tree 76622898310d190025402a10c5719b9478c145d5
parent 84fe1f479b88778a10416572db13fe26e88f271b
author Willy Tarreau <w@1wt.eu> 1677691558 +0100
committer Willy Tarreau <w@1wt.eu> 1682091686 +0200
encoding latin1

MINOR: receiver: add a struct shard_info to store info about each shard

In order to create multiple receivers for one multi-group shard, we'll
need some more info about the shard. Here we store:
  - the number of groups (= number of receivers)
  - the number of threads (will be used for accept LB)
  - pointer to the reference rx (to get the FD and to find all threads)
  - pointers to the other members (to iterate over all threads)

For now since there's only one group per shard it remains simple. The
listener deletion code already takes care of removing the current
member from its shards list and moving others' reference to the last
one if it was their reference (so as to avoid o(n^2) updates during
ordered deletes).

Since the vast majority of setups will not use multi-group shards, we
try to save memory usage by only allocating the shard_info when it is
needed, so the principle here is that a receiver shard_info==NULL is
alone and doesn't share its socket with another group.

Various approaches were considered and tests show that the management
of the listeners during boot makes it easier to just attach to or
detach from a shard_info and automatically allocate it if it does not
exist, which is what is being done here.

For now the attach code is not called, but detach is already called
on delete.