From cca4d3bf70c5e08e70cc23eb0fd627d9efae117e Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Fri, 24 Jun 2016 14:19:51 -0400
Subject: [PATCH] Bug 767938 part 9.  Move the JSAutoRequest from AutoCxPusher
 to AutoJSAPI, because we're about to kill off AutoCxPusher.  r=bholley

---
 dom/base/ScriptSettings.cpp | 15 ++++++---------
 dom/base/ScriptSettings.h   | 16 ++++++----------
 2 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/dom/base/ScriptSettings.cpp b/dom/base/ScriptSettings.cpp
index 12e96c43b4d2..222ec3d67d47 100644
--- a/dom/base/ScriptSettings.cpp
+++ b/dom/base/ScriptSettings.cpp
@@ -309,6 +309,11 @@ AutoJSAPI::~AutoJSAPI()
     JS::SetWarningReporter(JS_GetRuntime(cx()), mOldWarningReporter.value());
   }
 
+  // Leave the request before popping.
+  if (mIsMainThread) {
+    mAutoRequest.reset();
+  }
+
   ScriptSettingsStack::Pop(this);
 }
 
@@ -337,6 +342,7 @@ AutoJSAPI::InitInternal(nsIGlobalObject* aGlobalObject, JSObject* aGlobal,
     // nsIPrincipal.Equals. Once that is removed, the Rooted<> will no longer
     // be necessary.
     JS::Rooted<JSObject*> global(JS_GetRuntime(aCx), aGlobal);
+    mAutoRequest.emplace(mCx);
     mCxPusher.emplace(mCx);
     mAutoNullableCompartment.emplace(mCx, global);
   } else {
@@ -781,19 +787,10 @@ danger::AutoCxPusher::AutoCxPusher(JSContext* cx, bool allowNull)
   mPushedContext = cx;
   mCompartmentDepthOnEntry = cx ? js::GetEnterCompartmentDepth(cx) : 0;
 #endif
-
-  // Enter a request and a compartment for the duration that the cx is on the
-  // stack if non-null.
-  if (cx) {
-    mAutoRequest.emplace(cx);
-  }
 }
 
 danger::AutoCxPusher::~AutoCxPusher()
 {
-  // Leave the request before popping.
-  mAutoRequest.reset();
-
   // When we push a context, we may save the frame chain and pretend like we
   // haven't entered any compartment. This gets restored on Pop(), but we can
   // run into trouble if a Push/Pop are interleaved with a
diff --git a/dom/base/ScriptSettings.h b/dom/base/ScriptSettings.h
index 61992ccc072a..232008236e7d 100644
--- a/dom/base/ScriptSettings.h
+++ b/dom/base/ScriptSettings.h
@@ -41,7 +41,6 @@ public:
   ~AutoCxPusher();
 
 private:
-  mozilla::Maybe<JSAutoRequest> mAutoRequest;
 #ifdef DEBUG
   JSContext* mPushedContext;
   unsigned mCompartmentDepthOnEntry;
@@ -195,19 +194,15 @@ private:
  *   the JSContext stack.
  * * Entering an initial (possibly null) compartment, to ensure that the
  *   previously entered compartment for that JSContext is not used by mistake.
+ * * Reporting any exceptions left on the JSRuntime, unless the caller steals
+ *   or silences them.
+ * * On main thread, entering a JSAutoRequest.
  *
  * Additionally, the following duties are planned, but not yet implemented:
  *
- * * De-poisoning the JSRuntime to allow manipulation of JSAPI. We can't
- *   actually implement this poisoning until all the JSContext pushing in the
- *   system goes through AutoJSAPI (see bug 951991). For now, this de-poisoning
+ * * De-poisoning the JSRuntime to allow manipulation of JSAPI. This requires
+ *   implementing the poisoning first.  For now, this de-poisoning
  *   effectively corresponds to having a non-null cx on the stack.
- * * Reporting any exceptions left on the JSRuntime, unless the caller steals
- *   or silences them.
- * * Entering a JSAutoRequest. At present, this is handled by the cx pushing
- *   on the main thread, and by other code on workers. Depending on the order
- *   in which various cleanup lands, this may never be necessary, because
- *   JSAutoRequests may go away.
  *
  * In situations where the consumer expects to run script, AutoEntryScript
  * should be used, which does additional manipulation of the script settings
@@ -314,6 +309,7 @@ protected:
             Type aType);
 
 private:
+  mozilla::Maybe<JSAutoRequest> mAutoRequest;
   mozilla::Maybe<danger::AutoCxPusher> mCxPusher;
   mozilla::Maybe<JSAutoNullableCompartment> mAutoNullableCompartment;
   JSContext *mCx;