- If everything in the first buffer of a buffer chain is consumed,
then the whole chain and not just the first buffer was freed.
NOTE: gwbuf_rtrim needs to be fixed so that it removes data from the
tail of a chain and *not* from the end of the first buffer in
a chain. That cannot ever be what is wanted.
The readwritesplit now sends COM_PING queries to backend servers that have
been idle for too long. The option is configured with the
`connection_keepalive` parameter.
The contents of the existing filter.cc was copied into filter.c that
subsequently was renamed to filter.cc.
The way the session is called as the last filter in the filter chain
is really dubious and ought to be rearranged so that the blind casting
of a session to a filter and back is not needed.
It is now possible to specify what information the caller is interested
in. With this the cost for collecting information during the query parsing
that nobody is interested in can be avoided.
- Non-GCC intrinsics alternative implementation removed. Let's worry
about the absence of the intrinsics once/if that becomes relevant.
- Spinlock release now performed using __sync_lock_release, as per
svoj's advice.
- while-looping on the variable used as lock removed, so it no longer
need to be volatile.
- Boolean function returns bool.
- Size of profiling counters increased.
- Risk for division-by-zero removed.
- Documentation moved from implementation to header.
