Punit Soni Punit Soni - 1 year ago 102
Linux Question

difference between POLLIN and POLLPRI in poll() syscall

The documentation of poll() did not explain this in detail. While polling on an fd, when should one POLLIN and when should one use POLLPRI? Any insights will be useful.

Answer Source

I always use both of them, that's possible since they're bitmasks (so you can use POLLIN | POLLPRI).

The priority entries are for information that's considered more important than regular information. Ideally, you'd ask for both types and then check/process the priority ones first.