1 files changed, 24 insertions, 18 deletions

diff --git a/deps/v8/src/heap/read-only-heap.h b/deps/v8/src/heap/read-only-heap.h
index 27d34b4c034..ed105211296 100644
--- a/deps/v8/src/heap/read-only-heap.h
+++ b/deps/v8/src/heap/read-only-heap.h
@@ -5,6 +5,7 @@
 #ifndef V8_HEAP_READ_ONLY_HEAP_H_
 #define V8_HEAP_READ_ONLY_HEAP_H_
 
+#include <memory>
 #include <utility>
 
 #include "src/base/macros.h"
@@ -14,10 +15,14 @@
 #include "src/roots/roots.h"
 
 namespace v8 {
+
+class SharedMemoryStatistics;
+
 namespace internal {
 
 class Isolate;
 class Page;
+class ReadOnlyArtifacts;
 class ReadOnlyDeserializer;
 class ReadOnlySpace;
 
@@ -28,23 +33,27 @@ class ReadOnlyHeap final {
   static constexpr size_t kEntriesCount =
       static_cast<size_t>(RootIndex::kReadOnlyRootsCount);
 
-  // If necessary creates read-only heap and initializes its artifacts (if
-  // the deserializer is provided). Then attaches the read-only heap to the
-  // isolate.
+  // If necessary creates read-only heap and initializes its artifacts (if the
+  // deserializer is provided). Then attaches the read-only heap to the isolate.
+  // If the deserializer is not provided, then the read-only heap will be only
+  // finish initializing when initial heap object creation in the Isolate is
+  // completed, which is signalled by calling OnCreateHeapObjectsComplete. When
+  // V8_SHARED_RO_HEAP is enabled, a lock will be held until that method is
+  // called.
   // TODO(v8:7464): Ideally we'd create this without needing a heap.
   static void SetUp(Isolate* isolate, ReadOnlyDeserializer* des);
   // Indicates that the isolate has been set up and all read-only space objects
-  // have been created and will not be written to. This is not thread safe, and
-  // should really only be used during snapshot creation or when read-only heap
-  // sharing is disabled.
+  // have been created and will not be written to. This should only be called if
+  // a deserializer was not previously provided to Setup. When V8_SHARED_RO_HEAP
+  // is enabled, this releases the ReadOnlyHeap creation lock.
   void OnCreateHeapObjectsComplete(Isolate* isolate);
   // Indicates that the current isolate no longer requires the read-only heap
   // and it may be safely disposed of.
   void OnHeapTearDown();
-
-#ifdef V8_SHARED_RO_HEAP
-  static const ReadOnlyHeap* Instance();
-#endif
+  // If the read-only heap is shared, then populate |statistics| with its stats,
+  // otherwise the read-only heap stats are set to 0.
+  static void PopulateReadOnlySpaceStatistics(
+      SharedMemoryStatistics* statistics);
 
   // Returns whether the address is within the read-only space.
   V8_EXPORT_PRIVATE static bool Contains(Address address);
@@ -56,10 +65,6 @@ class ReadOnlyHeap final {
   V8_EXPORT_PRIVATE inline static ReadOnlyRoots GetReadOnlyRoots(
       HeapObject object);
 
-  // Clears any shared read-only heap artifacts for testing, forcing read-only
-  // heap to be re-created on next set up.
-  V8_EXPORT_PRIVATE static void ClearSharedHeapForTest();
-
   // Extends the read-only object cache with new zero smi and returns a
   // reference to it.
   Object* ExtendReadOnlyObjectCache();
@@ -71,14 +76,15 @@ class ReadOnlyHeap final {
 
  private:
   // Creates a new read-only heap and attaches it to the provided isolate.
-  static ReadOnlyHeap* CreateAndAttachToIsolate(Isolate* isolate);
-  // Runs the read-only deserailizer and calls InitFromIsolate to complete
+  static ReadOnlyHeap* CreateAndAttachToIsolate(
+      Isolate* isolate, std::shared_ptr<ReadOnlyArtifacts> artifacts);
+  // Runs the read-only deserializer and calls InitFromIsolate to complete
   // read-only heap initialization.
   void DeseralizeIntoIsolate(Isolate* isolate, ReadOnlyDeserializer* des);
   // Initializes read-only heap from an already set-up isolate, copying
   // read-only roots from the isolate. This then seals the space off from
-  // further writes, marks it as read-only and detaches it from the heap (unless
-  // sharing is disabled).
+  // further writes, marks it as read-only and detaches it from the heap
+  // (unless sharing is disabled).
   void InitFromIsolate(Isolate* isolate);
 
   bool init_complete_ = false;