D > B enters the synchronized block, and since instance is not null at this time, it immediately leaves the synchronized block and returns the result to the program calling the method. E > At this point, thread B intends to use the Singleton instance, only to find that it has not been initialized, so an error occurs. Therefore, there is still the possibility of errors in the program. In fact, the running process of the program is very complicated. From this, we can see that it is more difficult and challenging to write programs especially in multi-threaded environment. We further optimized the program:
1.「看不见的沉淀」
The policy mode is the packaging of the algorithm, which separates the responsibility of using the algorithm from the algorithm itself and delegates it to different objects. Policy patterns usually wrap a series of algorithms into a series of policy classes. To encapsulate the policy pattern in one sentence is to "encapsulate each algorithm into a different policy class so that they can be interchanged". The following is the structure diagram of the policy mode:
本剧讲述一群花样少年为追求游泳事业自强不息的奋斗历程。沈译（周孝安饰）被某大学游泳队顾问宫直美（曾恺玹饰）聘为该校游泳队教练，在训练中，沈译找出队员们存在的问题并用独特的方法帮助他们解决，充分挖掘他们的潜力，激励他们实现各自梦想。在帮助队员们实现目标的同时，沈译也找到了自己的人生 目标。在宫直美的帮助下，沈译与哥哥沈泽（周孝安饰）解除了多年的误会，重拾往日兄弟之情。经历种种波折后，沈译最终与宫直美共结连理，收获了亲情、爱情和友情。
《小戏骨：刘三姐》是在1960年电影《刘三姐》的基础之上精编而成，保留了原版《刘三姐》中的主要情节，并且着重演绎了“水边赛歌”的情节。
Https://www.kotsu.city.nagoya.jp/jp/sp/SUBWAY/TRP0001486/TRF0013526. Pdf
让他们的和谈不成，继而大打出手，继续我们之前坐山观虎斗的策略？看似是一个很好的提议，刘邦和项羽之间互相消耗自然是最好不过，在此之前一直是越国的国策。
In fact, when thinking about this problem, most of them are at a time when they have nothing to do. I am so busy that I have no time to think about this problem. If you don't understand, let it go. It is a kind of wisdom to let go. If you don't understand and don't put it down, you will be entangled, just like a fish that gets into layers of fishing nets, and the more you struggle, the more you can't get out.
The buckle clip is still tight, and it is better to increase friction with a little silica gel.
他虽自知算不上正人君子，但这样的罪名也未免太大了，太冤了，兢兢业业在皇帝身边当了十年巡按，尽忠职守稳定东南两年，换来的就是这样的结局么？胡宗宪奄奄一息之时，徐文长终于端着一碗粥进来了。
陈婶正好从厨房出来听见了，皱眉对春花道：这日头还高着哩，哪里就要准备晚饭了？再说。
故事以两个不同性格女人的遭遇，贯串中国二十至四十年代的离乱，中间以两女的角 度，穿插了不同的人物，与不同的故事。
公元前八世纪至公元前三世纪是中国的春秋战国时代，这是一个战争伴随着变革、动荡伴随着创新的时代。在这个强者生、弱者亡、智者兴、愚者衰的时代，我们的祖先用他们的智慧创造出流佳百世的兵法与计谋。本剧通过战国时期两位著名军事谋略家--孙膑和庞涓的故事，向人们形象展示最为杰出的兵法与计谋。
黎章和黎水心照不宣地相视一眼，同时装作若无其事地低头，用匕首将兔子等物切割成小块，方便食用。
奔向银行抢劫案时，本完全按照逮捕程序行事，结果却看到一名逃犯自杀。萨米和奈特调查了一名街头黑帮成员的谋杀案，此人最近被判强奸罪无罪，可能忽略了她是黑帮男爵路易斯·雷耶斯的女儿。罗素很高兴看到丽迪娅和他一样，从她新来的，专横的伴侣那里受到同样自私的粗鲁对待，但优雅地忍受了她。
这是一个波澜壮阔的恐龙世界，这是一个生命成长的伟大历程，这是一个亲情友情的永恒主题，这是一个奇异多彩的历险经历！动画片《渴望蓝天》，为你展现史前生物时代的恐龙史诗！
据悉，节目邀请了十位性格迥异的年轻人在厦门制造甜蜜约会，开启一场爱的“冒险”。此外，节目组还精心设置由明星嘉宾担任恋爱观察员的第三视角，为青年提供初恋启示，警示恋爱陷阱，历练进取人生。
