[Feature] Synchronized version of AwsCrtV4aSigner

[noCharger]

Describe the feature

The feature request is for an implementation of the AwsCrtV4aSigner that either uses synchronized signing method or employs non-daemon threads during signing operations.

aws-sdk-java-v2/core/auth-crt/src/main/java/software/amazon/awssdk/authcrt/signer/internal/AwsCrt4aSigningAdapter.java

Line 48 in 80e1821

HttpRequest signedRequest = future.get();

Use Case

The current SigV4a signer is implemented asynchronously using CompletableFuture, which defaults to using daemon thread. However, in specific scenarios such as when Spark's ShutdownHookManager is active, these daemon threads can be prematurely interrupted, leading to potential issues.

Proposed Solution

An implementation of the AwsCrtV4aSigner that either uses synchronized signing method or employs non-daemon threads during signing operations.

Pseudo code

public class AwsSigner {
    private static final ThreadFactory nonDaemonThreadFactory = new ThreadFactory() {
        private final AtomicInteger threadCount = new AtomicInteger(0);

        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);
            t.setDaemon(false); // Set the thread as non-daemon
            t.setName("AwsSignerThread-" + threadCount.getAndIncrement());
            return t;
        }
    };

    /**
     * Signs an http request according to the supplied signing configuration
     * @param request http request to sign
     * @param config signing configuration
     * @return future which will contain the signed request
     */
    static public CompletableFuture<HttpRequest> signRequest(HttpRequest request, AwsSigningConfig config) {
        CompletableFuture<HttpRequest> future = new CompletableFuture<HttpRequest>();
        CompletableFuture<AwsSigningResult> result = AwsSigner.sign(request, config);

        result.whenCompleteAsync((res, throwable) -> {
            if (throwable != null) {
                future.completeExceptionally(throwable);
            } else {
                future.complete(res.getSignedRequest());
            }
        }, Executors.newSingleThreadExecutor(nonDaemonThreadFactory));
        return future;
    }
}

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS Java SDK version used

2.25.23

JDK version used

openjdk version "14.0.2" 2020-07-14

Operating System and version

N/A