| -- C974004.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 the abortable part of an asynchronous select statement |
| -- is aborted if it does not complete before the triggering statement |
| -- completes, where the triggering statement is a task entry call, |
| -- the entry call is queued, and the entry call completes by propagating |
| -- an exception and that the sequence of statements of the triggering |
| -- alternative is not executed after the abortable part is left and that |
| -- the exception propagated by the entry call is re-raised immediately |
| -- following the asynchronous select. |
| -- |
| -- TEST DESCRIPTION: |
| -- Declare a main procedure containing an asynchronous select with a task |
| -- entry call as triggering statement. Force the entry call to be |
| -- queued by having the task call a procedure, prior to the corresponding |
| -- accept statement, which simulates a routine waiting for user input |
| -- (with a delay). |
| -- |
| -- Simulate a time-consuming routine in the abortable part by calling a |
| -- procedure containing an infinite loop. Meanwhile, simulate input by |
| -- the user (the delay expires), which causes the task to execute the |
| -- accept statement corresponding to the triggering entry call. Raise |
| -- an exception in the accept statement which is not handled by the task, |
| -- and which is thus propagated to the caller. |
| -- |
| -- |
| -- CHANGE HISTORY: |
| -- 06 Dec 94 SAIC ACVC 2.0 |
| -- |
| --! |
| |
| package C974004_0 is -- Automated teller machine abstraction. |
| |
| |
| -- Flags for testing purposes: |
| |
| Count : Integer := 1234; -- Global to defeat |
| -- optimization. |
| Propagated_From_Task : exception; |
| |
| |
| type Key_Enum is (None, Cancel, Deposit, Withdraw); |
| |
| type Card_Number_Type is private; |
| type Card_PIN_Type is private; |
| type ATM_Card_Type is private; |
| |
| |
| Transaction_Canceled : exception; |
| |
| |
| task type ATM_Keyboard_Task is |
| entry Cancel_Pressed; |
| end ATM_Keyboard_Task; |
| |
| |
| procedure Read_Card (Card : in out ATM_Card_Type); |
| |
| procedure Validate_Card (Card : in ATM_Card_Type); |
| |
| procedure Perform_Transaction (Card : in ATM_Card_Type); |
| |
| private |
| |
| type Card_Number_Type is range 1 .. 9999; |
| type Card_PIN_Type is range 100 .. 999; |
| |
| type ATM_Card_Type is record |
| Number : Card_Number_Type; |
| PIN : Card_PIN_Type; |
| end record; |
| |
| end C974004_0; |
| |
| |
| --==================================================================-- |
| |
| |
| with Report; |
| with ImpDef; |
| |
| package body C974004_0 is |
| |
| |
| procedure Listen_For_Input (Key : out Key_Enum) is |
| begin |
| -- Simulate the situation where a user waits a bit for the card to |
| -- be validated, then presses cancel before it completes. |
| |
| -- Delay long enough to force queuing of Keyboard.Cancel_Pressed. |
| delay ImpDef.Clear_Ready_Queue; |
| |
| if Report.Equal (3, 3) then -- Always true. |
| Key := Cancel; |
| end if; |
| end Listen_For_Input; |
| |
| |
| -- One of these gets created as "Keyboard" for each transaction |
| -- |
| task body ATM_Keyboard_Task is |
| Key_Pressed : Key_Enum := None; |
| begin |
| loop |
| -- Force entry calls to be |
| Listen_For_Input (Key_Pressed); -- queued, then set guard to |
| -- true. |
| select |
| when (Key_Pressed = Cancel) => -- Guard is now true, so accept |
| accept Cancel_Pressed do -- queued entry call. |
| null; --:::: user code for cancel |
| -- Now simulate an unexpected exception arising in the |
| -- user code |
| raise Propagated_From_Task; -- Propagate an exception. |
| |
| end Cancel_Pressed; |
| |
| Report.Failed |
| ("Exception not propagated in ATM_Keyboard_Task"); |
| |
| -- User has canceled the transaction so we exit the |
| -- loop and allow the task to terminate |
| exit; |
| else |
| Key_Pressed := None; |
| end select; |
| end loop; |
| exception |
| when Propagated_From_Task => |
| null; -- This is the expected test behavior |
| when others => |
| Report.Failed ("Unexpected Exception in ATM_Keyboard_Task"); |
| end ATM_Keyboard_Task; |
| |
| |
| |
| procedure Read_Card (Card : in out ATM_Card_Type) is |
| begin |
| Card.Number := 9999; |
| Card.PIN := 111; |
| end Read_Card; |
| |
| |
| procedure Validate_Card (Card : in ATM_Card_Type) is |
| begin |
| -- Simulate an exceedingly long validation activity. |
| loop -- Infinite loop. |
| Count := (Count + 1) mod Integer (Card.PIN); |
| -- Synch. point to allow transfer of control to Keyboard |
| -- task during this simulation |
| delay ImpDef.Minimum_Task_Switch; |
| exit when not Report.Equal (Count, Count); -- Always false. |
| end loop; |
| end Validate_Card; |
| |
| |
| procedure Perform_Transaction (Card : in ATM_Card_Type) is |
| begin |
| Report.Failed ("Exception not re-raised immediately following " & |
| "asynchronous select"); |
| if Count = 1234 then |
| -- Initial value is unchanged |
| Report.Failed ("Abortable part did not execute"); |
| end if; |
| end Perform_Transaction; |
| |
| |
| end C974004_0; |
| |
| |
| --==================================================================-- |
| |
| |
| with Report; |
| |
| with C974004_0; -- Automated teller machine abstraction. |
| use C974004_0; |
| |
| procedure C974004 is |
| |
| Card_Data : ATM_Card_Type; |
| |
| begin -- Main program. |
| |
| Report.Test ("C974004", "Asynchronous Select: Trigger is queued on a " & |
| "task entry and is completed first by an " & |
| "exception"); |
| |
| Read_Card (Card_Data); |
| |
| begin |
| |
| declare |
| -- Create the task for this transaction |
| Keyboard : C974004_0.ATM_Keyboard_Task; |
| begin |
| |
| -- -- |
| -- Asynchronous select is tested here -- |
| -- -- |
| |
| select |
| Keyboard.Cancel_Pressed; -- Entry call initially queued, so |
| -- abortable part starts. |
| |
| raise Transaction_Canceled; -- Should not be executed. |
| then abort |
| Validate_Card (Card_Data); -- Keyboard.Cancel_Pressed is accepted |
| -- and propagates an exception before |
| -- this call finishes; it is then |
| -- aborted. |
| |
| -- Check that the whole of the abortable part is aborted, not |
| -- just the statement in the abortable part that was executing |
| -- at the time |
| Report.Failed ("Abortable part not aborted"); |
| end select; |
| -- The propagated exception is |
| -- re-raised here; control passes to |
| -- the exception handler. |
| |
| Perform_Transaction(Card_Data); -- Should not be reached. |
| exception |
| when Transaction_Canceled => |
| Report.Failed ("Triggering alternative sequence of statements " & |
| "executed"); |
| when Propagated_From_Task => |
| -- This is the expected test path |
| if Count = 1234 then |
| -- Initial value is unchanged |
| Report.Failed ("Abortable part did not execute"); |
| end if; |
| when Tasking_Error => |
| Report.Failed ("Tasking_Error raised"); |
| when others => |
| Report.Failed ("Wrong exception raised"); |
| end; |
| |
| exception |
| when Propagated_From_Task => |
| Report.Failed ("Correct exception raised at wrong level"); |
| when others => |
| Report.Failed ("Wrong exception raised at wrong level"); |
| end; |
| |
| Report.Result; |
| |
| end C974004; |
