fix(swarm): eliminating protocol cloning when nothing is happening

Cargo.toml

@@ -102,7 +102,7 @@ libp2p-rendezvous = { version = "0.14.1", path = "protocols/rendezvous" }
 libp2p-request-response = { version = "0.26.4", path = "protocols/request-response" }
 libp2p-server = { version = "0.12.7", path = "misc/server" }
 libp2p-stream = { version = "0.1.0-alpha.1", path = "protocols/stream" }
-libp2p-swarm = { version = "0.45.0", path = "swarm" }
+libp2p-swarm = { version = "0.45.1", path = "swarm" }
 libp2p-swarm-derive = { version = "=0.34.2", path = "swarm-derive" } # `libp2p-swarm-derive` may not be compatible with different `libp2p-swarm` non-breaking releases. E.g. `libp2p-swarm` might introduce a new enum variant `FromSwarm` (which is `#[non-exhaustive]`) in a non-breaking release. Older versions of `libp2p-swarm-derive` would not forward this enum variant within the `NetworkBehaviour` hierarchy. Thus the version pinning is required.
 libp2p-swarm-test = { version = "0.3.0", path = "swarm-test" }
 libp2p-tcp = { version = "0.42.0", path = "transports/tcp" }

swarm/CHANGELOG.md

@@ -1,3 +1,10 @@
+
+## 0.45.1
+
+- Optimize internal connection `fn poll`. New implementation now scales much better with number of listen protocols active.
+  No changes to public API introduced.
+  See [PR 5026](https://github.com/libp2p/rust-libp2p/pull/5026)
+
 ## 0.45.0
 
 - Add peer_id to `FromSwarm::ListenFailure`.

swarm/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-swarm"
 edition = "2021"
 rust-version = { workspace = true }
 description = "The libp2p swarm"
-version = "0.45.0"
+version = "0.45.1"
 authors = ["Parity Technologies <[email protected]>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"
@@ -52,6 +52,7 @@ libp2p-swarm-derive = { path = "../swarm-derive" }                  # Using `pat
 libp2p-swarm-test = { path = "../swarm-test" }                      # Using `path` here because this is a cyclic dev-dependency which otherwise breaks releasing.
 libp2p-yamux = { path = "../muxers/yamux" }                         # Using `path` here because this is a cyclic dev-dependency which otherwise breaks releasing.
 quickcheck = { workspace = true }
+criterion = { version = "0.5", features = ["async_tokio"] }
 void = "1"
 once_cell = "1.19.0"
 trybuild = "1.0.95"
@@ -69,5 +70,9 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 rustc-args = ["--cfg", "docsrs"]
 
+[[bench]]
+name = "connection_handler"
+harness = false
+
 [lints]
 workspace = true