Blocking Call on DigestAlgorithm #6590

Describe the bug

Hello,

While using BlockHound to detect blocking calls on our service, we found out a blocking call on https://github.com/aws/aws-sdk-java-v2/blob/master/core/checksums/src/main/java/software/amazon/awssdk/checksums/internal/DigestAlgorithm.java#L55 . It seems this is related to a recent change in this class (c137348) that introduced a LinkedBlockingDeque.

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

The Async version of the SDK shouldn't block threads.

Current Behavior

Due to the internal code of LinkedBlockingDeque, the modified DigestAlgorithm blocks.

Reproduction Steps

Any HTTP request will trigger this issue, example the Async SDK for DynamoDB (GetItem).

Possible Solution

Use ConcurrentLinkedDeque or ThreadLocal perhaps.

Additional Information/Context

No response

AWS Java SDK version used

2.33.11

JDK version used

21

Operating System and version

Mac