enable parking_lot locks in dependencies (#589)

Tracing and Tokio both expose a feature flagged optional dependency on
the parking_lot crate's Mutex and RwLock implementations rather
than std's. Enabling this dependency causes these crates to use
parking_lot internally with no externally visible API change.

In microbenchmarks of Tokio's synchronization primitives, we've observed
better performance with parking_lot vs std, and tend to recommend it
in high-performance applications where the cost of another dependency is
acceptable.

This branch enables tokio and tracing's parking_lot features. I
also removed a bonus dependency on a vintage Tokio version that we must
have missed during the 0.2 update, as it was pulling an incompatible
parking_lot version.

Author: hawkw

Cargo.lock

@@ -63,7 +63,7 @@ linkerd2-stack-tracing = { path = "../../stack/tracing" }
 linkerd2-trace-context = { path = "../../trace-context" }
 rand = { version = "0.7", features = ["small_rng"] }
 regex = "1.0.0"
-tokio = { version = "0.2", features = ["macros", "sync"]}
+tokio = { version = "0.2", features = ["macros", "sync", "parking_lot"]}
 tokio-timer = "0.2"
 tower-request-modifier = { git = "https://github.com/tower-rs/tower-http" }
 tonic = { version = "0.2", default-features = false, features = ["prost"] }
@@ -73,10 +73,10 @@ tracing-log = "0.1"
 pin-project = "0.4"
 
 [dependencies.tracing-subscriber]
-version = "0.2.1"
+version = "0.2.7"
 # we don't need `chrono` time formatting
 default-features = false
-features = ["env-filter", "fmt", "smallvec", "tracing-log", "ansi", "json"]
+features = ["env-filter", "fmt", "smallvec", "tracing-log", "ansi", "json", "parking_lot"]
 
 [dependencies.tower]
 version = "0.3"

linkerd/app/core/Cargo.toml

@@ -39,7 +39,7 @@ tower = { version = "0.3", default-features = false}
 tonic = { version = "0.2", default-features = false }
 tracing = "0.1.9"
 tracing-futures = { version = "0.2", features = ["std-future"] }
-tracing-subscriber = "0.2.5"
+tracing-subscriber = "0.2.7"
 webpki = "0.21.0"
 
 [dev-dependencies]

linkerd/app/integration/Cargo.toml

@@ -16,9 +16,7 @@ indexmap = "1.0"
 linkerd2-error = { path  = "../error" }
 linkerd2-http-classify = { path  = "../http-classify" }
 linkerd2-metrics = { path  = "../metrics" }
-linkerd2-stack = { path  = "../stack" }
-tokio = "0.1"
-tokio-timer = "0.2"   # for tokio_timer::clock
+linkerd2-stack = { path  = "../stack" } 
 tracing = "0.1.9"
 pin-project = "0.4"
 

linkerd/http-metrics/Cargo.toml

@@ -13,7 +13,6 @@ use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 use std::task::{Context, Poll};
 use std::time::Instant;
-use tokio_timer::clock;
 
 /// A stack module that wraps services to record metrics.
 #[derive(Debug)]
@@ -285,7 +284,7 @@ where
 
         if req.body().is_end_stream() {
             if let Some(lock) = req_metrics.take() {
-                let now = clock::now();
+                let now = Instant::now();
                 if let Ok(mut metrics) = lock.lock() {
                     (*metrics).last_update = now;
                     (*metrics).total.incr();
@@ -307,7 +306,7 @@ where
         ResponseFuture {
             classify: Some(classify),
             metrics: self.metrics.clone(),
-            stream_open_at: clock::now(),
+            stream_open_at: Instant::now(),
             inner: self.inner.proxy(svc, req),
         }
     }
@@ -335,7 +334,7 @@ where
 
         if req.body().is_end_stream() {
             if let Some(lock) = req_metrics.take() {
-                let now = clock::now();
+                let now = Instant::now();
                 if let Ok(mut metrics) = lock.lock() {
                     (*metrics).last_update = now;
                     (*metrics).total.incr();
@@ -357,7 +356,7 @@ where
         ResponseFuture {
             classify: Some(classify),
             metrics: self.metrics.clone(),
-            stream_open_at: clock::now(),
+            stream_open_at: Instant::now(),
             inner: self.inner.call(req),
         }
     }
@@ -427,7 +426,7 @@ where
         let frame = ready!(this.inner.poll_data(cx));
 
         if let Some(lock) = this.metrics.take() {
-            let now = clock::now();
+            let now = Instant::now();
             if let Ok(mut metrics) = lock.lock() {
                 (*metrics).last_update = now;
                 (*metrics).total.incr();
@@ -472,7 +471,7 @@ where
         Self {
             status: http::StatusCode::OK,
             inner: B::default(),
-            stream_open_at: clock::now(),
+            stream_open_at: Instant::now(),
             classify: None,
             metrics: None,
             latency_recorded: false,
@@ -488,7 +487,7 @@ where
 {
     fn record_latency(self: Pin<&mut Self>) {
         let this = self.project();
-        let now = clock::now();
+        let now = Instant::now();
 
         let lock = match this.metrics.as_mut() {
             Some(lock) => lock,
@@ -537,7 +536,7 @@ fn measure_class<C: Hash + Eq>(
     class: C,
     status: Option<http::StatusCode>,
 ) {
-    let now = clock::now();
+    let now = Instant::now();
     let mut metrics = match lock.lock() {
         Ok(m) => m,
         Err(_) => return,

linkerd/http-metrics/src/requests/layer.rs

@@ -7,7 +7,6 @@ use std::fmt::Debug;
 use std::hash::Hash;
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
-use tokio_timer::clock;
 
 mod layer;
 mod report;
@@ -79,7 +78,7 @@ impl<T: Hash + Eq, C: Hash + Eq> Clone for Requests<T, C> {
 impl<C: Hash + Eq> Default for Metrics<C> {
     fn default() -> Self {
         Self {
-            last_update: clock::now(),
+            last_update: Instant::now(),
             total: Counter::default(),
             by_status: IndexMap::default(),
         }
@@ -110,8 +109,7 @@ mod tests {
     fn expiry() {
         use linkerd2_metrics::FmtLabels;
         use std::fmt;
-        use std::time::Duration;
-        use tokio_timer::clock;
+        use std::time::{Duration, Instant};
 
         #[derive(Clone, Debug, Hash, Eq, PartialEq)]
         struct Target(usize);
@@ -142,14 +140,14 @@ mod tests {
         let report = r.clone().into_report(retain_idle_for);
         let mut registry = r.0.lock().unwrap();
 
-        let before_update = clock::now();
+        let before_update = Instant::now();
         let metrics = registry
             .by_target
             .entry(Target(123))
             .or_insert_with(|| Default::default())
             .clone();
         assert_eq!(registry.by_target.len(), 1, "target should be registered");
-        let after_update = clock::now();
+        let after_update = Instant::now();
 
         registry.retain_since(after_update);
         assert_eq!(

linkerd/http-metrics/src/requests/mod.rs

@@ -3,7 +3,7 @@ use crate::{Prefixed, Registry, Report};
 use linkerd2_metrics::{latency, Counter, FmtLabels, FmtMetric, FmtMetrics, Histogram, Metric};
 use std::fmt;
 use std::hash::Hash;
-use tokio_timer::clock;
+use std::time::Instant;
 use tracing::trace;
 
 struct Status(http::StatusCode);
@@ -73,7 +73,7 @@ where
         metric.fmt_help(f)?;
         registry.fmt_by_class(f, metric, |s| &s.total)?;
 
-        registry.retain_since(clock::now() - self.retain_idle);
+        registry.retain_since(Instant::now() - self.retain_idle);
 
         Ok(())
     }

linkerd/http-metrics/src/requests/report.rs

@@ -4,7 +4,6 @@ use std::fmt;
 use std::hash::Hash;
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
-use tokio_timer::clock;
 use tracing::trace;
 
 #[derive(Debug)]
@@ -59,7 +58,7 @@ impl<T: Hash + Eq> Clone for Retries<T> {
 impl Handle {
     pub fn incr_retryable(&self, has_budget: bool) {
         if let Ok(mut m) = self.0.lock() {
-            m.last_update = clock::now();
+            m.last_update = Instant::now();
             m.retryable.incr();
             if !has_budget {
                 m.no_budget.incr();
@@ -73,7 +72,7 @@ impl Handle {
 impl Default for Metrics {
     fn default() -> Self {
         Self {
-            last_update: clock::now(),
+            last_update: Instant::now(),
             retryable: Counter::default(),
             no_budget: Counter::default(),
         }
@@ -129,7 +128,7 @@ where
             }
         }
 
-        registry.retain_since(clock::now() - self.retain_idle);
+        registry.retain_since(Instant::now() - self.retain_idle);
 
         Ok(())
     }