Before doing concurrent programming, you must first understand what is concurrency, what is parallelism, what is concurrent programming, and what is parallel programming.
Concurrency and parallelism are:
Explanation 1: Parallel means that two or more events occur at the same time; while concurrency means that two or more events occur at the same time interval.
Explanation 2: Parallelism is multiple events on different entities, and concurrency is multiple events on the same entity.
Explanation 3: Multiple tasks are processed "simultaneously" on one processor, and multiple tasks are processed simultaneously on multiple processors. Such as hadoop distributed cluster
, so the goal of concurrent programming is to fully utilize each core of the processor to achieve the highest processing performance
Among them: Concurrency includes synchronization and mutual exclusion of multiple threads; synchronization and asynchrony are relative
Example:
Parallel: Double Eleven, 0:00:00, 300,000 users log on Taobao at the same
time .