问iOS开发中的线程安全

EN

/**
 @brief
 Proxy that delegates all messages to the specified object
 */
@interface BMProxy : NSProxy {
    NSObject *object;
    BOOL threadSafe;
}

@property(atomic, assign) BOOL threadSafe;

- (id)initWithObject:(NSObject *)theObject;
- (id)initWithObject:(NSObject *)theObject threadSafe:(BOOL)threadSafe;

@end

@implementation BMProxy

@synthesize threadSafe;

- (id)initWithObject:(NSObject *)theObject {
    object = [theObject retain];
    return self;
}

- (id)initWithObject:(NSObject *)theObject threadSafe:(BOOL)b {
    if ((self = [self initWithObject:theObject])) {
        self.threadSafe = b;
    }
    return self;
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
    return [object methodSignatureForSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation {
    if (self.threadSafe) {
        @synchronized(object) {
            [anInvocation setTarget:object];
            [anInvocation invoke];
        }
    } else {
        [anInvocation setTarget:object];
        [anInvocation invoke];
    }
}

- (BOOL)respondsToSelector:(SEL)aSelector {
    BOOL responds = [super respondsToSelector:aSelector];
    if (!responds) {
        responds = [object respondsToSelector:aSelector];
    }
    return responds;
}

- (void)dealloc {
    [object release];
    [super dealloc];
}

@end