viewbarcode.com

Object-oriented programming and tasking in Software Encode PDF 417 in Software Object-oriented programming and tasking




How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
Object-oriented programming and tasking generate, create pdf417 none on software projects VS.NET An alternative implementation of this interface provides a reusable agent. package Asynchronous_Executio n.Reusable is task type Reusable_Agent is new Async_Executor with overriding entry Fork(This : Parameterless_Procedure; Id : out Async_Identifier); overriding entry Join(Id : Async_Identifier); end Reusable_Agent; end Asynchronous_Execution.Reusable; package body Asynchronous_Execution.

Reusable is task body Reusable_Agent is My_Procedure : Parameterless_Procedure; My_Id : Async_Identifier := 0; begin loop select accept Fork(This : Parameterless_Procedure; Id : out Async_Identifier) do My_Procedure := This; Id := My_Id; end Fork; or terminate; end select; My_Procedure.all; loop begin accept Join(Id : Async_Identifier) do if Id /= My_Id then raise Invalid_Join_Id; end if; end Join; exit; exception when Invalid_Join_Id => null; end; end loop; My_Id := My_Id + 1; end loop; end Reusable_Agent; end Asynchronous_Execution.Reusable;.

10.2 Tasks and interfaces Important As a task type cann ot be derived from other task types, it is not posnote: sible to share the code between the above two implementations for the Async Executor interface. Another implementation might provide a timeout on the calling of the Join procedure relative to when the fork occurred..

package Asynchronous_Executio pdf417 2d barcode for None n.Reusable_With_Timeout is task type Reusable_Agent is new Async_Executor with entry Set_Timeout(D : Duration); overriding entry Fork(This : Parameterless_Procedure; Id : out Async_Identifier); overriding entry Join(Id : Async_Identifier); end Reusable_Agent; end Asynchronous_Execution.Reusable_With_Timeout; with Ada.

Calendar; use Ada.Calendar; package body Asynchronous_Execution.Reusable_With_Timeout is task body Reusable_Agent is My_Procedure : Parameterless_Procedure; My_Timeout : Duration; My_Id : Async_Identifier := 0; Fork_Time : Time; begin accept Set_Timeout(D : Duration) do My_timeout := D; end Set_Timeout; loop select accept Fork(This : Parameterless_Procedure; Id : out Async_Identifier) do My_Procedure := This; Id := My_Id; Fork_Time := Clock; end Fork; or terminate; end select; My_Procedure.

all; loop begin select accept Join(Id : Async_Identifier) do if Id /= My_Id then raise Invalid_Join_Id; end if; end Join; or delay until Fork_Time + My_Timeout; end select; exit;. Object-oriented programming and tasking exception when Invalid_Join_I pdf417 for None d => null; end; end loop; My_Id := My_Id + 1; end loop; end Reusable_Agent; end Asynchronous_Execution.Reusable_With_Timeout;. Note, in the above example, t he task provides an additional entry to set the timeout value. Important As a consequence of a procedure in a limited interface being imnote: plementable by a task (or protected) entry, Ada 2005 now allows a timeout to be associated with the procedure call. Hence, the following could be used by the client.

. My_Agent : Async_Executor Cla barcode pdf417 for None ss := ...

; select My_Agent.Join(..

.); -- This can be any procedure call that uses a limited interface or delay 10.0; end select;.

10.2.1 Image processing examp le To illustrate the use of the above task interfaces, consider an image processing system using range images.

The image to be processed begins as an array of points whose values represent the distance from the camera to a corresponding point in the scene being viewed. A typical rst step in the processing is the calculation of the surface normals at each point of the array. This operation is ideally suited for parallel computation.

The problem is con gured so that the image acquisition is performed in a package, Image Acq, and the data is held in shared memory. Overall control is performed by a Manager task that processes segments of the image in parallel via calls to the Calc Seg package. A package, Images, contains the type declarations for the images and image segments.

It also contains the farm of worker tasks which support the Async Executor interface. Note, at this stage no commitment has been made to the actual worker task type to be used. Notice also the use of the pragmas to ensure that the shared data is properly accessed.

. 10.2 Tasks and interfaces with Asynchronous_Execution; package Images is type Seg_Index is range 1 .. 8; type Image_Index is range 1 .

. 4; type Image_Seg is array(Seg_Index, Seg_Index) of Integer; type Image is array (Image_Index, Image_Index) of Image_Seg; pragma Volatile_Components(Image); type Farm is array(Image_Index, Image_Index) of Asynchronous_Execution.Any_Async_Executor; pragma Atomic_Components(Farm); My_Farm : Farm; end Images;.

The Image Acq package contain Software PDF 417 s the code to take the picture, and stores the resulting image so that it can be accessed by the worker tasks:. with Images; use Images; pack age Image_Acq is procedure Get_The_Picture; Picture : Image; end Image_Acq;. The Manager package contains Software barcode pdf417 the code for managing the parallel execution. Worker tasks can request segments to be processed and return the results. The segments are identi ed by indices into the Picture image.

. with Images; use Images; with Asynchronous_Execution; use Asynchronous_Execution; package Manager is procedure Get_Segment_Index(I, J : out Image_Index); end Manager;. The body of Manager contains Software PDF-417 2d barcode a single task. The Controller rst takes the picture and then distributes the segments of the image to the worker tasks by calling the Fork method. At this time, run-time dispatching occurs to the agent that has been used to provide the parallel execution.

The Controller task is also responsible for collecting the results:. with Image_Acq; with Calc_Seg ; package body Manager is task Controller is entry Get_Segment_Index(I, J : out Image_Index); end Controller; procedure Get_Segment_Index(I, J : out Image_Index) is begin Controller.Get_Segment_Index(I,J); end Get_Segment_Index;.
Copyright © viewbarcode.com . All rights reserved.