Group: Enable aggregate exception to be passed as ptr

include/spinscale/co/group.h

@@ -564,10 +564,10 @@ struct Group
 		memberAdapterCoro(memberInvoker, settlementIndex);
 	}
 
-	void checkForAndReThrowGroupExceptions() const
+	std::exception_ptr captureAggregatedGroupExceptions() const
 	{
 		std::ostringstream ostream;
-		bool doThrow = false;
+		bool hasFailures = false;
 
 		for (auto &item : s.rsrc.settlements)
 		{
@@ -577,7 +577,7 @@ struct Group
 
 			assert(item.calleeException);
 
-			doThrow = true;
+			hasFailures = true;
 			ostream << "Exc thrown in Group Adapter: ";
 			try {
 				std::rethrow_exception(item.calleeException);
@@ -589,8 +589,19 @@ struct Group
 			ostream << "\n";
 		}
 
-		if (doThrow) {
+		if (!hasFailures) {
-			throw std::runtime_error(ostream.str());
+			return nullptr;
+		}
+
+		return std::make_exception_ptr(std::runtime_error(ostream.str()));
+	}
+
+	void checkForAndReThrowGroupExceptions() const
+	{
+		std::exception_ptr aggregatedException =
+			captureAggregatedGroupExceptions();
+		if (aggregatedException) {
+			std::rethrow_exception(aggregatedException);
 		}
 	}
 

include/spinscale/multiOperationResultSet.h

@@ -1,6 +1,8 @@
 #ifndef MULTI_OPERATION_RESULT_SET_H
 #define MULTI_OPERATION_RESULT_SET_H
 
+#include <exception>
+
 namespace sscl {
 
 /** Plain aggregate for fan-out / fan-in results returned from coroutines. */
@@ -24,6 +26,25 @@ struct MultiOperationResultSet
 	unsigned int nFailed;
 };
 
+/** Fan-out / fan-in counts plus optional aggregated member failure. */
+struct MultiOperationResultSetWithException
+{
+	MultiOperationResultSetWithException() = default;
+
+	MultiOperationResultSetWithException(
+		MultiOperationResultSet resultsIn,
+		std::exception_ptr memberFailureExceptionIn = nullptr)
+	: results(resultsIn),
+	  memberFailureException(memberFailureExceptionIn)
+	{}
+
+	bool hasMemberFailure() const
+		{ return memberFailureException != nullptr; }
+
+	MultiOperationResultSet results;
+	std::exception_ptr memberFailureException = nullptr;
+};
+
 } // namespace sscl
 
 #endif // MULTI_OPERATION_RESULT_SET_H