Fix time offset handling

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/http/HttpClientDependencies.java

@@ -19,7 +19,6 @@
 
 import java.util.function.Consumer;
 import software.amazon.awssdk.annotations.SdkInternalApi;
-import software.amazon.awssdk.core.SdkGlobalTime;
 import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
 import software.amazon.awssdk.core.internal.http.pipeline.RequestPipeline;
 import software.amazon.awssdk.core.internal.http.pipeline.RequestPipelineBuilder;
@@ -32,15 +31,15 @@
  */
 @SdkInternalApi
 public final class HttpClientDependencies implements SdkAutoCloseable {
-    private final ClockSkewAdjuster clockSkewAdjuster;
-    private final SdkClientConfiguration clientConfiguration;
-
     /**
      * Time offset may be mutated by {@link RequestPipeline} implementations if a clock skew is detected.
      */
-    private volatile int timeOffset = SdkGlobalTime.getGlobalTimeOffset();
+    private final SdkClientTime sdkClientTime;
+    private final ClockSkewAdjuster clockSkewAdjuster;
+    private final SdkClientConfiguration clientConfiguration;
 
     private HttpClientDependencies(Builder builder) {
+        this.sdkClientTime = builder.sdkClientTime != null ? builder.sdkClientTime : new SdkClientTime();
         this.clockSkewAdjuster = builder.clockSkewAdjuster != null ? builder.clockSkewAdjuster : new ClockSkewAdjuster();
         this.clientConfiguration = paramNotNull(builder.clientConfiguration, "ClientConfiguration");
     }
@@ -64,15 +63,14 @@ public ClockSkewAdjuster clockSkewAdjuster() {
      * @return Current time offset. This is mutable and should not be cached.
      */
     public int timeOffset() {
-        return timeOffset;
+        return sdkClientTime.getTimeOffset();
     }
 
     /**
      * Updates the time offset of the client as well as the global time offset.
      */
     public void updateTimeOffset(int timeOffset) {
-        this.timeOffset = timeOffset;
-        SdkGlobalTime.setGlobalTimeOffset(timeOffset);
+        sdkClientTime.setTimeOffset(timeOffset);
     }
 
     public Builder toBuilder() {
@@ -88,13 +86,15 @@ public void close() {
      * Builder for {@link HttpClientDependencies}.
      */
     public static class Builder {
+        private SdkClientTime sdkClientTime;
         private ClockSkewAdjuster clockSkewAdjuster;
         private SdkClientConfiguration clientConfiguration;
 
         private Builder() {
         }
 
         private Builder(HttpClientDependencies from) {
+            this.sdkClientTime = from.sdkClientTime;
             this.clientConfiguration = from.clientConfiguration;
             this.clockSkewAdjuster = from.clockSkewAdjuster;
         }

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/http/SdkClientTime.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.awssdk.core.internal.http;
+
+import software.amazon.awssdk.annotations.SdkInternalApi;
+import software.amazon.awssdk.core.SdkGlobalTime;
+import software.amazon.awssdk.core.internal.http.pipeline.RequestPipeline;
+
+/**
+ * Used for clock skew adjustment between the client JVM where the SDK is run,
+ * and the server side. This class mirrors {@link SdkGlobalTime} but it's local to the current client and only accessed
+ * internally by {@link HttpClientDependencies}.
+ */
+@SdkInternalApi
+public final class SdkClientTime {
+    /**
+     * Time offset may be mutated by {@link RequestPipeline} implementations if a clock skew is detected.
+     */
+    private volatile int timeOffset = SdkGlobalTime.getGlobalTimeOffset();
+
+    /**
+     * Gets the latest recorded time offset.
+     */
+    public int getTimeOffset() {
+        return timeOffset;
+    }
+
+    /**
+     * Sets the latest recorded time offset.
+     */
+    public void setTimeOffset(int timeOffset) {
+        this.timeOffset = timeOffset;
+        SdkGlobalTime.setGlobalTimeOffset(timeOffset);
+    }
+}