Switch to std::time

There is a weird contention problem in tokio::time
that causes each call to `Instant::now` lock and unlock
a mutex.

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "latte"
 description = "A database benchmarking tool for Apache Cassandra"
-version = "0.10.0"
+version = "0.10.1"
 authors = ["Piotr Kołaczkowski <pkolaczk@datastax.com>"]
-edition = "2018"
+edition = "2021"
 readme = "README.md"
 license = "Apache-2.0"
 
@@ -36,15 +36,17 @@ strum = { version = "0.19.5", features = ["derive"] }
 strum_macros = "0.19.4"
 time = "0.1.44"
 thiserror = "1.0.26"
-tokio = { version = "1.14", features = ["rt", "rt-multi-thread", "time"] }
+tokio = { version = "1.14", features = ["rt", "rt-multi-thread", "time", "parking_lot"] }
 tokio-stream = "0.1"
 uuid = { version = "0.8", features = ["v4"] }
 
 [dev-dependencies]
 tokio = { version = "1.11", features = ["rt", "test-util", "macros"] }
 
 [profile.release]
+opt-level = 3
 lto = true
+debug = true
 panic = "abort"
 
 [package.metadata.deb]

src/main.rs

@@ -3,6 +3,7 @@ use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
 use std::process::exit;
 use std::sync::Arc;
+use std::time::{Duration, Instant};
 
 use clap::Parser;
 use futures::channel::mpsc::Sender;
@@ -12,7 +13,6 @@ use itertools::Itertools;
 use rune::Source;
 use status_line::StatusLine;
 use tokio::runtime::Builder;
-use tokio::time::{Duration, Instant};
 use tokio_stream::wrappers::IntervalStream;
 
 use config::RunCommand;
@@ -60,9 +60,10 @@ async fn send_stats(workload: &Workload, time: Instant, tx: &mut Sender<Result<W
     tx.send(Ok(stats)).await.unwrap();
 }
 
+
 /// Runs a series of requests on a separate thread and
 /// produces a stream of QueryStats
-async fn req_stream(
+fn spawn_stream(
     concurrency: NonZeroUsize,
     rate: Option<f64>,
     sampling_period: Duration,
@@ -71,7 +72,7 @@ async fn req_stream(
     progress: Arc<StatusLine<Progress>>,
     interrupt: Arc<InterruptHandler>,
 ) -> impl Stream<Item = Result<WorkloadStats>> {
-    let (mut tx, rx) = futures::channel::mpsc::channel(16);
+    let (mut tx, rx) = futures::channel::mpsc::channel(20);
 
     tokio::spawn(async move {
         // prevent further moves, make it shared for all iterations in this thread
@@ -93,7 +94,7 @@ async fn req_stream(
 
         // The following loop takes the stats generated by the stream and aggregates them
         // into chunks of `sampling_period` length. When a chunk is ready, it is sent out.
-        let mut start_time = Instant::now();
+        let mut start_time = std::time::Instant::now();
         workload.reset(start_time);
         while let Some(req) = req_stats.next().await {
             if interrupt.is_interrupted() {
@@ -102,7 +103,7 @@ async fn req_stream(
 
             match req {
                 Ok(_) | Err(LatteError::Cassandra(CassError(CassErrorKind::Overloaded(_)))) => {
-                    let now = Instant::now();
+                    let now = std::time::Instant::now();
                     if now - start_time > sampling_period {
                         start_time += round(now - start_time, sampling_period);
                         send_stats(workload, start_time, &mut tx).await;
@@ -187,7 +188,7 @@ async fn par_execute(
     let mut streams = Vec::with_capacity(threads_count);
 
     for _ in 0..threads_count {
-        let s = req_stream(
+        let s = spawn_stream(
             concurrency,
             rate.map(|r| r / (threads_count as f64)),
             sampling_period,
@@ -196,7 +197,7 @@ async fn par_execute(
             progress.clone(),
             signals.clone(),
         );
-        streams.push(s.await)
+        streams.push(s)
     }
 
     while !streams.is_empty() {

src/stats.rs

@@ -1,6 +1,7 @@
 use std::cmp::min;
 use std::collections::HashSet;
 use std::num::NonZeroUsize;
+use std::time::Instant;
 
 use crate::workload::WorkloadStats;
 use cpu_time::ProcessTime;
@@ -10,7 +11,6 @@ use statrs::distribution::{StudentsT, Univariate};
 use strum::EnumCount;
 use strum::IntoEnumIterator;
 use strum_macros::{EnumCount as EnumCountM, EnumIter};
-use tokio::time::Instant;
 
 /// Controls the maximum order of autocovariance taken into
 /// account when estimating the long run mean error. Higher values make the estimator

src/workload.rs

@@ -1,15 +1,14 @@
 use std::cmp::max;
 use std::collections::HashMap;
 use std::fmt::Debug;
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+use std::time::Instant;
 
 use hdrhistogram::Histogram;
 use rune::runtime::{AnyObj, Args, RuntimeContext, Shared, VmError};
 use rune::termcolor::{ColorChoice, StandardStream};
 use rune::{Any, Diagnostics, Module, Source, Sources, ToValue, Unit, Value, Vm};
-use tokio::sync::Mutex;
-use tokio::time::Duration;
-use tokio::time::Instant;
 
 use crate::error::LatteError;
 use crate::{CassError, Session, SessionStats};
@@ -379,7 +378,7 @@ impl Workload {
             .await
             .map(|_| ()); // erase Value, because Value is !Send
         let end_time = Instant::now();
-        let mut state = self.state.lock().await;
+        let mut state = self.state.try_lock().unwrap();
         state.fn_stats.operation_completed(end_time - start_time);
         result?;
         Ok(())