Fix SpotBugs: suppress AT_NONATOMIC warnings for owner-thread fast path

bm1549 · claude · bm1549 · commit 8d5c038a1d3c · 2026-04-14T13:16:33.000-04:00
SpotBugs flags *Impl methods in OptimizedTagMap for non-atomic access to
the `size` and `frozen` fields. These methods run either on the owner
thread (lock-free by design) or inside synchronized(this) via reentrant
calls. Also fix null-safe containsValue using Objects.equals.

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java
@@ -1,6 +1,7 @@
 package datadog.trace.api;
 
 import datadog.trace.api.function.TriConsumer;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.AbstractCollection;
 import java.util.AbstractSet;
 import java.util.Arrays;
@@ -1285,6 +1286,11 @@ public LegacyTagMap empty() {
  * #withLock(Runnable)} which always acquires the monitor. Inner per-operation calls are reentrant
  * on the same monitor and add zero overhead.
  */
+@SuppressFBWarnings(
+    value = {"AT_NONATOMIC_OPERATIONS_ON_SHARED_VARIABLE", "AT_STALE_THREAD_WRITE_OF_PRIMITIVE"},
+    justification =
+        "Owner-thread fast path: *Impl methods run either on the owner thread (no lock needed)"
+            + " or inside synchronized(this) via reentrant calls. See class javadoc.")
 final class OptimizedTagMap implements TagMap {
   // Using special constructor that creates a frozen view of an existing array
   // Bucket calculation requires that array length is a power of 2
