Until now it has been necessary to separately define a k_fifo and
an array of buffers when creating net_buf pools. This has been a bit
of an inconvenience as well as blurred the line of what exactly
constitutes the "pool".
This patch removes the NET_BUF_POOL() macro and replaces it with a
NET_BUF_POOL_DEFINE() macro that internally expands into the buffer
array and new net_buf_pool struct with a given name:
NET_BUF_POOL_DEFINE(pool_name, ...);
Having a dedicated context struct for the pool has the added benefit
that we can start moving there net_buf members that have the same
value for all buffers from the same pool. The first such member that
gets moved is the destroy callback, thus shrinking net_buf by four
bytes. Another potential candidate is the user_data_size, however
right not that's left out since it would just leave 2 bytes of padding
in net_buf (i.e. not influence its size). Another common value is
buf->size, however that one is also used by net_buf_simple and can
therefore not be moved.
This patch also splits getting buffers from a FIFO and allocating a
new buffer from a pool into two separate APIs: net_buf_get and
net_buf_alloc, thus simplifying the APIs and their usage. There is no
separate 'reserve_head' parameter anymore when allocating, rather the
user is expected to call net_buf_reserve() afterwards if something
else than 0 headroom is desired.
Change-Id: Id91b1e5c2be2deb1274dde47f5edebfe29af383a
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
c3e08c8fea