Moore's Law:
It was proposed by Gordon Moore, one of the founders of Intel. Its content is:
When the price remains constant, the number of components that can be accommodated on an integrated circuit will double approximately every 18-24 months, and the performance will also double.
In other words, the performance of computers that can be bought at the same price will more than double every 18-24 months.
However, since 2003, the main frequency of the CPU is no longer doubled, but multi-core
In the case that the single-core cpu performance does not change much, parallel or concurrent programming must be used to make the program faster.
That is to make multi-core processors work together.
Improve program performance, high concurrent system.
Improve program throughput, asynchronous + callback and other production requirements.
The resulting problems:
Thread safety issues, such as: i++, whether the collection class is safe
thread lock problem,
Thread performance issues.