. They -- should be waiting on the Distributor's 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 Transaction.Time_Stamp = Base_Time 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 : Credit_Overloaded.Set_True; -- Now flag the Line_Driver that the second and subsequent -- messages may now be sent TC_First_Message_Has_Arrived.Set_True; end if; if Message_Count = 3 then -- The two high priority transactions created subsequent -- to the overload have now been processed Credit_Overloaded.Set_False; 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 Transaction.Time_Stamp = Base_Time 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.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 -- c954012 Report.Test ("C954012", "Requeue within an accept body" & " to another entry in the same task"); Line_Driver.Start; -- Start the test -- Ensure that the message tasks complete before reporting the result while (TC_Tasks_Completed.Count < TC_Credit_Messages_Expected) or (not TC_Debit_Message_Complete.Value) loop delay ImpDef.Minimum_Task_Switch; end loop; Report.Result; end C954012;