Issue #618 - Add clarifying code comments.

2 files changed, 12 insertions, 0 deletions

diff --git a/dom/script/ModuleLoadRequest.cpp b/dom/script/ModuleLoadRequest.cpp
index e72edca2e8..98106df1b9 100644
--- a/dom/script/ModuleLoadRequest.cpp
+++ b/dom/script/ModuleLoadRequest.cpp
@@ -52,6 +52,14 @@ void ModuleLoadRequest::Cancel()
 void
 ModuleLoadRequest::SetReady()
 {
+  // Mark a module as ready to execute. This means that this module and all it
+  // dependencies have had their source loaded, parsed as a module and the
+  // modules instantiated.
+  //
+  // The mReady promise is used to ensure that when all dependencies of a module
+  // have become ready, DependenciesLoaded is called on that module
+  // request. This is set up in StartFetchingModuleDependencies.
+
 #ifdef DEBUG
   for (size_t i = 0; i < mImports.Length(); i++) {
     MOZ_ASSERT(mImports[i]->IsReadyToRun());
diff --git a/dom/script/ScriptLoader.cpp b/dom/script/ScriptLoader.cpp
index ffbe37f281..7aca04da5c 100644
--- a/dom/script/ScriptLoader.cpp
+++ b/dom/script/ScriptLoader.cpp
@@ -420,6 +420,10 @@ ScriptLoader::SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest *
 {
   // Update module map with the result of fetching a single module script.  The
   // module script pointer is nullptr on error.
+  //
+  // If any requests for the same URL are waiting on this one to complete, they
+  // will have ModuleLoaded or LoadFailed on them when the promise is
+  // resolved/rejected. This is set up in StartLoad.
 
   MOZ_ASSERT(!aRequest->IsReadyToRun());