-- C954A03.A
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-- C954A03.A
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--
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--
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-- Grant of Unlimited Rights
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-- Grant of Unlimited Rights
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--
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--
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-- Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
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-- Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
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-- F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained
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-- F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained
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-- unlimited rights in the software and documentation contained herein.
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-- unlimited rights in the software and documentation contained herein.
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-- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making
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-- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making
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-- this public release, the Government intends to confer upon all
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-- this public release, the Government intends to confer upon all
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-- recipients unlimited rights equal to those held by the Government.
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-- recipients unlimited rights equal to those held by the Government.
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-- These rights include rights to use, duplicate, release or disclose the
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-- These rights include rights to use, duplicate, release or disclose the
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-- released technical data and computer software in whole or in part, in
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-- released technical data and computer software in whole or in part, in
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-- any manner and for any purpose whatsoever, and to have or permit others
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-- any manner and for any purpose whatsoever, and to have or permit others
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-- to do so.
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-- to do so.
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--
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--
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-- DISCLAIMER
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-- DISCLAIMER
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--
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--
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-- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
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-- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
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-- DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED
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-- DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED
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-- WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
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-- WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
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-- SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE
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-- SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE
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-- OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
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-- OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
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-- PARTICULAR PURPOSE OF SAID MATERIAL.
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-- PARTICULAR PURPOSE OF SAID MATERIAL.
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--*
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--*
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--
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--
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-- OBJECTIVE:
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-- OBJECTIVE:
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-- Check that a requeue statement in an accept_statement with
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-- Check that a requeue statement in an accept_statement with
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-- parameters may requeue the entry call to a protected entry with no
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-- parameters may requeue the entry call to a protected entry with no
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-- parameters. Check that, if the call is queued on the new entry's
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-- parameters. Check that, if the call is queued on the new entry's
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-- queue, the original caller remains blocked after the requeue, but
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-- queue, the original caller remains blocked after the requeue, but
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-- the accept_statement containing the requeue is completed.
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-- the accept_statement containing the requeue is completed.
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--
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--
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-- Note that this test uses a requeue "with abort," although it does not
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-- Note that this test uses a requeue "with abort," although it does not
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-- check that such a requeued caller can be aborted; that feature is
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-- check that such a requeued caller can be aborted; that feature is
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-- tested elsewhere.
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-- tested elsewhere.
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--
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--
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-- TEST DESCRIPTION:
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-- TEST DESCRIPTION:
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-- Declare a protected type which simulates a printer device driver
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-- Declare a protected type which simulates a printer device driver
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-- (foundation code).
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-- (foundation code).
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--
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--
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-- Declare a task which simulates a printer server for multiple printers.
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-- Declare a task which simulates a printer server for multiple printers.
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--
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--
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-- For the protected type, declare an entry with a barrier that is set
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-- For the protected type, declare an entry with a barrier that is set
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-- false by a protected procedure (which simulates starting a print job
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-- false by a protected procedure (which simulates starting a print job
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-- on the printer), and is set true by a second protected procedure (which
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-- on the printer), and is set true by a second protected procedure (which
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-- simulates a handler called when the printer interrupts, indicating
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-- simulates a handler called when the printer interrupts, indicating
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-- that printing is done).
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-- that printing is done).
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--
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--
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-- For the task, declare an entry whose corresponding accept statement
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-- For the task, declare an entry whose corresponding accept statement
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-- contains a call to first protected procedure of the protected type
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-- contains a call to first protected procedure of the protected type
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-- (which sets the barrier of the protected entry to false), followed by
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-- (which sets the barrier of the protected entry to false), followed by
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-- a requeue with abort to the protected entry. Declare a second entry
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-- a requeue with abort to the protected entry. Declare a second entry
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-- which does nothing.
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-- which does nothing.
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--
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--
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-- Declare a "requesting" task which calls the printer server task entry
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-- Declare a "requesting" task which calls the printer server task entry
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-- (and thus executes the requeue). Verify that, following the requeue,
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-- (and thus executes the requeue). Verify that, following the requeue,
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-- the requesting task remains blocked. Call the second entry of the
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-- the requesting task remains blocked. Call the second entry of the
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-- printer server task (the acceptance of this entry call verifies that
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-- printer server task (the acceptance of this entry call verifies that
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-- the requeue statement completed the entry call by the requesting task.
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-- the requeue statement completed the entry call by the requesting task.
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-- Call the second protected procedure of the protected type (the
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-- Call the second protected procedure of the protected type (the
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-- interrupt handler) and verify that the protected entry completes for
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-- interrupt handler) and verify that the protected entry completes for
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-- the requesting task (which verifies that the requeue statement queued
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-- the requesting task (which verifies that the requeue statement queued
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-- the first task object to the protected entry).
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-- the first task object to the protected entry).
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--
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--
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-- TEST FILES:
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-- TEST FILES:
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-- This test depends on the following foundation code:
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-- This test depends on the following foundation code:
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--
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--
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-- F954A00.A
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-- F954A00.A
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--
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--
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--
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--
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-- CHANGE HISTORY:
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-- CHANGE HISTORY:
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-- 06 Dec 94 SAIC ACVC 2.0
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-- 06 Dec 94 SAIC ACVC 2.0
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-- 10 Oct 96 SAIC Added pragma elaborate.
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-- 10 Oct 96 SAIC Added pragma elaborate.
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--
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--
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--!
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--!
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package C954A03_0 is -- Printer server abstraction.
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package C954A03_0 is -- Printer server abstraction.
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-- Simulate a system with multiple printers. The entry Print requests
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-- Simulate a system with multiple printers. The entry Print requests
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-- that data be printed on the next available printer. The entry call
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-- that data be printed on the next available printer. The entry call
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-- is accepted when a printer is available, and completes when printing
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-- is accepted when a printer is available, and completes when printing
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-- is done.
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-- is done.
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task Printer_Server is
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task Printer_Server is
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entry Print (File_Name : String); -- Test the requeue statement.
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entry Print (File_Name : String); -- Test the requeue statement.
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entry Verify_Results; -- Artifice for test purposes.
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entry Verify_Results; -- Artifice for test purposes.
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end Printer_Server;
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end Printer_Server;
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end C954A03_0;
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end C954A03_0;
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--==================================================================--
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--==================================================================--
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with Report;
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with Report;
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with ImpDef;
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with ImpDef;
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with F954A00; -- Printer device abstraction.
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with F954A00; -- Printer device abstraction.
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use F954A00;
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use F954A00;
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pragma Elaborate(F954a00);
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pragma Elaborate(F954a00);
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package body C954A03_0 is -- Printer server abstraction.
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package body C954A03_0 is -- Printer server abstraction.
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task body Printer_Server is
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task body Printer_Server is
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Printers_Busy : Boolean := True;
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Printers_Busy : Boolean := True;
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Index : Printer_ID := 1;
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Index : Printer_ID := 1;
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Print_Accepted : Boolean := False;
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Print_Accepted : Boolean := False;
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begin
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begin
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loop
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loop
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-- Wait for a printer to become available:
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-- Wait for a printer to become available:
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while Printers_Busy loop
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while Printers_Busy loop
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Printers_Busy := False; -- Exit loop if
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Printers_Busy := False; -- Exit loop if
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-- entry accepted.
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-- entry accepted.
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select
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select
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Printer(Index).Done_Printing; -- Accepted immed.
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Printer(Index).Done_Printing; -- Accepted immed.
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-- when printer is
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-- when printer is
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-- available.
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-- available.
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else
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else
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Index := 1 + (Index mod Number_Of_Printers);-- Entry not immed.
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Index := 1 + (Index mod Number_Of_Printers);-- Entry not immed.
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Printers_Busy := True; -- accepted; keep
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Printers_Busy := True; -- accepted; keep
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end select; -- looping.
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end select; -- looping.
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-- Allow other tasks to get control
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-- Allow other tasks to get control
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delay ImpDef.Minimum_Task_Switch;
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delay ImpDef.Minimum_Task_Switch;
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end loop;
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end loop;
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-- Value of Index
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-- Value of Index
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-- at loop exit
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-- at loop exit
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-- identifies the
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-- identifies the
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-- avail. printer.
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-- avail. printer.
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-- Wait for a print request or terminate:
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-- Wait for a print request or terminate:
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select
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select
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accept Print (File_Name : String) do
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accept Print (File_Name : String) do
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Print_Accepted := True; -- Allow
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Print_Accepted := True; -- Allow
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-- Verify_Results
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-- Verify_Results
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-- to be accepted.
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-- to be accepted.
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Printer(Index).Start_Printing (File_Name); -- Begin printing on
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Printer(Index).Start_Printing (File_Name); -- Begin printing on
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-- the available
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-- the available
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-- -- -- printer.
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-- -- -- printer.
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-- Requeue is tested here --
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-- Requeue is tested here --
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-- --
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-- --
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-- Requeue caller so
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-- Requeue caller so
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requeue Printer(Index).Done_Printing -- server task free
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requeue Printer(Index).Done_Printing -- server task free
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with abort; -- to accept other
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with abort; -- to accept other
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end Print; -- requests.
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end Print; -- requests.
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or
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or
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-- Guard ensures that Verify_Results cannot be accepted
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-- Guard ensures that Verify_Results cannot be accepted
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-- until after Print has been accepted. This avoids a
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-- until after Print has been accepted. This avoids a
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-- race condition in the main program.
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-- race condition in the main program.
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when Print_Accepted => accept Verify_Results; -- Artifice for
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when Print_Accepted => accept Verify_Results; -- Artifice for
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-- testing purposes.
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-- testing purposes.
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or
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or
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terminate;
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terminate;
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end select;
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end select;
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end loop;
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end loop;
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exception
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exception
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when others =>
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when others =>
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Report.Failed ("Exception raised in Printer_Server task");
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Report.Failed ("Exception raised in Printer_Server task");
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end Printer_Server;
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end Printer_Server;
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end C954A03_0;
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end C954A03_0;
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--==================================================================--
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--==================================================================--
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with Report;
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with Report;
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with ImpDef;
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with ImpDef;
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with F954A00; -- Printer device abstraction.
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with F954A00; -- Printer device abstraction.
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with C954A03_0; -- Printer server abstraction.
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with C954A03_0; -- Printer server abstraction.
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use C954A03_0;
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use C954A03_0;
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use F954A00;
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use F954A00;
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procedure C954A03 is
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procedure C954A03 is
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Long_Enough : constant Duration := ImpDef.Clear_Ready_Queue;
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Long_Enough : constant Duration := ImpDef.Clear_Ready_Queue;
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--==============================================--
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--==============================================--
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Task_Completed : Boolean := False; -- Testing flag.
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Task_Completed : Boolean := False; -- Testing flag.
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protected Interlock is -- Artifice for test purposes.
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protected Interlock is -- Artifice for test purposes.
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entry Wait; -- Wait for lock to be released.
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entry Wait; -- Wait for lock to be released.
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procedure Release; -- Release the lock.
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procedure Release; -- Release the lock.
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private
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private
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Locked : Boolean := True;
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Locked : Boolean := True;
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end Interlock;
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end Interlock;
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protected body Interlock is
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protected body Interlock is
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entry Wait when not Locked is -- Calls are queued until after
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entry Wait when not Locked is -- Calls are queued until after
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-- -- Release is called.
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-- -- Release is called.
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begin
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begin
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Task_Completed := True;
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Task_Completed := True;
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end Wait;
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end Wait;
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procedure Release is -- Called by Print_Request.
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procedure Release is -- Called by Print_Request.
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begin
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begin
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Locked := False;
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Locked := False;
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end Release;
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end Release;
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end Interlock;
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end Interlock;
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--==============================================--
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--==============================================--
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task Print_Request is -- Send a print request.
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task Print_Request is -- Send a print request.
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end Print_Request;
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end Print_Request;
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task body Print_Request is
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task body Print_Request is
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My_File : constant String := "MYFILE.DAT";
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My_File : constant String := "MYFILE.DAT";
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begin
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begin
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Printer_Server.Print (My_File); -- Invoke requeue statement.
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Printer_Server.Print (My_File); -- Invoke requeue statement.
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Interlock.Release; -- Allow main to continue.
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Interlock.Release; -- Allow main to continue.
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exception
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exception
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when others =>
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when others =>
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Report.Failed ("Exception raised in Print_Request task");
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Report.Failed ("Exception raised in Print_Request task");
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end Print_Request;
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end Print_Request;
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--==============================================--
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--==============================================--
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begin -- Main program.
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begin -- Main program.
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Report.Test ("C954A03", "Requeue from an Accept with parameters" &
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Report.Test ("C954A03", "Requeue from an Accept with parameters" &
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" to a Protected Entry without parameters");
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" to a Protected Entry without parameters");
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-- To pass this test, the following must be true:
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-- To pass this test, the following must be true:
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--
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--
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-- (A) The Print entry call made by the task Print_Request must be
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-- (A) The Print entry call made by the task Print_Request must be
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-- completed by the requeue statement.
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-- completed by the requeue statement.
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-- (B) Print_Request must remain blocked following the requeue.
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-- (B) Print_Request must remain blocked following the requeue.
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-- (C) Print_Request must be queued on the Done_Printing queue of
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-- (C) Print_Request must be queued on the Done_Printing queue of
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-- Printer(1).
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-- Printer(1).
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-- (D) Print_Request must continue execution after Done_Printing is
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-- (D) Print_Request must continue execution after Done_Printing is
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-- complete.
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-- complete.
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--
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--
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-- First, verify (A): that the Print entry call is complete.
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-- First, verify (A): that the Print entry call is complete.
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--
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--
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-- Call the entry Verify_Results. If the requeue statement completed the
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-- Call the entry Verify_Results. If the requeue statement completed the
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-- entry call to Print, the entry call to Verify_Results should be
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-- entry call to Print, the entry call to Verify_Results should be
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-- accepted. Since the main will hang if this is NOT the case, make this
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-- accepted. Since the main will hang if this is NOT the case, make this
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-- a timed entry call.
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-- a timed entry call.
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select
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select
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Printer_Server.Verify_Results; -- Accepted if requeue completed
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Printer_Server.Verify_Results; -- Accepted if requeue completed
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-- entry call to Print.
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-- entry call to Print.
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or
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or
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delay Long_Enough; -- Time out otherwise.
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delay Long_Enough; -- Time out otherwise.
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Report.Failed ("Requeue did not complete entry call");
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Report.Failed ("Requeue did not complete entry call");
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end select;
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end select;
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-- Now verify (B): that Print_Request remains blocked following the
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-- Now verify (B): that Print_Request remains blocked following the
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-- requeue. Also verify that Done_Printing (the entry to which
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-- requeue. Also verify that Done_Printing (the entry to which
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-- Print_Request should have been queued) has not yet executed.
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-- Print_Request should have been queued) has not yet executed.
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if Printer(1).Is_Done then
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if Printer(1).Is_Done then
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Report.Failed ("Target entry of requeue executed prematurely");
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Report.Failed ("Target entry of requeue executed prematurely");
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elsif Print_Request'Terminated then
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elsif Print_Request'Terminated then
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Report.Failed ("Caller did not remain blocked after the requeue");
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Report.Failed ("Caller did not remain blocked after the requeue");
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else
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else
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-- Verify (C): that Print_Request is queued on the
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-- Verify (C): that Print_Request is queued on the
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-- Done_Printing queue of Printer(1).
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-- Done_Printing queue of Printer(1).
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--
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--
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-- Set the barrier for Printer(1).Done_Printing to true. Check
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-- Set the barrier for Printer(1).Done_Printing to true. Check
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-- that the Done flag is updated and that Print_Request terminates.
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-- that the Done flag is updated and that Print_Request terminates.
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Printer(1).Handle_Interrupt; -- Simulate a printer interrupt,
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Printer(1).Handle_Interrupt; -- Simulate a printer interrupt,
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-- signaling that printing is
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-- signaling that printing is
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-- done.
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-- done.
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-- The Done_Printing entry body will complete before the next
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-- The Done_Printing entry body will complete before the next
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-- protected action is called (Printer(1).Is_Done).
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-- protected action is called (Printer(1).Is_Done).
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if not Printer(1).Is_Done then
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if not Printer(1).Is_Done then
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Report.Failed ("Caller was not requeued on target entry");
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Report.Failed ("Caller was not requeued on target entry");
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end if;
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end if;
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-- Finally, verify (D): that Print_Request continues after Done_Printing
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-- Finally, verify (D): that Print_Request continues after Done_Printing
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-- completes.
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-- completes.
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--
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--
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-- After Done_Printing completes, there is a potential race condition
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-- After Done_Printing completes, there is a potential race condition
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-- between the main program and Print_Request. The protected object
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-- between the main program and Print_Request. The protected object
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-- Interlock is provided to ensure that the check of whether
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-- Interlock is provided to ensure that the check of whether
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-- Print_Request continued is made *after* it has had a chance to do so.
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-- Print_Request continued is made *after* it has had a chance to do so.
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-- The main program waits until the statement in Print_Request following
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-- The main program waits until the statement in Print_Request following
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-- the requeue-causing statement has executed, then checks to see
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-- the requeue-causing statement has executed, then checks to see
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-- whether Print_Request did in fact continue executing.
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-- whether Print_Request did in fact continue executing.
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--
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--
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-- Note that the test will hang here if Print_Request does not continue
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-- Note that the test will hang here if Print_Request does not continue
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-- executing following the completion of the requeued entry call.
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-- executing following the completion of the requeued entry call.
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Interlock.Wait; -- Wait until Print_Request is
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Interlock.Wait; -- Wait until Print_Request is
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-- done.
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-- done.
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if not Task_Completed then
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if not Task_Completed then
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Report.Failed ("Caller remained blocked after target " &
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Report.Failed ("Caller remained blocked after target " &
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"entry released");
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"entry released");
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end if;
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end if;
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-- Wait for Print_Request to finish before calling Report.Result.
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-- Wait for Print_Request to finish before calling Report.Result.
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while not Print_Request'Terminated loop
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while not Print_Request'Terminated loop
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delay ImpDef.Minimum_Task_Switch;
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delay ImpDef.Minimum_Task_Switch;
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end loop;
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end loop;
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end if;
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end if;
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Report.Result;
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Report.Result;
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end C954A03;
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end C954A03;
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