[QUEUED scylladb next] service/raft: raft_group_registry: pass `direct_fd_pinger` by reference

[Commit Bot]

From: Kamil Braun <kbr...@scylladb.com>
Committer: Tomasz Grabiec <tgra...@scylladb.com>
Branch: next

service/raft: raft_group_registry: pass `direct_fd_pinger` by reference

It was passed to `raft_group_registry::direct_fd_proxy` by value. That
is a bug, we want to pass a reference to the instance that is living
inside `gossiper`.

Fortunately this bug didn't cause problems, because the pinger is only
used for one function, `get_address`, which looks up an address in a map
and if it doesn't find it, accesses the map that lives inside
`gossiper` on shard 0 (and then caches it in the local copy).

Explicitly delete the copy constructor of `direct_fd_pinger` so this
doesn't happen again.

Closes #11661

---
diff --git a/gms/gossiper.hh b/gms/gossiper.hh
--- a/gms/gossiper.hh
+++ b/gms/gossiper.hh
@@ -632,7 +632,10 @@ public:
future<> update_generation_number(int64_t n);

direct_fd_pinger(gossiper& g) : _gossiper(g) {}
+
public:
+ direct_fd_pinger(const direct_fd_pinger&) = delete;
+
// Allocate a new endpoint_id for `addr`, or if one already exists, return it.
// Call only on shard 0.
direct_failure_detector::pinger::endpoint_id allocate_id(gms::inet_address addr);
diff --git a/service/raft/raft_group_registry.cc b/service/raft/raft_group_registry.cc
--- a/service/raft/raft_group_registry.cc
+++ b/service/raft/raft_group_registry.cc
@@ -21,13 +21,13 @@ namespace service {
logging::logger rslog("raft_group_registry");

class raft_group_registry::direct_fd_proxy : public raft::failure_detector, public direct_failure_detector::listener {
- gms::gossiper::direct_fd_pinger _fd_pinger;
+ gms::gossiper::direct_fd_pinger& _fd_pinger;
raft_address_map<>& _address_map;

std::unordered_set<gms::inet_address> _alive_set;

public:
- direct_fd_proxy(gms::gossiper::direct_fd_pinger fd_pinger, raft_address_map<>& address_map)
+ direct_fd_proxy(gms::gossiper::direct_fd_pinger& fd_pinger, raft_address_map<>& address_map)
: _fd_pinger(fd_pinger), _address_map(address_map) {
}

[Commit Bot]

From: Kamil Braun <kbr...@scylladb.com>
Committer: Tomasz Grabiec <tgra...@scylladb.com>

Branch: master