在上一篇NSOperation简单使用中介绍了使用NSInvocationOperation和NSBlockOperation配合NSOperationQueue来实现多线程编程。
这一篇来看一下通过自定义NSOperation的子类来实现多线程编程。
创建SHOperation继承NSOperation
#import <Foundation/Foundation.h>
@interface SHOperation : NSOperation
/**NSOperation的线程锁 */
@property (readwrite, nonatomic, strong) NSRecursiveLock *lock;
/**NSOperation的线程runloop模式 */
@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(@"这里是start,线程号：%@", [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
创建线程类，继承SHOperation类
#import <Foundation/Foundation.h>
#import "SHOperation.h"
@interface T1Operation : SHOperation
@end
#import "T1Operation.h"
@implementation T1Operation
- (void)operationDidStart
{
[self.lock lock];
if (![self isCancelled])
{
//需要在线程中运行的代码
NSLog(@"T1 operationDidStart");
}
[self.lock unlock];
}
@end
开启线程
//创建队列
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
//创建操作
T1Operation *t1 = [[T1Operation alloc] init];
//将操作加入队列中
[queue addOperation:t1];
