crystal reports 2013 qr code A person is eating a plate of spaghetti for dinner. He decides to add some salt. He picks in Font

Print QR Code ISO/IEC18004 in Font A person is eating a plate of spaghetti for dinner. He decides to add some salt. He picks

Example 22 A person is eating a plate of spaghetti for dinner. He decides to add some salt. He picks
QR Code Maker In None
Using Barcode creation for Font Control to generate, create QR Code image in Font applications.
www.OnBarcode.com
EAN-13 Creation In None
Using Barcode creation for Font Control to generate, create UPC - 13 image in Font applications.
www.OnBarcode.com
up the saltshaker and shakes it over the pasta repeatedly until the desired amount of salt has been added. In this example, the command is add salt to spaghetti. The caller is the person; the callee is the saltshaker. The handshake is the image of the salt falling on the spaghetti. The interaction is a caller-controlled handshake, because it is the person who decides when to stop adding salt.
EAN / UCC - 14 Generation In None
Using Barcode generator for Font Control to generate, create EAN / UCC - 14 image in Font applications.
www.OnBarcode.com
Painting Code 128 In None
Using Barcode drawer for Font Control to generate, create Code128 image in Font applications.
www.OnBarcode.com
CHAPTER 9 EVENT-BASED INTERACTION PATTERNS
Code 39 Full ASCII Creation In None
Using Barcode maker for Font Control to generate, create Code 39 Extended image in Font applications.
www.OnBarcode.com
Barcode Printer In None
Using Barcode generator for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Example 23 A system is designed to transmit satellite images over a network. The transmission
Data Matrix ECC200 Generation In None
Using Barcode generation for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
Royal Mail Barcode Drawer In None
Using Barcode creator for Font Control to generate, create RoyalMail4SCC image in Font applications.
www.OnBarcode.com
channel uses packets to carry information, and each packet can hold 2 KB. Typical images are more than 50 MB in size, so you must break them down into blocks that fit into channel packets. Figure 9-20 shows the interactions between the transmitter and receiver components.
QR Creation In None
Using Barcode generator for Office Word Control to generate, create QR Code image in Office Word applications.
www.OnBarcode.com
Encoding QR Code JIS X 0510 In Objective-C
Using Barcode creation for iPad Control to generate, create Denso QR Bar Code image in iPad applications.
www.OnBarcode.com
Transmitter
Print Code 39 Full ASCII In None
Using Barcode creator for Online Control to generate, create Code 3 of 9 image in Online applications.
www.OnBarcode.com
Paint Code 128 Code Set A In C#
Using Barcode generation for VS .NET Control to generate, create Code 128 Code Set C image in .NET applications.
www.OnBarcode.com
Receiver
DataMatrix Generation In Java
Using Barcode creator for Android Control to generate, create ECC200 image in Android applications.
www.OnBarcode.com
Decode USS Code 39 In VB.NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Cycle Repeats Until a Zero-Length Packet Is Sent.
Barcode Creation In Visual Studio .NET
Using Barcode creator for VS .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
Denso QR Bar Code Recognizer In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Send Packet Handshake
Generate Code 39 Extended In None
Using Barcode drawer for Office Excel Control to generate, create Code 39 image in Office Excel applications.
www.OnBarcode.com
Barcode Creator In VS .NET
Using Barcode drawer for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
Figure 9-20. Handshaking in an image transmission system The transmitter acts as the caller, the receiver as the callee. To signal the end of an image, a last packet is sent with zero bytes. During the interaction, the receiver doesn t know how much data will arrive. Only the caller does, and it uses a special signal to tell the receiver when the interaction is complete.
PDF 417 Generator In None
Using Barcode encoder for Online Control to generate, create PDF417 image in Online applications.
www.OnBarcode.com
Code-128 Generation In Java
Using Barcode creation for Java Control to generate, create Code 128 Code Set A image in Java applications.
www.OnBarcode.com
Summary
Many of the interaction patterns that occur between software processes are similar to those that occur in the hardware world. When deciding which type of pattern to use, you should first determine whether you need a push or pull interaction. This decision usually depends on who has control of the interaction the caller or the callee. The timing of the interaction (synchronous or asynchronous) is probably the second-most important decision. When creating asynchronous interactions, remember that it is usually better to handle the asynchrony on the caller side than the callee side.
Functional Roles
f you look at lots of different types of software systems, you soon realize that they have certain things in common. On the surface, a financial-planning system might not seem to have anything in common with an elevator-control system; a washing-machine program might not seem to have anything in common with a data-decryption system. However, if you step back a bit and look at the broader picture, similarities start to emerge. For example, all software systems need an initialization process before they can perform their main task. Many software systems have a shutdown process when they are terminated. All useful software systems must implement some level of business logic. The expression business logic is used in the broadest sense and includes the rules of whatever domain the software system is designed for. For example, in a temperature-control system, the business rules relate to heating and cooling laws. In a flight-control system, the rules relate to controlling the attitude1 and heading of an aircraft according to the laws of aerodynamics. In an accounting system, the rules might describe how to calculate a person s withholdings from his gross salary. Among the many similarities across software systems, functional roles are important. A functional role, often called simply a role, denotes what function a part has in relationship to the rest of the system. A part might be an object or a component. It is interesting to note that decoupled parts can often operate in a functional role without knowing how the rest of the system works. For example, an accounting system part that computes a person s withholdings could do so without knowing why its calculations were needed or where. The part would be able to function normally without knowing which other parts existed in the system, how the system worked, or how the various parts in the system were interconnected. When it comes to functional roles, probably the easiest one to understand is what I call the worker role, to use a business metaphor. In a software system, workers are the specialized parts that produce tangible results, as it were. Workers are the ones that implement the business logic of the system. Workers are the most valuable parts of a system, because they contain the rules for solving problems in a specific domain. Those rules are often nontrivial and often take the author a lot of time to learn and understand. A business organization is more than just a collection of workers, and so is a software system. When complex business rules need to be implemented, a common strategy is to divide the overall work into smaller increments and distribute the workload across groups of workers. Since the workers must interact and collaborate to be successful, it becomes important for the workers to be managed somehow. Those software parts that fulfill management roles are called coordinators in this book. Coordinators manage workers. Large business organizations often have several layers of management, with higher-level managers managing groups of lower-level managers. In an EBS, the management layers become a hierarchy of coordinators, with groups of lower-level coordinators managed by higher-level ones.
1. For readers unfamiliar with aviation terms, a plane s attitude includes the aircraft s pitch, roll, and yaw. Essentially, the attitude measures the orientation of the plane relative to the direction of motion, in three dimensions. Don t confuse attitude with altitude!
Copyright © OnBarcode.com . All rights reserved.