ThinkerQAQ

14.ThreadPool

Java · 4 notes

  1. 6.14 14.ThreadPoolhistorical

    1. What it is. Java's thread-pool framework separates task submission from task execution. 1.1. Why thread pools are needed: reuse threads, because creating/destroying threads is expensive and too many threads cause excessive CPU context switching. 1.2. Use cases: individual tasks should not run too long, and there are many tasks.

  2. 6.28 Executorshistorical

    1. Usage 2. newCachedThreadPool 3. newScheduledThreadPool 4. newFixedThreadPool 5. newSingleThreadExecutor

  3. 6.36 RejectedExecutionHandlerhistorical

    1. What is RejectedExecutionHandler? When corePoolSize is full, blockingQueue is full, and maxPoolSize is also full, how should a new task be handled? This is determined by RejectedExecutionHandler. 2. Types: CallerRunsPolicy, AbortPolicy, DiscardPolicy, DiscardOldestPolicy.

  4. Estimating Thread Pool Sizehistorical

    1. Estimate the number of threads 1.1. Throughput = concurrency / response time 1.2. TPS estimation 1.3. I/O-intensive or CPU-intensive 1.4. Dark Magic 2. References