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/body/body.cpp

@@ -2,6 +2,7 @@
 #include <opts.h>
 #include <asynchronousContinuation.h>
 #include <asynchronousLoop.h>
+#include <callback.h>
 #include <body/body.h>
 #include <componentThread.h>
 #include <mind.h>
@@ -21,7 +22,7 @@ class Body::InitializeReq
 public:
 	InitializeReq(
 		Mind &parent, const std::shared_ptr<ComponentThread> &caller,
-		bodyLifetimeMgmtOpCbFn callback)
+		Callback<bodyLifetimeMgmtOpCbFn> callback)
 	:	PostedAsynchronousContinuation<bodyLifetimeMgmtOpCbFn>(caller, callback),
 	parent(parent)
 	{}
@@ -78,10 +79,10 @@ public:
 		}
 		sense_api::SenseApiManager::getInstance()
 			.attachAllSenseDevicesFromSpecsReq(
-				std::bind(
+				{context, std::bind(
 					&InitializeReq::initializeReq2,
 					context.get(), context,
-					std::placeholders::_1));
+					std::placeholders::_1)});
 	}
 
 	void initializeReq2(
@@ -117,10 +118,10 @@ public:
 
 		std::cout << "Mrntt: About to detach all sense devices." << "\n";
 		sense_api::SenseApiManager::getInstance().detachAllSenseDevicesReq(
-			std::bind(
+			{context, std::bind(
 				&FinalizeReq::finalizeReq2,
 				context.get(), context,
-				std::placeholders::_1));
+				std::placeholders::_1)});
 	}
 
 	void finalizeReq2(
@@ -141,7 +142,7 @@ public:
 	}
 };
 
-void Body::initializeReq(bodyLifetimeMgmtOpCbFn callback)
+void Body::initializeReq(Callback<bodyLifetimeMgmtOpCbFn> callback)
 {
 	auto mrntt = ComponentThread::getSelf();
 
@@ -160,7 +161,7 @@ void Body::initializeReq(bodyLifetimeMgmtOpCbFn callback)
 			request.get(), request));
 }
 
-void Body::finalizeReq(bodyLifetimeMgmtOpCbFn callback)
+void Body::finalizeReq(Callback<bodyLifetimeMgmtOpCbFn> callback)
 {
 	auto mrntt = ComponentThread::getSelf();
 
@@ -168,7 +169,7 @@ void Body::finalizeReq(bodyLifetimeMgmtOpCbFn callback)
 	{
 		std::cerr << __func__ << ": Must be invoked by Mrntt thread"
 		          << std::endl;
-		callback(false);
+		callback.callbackFn(false);
 		return;
 	}
 
@@ -176,7 +177,7 @@ void Body::finalizeReq(bodyLifetimeMgmtOpCbFn callback)
 	{
 		std::cout << "Mrntt: Body component not initialized. "
 			<< "Skipping finalization." << "\n";
-		callback(true);
+		callback.callbackFn(true);
 		return;
 	}