From 2f5f7cb0d79b900d808a5a578a132e5ca72a9640 Mon Sep 17 00:00:00 2001
From: Nadja Reitzenstein <me@dequbed.space>
Date: Thu, 23 Jun 2022 14:37:17 +0200
Subject: [PATCH] More ideas about how to record data

---
 Cargo.lock                           | 35 ++++++++++++++++++++++++++++
 runtime/executor/Cargo.toml          |  6 ++++-
 runtime/executor/src/pool.rs         | 11 ---------
 runtime/lightproc/src/proc_handle.rs |  8 +++++++
 4 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 4764797..6932cc5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1119,11 +1119,13 @@ dependencies = [
  "crossbeam-utils",
  "futures-timer",
  "futures-util",
+ "hdrhistogram",
  "lazy_static",
  "libc",
  "lightproc",
  "num_cpus",
  "once_cell",
+ "parking_lot",
  "pin-utils",
  "rand",
  "slab",
@@ -1782,6 +1784,16 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "lock_api"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327fa5b6a6940e4699ec49a9beae1ea4845c6bab9314e4f84ac68742139d8c53"
+dependencies = [
+ "autocfg",
+ "scopeguard",
+]
+
 [[package]]
 name = "log"
 version = "0.4.17"
@@ -2029,6 +2041,29 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "427c3892f9e783d91cc128285287e70a59e206ca452770ece88a76f7a3eddd72"
 
+[[package]]
+name = "parking_lot"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3742b2c103b9f06bc9fff0a37ff4912935851bee6d36f3c02bcc755bcfec228f"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09a279cbf25cb0757810394fbc1e359949b59e348145c643a939a525692e6929"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-sys",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
diff --git a/runtime/executor/Cargo.toml b/runtime/executor/Cargo.toml
index ac3a2c3..85c6df6 100644
--- a/runtime/executor/Cargo.toml
+++ b/runtime/executor/Cargo.toml
@@ -40,13 +40,17 @@ libc = "0.2"
 num_cpus = "1.13"
 pin-utils = "0.1.0"
 slab = "0.4"
+parking_lot = "0.12"
 
 # Allocator
 arrayvec = { version = "0.7.0" }
 futures-timer = "3.0.2"
 once_cell = "1.4.0"
-tracing = "0.1.19"
 crossbeam-queue = "0.3.0"
+hdrhistogram = "7.5"
+
+# Stats & Tracing
+tracing = "0.1"
 
 [dev-dependencies]
 async-std = "1.10.0"
diff --git a/runtime/executor/src/pool.rs b/runtime/executor/src/pool.rs
index 50adb8b..4f288d6 100644
--- a/runtime/executor/src/pool.rs
+++ b/runtime/executor/src/pool.rs
@@ -48,21 +48,12 @@ impl Spooler<'_> {
 /// Global executor
 pub struct Executor<'a> {
     spooler: Arc<Spooler<'a>>,
-    span: Span,
 }
 
 impl<'a, 'executor: 'a> Executor<'executor> {
     pub fn new() -> Self {
         Executor {
             spooler: Arc::new(Spooler::new()),
-            span: tracing::span!(Level::INFO, "executor"),
-        }
-    }
-
-    pub fn new_with_parent_span(parent: &Span) -> Self {
-        Executor {
-            spooler: Arc::new(Spooler::new()),
-            span: tracing::span!(parent: parent, Level::INFO, "executor"),
         }
     }
 
@@ -115,7 +106,6 @@ impl<'a, 'executor: 'a> Executor<'executor> {
         let location = std::panic::Location::caller();
         let span = tracing::trace_span!(
             target: "executor::task",
-            parent: Span::current(),
             "runtime.spawn",
             loc.file = location.file(),
             loc.line = location.line(),
@@ -138,7 +128,6 @@ impl<'a, 'executor: 'a> Executor<'executor> {
         let location = std::panic::Location::caller();
         let span = tracing::trace_span!(
             target: "executor::task",
-            parent: Span::current(),
             "runtime.spawn",
             loc.file = location.file(),
             loc.line = location.line(),
diff --git a/runtime/lightproc/src/proc_handle.rs b/runtime/lightproc/src/proc_handle.rs
index 2dd7666..7a399d6 100644
--- a/runtime/lightproc/src/proc_handle.rs
+++ b/runtime/lightproc/src/proc_handle.rs
@@ -191,6 +191,14 @@ impl<R> Drop for ProcHandle<R> {
         let mut output = None;
 
         unsafe {
+            // Record dropping the handle for this task
+            let id = (&(*pdata).span).id().map(|id| id.into_u64()).unwrap_or(0);
+            tracing::trace!(
+                target: "executor::handle",
+                op = "handle.drop",
+                task.id = id,
+            );
+
             // Optimistically assume the `ProcHandle` is being dropped just after creating the
             // proc. This is a common case so if the handle is not used, the overhead of it is only
             // one compare-exchange operation.