cleanup panics and atomic orderings

README.md

@@ -2,8 +2,6 @@
 [Latest Version]: https://img.shields.io/crates/v/tracing-texray.svg
 [crates.io]: https://crates.io/crates/tracing-texray
 
-> First, a word of warning: **This is alpha software.** Don't run this in prod or anywhere where a panic would ruin your day.
-
 `tracing-texray` is a [tracing](https://tracing.rs) layer to introspect spans and events in plain text. By `examine`-ing a specific
 span, a full tree will be output when that span exits. Using code like the following (actual program elided):
 

src/tracked_spans.rs

@@ -68,13 +68,13 @@ impl TrackedSpans {
         while attempt < self.size() {
             let idx = self.hash(value, attempt);
             let atomic = self.els.get(idx).expect("idx guaranteed to be less");
-            let old_val = atomic.load(Ordering::Relaxed);
+            let old_val = atomic.load(Ordering::SeqCst);
             if old_val == value {
                 return Ok(InsertResult::AlreadyPresent);
             }
             if (old_val == 0 || old_val == TOMBSTONE)
                 && atomic
-                    .compare_exchange(old_val, value, Ordering::Relaxed, Ordering::Relaxed)
+                    .compare_exchange(old_val, value, Ordering::SeqCst, Ordering::SeqCst)
                     .is_ok()
             {
                 return Ok(InsertResult::NotPresent);
@@ -94,7 +94,7 @@ impl TrackedSpans {
         while attempt < self.size() {
             let idx = self.hash(value, attempt);
             let atomic = self.els.get(idx).expect("idx guaranteed to be less");
-            let stored_value = atomic.load(Ordering::SeqCst);
+            let stored_value = atomic.load(Ordering::Acquire);
             match stored_value {
                 0 => return None,
                 v if v == value => return Some(idx),
@@ -112,7 +112,7 @@ impl TrackedSpans {
                 _ => TOMBSTONE,
             };
             self.els[idx]
-                .compare_exchange(value.get(), new_value, Ordering::Relaxed, Ordering::Relaxed)
+                .compare_exchange(value.get(), new_value, Ordering::AcqRel, Ordering::Acquire)
                 .is_ok()
         } else {
             false

src/tracker.rs

@@ -146,10 +146,9 @@ impl SpanInfo {
         let offset = width(
             render_conf.chart_width(),
             render_conf.total(),
-            match ev_start_ts.duration_since(render_conf.start_ts) {
-                Ok(dur) => dur,
-                Err(_) => return Ok(()),
-            },
+            ev_start_ts
+                .duration_since(render_conf.start_ts)
+                .unwrap_or_default(),
         );
         write!(out, "{}", " ".repeat(offset))?;
         let interval_width = width(render_conf.chart_width(), render_conf.total(), span_len);
@@ -407,7 +406,9 @@ impl InterestTracker {
             let event_offset = (width(
                 render_conf.chart_width(),
                 render_conf.total(),
-                ev.timestamp.duration_since(span_info.start).unwrap(),
+                ev.timestamp
+                    .duration_since(span_info.start)
+                    .unwrap_or_default(),
             ) as i32)
                 - 1;
             write!(out, "{}", " ".repeat(DURATION_WIDTH + 2))?;
@@ -434,11 +435,13 @@ impl RootTracker {
     }
 
     pub(crate) fn register_interest(&self, id: Id, settings: SpanSettings) {
+        // put the insertion into examined_spans inside the critical block
+        let mut span_guard = self.span_metadata.write();
         if self.examined_spans.insert(id.into_non_zero_u64()).is_err() {
             tracing::warn!("map is full, too many spans. this span will not be tracked");
             return;
         }
-        self.span_metadata.write().insert(
+        span_guard.insert(
             id.clone(),
             InterestTracker::new(id, settings.render, settings.fields, settings.out),
         );