vb.net barcode printing 16: Concurrency in Java

Make Data Matrix ECC200 in Java 16: Concurrency

CHAPTER 16: Concurrency
Data Matrix 2d Barcode Encoder In Java
Using Barcode printer for Android Control to generate, create Data Matrix ECC200 image in Android applications.
www.OnBarcode.com
Draw Data Matrix 2d Barcode In Java
Using Barcode creation for Android Control to generate, create Data Matrix 2d barcode image in Android applications.
www.OnBarcode.com
Operation Queues
Draw QR Code 2d Barcode In Java
Using Barcode encoder for Android Control to generate, create QR-Code image in Android applications.
www.OnBarcode.com
Drawing Code 128 Code Set B In Java
Using Barcode creator for Android Control to generate, create Code-128 image in Android applications.
www.OnBarcode.com
Since the release of Leopard, Apple has provided us with a pair of classes called NSOperation and NSOperationQueue that work together to provide operation queues. The idea is that you split your computational tasks into chunks or units of work, wrap each of them up in an NSOperation, and put each operation into an NSOperationQueue. You can also establish interoperation dependencies, specifying that an operation won t begin executing until another one is complete. The NSOperationQueue then takes care of these units the best it can, using the order that operations were added to the queue, along with the dependencies you specified, to determine its course of action. If the dependencies you specify allow some operations to execute at the same time, and there are enough cores available to run them, the operation queue will use multiple threads to execute multiple operations simultaneously.
EAN / UCC - 13 Encoder In Java
Using Barcode encoder for Android Control to generate, create GS1-128 image in Android applications.
www.OnBarcode.com
Encoding Barcode In Java
Using Barcode creator for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Vitalizing SlowWorker
Painting UPC - 13 In Java
Using Barcode creator for Android Control to generate, create EAN13 image in Android applications.
www.OnBarcode.com
Code 93 Full ASCII Generator In Java
Using Barcode creation for Android Control to generate, create USS Code 93, USS 93 image in Android applications.
www.OnBarcode.com
To see how operation queues work, let s put them to the test in SlowWorker. Before we start, make a copy of the entire folder containing your SlowWorker project. Later on in this chapter, we re going to use the original version of SlowWorker as a starting point for another way to implement concurrency, so keep a copy of it lying around. As you will recall, the problem with this app is that the single action method calls several other methods in sequence, the total length of which is enough to make the app feel unresponsive. What we re going to do is put each of those other methods into an operation, put all the operations into a queue, and let the queue do its thing. In order for this to work, one of the things we have to do is find a way for each operation to get its input from somewhere, and store its return value somewhere. The solution we re going to use here is to make what were previously return values into instance variables in our controller class. Each method will read any input it needs from an instance variable, and put its results into another. Start by adding instance variables and properties for each of the work-methods return values, along with a new isWorking attribute of type BOOL, which we ll use to keep track of whether the background operations are underway. Because the work-processing is being handled in a different way, we also need to make startTime into an instance variable. Add the lines shown in bold below to SlowWorkerAppDelegate.h:
Encoding Data Matrix In .NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Data Matrix 2d barcode image in VS .NET applications.
www.OnBarcode.com
ECC200 Encoder In None
Using Barcode generation for Office Excel Control to generate, create Data Matrix 2d barcode image in Office Excel applications.
www.OnBarcode.com
#import <Cocoa/Cocoa.h> @interface SlowWorkerAppDelegate : NSObject { IBOutlet NSButton *startButton; IBOutlet NSTextView *resultsTextView; NSString *fetchedData; NSString *processed; NSString *firstResult; NSString *secondResult; BOOL isWorking; NSDate *startTime; }
Printing Denso QR Bar Code In None
Using Barcode encoder for Online Control to generate, create QR Code image in Online applications.
www.OnBarcode.com
Barcode Generation In VB.NET
Using Barcode printer for Visual Studio .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 16: Concurrency
QR Code 2d Barcode Scanner In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Barcode Creation In None
Using Barcode generator for Microsoft Word Control to generate, create Barcode image in Word applications.
www.OnBarcode.com
@property (retain) NSString *fetchedData; @property (retain) NSString *processed; @property (retain) NSString *firstResult; @property (retain) NSString *secondResult; @property (assign) BOOL isWorking; - (IBAction)doWork:(id)sender; @end
Drawing GTIN - 128 In None
Using Barcode creator for Office Word Control to generate, create GTIN - 128 image in Microsoft Word applications.
www.OnBarcode.com
Painting UCC.EAN - 128 In None
Using Barcode maker for Microsoft Excel Control to generate, create EAN / UCC - 13 image in Excel applications.
www.OnBarcode.com
Now, in SlowWorkerAppDelegate.m, inside the @implementation section, add @synthesize declarations for the new properties, and replace the old work-methods with the new ones shown below. We re also going to add a new work-method called finishWorking, which takes care of updating the GUI when the work is done.
Generate Barcode In .NET
Using Barcode generation for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
USS Code 39 Generation In None
Using Barcode drawer for Office Word Control to generate, create Code 3 of 9 image in Microsoft Word applications.
www.OnBarcode.com
@synthesize fetchedData; @synthesize processed; @synthesize firstResult; @synthesize secondResult; @synthesize isWorking; - (void)fetchSomethingFromServer { sleep(1); self.fetchedData = @"Hi there"; } - (void)processData { sleep(2); self.processed = [self.fetchedData uppercaseString]; } - (void)calculateFirstResult { sleep(3); self.firstResult = [NSString stringWithFormat:@"Number of chars: %d", [self.processed length]]; } - (void)calculateSecondResult { sleep(4); self.secondResult = [self.processed stringByReplacingOccurrencesOfString:@"E" withString:@"e"]; } - (void)finishWorking { NSString *resultsSummary = [NSString stringWithFormat: @"First: [%@]\nSecond: [%@]", self.firstResult, self.secondResult]; [resultsTextView setString:resultsSummary]; NSDate *endTime = [NSDate date]; NSLog(@"Completed in %f seconds", [endTime timeIntervalSinceDate:startTime]); self.isWorking = NO; }
PDF 417 Maker In C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Draw GTIN - 12 In VB.NET
Using Barcode generation for Visual Studio .NET Control to generate, create UPC Symbol image in .NET framework applications.
www.OnBarcode.com
Now it s time to update the doWork: method itself. Instead of simply executing each method directly, it creates an NSOperation for each. Then it defines a set of dependencies between these operations, so that processData is only called after fetchSomethingFromServer is done, and the two calculate methods are only called after processData is done. Here s what it looks like:
- (IBAction)doWork:(id)sender {
Copyright © OnBarcode.com . All rights reserved.