Recently I heard that a small partner only relies on two technical points, so he took two offers...
Only two thoughts flashed through my mind at the time
I do not believe! Can you get two offers with two knowledge points?
Which two knowledge points are they? So amazing! ! !
emmm, how did you get the offer? The "answer" is below, turn to the bottom, there are pictures and the truth...
Let's take a look at these interview questions that Ali must ask first, and see how many answers you can perfectly?
Is there a way to write code that can guarantee thread safety? (Tell you secretly, there really is!)
How to keep multiple threads alternately output A1B2C3 etc.?
How is the CPU primitive of synchronized volatile implemented?
What is the difference between no lock, bias lock, lightweight lock, and heavyweight lock?
How to start and stop a thread correctly?
What is the difference between thread and fiber? Why is fiber relatively lightweight?
Does ThreadLocal have memory leaks? why?
How to use thread pool for the following three businesses:
High concurrency, short task execution time
Low concurrency, long task execution time
High concurrency and long business execution time
I have collected a lot of answers online, all kinds, alas! ! !
If you only have CRUD experience and don't understand multi-threading and high concurrency , you will most likely be confused when faced with such interview questions.
If this is true for you, it is recommended to spend 2 hours to participate in a training camp "Multithreading and High Concurrency" taught by Mr. Ma Yingjun . Limited time benefits, this time fans 2 cents...
Hey , who is the horse soldier?
Graduated from Tsinghua University in 1999, from programmer to CTO, he has been committed to promoting Java, big data, and AI to take root in China. Its high-concurrency live courses are very popular, with millions of broadcasts and learning.
Horse soldier
Let the ashes sweeping god Seng Ma soldier teacher take you to systemize the knowledge of multi-threading, help you understand the realization of multi-threading at the CPU level , and how these realizations map layer by layer to those hundreds of millions of users, tens of millions of QPS, Million TPS system.
Training camp time :
October 8th-October 9th, 20:00
Limited time benefits, 2 cents for fans this time...
Preview materials:
Long press and scan code to add WeChat
Only for the top 200, scan the code to note " 666 "
If you encounter frequent scan codes, please identify again
(The value of the content depends on your actions, never be a collector)
I believe you already know what one of the knowledge points is, yes, it is " multi-threading" , but it is nothing more detailed than what Teacher Ma said . Please scan the QR code above to join the training camp...
(Relying on multi-threading and JVM alone, I can get two offers)
The first day of training camp:
The nature of threads (how the operating system and CPU execute threads)
The essence of fiber (why go language fiber is related to thread pool)
What is the nature of concurrency? What is the nature of the lock?
What are these frequently occurring interview concepts of synchronized JMM CAS AQS lock?
No lock, deflection lock, lightweight lock, heavyweight lock upgrade process
Pessimistic lock/optimistic lock shared lock/exclusive lock overall lock/segment lock reentrant lock/non-reentrant lock
(First public) Has the silver bullet been born? Is there an ultimate code that can guarantee thread safety?
(First public) What is the most appropriate number of working threads? How to understand the calculation formula of N*C*(1+C/W)?
The second day of training camp:
What is CPU cache L1 L2 L3?
What is a cache line?
Why are there cache lines?
What is the size of the cache line?
How cache lines affect Java programming
How does the Disruptor framework use cache line filling to improve efficiency?
What is out-of-order execution of the CPU?
How to prove out of order execution of CPU?
What is a memory barrier?
How does JVM use memory barriers to prohibit reordering?
What are the serious consequences of not prohibiting reordering in a DCL singleton?
(First public) Understand the requirements of multi-threaded code questions in Dachang interviews through an interview question from Ali
Training camp time :
October 8th-October 9th, 20:00
The whole training camp is broadcast live, limited-time benefits, this time is free to listen...
Super welfare one
You can choose one of three when you come, and the physical information will be mailed directly to your home~
Super Welfare II (A must-have for major manufacturers-Zuoshen algorithm, Baidu Zuoshen!)
Again, scan the code:
1. Preview learning materials
2. Participate in the mini game and get the physical book "Multithreading and High Concurrency"
3. Participate in live courses and draw prizes for free
Scan the QR code to receive preview materials, limited to the top 200
Only for the top 200, scan the code to note " 666 "
(The value of the content depends on your actions, never be a collector)
Scan the "QR code" above and study for 2 hours, it is worth it! ! !
In addition, Mr. Ma Junjun guarantees that the first-line major factory will start the class that night, and promises to be able to join one of the following ten major factories: if you can't enter the first-line major factory, you will not charge a penny for tuition! It's so domineering!
Ali, Tencent, Baidu, Jingdong, Huawei, Byte Pinduoduo, Meituan, Didi Kuaishou
Guarantee to enter the big factory, guarantee high salary! Each student has a dedicated teacher working at Dachang. In September, Dachang first-line developers will close their doors and accept apprentices, only 20 people!
Zero risk, zero risk, zero risk, must enter the big factory!
Missed to wait another six months!