youmoo
2021 年 4 月 13 日
维基百科上有词条专门解释了这个。我抽取 2 句吧：
1. Polling, or polled operation, in computer science, refers to actively sampling the status of an external device by a client program as a synchronous activity. Polling is most often used in terms of input/output (I/O), and is also referred to as polled I/O or software-driven I/O.
2. Polling is the process where the computer or controlling device waits for an external device to check for its readiness or state, often with low-level hardware.
简单地说，poll 是(主动地)检查外部设备的(就绪)状态。这里的外部设备不一定指硬件，只要有(多种)状态，都可以拿来 poll 。