func (c *client) waitOnRegion(rpc hrpc.Call, reg hrpc.RegionInfo) (proto.Message, error) {
ch := reg.AvailabilityChan()
if ch == nil {
// WTF, this region is available? Maybe it was marked as such
// since waitOnRegion was called.
return c.sendRPC(rpc)
}
// The region is unavailable. Wait for it to become available,
// or for the deadline to be exceeded.
select {
case <-ch:
return c.sendRPC(rpc)
case <-rpc.Context().Done():
return nil, ErrDeadline
}
}
