Merge pull request #101 from aqrln/duration-histogram-guard-consistency

fix: make the timings recorded in wait_duration and histogram consistent

src/lib.rs

@@ -442,8 +442,7 @@ impl<M: Manager> Pool<M> {
 
         let mut internals = self.0.internals.lock().await;
 
-        internals.wait_duration += wait_guard.elapsed();
-        drop(wait_guard);
+        internals.wait_duration += wait_guard.into_elapsed();
 
         let conn = internals.free_conns.pop();
         let internal_config = internals.config.clone();

src/metrics_utils.rs

@@ -1,4 +1,7 @@
-use std::time::{Duration, Instant};
+use std::{
+    mem::ManuallyDrop,
+    time::{Duration, Instant},
+};
 
 use metrics::{describe_counter, describe_gauge, describe_histogram, gauge, histogram};
 
@@ -71,8 +74,11 @@ impl DurationHistogramGuard {
         }
     }
 
-    pub(crate) fn elapsed(&self) -> Duration {
-        self.start.elapsed()
+    pub(crate) fn into_elapsed(self) -> Duration {
+        let this = ManuallyDrop::new(self);
+        let elapsed = this.start.elapsed();
+        histogram!(this.key).record(elapsed);
+        elapsed
     }
 }