Return the channel pool unique identifier.
Returns the channel pool identification. Every channel pool created have an unique id ranging from 1 to MAX_CHANNEL_NO which is really large. This means you can't create more channel pools than channels allowed over a connection.
This unique identifier can be used for several application purposes but from the vortex view it's used to get a given channel pool for a given connection using vortex_connection_get_channel_pool. If you create only one channel pool over a connection the previous function will return this channel pool if 1 is passed in as pool_id.
Every channel pool identifier is unique from inside a connection. You can actually create several channel pool which may have as unique id = 1 over different connections.