From 63bfd2eb94591b5f8272ad5140502018c4da9e10 Mon Sep 17 00:00:00 2001
From: Bobby Holley <bobbyholley@gmail.com>
Date: Wed, 13 Aug 2014 15:36:44 -0700
Subject: [PATCH] Bug 1052042 - Move the pre-pop GC to AutoEntryScript. r=billm

---
 dom/base/ScriptSettings.cpp     | 8 ++++++++
 dom/base/ScriptSettings.h       | 2 ++
 js/xpconnect/src/nsCxPusher.cpp | 9 ---------
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/dom/base/ScriptSettings.cpp b/dom/base/ScriptSettings.cpp
index f0a1cd1427b..da27c09ad69 100644
--- a/dom/base/ScriptSettings.cpp
+++ b/dom/base/ScriptSettings.cpp
@@ -348,6 +348,14 @@ AutoEntryScript::AutoEntryScript(nsIGlobalObject* aGlobalObject,
   MOZ_ASSERT_IF(aCx && aIsMainThread, aCx == FindJSContext(aGlobalObject));
 }
 
+AutoEntryScript::~AutoEntryScript()
+{
+  // GC when we pop a script entry point. This is a useful heuristic that helps
+  // us out on certain (flawed) benchmarks like sunspider, because it lets us
+  // avoid GCing during the timing loop.
+  JS_MaybeGC(cx());
+}
+
 AutoIncumbentScript::AutoIncumbentScript(nsIGlobalObject* aGlobalObject)
   : ScriptSettingsStackEntry(aGlobalObject, /* aCandidate = */ false)
   , mCallerOverride(nsContentUtils::GetCurrentJSContextForThread())
diff --git a/dom/base/ScriptSettings.h b/dom/base/ScriptSettings.h
index 17b8360a11c..b17def8e40f 100644
--- a/dom/base/ScriptSettings.h
+++ b/dom/base/ScriptSettings.h
@@ -201,6 +201,8 @@ public:
                   // Note: aCx is mandatory off-main-thread.
                   JSContext* aCx = nullptr);
 
+  ~AutoEntryScript();
+
   void SetWebIDLCallerPrincipal(nsIPrincipal *aPrincipal) {
     mWebIDLCallerPrincipal = aPrincipal;
   }
diff --git a/js/xpconnect/src/nsCxPusher.cpp b/js/xpconnect/src/nsCxPusher.cpp
index 3c1d9827120..df0cbd72476 100644
--- a/js/xpconnect/src/nsCxPusher.cpp
+++ b/js/xpconnect/src/nsCxPusher.cpp
@@ -51,15 +51,6 @@ AutoCxPusher::AutoCxPusher(JSContext* cx, bool allowNull)
 
 AutoCxPusher::~AutoCxPusher()
 {
-  // GC when we pop a script entry point. This is a useful heuristic that helps
-  // us out on certain (flawed) benchmarks like sunspider, because it lets us
-  // avoid GCing during the timing loop.
-  //
-  // NB: We need to take care to only do this if we're in a compartment,
-  // otherwise JS_MaybeGC will segfault.
-  if (mScx && !mAutoCompartment.empty())
-    JS_MaybeGC(nsXPConnect::XPConnect()->GetCurrentJSContext());
-
   // Leave the compartment and request before popping.
   mAutoCompartment.destroyIfConstructed();
   mAutoRequest.destroyIfConstructed();