| -- C960002.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 simple "delay until" when the request time is "now" and |
| -- also some time already in the past is obeyed and returns immediately |
| -- |
| -- TEST DESCRIPTION: |
| -- Simulate a task that sends a "pulse" at regular intervals. The Delay |
| -- Until statement is used to avoid accumulated drift. In this test |
| -- three simple situations simulating the start of drift are used: the |
| -- next pulse being called for at the normal time, the next pulse being |
| -- called for at exactly the current time and then at some time which has |
| -- already past. We assume the delay is within a While Loop and, to |
| -- simplify the test, we "unfold" the While Loop and execute the Delays |
| -- in a serial fashion. This loop is shown in test C960001. |
| -- It is not possible to test the actual immediacy of the expiration. We |
| -- can only check that it returns in a "reasonable" time. In this case |
| -- we check that it expires before the next "pulse" should have been |
| -- issued. |
| -- |
| -- |
| -- CHANGE HISTORY: |
| -- 06 Dec 94 SAIC ACVC 2.0 |
| -- |
| --! |
| |
| with Report; |
| with ImpDef; |
| |
| with Ada.Calendar; |
| with System; |
| |
| procedure C960002 is |
| |
| begin |
| |
| Report.Test ("C960002", "Simple Delay Until with requested time being" & |
| " ""now"" and time already in the past"); |
| |
| declare -- To get the Report.Result after all has completed |
| |
| function "+" (Left : Ada.Calendar.Time; Right: Duration) |
| return Ada.Calendar.Time renames Ada.Calendar."+"; |
| function "-" (Left : Ada.Calendar.Time; Right: Duration) |
| return Ada.Calendar.Time renames Ada.Calendar."-"; |
| function "-" (Left, Right : Ada.Calendar.Time) |
| return duration renames Ada.Calendar."-"; |
| function ">" (Left, Right : Ada.Calendar.Time) |
| return Boolean renames Ada.Calendar.">"; |
| |
| |
| task Pulse_Task is |
| entry Trigger; |
| end Pulse_Task; |
| |
| |
| -- Task to synchronize all qualified receivers. |
| -- The entry Trigger starts the synchronization. |
| -- |
| task body Pulse_Task is |
| Pulse_Time : Ada.Calendar.Time; |
| Pulse_Time_Delta : constant duration := ImpDef.Clear_Ready_Queue; |
| |
| |
| |
| TC_Time_Back : Ada.Calendar.Time; |
| |
| |
| -- This routine transmits a synchronizing "pulse" to |
| -- all receivers |
| procedure Pulse is |
| begin |
| null; -- Stub |
| Report.Comment (".......PULSE........"); |
| end Pulse; |
| |
| begin |
| accept Trigger; |
| Pulse; |
| --------------- |
| -- normal calculation for "next" |
| Pulse_Time := Ada.Calendar.Clock + Pulse_Time_Delta; |
| |
| -- TC: unfold the "while" loop in C960001. Four passes through |
| -- the loop are shown |
| |
| delay until Pulse_Time; |
| |
| Pulse; |
| --------------- |
| -- TC: the normal calculation for "next" would be |
| -- Pulse_Time := Pulse_Time + Pulse_Time_Delta; |
| -- Instead of this normal pulse time calculation simulate |
| -- the new pulse time to be exactly "now" (or, as exactly as |
| -- we can) |
| Pulse_Time := Ada.Calendar.Clock; |
| delay until Ada.Calendar.Clock; |
| |
| TC_Time_Back := Ada.Calendar.Clock; |
| |
| -- Now check for reasonableness |
| if TC_Time_Back > Pulse_Time + Pulse_Time_Delta then |
| Report.Failed |
| ("""Now"" delayed for more than Pulse_Time_Delta - A"); |
| end if; |
| Pulse; |
| --------------- |
| -- normal calculation for "next" would be |
| Pulse_Time := Pulse_Time + Pulse_Time_Delta; |
| |
| -- TC: Instead of this, simulate the new calculated pulse time |
| -- being already past |
| Pulse_Time := Ada.Calendar.Clock - System.Tick; |
| delay until Pulse_Time; |
| |
| TC_Time_Back := Ada.Calendar.Clock; |
| |
| -- Now check for reasonableness |
| if TC_Time_Back > Pulse_Time + Pulse_Time_Delta then |
| Report.Failed |
| ("""Now"" delayed for more than Pulse_Time_Delta - B"); |
| end if; |
| Pulse; |
| --------------- |
| -- normal calculation for "next" |
| Pulse_Time := Pulse_Time + Pulse_Time_Delta; |
| -- Now simulate getting back into synch |
| delay until Pulse_Time; |
| Pulse; |
| --------------- |
| -- This would be the end of the "while" loop |
| |
| exception |
| when others => |
| Report.Failed ("Unexpected exception in Pulse_Task"); |
| end Pulse_Task; |
| |
| |
| |
| begin -- declare |
| |
| Pulse_Task.Trigger; -- Start test |
| |
| end; -- declare |
| |
| Report.Result; |
| |
| end C960002; |