From b18646810dfa4696ee110b0293b8b26c5734a08a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 29 Sep 2025 20:54:27 +0000
Subject: [PATCH 1/2] Initial plan


From dc75cc9281c42532fad0bc232b77ddfc572df3f6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 29 Sep 2025 21:08:24 +0000
Subject: [PATCH 2/2] Make enabled fields volatile in SdkTracer, SdkMeter, and
 MetricStorage implementations

Co-authored-by: trask <218610+trask@users.noreply.github.com>
---
 .../src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java | 2 +-
 .../metrics/internal/state/AsynchronousMetricStorage.java    | 2 +-
 .../internal/state/DefaultSynchronousMetricStorage.java      | 2 +-
 .../src/main/java/io/opentelemetry/sdk/trace/SdkTracer.java  | 5 ++---
 4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java
index b31b3721428..470d1b96098 100644
--- a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java
+++ b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java
@@ -89,7 +89,7 @@ final class SdkMeter implements Meter {
   private final InstrumentationScopeInfo instrumentationScopeInfo;
   private final Map<RegisteredReader, MetricStorageRegistry> readerStorageRegistries;
 
-  private boolean meterEnabled;
+  private volatile boolean meterEnabled;
 
   SdkMeter(
       MeterProviderSharedState meterProviderSharedState,
diff --git a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/AsynchronousMetricStorage.java b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/AsynchronousMetricStorage.java
index 6463226f8bc..318bd4847d7 100644
--- a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/AsynchronousMetricStorage.java
+++ b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/AsynchronousMetricStorage.java
@@ -87,7 +87,7 @@ public final class AsynchronousMetricStorage<T extends PointData, U extends Exem
   private long startEpochNanos;
   private long epochNanos;
 
-  private boolean enabled;
+  private volatile boolean enabled;
 
   private AsynchronousMetricStorage(
       RegisteredReader registeredReader,
diff --git a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/DefaultSynchronousMetricStorage.java b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/DefaultSynchronousMetricStorage.java
index 77070ace40d..c46c5462e0a 100644
--- a/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/DefaultSynchronousMetricStorage.java
+++ b/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/state/DefaultSynchronousMetricStorage.java
@@ -74,7 +74,7 @@ public final class DefaultSynchronousMetricStorage<T extends PointData, U extend
   private final ConcurrentLinkedQueue<AggregatorHandle<T, U>> aggregatorHandlePool =
       new ConcurrentLinkedQueue<>();
 
-  private boolean enabled;
+  private volatile boolean enabled;
 
   DefaultSynchronousMetricStorage(
       RegisteredReader registeredReader,
diff --git a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/SdkTracer.java b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/SdkTracer.java
index b148d0cf8c6..d90f4d8cb01 100644
--- a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/SdkTracer.java
+++ b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/SdkTracer.java
@@ -30,9 +30,8 @@ class SdkTracer implements Tracer {
 
   private final TracerSharedState sharedState;
   private final InstrumentationScopeInfo instrumentationScopeInfo;
-  // deliberately not volatile because of performance concerns
-  // - which means its eventually consistent
-  protected boolean tracerEnabled;
+
+  protected volatile boolean tracerEnabled;
 
   SdkTracer(
       TracerSharedState sharedState,