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-- CB20005.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 exceptions are raised and properly handled locally in
-- protected operations.
--
-- TEST DESCRIPTION:
-- Declare a package with a protected type, including protected operation
-- declarations and private data, simulating a counting semaphore.
-- In the main procedure, perform calls on protected operations
-- of the protected object designed to induce the raising of exceptions.
--
-- Ensure that the exceptions are raised and handled locally in a
-- protected procedures and functions, and that in this case the
-- exceptions will not propagate to the calling unit. Use specific
-- exception handlers in the protected functions.
--
--
--
-- CHANGE HISTORY:
-- 06 Dec 94 SAIC ACVC 2.0
--
--!
package CB20005_0 is -- Package Semaphore.
Handled_In_Function,
Handled_In_Procedure : Boolean := False;
Resource_Overflow,
Resource_Underflow : exception;
protected type Counting_Semaphore (Max_Resources : Integer) is
procedure Secure;
function Resource_Limit_Exceeded return Boolean;
procedure Release;
private
Count : Integer := Max_Resources;
end Counting_Semaphore;
end CB20005_0;
--=================================================================--
with Report;
package body CB20005_0 is -- Package Semaphore.
protected body Counting_Semaphore is
procedure Secure is
begin
if (Count = 0) then -- No resources left to secure.
raise Resource_Underflow;
Report.Failed
("Program control not transferred by raise in Secure");
else
Count := Count - 1; -- Avail resources decremented.
end if;
exception
when Resource_Underflow => -- Exception handled locally in
Handled_In_Procedure := True; -- this protected operation.
when others =>
Report.Failed ("Unexpected exception raised in Secure");
end Secure;
function Resource_Limit_Exceeded return Boolean is
begin
if (Count > Max_Resources) then
raise Resource_Overflow; -- Exception used as control flow
-- mechanism.
Report.Failed
("Program control not transferred by raise in " &
"Resource_Limit_Exceeded");
else
return (False);
end if;
exception
when Resource_Overflow => -- Handle its own raised
Handled_In_Function := True; -- exception.
return (True);
when others =>
Report.Failed
("Unexpected exception raised in Resource_Limit_Exceeded");
end Resource_Limit_Exceeded;
procedure Release is
begin
Count := Count + 1; -- Count of resources available
-- incremented.
if Resource_Limit_Exceeded then -- Call to protected operation
Count := Count - 1; -- function that raises/handles
end if; -- an exception.
exception
when Resource_Overflow =>
Handled_In_Function := False;
Report.Failed ("Exception propagated to Function Release");
when others =>
Report.Failed ("Unexpected exception raised in Function Release");
end Release;
end Counting_Semaphore;
end CB20005_0;
--=================================================================--
with CB20005_0; -- Package Semaphore.
with Report;
procedure CB20005 is
begin
Report.Test ("CB20005", "Check that exceptions are raised and handled " &
"correctly in protected operations" );
Test_Block:
declare
package Semaphore renames CB20005_0;
Total_Resources_Available : constant := 1;
Resources : Semaphore.Counting_Semaphore(Total_Resources_Available);
-- An object of protected type.
begin
Allocate_Resources:
declare
Loop_Count : Integer := Total_Resources_Available + 1;
begin
for I in 1..Loop_Count loop -- Force exception.
Resources.Secure;
end loop;
exception
when Semaphore.Resource_Underflow =>
Semaphore.Handled_In_Procedure := False; -- Excptn not handled
Report.Failed -- in prot. operation.
("Resource_Underflow exception not handled " &
"in Allocate_Resources");
when others =>
Report.Failed
("Exception unexpectedly raised during resource allocation");
end Allocate_Resources;
Deallocate_Resources:
declare
Loop_Count : Integer := Total_Resources_Available + 1;
begin
for I in 1..Loop_Count loop -- Force excptn.
Resources.Release;
end loop;
exception
when Semaphore.Resource_Overflow =>
Semaphore.Handled_In_Function := False; -- Exception not handled
Report.Failed -- in prot. operation.
("Resource overflow not handled by function");
when others =>
Report.Failed
("Exception raised during resource deallocation");
end Deallocate_Resources;
if not (Semaphore.Handled_In_Procedure and -- Incorrect excpt. handling
Semaphore.Handled_In_Function) -- in protected operations.
then
Report.Failed
("Improper exception handling by protected operations");
end if;
exception
when others =>
Report.Failed ("Exception raised and propagated in test");
end Test_Block;
Report.Result;
end CB20005;
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