[5095] Updated loadLibraries comment

src/lib/hooks/library_manager_collection.cc

@@ -53,19 +53,28 @@ LibraryManagerCollection::loadLibraries() {
     // Unload libraries if any are loaded.
     static_cast<void>(unloadLibraries());
 
-    // Create the callout manager.  A pointer to this is maintained by
-    // each library.  Note that the callout manager does not hold any memory
-    // allocated by a library: although a library registers a callout (and so
-    // causes the creation of an entry in the CalloutManager's callout list),
-    // that creation is done by the CalloutManager itself.  The CalloutManager
-    // is created within the server.
+    // Access the callout manager, (re)creating it if required.
     //
-    // The upshot of this is that it is therefore safe for the CalloutManager
-    // to be deleted after all associated libraries are deleted, hence this
-    // link (LibraryManager -> CalloutManager) is safe.
+    // A pointer to the callout manager is maintained by each each as well as by
+    // the HooksManager itself.  Note that the callout manager does not hold any
+    // memory allocated by a library: although a library registers a callout
+    // (and so causes the creation of an entry in the CalloutManager's callout
+    // list), that creation is done by the CalloutManager itself.  The
+    // CalloutManager is created within the server. The upshot of this is that
+    // it is therefore safe for the CalloutManager to be deleted after all
+    // associated libraries are deleted, hence this link (LibraryManager ->
+    // CalloutManager) is safe.
     //
-    // To survive reloads an attempt to re-use the shared manager
-    // is performed when the list of library names is empty.
+    // If the list of libraries is not empty, re-create the callout manager.
+    // This deletes all callouts (including the pre-library and post-
+    // library) ones.  It is up to the libraries to re-register their callouts.
+    //  The pre-library and post-library callouts will also need to be
+    // re-registered.
+    //
+    // If the list of libraries stays empty (as in the case of a reconfiguration
+    // where the hooks-libraries clause was empty and is not changed), try
+    // to re-use the existing callout manager (so retaining registered pre-
+    // and post-library callouts).
     if (library_names_.empty()) {
         callout_manager_ = HooksManager::getSharedCalloutManager();
     }