refine the example, drop some overhead

Author: martintmk

examples/metrics-lock-contention/src/main.rs

@@ -4,6 +4,8 @@ use opentelemetry_sdk::metrics::{ManualReader, SdkMeterProvider};
 use std::env::args;
 use std::fmt::Debug;
 use std::str::FromStr;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::thread::{spawn, JoinHandle};
 use std::time::{Duration, Instant};
 
@@ -13,19 +15,27 @@ const RUN_TIME: Duration = Duration::from_secs(120);
 
 fn main() {
     let mode: Mode = args().nth(1).unwrap_or("shared".to_string()).parse().unwrap();
+    let exit_signal = Arc::new(AtomicBool::new(false));
 
     println!("Running with mode: {:?}, Duration: {}s, Threads: {}", mode, RUN_TIME.as_secs(), NUM_THREADS);
 
     let handles: Vec<JoinHandle<_>> = match mode {
         Mode::Shared =>  {
             let provider = create_meter_provider();
-            (0..NUM_THREADS).map(move |_|start_work(provider.clone())).collect()
+            let signal = Arc::clone(&exit_signal);
+            (0..NUM_THREADS).map(move |_|start_work(provider.clone(), signal.clone())).collect()
         }
         Mode::PerThread => {
-            (0..NUM_THREADS).map(move |_|start_work(create_meter_provider())).collect()
+            let signal = Arc::clone(&exit_signal);
+            (0..NUM_THREADS).map(move |_|start_work(create_meter_provider(), signal.clone())).collect()
         }
     };
 
+    _ = spawn(move || {
+        std::thread::sleep(RUN_TIME);
+        exit_signal.store(true, Ordering::Relaxed);
+    });
+
     let sum = handles
         .into_iter()
         .map(|h| h.join().unwrap())
@@ -34,29 +44,17 @@ fn main() {
     println!("Reported Metrics: {} millions", (sum / 1_000_000));
 }
 
-fn start_work(meter_provider: SdkMeterProvider) -> JoinHandle<usize> {
+fn start_work(meter_provider: SdkMeterProvider, exit_signal: Arc<AtomicBool>) -> JoinHandle<usize> {
     let histogram = meter_provider.meter("dummy").f64_histogram("histogram").build();
     spawn(move || {
         let mut count = 0_usize;
         let now = Instant::now();
 
         loop {
-            histogram.record(
-                10.5,
-                &[
-                    KeyValue::new("mykey1", "myvalue1"),
-                    KeyValue::new("mykey2", "myvalue2"),
-                    KeyValue::new("mykey3", "myvalue3"),
-                    KeyValue::new("mykey4", "myvalue4"),
-                    KeyValue::new("mykey5", "myvalue5"),
-                    KeyValue::new("mykey6", "myvalue6"),
-                    KeyValue::new("mykey7", "myvalue7"),
-                ],
-            );
-
+            histogram.record(10.5, &[]);
             count = count.checked_add(1).unwrap();
 
-            if now.elapsed() > RUN_TIME {
+            if exit_signal.load(Ordering::Relaxed) {
                 break;
             }
         }