看源碼，autoconnect

- (RACSignal *)autoconnect {
    __block volatile int32_t subscriberCount = 0;

    return [[RACSignal
        createSignal:^(id<RACSubscriber> subscriber) {
            OSAtomicIncrement32Barrier(&subscriberCount);

            RACDisposable *subscriptionDisposable = [self.signal subscribe:subscriber];
            RACDisposable *connectionDisposable = [self connect];

            return [RACDisposable disposableWithBlock:^{
                [subscriptionDisposable dispose];

                if (OSAtomicDecrement32Barrier(&subscriberCount) == 0) {
                    [connectionDisposable dispose];
                }
            }];
        }]
        setNameWithFormat:@"[%@] -autoconnect", self.signal.name];
}

在autoconnect里有調(diào)用[connectionDisposable dispose];而ReactiveCoca里的replay族方法如replayLazily，用的connect，卻對(duì)返回的connectionDisposable沒有處理，會(huì)導(dǎo)致后果 connection.signal結(jié)束了而沒有dispose掉source signal