NSOperationのサブクラスのカスタマイズ

前回のNSOperationの簡単な使用ではNSInvocationOperationとNSBlockOperationをNSOperationQueueと組み合わせてマルチスレッドプログラミングを実現することを紹介した.この記事では,NSOperationのサブクラスをカスタマイズしてマルチスレッドプログラミングを実現する.
SHOP継承NSOperationの作成

#import 

@interface SHOperation : NSOperation

/**NSOperation     */
@property (readwrite, nonatomic, strong) NSRecursiveLock *lock;

/**NSOperation   runloop   */
@property (nonatomic, strong) NSSet *runLoopModes;

@end

#import "SHOperation.h"

static NSString * const kMsspSDKLockName = @"operation.lock";

@implementation SHOperation
{
    BOOL finished;
    BOOL executing;
}

- (instancetype)init
{
    self = [super init];
    if (!self)
    {
        return nil;
    }
    self.lock = [[NSRecursiveLock alloc] init];
    self.lock.name = kMsspSDKLockName;
    self.runLoopModes = [NSSet setWithObject:NSRunLoopCommonModes];
    
    return self;
}

- (void)start
{
    [self.lock lock];
    if ([self isCancelled])
    {
        [self willChangeValueForKey:@"isFinished"];
        finished = YES;
        [self didChangeValueForKey:@"isFinished"];
        return;
    }
    else if ([self isReady])
    {
        [self willChangeValueForKey:@"isFinished"];
        finished  = NO;
        [self didChangeValueForKey:@"isFinished"];
        
        [self willChangeValueForKey:@"isExecuting"];
        executing = YES;
        [self willChangeValueForKey:@"isExecuting"];
        
        NSLog(@"   start,   ：%@", [NSThread currentThread]);
        //[self performSelector:@selector(operationDidStart) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO];
        [self performSelector:@selector(operationDidStart) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO modes:[self.runLoopModes allObjects]];
    }
    [self.lock unlock];
}

+ (NSThread *)networkRequestThread
{
    NSLog(@"networkRequestThread");
    static NSThread *_networkRequestThread = nil;
    static dispatch_once_t oncePredicate;
    dispatch_once(&oncePredicate, ^{
        _networkRequestThread = [[NSThread alloc] initWithTarget:self selector:@selector(networkRequestThreadEntryPoint:) object:nil];
        [_networkRequestThread start];
    });
    
    return _networkRequestThread;
}

+ (void)networkRequestThreadEntryPoint:(id)__unused object {
    @autoreleasepool {
        NSLog(@"networkRequestThreadEntryPoint");
        [[NSThread currentThread] setName:@"TestThread"];
        NSRunLoop *runloop = [NSRunLoop currentRunLoop];
        [runloop addPort:[NSMachPort port] forMode:NSDefaultRunLoopMode];
        [runloop run];
    }
}

- (void)operationDidStart
{
    [self.lock lock];
    if (![self isCancelled])
    {
        NSLog(@"operationDidStart");
    }
    [self.lock unlock];
}

- (void)finishOperation
{
    [self.lock lock];
    NSLog(@"is finishOperation");
    [self willChangeValueForKey:@"isExecuting"];
    executing = NO;
    [self didChangeValueForKey:@"isExecuting"];
    
    [self willChangeValueForKey:@"isFinished"];
    finished  = YES;
    [self didChangeValueForKey:@"isFinished"];
    [self.lock unlock];
}

- (BOOL) isConcurrent{
    NSLog(@"is concurrent");
    return YES;
}

- (BOOL) isFinished{
    NSLog(@"is finished");
    return finished;
}

- (BOOL) isExecuting{
    NSLog(@"is executing");
    return executing;
}

//- (void)cancel
//{
//    [self.lock lock];
//    if (![self isFinished] && ![self isCancelled])
//    {
//        [super cancel];
//    }
//    [self.lock unlock];
//}

@end

スレッドクラスを作成し、SHOPクラスを継承

#import 
#import "SHOperation.h"

@interface T1Operation : SHOperation

@end

#import "T1Operation.h"

@implementation T1Operation

- (void)operationDidStart
{
    [self.lock lock];
    if (![self isCancelled])
    {
        //           
        NSLog(@"T1   operationDidStart");
    }
    [self.lock unlock];
}

@end

スレッドを開く

//    
 NSOperationQueue *queue = [[NSOperationQueue alloc] init];
//    
    T1Operation *t1 = [[T1Operation alloc] init];
//        
    [queue addOperation:t1];

プロジェクトコード:github
リファレンス

参照1

参照2

参照3