refactor channel::net client loop (#1823)

Summary:
Pull Request resolved: #1823

First, we break down the client loop into several functions, breaking up its monolithic nature.

Second, instead of relying on custom rendering of loop states, we formalize this into a span, which efficiently pulls out the (structured) fields as required. This means we don't pay a formatting/string construction overhead on each iteration, and also make available the underlying fields in our structured logs.

This is just the first salvo in improving how the `net` module is factored.
ghstack-source-id: 322824631
exported-using-ghexport

Reviewed By: shayne-fletcher

Differential Revision: D86783166

fbshipit-source-id: 95e5bf68981f96033774f042153dc6a0af4a5c0b

Author: mariusae

.cargo/config.toml

@@ -0,0 +1,5 @@
+[build]
+rustflags = [
+    "--cfg",
+    "tracing_unstable",
+]

.github/workflows/doc_build.yml

@@ -44,7 +44,7 @@ jobs:
         # Set environment variables for CUDA build
         export USE_CUDA=1
         export USE_TENSOR_ENGINE=1
-        export RUSTFLAGS="-Zthreads=16"
+        export RUSTFLAGS="-Zthreads=16 ${RUSTFLAGS:-}"
         export _GLIBCXX_USE_CXX11_ABI=1
         export CUDA_LIB_DIR=/usr/lib64
 

hyperactor/Cargo.toml

@@ -83,6 +83,7 @@ tokio-util = { version = "0.7.15", features = ["full"] }
 tracing = { version = "0.1.41", features = ["attributes", "valuable"] }
 unicode-ident = "1.0.12"
 uuid = { version = "1.17", features = ["rng-getrandom", "serde", "v4", "v5", "v6", "v7", "v8"] }
+valuable = { version = "0.1", features = ["derive"] }
 
 [dev-dependencies]
 buck-resources = "1"