umad_poll(3) poll umad

SYNOPSIS

#include <infiniband/umad.h>


int umad_poll(int portid, int timeout_ms);

DESCRIPTION

umad_poll() waits up to timeout_ms milliseconds for a packet to be received from the port specified by portid. Once a packet is ready to be read, the function returns 0. After that the packet can be read using umad_recv(). Otherwise, -ETIMEDOUT is returned. Note that successfully polling a port does not guarantee that the subsequent umad_recv() will be non blocking when several threads are using the same port. Instead, use a timeout_ms parameter of zero to umad_recv() to ensure a non-blocking read.

RETURN VALUE

umad_poll() returns 0 on success, and a negative value on error as follows:
 -EINVAL    invalid port handle or agentid
 -ETIMEDOUT poll operation timed out
 -EIO       poll operation failed

AUTHOR

Hal Rosenstock <halr@voltaire.com>