Bug 767938 part 11. Move the "safe JS context" to where it belongs: the CycleCollectedJSRuntime. r=bholley

js/xpconnect/src/XPCJSContextStack.cpp

@@ -1,46 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/* vim: set ts=8 sts=4 et sw=4 tw=99: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/* Implement global service to track stack of JSContext. */
-
-#include "xpcprivate.h"
-#include "XPCWrapper.h"
-#include "nsDOMJSUtils.h"
-#include "nsNullPrincipal.h"
-#include "mozilla/dom/BindingUtils.h"
-
-using namespace mozilla;
-using namespace JS;
-using namespace xpc;
-
-/***************************************************************************/
-
-XPCJSContextStack::~XPCJSContextStack()
-{
-    if (mSafeJSContext) {
-        mSafeJSContext = nullptr;
-    }
-}
-
-JSContext*
-XPCJSContextStack::GetSafeJSContext()
-{
-    MOZ_ASSERT(mSafeJSContext);
-    return mSafeJSContext;
-}
-
-void
-XPCJSContextStack::InitSafeJSContext()
-{
-    MOZ_ASSERT(!mSafeJSContext);
-
-    mSafeJSContext = JS_GetContext(mRuntime->Runtime());
-    if (!JS::InitSelfHostedCode(mSafeJSContext))
-        MOZ_CRASH("InitSelfHostedCode failed");
-
-    if (!mRuntime->JSContextInitialized(mSafeJSContext))
-        MOZ_CRASH("JSContextCreated failed");
-}

js/xpconnect/src/XPCJSRuntime.cpp

@@ -1546,12 +1546,6 @@ CompartmentPrivate::SizeOfIncludingThis(MallocSizeOf mallocSizeOf)
 
 /***************************************************************************/
 
-void XPCJSRuntime::DestroyJSContextStack()
-{
-    delete mJSContextStack;
-    mJSContextStack = nullptr;
-}
-
 void XPCJSRuntime::SystemIsBeingShutDown()
 {
     for (auto i = mDetachedWrappedNativeProtoMap->Iter(); !i.Done(); i.Next()) {
@@ -3386,8 +3380,7 @@ static const JSWrapObjectCallbacks WrapObjectCallbacks = {
 };
 
 XPCJSRuntime::XPCJSRuntime()
- : mJSContextStack(new XPCJSContextStack(this)),
-   mCallContext(nullptr),
+ : mCallContext(nullptr),
    mAutoRoots(nullptr),
    mResolveName(JSID_VOID),
    mResolvingWrapper(nullptr),
@@ -3777,6 +3770,7 @@ XPCJSRuntime::DebugDump(int16_t depth)
     XPC_LOG_ALWAYS(("XPCJSRuntime @ %x", this));
         XPC_LOG_INDENT();
         XPC_LOG_ALWAYS(("mJSRuntime @ %x", Runtime()));
+        XPC_LOG_ALWAYS(("mJSContext @ %x", Context()));
 
         XPC_LOG_ALWAYS(("mWrappedJSClassMap @ %x with %d wrapperclasses(s)",
                         mWrappedJSClassMap, mWrappedJSClassMap->Count()));
@@ -3884,7 +3878,7 @@ void
 XPCJSRuntime::InitSingletonScopes()
 {
     // This all happens very early, so we don't bother with cx pushing.
-    JSContext* cx = GetJSContextStack()->GetSafeJSContext();
+    JSContext* cx = Context();
     JSAutoRequest ar(cx);
     RootedValue v(cx);
     nsresult rv;

js/xpconnect/src/moz.build

@@ -22,7 +22,6 @@ UNIFIED_SOURCES += [
     'XPCConvert.cpp',
     'XPCDebug.cpp',
     'XPCException.cpp',
-    'XPCJSContextStack.cpp',
     'XPCJSID.cpp',
     'XPCJSRuntime.cpp',
     'XPCJSWeakReference.cpp',

js/xpconnect/src/nsXPConnect.cpp

@@ -72,7 +72,6 @@ nsXPConnect::nsXPConnect()
 nsXPConnect::~nsXPConnect()
 {
     mRuntime->DeleteSingletonScopes();
-    mRuntime->DestroyJSContextStack();
 
     // In order to clean up everything properly, we need to GC twice: once now,
     // to clean anything that can go away on its own (like the Junk Scope, which
@@ -124,8 +123,10 @@ nsXPConnect::InitStatics()
     gScriptSecurityManager->GetSystemPrincipal(&gSystemPrincipal);
     MOZ_RELEASE_ASSERT(gSystemPrincipal);
 
-    // Initialize the SafeJSContext.
-    gSelf->mRuntime->GetJSContextStack()->InitSafeJSContext();
+    if (!JS::InitSelfHostedCode(gSelf->mRuntime->Context()))
+        MOZ_CRASH("InitSelfHostedCode failed");
+    if (!gSelf->mRuntime->JSContextInitialized(gSelf->mRuntime->Context()))
+        MOZ_CRASH("JSContextInitialized failed");
 
     // Initialize our singleton scopes.
     gSelf->mRuntime->InitSingletonScopes();
@@ -982,7 +983,7 @@ nsXPConnect::JSToVariant(JSContext* ctx, HandleValue value, nsIVariant** _retval
 JSContext*
 nsXPConnect::GetSafeJSContext()
 {
-    return GetRuntime()->GetJSContextStack()->GetSafeJSContext();
+    return GetRuntime()->Context();
 }
 
 nsIPrincipal*

js/xpconnect/src/xpcprivate.h

@@ -354,7 +354,6 @@ private:
 // In the current xpconnect system there can only be one XPCJSRuntime.
 // So, xpconnect can only be used on one JSRuntime within the process.
 
-class XPCJSContextStack;
 class WatchdogManager;
 
 enum WatchdogTimestampCategory
@@ -420,9 +419,6 @@ public:
     static XPCJSRuntime* newXPCJSRuntime();
     static XPCJSRuntime* Get() { return nsXPConnect::XPConnect()->GetRuntime(); }
 
-    XPCJSContextStack* GetJSContextStack() {return mJSContextStack;}
-    void DestroyJSContextStack();
-
     void RemoveWrappedJS(nsXPCWrappedJS* wrapper);
     void AssertInvalidWrappedJSNotInTable(nsXPCWrappedJS* wrapper) const;
 
@@ -614,7 +610,6 @@ private:
     jsid mStrIDs[IDX_TOTAL_COUNT];
     JS::Value mStrJSVals[IDX_TOTAL_COUNT];
 
-    XPCJSContextStack*       mJSContextStack;
     XPCCallContext*          mCallContext;
     AutoMarkingPtr*          mAutoRoots;
     jsid                     mResolveName;
@@ -2666,27 +2661,6 @@ private:
 };
 
 
-/***************************************************************************/
-// XPCJSContextStack is not actually an xpcom object, but xpcom calls are
-// delegated to it as an implementation detail.
-class XPCJSContextStack
-{
-public:
-    explicit XPCJSContextStack(XPCJSRuntime* aRuntime)
-      : mRuntime(aRuntime)
-      , mSafeJSContext(nullptr)
-    { }
-
-    virtual ~XPCJSContextStack();
-
-    void InitSafeJSContext();
-    JSContext* GetSafeJSContext();
-
-private:
-    XPCJSRuntime* mRuntime;
-    JSContext*  mSafeJSContext;
-};
-
 /***************************************************************************/
 // 'Components' object implementations. nsXPCComponentsBase has the
 // less-privileged stuff that we're willing to expose to XBL.
@@ -3172,7 +3146,7 @@ xpc_GetJSPrivate(JSObject* obj)
 inline JSContext*
 xpc_GetSafeJSContext()
 {
-    return XPCJSRuntime::Get()->GetJSContextStack()->GetSafeJSContext();
+    return XPCJSRuntime::Get()->Context();
 }
 
 namespace xpc {

xpcom/base/CycleCollectedJSRuntime.cpp

@@ -438,6 +438,7 @@ CycleCollectedJSRuntime::CycleCollectedJSRuntime()
   : mGCThingCycleCollectorGlobal(sGCThingCycleCollectorGlobal)
   , mJSZoneCycleCollectorGlobal(sJSZoneCycleCollectorGlobal)
   , mJSRuntime(nullptr)
+  , mJSContext(nullptr)
   , mPrevGCSliceCallback(nullptr)
   , mPrevGCNurseryCollectionCallback(nullptr)
   , mJSHolders(256)
@@ -479,6 +480,7 @@ CycleCollectedJSRuntime::~CycleCollectedJSRuntime()
 
   JS_DestroyRuntime(mJSRuntime);
   mJSRuntime = nullptr;
+  mJSContext = nullptr;
   nsCycleCollector_forgetJSRuntime();
 
   mozilla::dom::DestroyScriptSettings();
@@ -509,6 +511,7 @@ CycleCollectedJSRuntime::Initialize(JSRuntime* aParentRuntime,
   if (!mJSRuntime) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
+  mJSContext = JS_GetContext(mJSRuntime);
 
   if (!JS_AddExtraGCRootsTracer(mJSRuntime, TraceBlackJS, this)) {
     MOZ_CRASH("JS_AddExtraGCRootsTracer failed");

xpcom/base/CycleCollectedJSRuntime.h

@@ -328,6 +328,12 @@ public:
     return mJSRuntime;
   }
 
+  JSContext* Context() const
+  {
+    MOZ_ASSERT(mJSContext);
+    return mJSContext;
+  }
+
 protected:
   JSRuntime* MaybeRuntime() const { return mJSRuntime; }
 
@@ -394,6 +400,7 @@ private:
   JSZoneParticipant mJSZoneCycleCollectorGlobal;
 
   JSRuntime* mJSRuntime;
+  JSContext* mJSContext;
 
   JS::GCSliceCallback mPrevGCSliceCallback;
   JS::GCNurseryCollectionCallback mPrevGCNurseryCollectionCallback;