مجمّعات الخيوط: الحجم والطابور والرفض

في هذا الدرس

size a pool and predict its queueing behavior.

الموضوعات المخطط لها

• ThreadPoolExecutor: core size, max size, queue, rejection policy.
• Order of growth: use core threads, then enqueue, and only add threads up to max when the queue is full. An unbounded queue means max is never used.
• CPU-bound: about the number of cores. I/O-bound: more, roughly cores x (1 + wait/compute); measure.
• Use a bounded queue plus an explicit rejection policy (e.g., caller-runs, or abort and report) to create backpressure.
• newCachedThreadPool has unbounded threads; newFixedThreadPool has an unbounded queue. Both can hurt under load.