Keep Record of Original Exception in S3 Callbacks (#700)

src/main/java/software/amazon/awssdk/crt/s3/S3FinishedResponseContext.java

@@ -11,48 +11,62 @@ public class S3FinishedResponseContext {
     private final ChecksumAlgorithm checksumAlgorithm;
     private final boolean didValidateChecksum;
 
+    private final Throwable cause;
+
     /*
      * errorCode The CRT error code
      * responseStatus statusCode of the HTTP response
      * errorPayload body of the error response. Can be null if the request completed successfully
      * checksumAlgorithm, the algorithm used to validate the Body, None if not validated
      * didValidateChecksum which is true if the response was validated.
+     * cause of the error such as a Java exception in a callback. Maybe NULL if there was no exception in a callback.
      */
-    S3FinishedResponseContext(final int errorCode, final int responseStatus, final byte[] errorPayload, final ChecksumAlgorithm checksumAlgorithm, final boolean didValidateChecksum) {
+    S3FinishedResponseContext(final int errorCode, final int responseStatus, final byte[] errorPayload, final ChecksumAlgorithm checksumAlgorithm, final boolean didValidateChecksum, Throwable cause) {
         this.errorCode = errorCode;
         this.responseStatus = responseStatus;
         this.errorPayload = errorPayload;
         this.checksumAlgorithm = checksumAlgorithm;
         this.didValidateChecksum = didValidateChecksum;
+        this.cause = cause;
     }
 
-    public int getErrorCode () {
+    public int getErrorCode() {
         return this.errorCode;
     }
 
     /*
      * If the request didn't receive a response due to a connection
      * failure or some other issue the response status will be 0.
      */
-    public int getResponseStatus () {
+    public int getResponseStatus() {
         return this.responseStatus;
     }
 
     /*
      * In the case of a failed http response get the payload of the response.
      */
-    public byte[] getErrorPayload () {
+    public byte[] getErrorPayload() {
         return this.errorPayload;
     }
 
     /*
      * if no checksum is found, or the request finished with an error the Algorithm will be None,
      * otherwise the algorithm will correspond to the one attached to the object when uploaded.
      */
-    public ChecksumAlgorithm getChecksumAlgorithm () {
+    public ChecksumAlgorithm getChecksumAlgorithm() {
         return this.checksumAlgorithm;
     }
-    public boolean isChecksumValidated () {
+
+    public boolean isChecksumValidated() {
         return this.didValidateChecksum;
     }
+
+    /**
+     * Cause of the error, such as a Java exception from a callback. May be NULL if there was no exception in a callback.
+     * @return throwable
+     */
+    public Throwable getCause() {
+        return cause;
+    }
+
 }

src/main/java/software/amazon/awssdk/crt/s3/S3MetaRequestResponseHandlerNativeAdapter.java

@@ -19,8 +19,8 @@ int onResponseBody(byte[] bodyBytesIn, long objectRangeStart, long objectRangeEn
         return this.responseHandler.onResponseBody(ByteBuffer.wrap(bodyBytesIn), objectRangeStart, objectRangeEnd);
     }
 
-    void onFinished(int errorCode, int responseStatus, byte[] errorPayload, int checksumAlgorithm, boolean didValidateChecksum) {
-        S3FinishedResponseContext context = new S3FinishedResponseContext(errorCode, responseStatus, errorPayload, ChecksumAlgorithm.getEnumValueFromInteger(checksumAlgorithm), didValidateChecksum);
+    void onFinished(int errorCode, int responseStatus, byte[] errorPayload, int checksumAlgorithm, boolean didValidateChecksum, Throwable cause) {
+        S3FinishedResponseContext context = new S3FinishedResponseContext(errorCode, responseStatus, errorPayload, ChecksumAlgorithm.getEnumValueFromInteger(checksumAlgorithm), didValidateChecksum, cause);
         this.responseHandler.onFinished(context);
     }
 

src/native/crt.c

@@ -286,6 +286,16 @@ bool aws_jni_check_and_clear_exception(JNIEnv *env) {
     return exception_pending;
 }
 
+bool aws_jni_get_and_clear_exception(JNIEnv *env, jthrowable *out) {
+    bool exception_pending = (*env)->ExceptionCheck(env);
+    if (exception_pending) {
+        (*env)->DeleteGlobalRef(env, *out);
+        *out = (jthrowable)(*env)->NewGlobalRef(env, (*env)->ExceptionOccurred(env));
+        (*env)->ExceptionClear(env);
+    }
+    return exception_pending;
+}
+
 int aws_size_t_from_java(JNIEnv *env, size_t *out_size, jlong java_long, const char *errmsg_prefix) {
     if (java_long < 0) {
         aws_jni_throw_illegal_argument_exception(env, "%s cannot be negative", errmsg_prefix);

src/native/crt.h

@@ -59,6 +59,21 @@ void aws_jni_throw_illegal_argument_exception(JNIEnv *env, const char *msg, ...)
  ******************************************************************************/
 bool aws_jni_check_and_clear_exception(JNIEnv *env);
 
+/*******************************************************************************
+ * Checks whether or not an exception is pending on the stack.
+ * If the exception is pending, deletes existing global reference of `out`, sets `out` to the new exception and clears
+ * it.
+ *
+ * @param env A pointer to the JNI environment, used to interact with the JVM.
+ * @param out A pointer to a jthrowable object. If an exception is pending, the function
+ *            deletes any existing global reference pointed to by 'out', and sets 'out'
+ *            to point to the new exception. Must not be NULL.
+ *
+ * @return true if an exception was pending and has been cleared; false otherwise.
+ *
+ ******************************************************************************/
+bool aws_jni_get_and_clear_exception(JNIEnv *env, jthrowable *out);
+
 /*******************************************************************************
  * Set a size_t based on a jlong.
  * If conversion fails, a java IllegalArgumentException is thrown like

src/native/java_class_ids.c

@@ -693,7 +693,7 @@ static void s_cache_s3_meta_request_response_handler_native_adapter_properties(J
     AWS_FATAL_ASSERT(s3_meta_request_response_handler_native_adapter_properties.onResponseBody);
 
     s3_meta_request_response_handler_native_adapter_properties.onFinished =
-        (*env)->GetMethodID(env, cls, "onFinished", "(II[BIZ)V");
+        (*env)->GetMethodID(env, cls, "onFinished", "(II[BIZLjava/lang/Throwable;)V");
     AWS_FATAL_ASSERT(s3_meta_request_response_handler_native_adapter_properties.onFinished);
 
     s3_meta_request_response_handler_native_adapter_properties.onResponseHeaders =

src/native/s3_client.c

@@ -46,6 +46,7 @@ struct s3_client_make_meta_request_callback_data {
     jobject java_s3_meta_request_response_handler_native_adapter;
     struct aws_input_stream *input_stream;
     struct aws_signing_config_data signing_config_data;
+    jthrowable java_exception;
 };
 
 static void s_on_s3_client_shutdown_complete_callback(void *user_data);
@@ -354,10 +355,10 @@ static int s_on_s3_meta_request_body_callback(
             range_start,
             range_end);
 
-        if (aws_jni_check_and_clear_exception(env)) {
+        if (aws_jni_get_and_clear_exception(env, &(callback_data->java_exception))) {
             AWS_LOGF_ERROR(
                 AWS_LS_S3_META_REQUEST,
-                "id=%p: Ignored Exception from S3MetaRequest.onResponseBody callback",
+                "id=%p: Received exception from S3MetaRequest.onResponseBody callback",
                 (void *)meta_request);
             aws_raise_error(AWS_ERROR_HTTP_CALLBACK_FAILURE);
             goto cleanup;
@@ -432,7 +433,7 @@ static int s_on_s3_meta_request_headers_callback(
             response_status,
             java_headers_buffer);
 
-        if (aws_jni_check_and_clear_exception(env)) {
+        if (aws_jni_get_and_clear_exception(env, &(callback_data->java_exception))) {
             AWS_LOGF_ERROR(
                 AWS_LS_S3_META_REQUEST,
                 "id=%p: Exception thrown from S3MetaRequest.onResponseHeaders callback",
@@ -481,6 +482,10 @@ static void s_on_s3_meta_request_finish_callback(
             error_response_cursor = aws_byte_cursor_from_buf(error_response_body);
         }
         jbyteArray jni_payload = aws_jni_byte_array_from_cursor(env, &error_response_cursor);
+        /* Only propagate java_exception if crt error code is callback failure */
+        jthrowable java_exception =
+            meta_request_result->error_code == AWS_ERROR_HTTP_CALLBACK_FAILURE ? callback_data->java_exception : NULL;
+
         (*env)->CallVoidMethod(
             env,
             callback_data->java_s3_meta_request_response_handler_native_adapter,
@@ -489,7 +494,8 @@ static void s_on_s3_meta_request_finish_callback(
             meta_request_result->response_status,
             jni_payload,
             meta_request_result->validation_algorithm,
-            meta_request_result->did_validate);
+            meta_request_result->did_validate,
+            java_exception);
 
         if (aws_jni_check_and_clear_exception(env)) {
             AWS_LOGF_ERROR(
@@ -571,6 +577,7 @@ static void s_s3_meta_request_callback_cleanup(
     if (callback_data) {
         (*env)->DeleteGlobalRef(env, callback_data->java_s3_meta_request);
         (*env)->DeleteGlobalRef(env, callback_data->java_s3_meta_request_response_handler_native_adapter);
+        (*env)->DeleteGlobalRef(env, callback_data->java_exception);
         aws_signing_config_data_clean_up(&callback_data->signing_config_data, env);
         aws_mem_release(aws_jni_get_allocator(), callback_data);
     }