The pool is checked for expansion before processing
items from the queue. By tracking the number of idle
thread (i.e. not currently sending data) we ensure
that there is at least one idle thread before
we invoke the socket.
If there is not enough idle threads at that point,
a new thread is spawned, so long as we're below the
limit. This guarantees that even if all the active
threads block on the socket, we'd always have one
more to process new data (until we reach the limit,
which is as many client connections as we have).
Technically, a single slow connection could
still monopolize all connections if there are
many messages to be sent to it. For that we'd
need to track and assign one thread per connection,
something we don't currently do.
Change-Id: Ic8b5e064da068b37bcfa773005495b198763c31d
Reviewed-on: https://gerrit.libreoffice.org/31886
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
Tested-by: Ashod Nakashian <ashnakash@gmail.com>