Practical Java high Concurrency programming 1

Important Concepts

1. Synchronous (synchronous) and asynchronous (asynchronous)
   • Synchronous Wait method returns
   • Asynchronously returns, continuing the next call
2. Concurrency (Concurrency) and parallelism (Parallelism)
   • Concurrency is consistent with parallel external performance
   • Single-core CPUs cannot be parallelized, but can handle parallel transactions
3. Critical section
   • Public resources or shared data
   • Critical section data corruption may occur when accessing multiple threads
4. Blocking (Blocking) and non-blocking (non-blocking)
   • Non-blocking allows multiple threads to enter the critical section at the same time
5. Deadlock (Deadlock), hunger (starvation) and live lock (Livelock)
   • Deadlock cannot stop service, static problem. Cyclic dependency
   • Live lock Dynamic Lock, run-time resource requisition
   • Hunger is lacking in certain resources and is always impossible to enforce

Concurrency level

1. Blocking
2. Non-blocking
   
   1. Barrier-Free
   2. No lock
   3. No wait

Amdahl Law (Amdahl Law)

Acceleration ratio Definition:

Acceleration ratio = System time-consuming/optimized system time before optimization

Gustafson Law (Gustafson)

Practical Java high Concurrency programming 1