摘要：
1、低速系统调用 ：可能会使进程永远“阻塞”的一类系统调用。包括：the system calls are divided into two categories: the "slow" ones and all the others.The slow system calls are those that can block forever.They includeReads that can block the caller forever if data isn't present with certain file types (pipes, termina 阅读全文