执行到 sleep 时，线程会进入阻塞状态，操作系统把它挂起，不分配 CPU 时间片。但这个线程仍然被占用着，线程池里它的“坑位”一直没释放。如果同时有 200 个请求进来，线程池的 200 个线程全被占满，都在等 IO，第 201 个请求就得排队，哪怕 CPU 空闲 99%。
Российская пенсионерка купила золота на 19 миллионов рублей14:50。业内人士推荐新收录的资料作为进阶阅读
Российская пенсионерка купила золота на 19 миллионов рублей14:50。PDF资料对此有专业解读
During Iraq’s 1990-1991 invasion of Kuwait and the subsequent Gulf War, Iraqi forces sabotaged power stations and desalination facilities as they retreated, said the University of Utah’s Low. At the same time, millions of barrels of crude oil were deliberately released into the Persian Gulf, creating one of the largest oil spills in history.。新收录的资料对此有专业解读
Credit: Timothy Werth / Mashable