Mu Jindi interview record

10.25 My colleague helped deliver it in the afternoon. I had an interview in the evening, and I went there as soon as I got off work. I said that the

interview was very hard. HR didn’t print my resume

, so I asked directly.

, because I'm not ready

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Q: The concept of thread?
Answer: A process is a unit of operation, and a thread is its sub-unit. It shares the space and resources of the process and can run independently of each other.

Q : What will be the impact of large concurrency?
A: Data inconsistency

Q :
JVM partitions Counter

Q : Is int placed in the heap or the stack
A: In the stack
(int is placed in the stack, but the heap also has the attribute int defined in the class)

Q: Will the value of int be changed during concurrency?
A: No , (actually yes)

Q: Since int is thread-safe, why is there an AtomeInteger?
Answer: Unsafe

Q : Briefly describe the implementation principle of AtomicInteger, how to achieve decrement without using locks
A:  …

Q: The implementation of shared data between ThreadLocal threads, each thread has an independent storage space
A : Forced to update each other's space, errors
are independent

Q : The difference between database, INNODB MYISAM, row lock, table lock

Database storage engine The difference between InnoDB and MyISAM

Q: The difference between synchronized and lock


Summary : Be prepared, hey, the gap is too big

Q: What are the levels of atomicity, ACID, and atomicity?