Bug 1150253 - Part 2: Gecko should provide a callback for SpiderMonkey to

enqueue the onGarbageCollection hook runnable; r=mccr8

xpcom/base/CycleCollectedJSRuntime.cpp

@@ -60,6 +60,7 @@
 #include "mozilla/AutoRestore.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/dom/BindingUtils.h"
+#include "mozilla/DebuggerOnGCRunnable.h"
 #include "mozilla/dom/DOMJSClass.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "jsprf.h"
@@ -466,6 +467,7 @@ CycleCollectedJSRuntime::CycleCollectedJSRuntime(JSRuntime* aParentRuntime,
   : mGCThingCycleCollectorGlobal(sGCThingCycleCollectorGlobal)
   , mJSZoneCycleCollectorGlobal(sJSZoneCycleCollectorGlobal)
   , mJSRuntime(nullptr)
+  , mPrevGCSliceCallback(nullptr)
   , mJSHolders(256)
   , mOutOfMemoryState(OOMState::OK)
   , mLargeAllocationFailureState(OOMState::OK)
@@ -482,6 +484,7 @@ CycleCollectedJSRuntime::CycleCollectedJSRuntime(JSRuntime* aParentRuntime,
   }
   JS_SetGrayGCRootsTracer(mJSRuntime, TraceGrayJS, this);
   JS_SetGCCallback(mJSRuntime, GCCallback, this);
+  mPrevGCSliceCallback = JS::SetGCSliceCallback(mJSRuntime, GCSliceCallback);
   JS::SetOutOfMemoryCallback(mJSRuntime, OutOfMemoryCallback, this);
   JS::SetLargeAllocationFailureCallback(mJSRuntime,
                                         LargeAllocationFailureCallback, this);
@@ -745,6 +748,23 @@ CycleCollectedJSRuntime::GCCallback(JSRuntime* aRuntime,
   self->OnGC(aStatus);
 }
 
+/* static */ void
+CycleCollectedJSRuntime::GCSliceCallback(JSRuntime* aRuntime,
+                                         JS::GCProgress aProgress,
+                                         const JS::GCDescription& aDesc)
+{
+  CycleCollectedJSRuntime* self = CycleCollectedJSRuntime::Get();
+  MOZ_ASSERT(self->Runtime() == aRuntime);
+
+  if (aProgress == JS::GC_CYCLE_END) {
+    NS_WARN_IF(NS_FAILED(DebuggerOnGCRunnable::Enqueue(aRuntime, aDesc)));
+  }
+
+  if (self->mPrevGCSliceCallback) {
+    self->mPrevGCSliceCallback(aRuntime, aProgress, aDesc);
+  }
+}
+
 /* static */ void
 CycleCollectedJSRuntime::OutOfMemoryCallback(JSContext* aContext,
                                              void* aData)

xpcom/base/CycleCollectedJSRuntime.h

@@ -194,6 +194,8 @@ private:
   static void TraceBlackJS(JSTracer* aTracer, void* aData);
   static void TraceGrayJS(JSTracer* aTracer, void* aData);
   static void GCCallback(JSRuntime* aRuntime, JSGCStatus aStatus, void* aData);
+  static void GCSliceCallback(JSRuntime* aRuntime, JS::GCProgress aProgress,
+                              const JS::GCDescription& aDesc);
   static void OutOfMemoryCallback(JSContext* aContext, void* aData);
   static void LargeAllocationFailureCallback(void* aData);
   static bool ContextCallback(JSContext* aCx, unsigned aOperation,
@@ -308,6 +310,8 @@ private:
 
   JSRuntime* mJSRuntime;
 
+  JS::GCSliceCallback mPrevGCSliceCallback;
+
   nsDataHashtable<nsPtrHashKey<void>, nsScriptObjectTracer*> mJSHolders;
 
   typedef nsDataHashtable<nsFuncPtrHashKey<DeferredFinalizeFunction>, void*>

xpcom/base/DebuggerOnGCRunnable.cpp

@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "mozilla/DebuggerOnGCRunnable.h"
+
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/CycleCollectedJSRuntime.h"
+#include "mozilla/Move.h"
+#include "js/Debug.h"
+
+namespace mozilla {
+
+/* static */ NS_METHOD
+DebuggerOnGCRunnable::Enqueue(JSRuntime* aRt, const JS::GCDescription& aDesc)
+{
+  auto gcEvent = aDesc.toGCEvent(aRt);
+  if (!gcEvent) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  nsRefPtr<DebuggerOnGCRunnable> runOnGC =
+    new DebuggerOnGCRunnable(Move(gcEvent));
+  return NS_DispatchToCurrentThread(runOnGC);
+}
+
+NS_IMETHODIMP
+DebuggerOnGCRunnable::Run()
+{
+  AutoJSAPI jsapi;
+  jsapi.Init();
+  if (!JS::dbg::FireOnGarbageCollectionHook(jsapi.cx(), Move(mGCData))) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+DebuggerOnGCRunnable::Cancel()
+{
+  mGCData = nullptr;
+  return NS_OK;
+}
+
+} // namespace mozilla

xpcom/base/DebuggerOnGCRunnable.h

@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef mozilla_DebuggerOnGCRunnable_h
+#define mozilla_DebuggerOnGCRunnable_h
+
+#include "nsThreadUtils.h"
+#include "js/GCAPI.h"
+#include "mozilla/Move.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+
+// Runnable to fire the SpiderMonkey Debugger API's onGarbageCollection hook.
+class DebuggerOnGCRunnable : public nsCancelableRunnable
+{
+  JS::dbg::GarbageCollectionEvent::Ptr mGCData;
+
+  explicit DebuggerOnGCRunnable(JS::dbg::GarbageCollectionEvent::Ptr&& aGCData)
+    : mGCData(Move(aGCData))
+  { }
+
+public:
+  static NS_METHOD Enqueue(JSRuntime* aRt, const JS::GCDescription& aDesc);
+
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSICANCELABLERUNNABLE
+};
+
+} // namespace mozilla
+
+#endif // ifdef mozilla_dom_DebuggerOnGCRunnable_h

xpcom/base/moz.build

@@ -77,6 +77,7 @@ EXPORTS.mozilla += [
     'CountingAllocatorBase.h',
     'CycleCollectedJSRuntime.h',
     'Debug.h',
+    'DebuggerOnGCRunnable.h',
     'DeferredFinalize.h',
     'ErrorNames.h',
     'HoldDropJSObjects.h',
@@ -101,6 +102,7 @@ UNIFIED_SOURCES += [
     'ClearOnShutdown.cpp',
     'CycleCollectedJSRuntime.cpp',
     'Debug.cpp',
+    'DebuggerOnGCRunnable.cpp',
     'DeferredFinalize.cpp',
     'ErrorNames.cpp',
     'HoldDropJSObjects.cpp',