Pass the pointer of owning object in ctor of GCHermesValueBase (faceb…

…ook#1508)

Summary: Pull Request resolved: facebook#1508

Differential Revision: D62222238

include/hermes/VM/ArrayStorage.h

@@ -185,7 +185,7 @@ class ArrayStorageBase final
     assert(sz < capacity());
     // Use the constructor of GCHermesValue to use the correct write barrier
     // for uninitialized memory.
-    new (&data()[sz]) GCHVType(value, runtime.getHeap());
+    new (&data()[sz]) GCHVType(value, runtime.getHeap(), this);
     size_.store(sz + 1, std::memory_order_release);
   }
 

include/hermes/VM/Callable.h

@@ -99,7 +99,8 @@ class Environment final
         getSlots(),
         getSlots() + size,
         HermesValue::encodeUndefinedValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        this);
   }
 
   /// Create an environment using the given function to retrieve the parent
@@ -369,7 +370,8 @@ Environment::Environment(
       getSlots(),
       getSlots() + size,
       HermesValue::encodeUndefinedValue(),
-      runtime.getHeap());
+      runtime.getHeap(),
+      this);
 }
 
 /// A function produced by Function.prototype.bind(). It packages a function

include/hermes/VM/HermesValue-inline.h

@@ -31,8 +31,13 @@ inline PinnedHermesValue &PinnedHermesValue::operator=(PseudoHandle<T> &&hv) {
 
 template <typename HVType>
 template <typename NeedsBarriers>
-GCHermesValueBase<HVType>::GCHermesValueBase(HVType hv, GC &gc) : HVType{hv} {
+GCHermesValueBase<HVType>::GCHermesValueBase(
+    HVType hv,
+    GC &gc,
+    const GCCell *cell)
+    : HVType{hv} {
   assert(!hv.isPointer() || hv.getPointer());
+  (void)cell;
   if (NeedsBarriers::value)
     gc.constructorWriteBarrier(this, hv);
 }
@@ -103,11 +108,12 @@ inline void GCHermesValueBase<HVType>::uninitialized_fill(
     InputIt start,
     InputIt end,
     HVType fill,
-    GC &gc) {
+    GC &gc,
+    const GCCell *cell) {
   if (fill.isPointer()) {
     for (auto cur = start; cur != end; ++cur) {
       // Use the constructor write barrier. Assume it needs barriers.
-      new (&*cur) GCHermesValueBase<HVType>(fill, gc);
+      new (&*cur) GCHermesValueBase<HVType>(fill, gc, cell);
     }
   } else {
     for (auto cur = start; cur != end; ++cur) {
@@ -141,13 +147,14 @@ inline OutputIt GCHermesValueBase<HVType>::uninitialized_copy(
     InputIt first,
     InputIt last,
     OutputIt result,
-    GC &gc) {
+    GC &gc,
+    const GCCell *cell) {
   static_assert(
       !std::is_same<InputIt, GCHermesValueBase *>::value ||
           !std::is_same<OutputIt, GCHermesValueBase *>::value,
       "Pointer arguments must invoke pointer overload.");
   for (; first != last; ++first, (void)++result) {
-    new (&*result) GCHermesValueBase<HVType>(*first, gc);
+    new (&*result) GCHermesValueBase<HVType>(*first, gc, cell);
   }
   return result;
 }

include/hermes/VM/HermesValue.h

@@ -523,7 +523,7 @@ class GCHermesValueBase final : public HVType {
   GCHermesValueBase() : HVType(HVType::encodeUndefinedValue()) {}
   /// Initialize a GCHermesValue from another HV. Performs a write barrier.
   template <typename NeedsBarriers = std::true_type>
-  GCHermesValueBase(HVType hv, GC &gc);
+  GCHermesValueBase(HVType hv, GC &gc, const GCCell *cell);
   /// Initialize a GCHermesValue from a non-pointer HV. Might perform a write
   /// barrier, depending on the GC.
   /// NOTE: The last parameter is unused, but acts as an overload selector.
@@ -564,8 +564,12 @@ class GCHermesValueBase final : public HVType {
   /// been previously initialized. Cannot use this on previously initialized
   /// memory, as it will use an incorrect write barrier.
   template <typename InputIt>
-  static inline void
-  uninitialized_fill(InputIt first, InputIt last, HVType fill, GC &gc);
+  static inline void uninitialized_fill(
+      InputIt first,
+      InputIt last,
+      HVType fill,
+      GC &gc,
+      const GCCell *cell);
 
   /// Copies a range of values and performs a write barrier on each.
   template <typename InputIt, typename OutputIt>
@@ -576,8 +580,12 @@ class GCHermesValueBase final : public HVType {
   /// been previously initialized. Cannot use this on previously initialized
   /// memory, as it will use an incorrect write barrier.
   template <typename InputIt, typename OutputIt>
-  static inline OutputIt
-  uninitialized_copy(InputIt first, InputIt last, OutputIt result, GC &gc);
+  static inline OutputIt uninitialized_copy(
+      InputIt first,
+      InputIt last,
+      OutputIt result,
+      GC &gc,
+      const GCCell *cell);
 
   /// Same as \p copy, but specialized for raw pointers.
   static inline GCHermesValueBase<HVType> *copy(

include/hermes/VM/JSObject.h

@@ -1676,7 +1676,8 @@ inline T *JSObject::initDirectPropStorage(Runtime &runtime, T *self) {
       self->directProps() + numOverlapSlots<T>(),
       self->directProps() + DIRECT_PROPERTY_SLOTS,
       SmallHermesValue::encodeUndefinedValue(),
-      runtime.getHeap());
+      runtime.getHeap(),
+      self);
   return self;
 }
 

lib/VM/ArrayStorage.cpp

@@ -112,15 +112,17 @@ ExecutionStatus ArrayStorageBase<HVType>::reallocateToLarger(
       newSelf->data(),
       newSelf->data() + toFirst,
       HVType::encodeEmptyValue(),
-      runtime.getHeap());
+      runtime.getHeap(),
+      newSelf);
 
   // Initialize the elements after the last copied element and toLast.
   if (toFirst + copySize < toLast) {
     GCHVType::uninitialized_fill(
         newSelf->data() + toFirst + copySize,
         newSelf->data() + toLast,
         HVType::encodeEmptyValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        newSelf);
   }
 
   newSelf->size_.store(toLast, std::memory_order_release);
@@ -152,7 +154,8 @@ void ArrayStorageBase<HVType>::resizeWithinCapacity(
         self->data() + sz,
         self->data() + newSize,
         HVType::encodeEmptyValue(),
-        gc);
+        gc,
+        self);
   } else if (newSize < sz) {
     // Execute write barriers on elements about to be conceptually changed to
     // null.
@@ -212,7 +215,8 @@ ExecutionStatus ArrayStorageBase<HVType>::shift(
           self->data() + toFirst + copySize,
           self->data() + toLast,
           HVType::encodeEmptyValue(),
-          runtime.getHeap());
+          runtime.getHeap(),
+          self);
     }
     if (toLast < self->size()) {
       // Some elements are becoming unreachable, let the GC know.

lib/VM/SegmentedArray.cpp

@@ -62,7 +62,8 @@ void SegmentedArrayBase<HVType>::Segment::setLength(
         data_ + len,
         data_ + newLength,
         HVType::encodeEmptyValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        this);
     length_.store(newLength, std::memory_order_release);
   } else if (newLength < len) {
     // If length is decreasing a write barrier needs to be done.
@@ -193,8 +194,16 @@ ExecutionStatus SegmentedArrayBase<HVType>::push_back(
     return ExecutionStatus::EXCEPTION;
   }
   const auto shv = HVType::encodeHermesValue(*value, runtime);
-  auto &elm = self->atRef(runtime, oldSize);
-  new (&elm) GCHVType(shv, runtime.getHeap());
+  if (oldSize < kValueToSegmentThreshold) {
+    auto &elm = self->inlineStorage()[oldSize];
+    new (&elm) GCHVType(shv, runtime.getHeap(), *self);
+  } else {
+    auto segmentNumber = toSegment(oldSize);
+    auto *segment = self->segmentAt(runtime, segmentNumber);
+    auto &elm = segment->at(toInterior(oldSize));
+    // elm lives in segment, which is not the same cell as SegmentedArrayBase.
+    new (&elm) GCHVType(shv, runtime.getHeap(), segment);
+  }
   return ExecutionStatus::RETURNED;
 }
 
@@ -395,7 +404,8 @@ void SegmentedArrayBase<HVType>::increaseSizeWithinCapacity(
         inlineStorage() + currSize,
         inlineStorage() + finalSize,
         HVType::encodeEmptyValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        this);
     // Set the final size.
     numSlotsUsed_.store(finalSize, std::memory_order_release);
     return;
@@ -410,7 +420,8 @@ void SegmentedArrayBase<HVType>::increaseSizeWithinCapacity(
         inlineStorage() + currSize,
         inlineStorage() + kValueToSegmentThreshold,
         HVType::encodeEmptyValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        this);
   }
   segmentAt(runtime, segment)->setLength(runtime, segmentLength);
 }
@@ -443,7 +454,8 @@ SegmentedArrayBase<HVType>::increaseSize(
         self->inlineStorage() + currSize,
         self->inlineStorage() + kValueToSegmentThreshold,
         HVType::encodeEmptyValue(),
-        runtime.getHeap());
+        runtime.getHeap(),
+        self.get());
     // Set the size to the inline storage threshold.
     self->numSlotsUsed_.store(
         kValueToSegmentThreshold, std::memory_order_release);
@@ -469,7 +481,8 @@ SegmentedArrayBase<HVType>::increaseSize(
           self->numSlotsUsed_.load(std::memory_order_relaxed),
       self->inlineStorage() + newNumSlotsUsed,
       HVType::encodeEmptyValue(),
-      runtime.getHeap());
+      runtime.getHeap(),
+      self.get());
   self->numSlotsUsed_.store(newNumSlotsUsed, std::memory_order_release);
 
   // Allocate a handle to track the current array.