Async: add sh_ptr<ContinuationChainLink> to Callback<>

This change enables us to finally implement the tracing of
continuations backward from the point of acquisition for deadlock
debugging.

smocore/marionette/main.cpp

@@ -56,10 +56,9 @@ void marionetteInitializeReqCb(bool success)
 	std::cerr << __func__ << ": Failed to initialize Marionette. Shutting down."
 		<< '\n';
 
-	mrntt::mrntt.finalizeReq(
-		std::bind(
-			&mrntt::marionetteFinalizeReqCb,
-			std::placeholders::_1));
+	mrntt::mrntt.finalizeReq({nullptr, std::bind(
+		&mrntt::marionetteFinalizeReqCb,
+		std::placeholders::_1)});
 }
 
 } // namespace mrntt
@@ -92,10 +91,9 @@ void MarionetteThread::main(MarionetteThread& self)
 					default:
 						break;
 				}
-				mrntt::mrntt.finalizeReq(
-					std::bind(
-						&mrntt::marionetteFinalizeReqCb,
-						std::placeholders::_1));
+				mrntt::mrntt.finalizeReq({nullptr, std::bind(
+					&mrntt::marionetteFinalizeReqCb,
+					std::placeholders::_1)});
 			}
 		);
 
@@ -137,9 +135,8 @@ void MarionetteThread::main(MarionetteThread& self)
 		callShutdownSalmanoff = true;
 
 		// Create new Mind instance just before initializeReq
-		mrntt::mrntt.initializeReq(
-			std::bind(
-				&mrntt::marionetteInitializeReqCb, std::placeholders::_1));
+		mrntt::mrntt.initializeReq({nullptr, std::bind(
+			&mrntt::marionetteInitializeReqCb, std::placeholders::_1)});
 
 		std::cout << __func__ << ": Entering event loop" << "\n";
 
@@ -183,10 +180,9 @@ void MarionetteThread::main(MarionetteThread& self)
 			if (sendExceptionInd)
 			{
 				mrntt::exitCode = EXIT_FAILURE;
-				mrntt::mrntt.finalizeReq(
-					std::bind(
-						&mrntt::marionetteFinalizeReqCb,
-						std::placeholders::_1));
+				mrntt::mrntt.finalizeReq({nullptr, std::bind(
+					&mrntt::marionetteFinalizeReqCb,
+					std::placeholders::_1)});
 			}
         }