1 files changed, 245 insertions, 0 deletions
diff --git a/js/src/vm/ShapeZone.h b/js/src/vm/ShapeZone.h
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+/* -*- 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 vm_ShapeZone_h
+#define vm_ShapeZone_h
+
+#include "mozilla/MemoryReporting.h"
+
+#include "gc/Barrier.h"
+#include "gc/SweepingAPI.h"
+#include "js/GCHashTable.h"
+#include "vm/PropertyKey.h"
+#include "vm/PropMap.h"
+#include "vm/Shape.h"
+#include "vm/TaggedProto.h"
+
+namespace js {
+
+// Hash policy for the per-zone baseShapes set.
+struct BaseShapeHasher {
+  struct Lookup {
+    const JSClass* clasp;
+    JS::Realm* realm;
+    TaggedProto proto;
+
+    Lookup(const JSClass* clasp, JS::Realm* realm, TaggedProto proto)
+        : clasp(clasp), realm(realm), proto(proto) {}
+  };
+
+  static HashNumber hash(const Lookup& lookup) {
+    HashNumber hash = StableCellHasher<TaggedProto>::hash(lookup.proto);
+    return mozilla::AddToHash(hash, lookup.clasp, lookup.realm);
+  }
+  static bool match(const WeakHeapPtr<BaseShape*>& key, const Lookup& lookup) {
+    return key.unbarrieredGet()->clasp() == lookup.clasp &&
+           key.unbarrieredGet()->realm() == lookup.realm &&
+           key.unbarrieredGet()->proto() == lookup.proto;
+  }
+};
+using BaseShapeSet = WeakCache<
+    JS::GCHashSet<WeakHeapPtr<BaseShape*>, BaseShapeHasher, SystemAllocPolicy>>;
+
+// Hash policy for the per-zone initialPropMaps set, mapping property key + info
+// to a shared property map.
+struct InitialPropMapHasher {
+  struct Lookup {
+    PropertyKey key;
+    PropertyInfo prop;
+
+    Lookup(PropertyKey key, PropertyInfo prop) : key(key), prop(prop) {}
+  };
+  static HashNumber hash(const Lookup& lookup) {
+    HashNumber hash = HashPropertyKey(lookup.key);
+    return mozilla::AddToHash(hash, lookup.prop.toRaw());
+  }
+  static bool match(const WeakHeapPtr<SharedPropMap*>& key,
+                    const Lookup& lookup) {
+    const SharedPropMap* map = key.unbarrieredGet();
+    return map->matchProperty(0, lookup.key, lookup.prop);
+  }
+};
+using InitialPropMapSet =
+    WeakCache<JS::GCHashSet<WeakHeapPtr<SharedPropMap*>, InitialPropMapHasher,
+                            SystemAllocPolicy>>;
+
+// Helper class to hash information relevant for all shapes.
+struct ShapeBaseHasher {
+  struct Lookup {
+    const JSClass* clasp;
+    JS::Realm* realm;
+    TaggedProto proto;
+    ObjectFlags objectFlags;
+
+    Lookup(const JSClass* clasp, JS::Realm* realm, const TaggedProto& proto,
+           ObjectFlags objectFlags)
+        : clasp(clasp), realm(realm), proto(proto), objectFlags(objectFlags) {}
+  };
+
+  static HashNumber hash(const Lookup& lookup) {
+    HashNumber hash = StableCellHasher<TaggedProto>::hash(lookup.proto);
+    return mozilla::AddToHash(hash, lookup.clasp, lookup.realm,
+                              lookup.objectFlags.toRaw());
+  }
+  static bool match(const Shape* shape, const Lookup& lookup) {
+    return lookup.clasp == shape->getObjectClass() &&
+           lookup.realm == shape->realm() && lookup.proto == shape->proto() &&
+           lookup.objectFlags == shape->objectFlags();
+  }
+};
+
+// Hash policy for the per-zone initialShapes set storing initial shapes for
+// objects in the zone.
+//
+// These are empty shapes, except for certain classes (e.g. String, RegExp)
+// which may add certain baked-in properties. See insertInitialShape.
+struct InitialShapeHasher {
+  struct Lookup : public ShapeBaseHasher::Lookup {
+    uint32_t nfixed;
+
+    Lookup(const JSClass* clasp, JS::Realm* realm, const TaggedProto& proto,
+           uint32_t nfixed, ObjectFlags objectFlags)
+        : ShapeBaseHasher::Lookup(clasp, realm, proto, objectFlags),
+          nfixed(nfixed) {}
+  };
+
+  static HashNumber hash(const Lookup& lookup) {
+    HashNumber hash = ShapeBaseHasher::hash(lookup);
+    return mozilla::AddToHash(hash, lookup.nfixed);
+  }
+  static bool match(const WeakHeapPtr<SharedShape*>& key,
+                    const Lookup& lookup) {
+    const SharedShape* shape = key.unbarrieredGet();
+    return ShapeBaseHasher::match(shape, lookup) &&
+           lookup.nfixed == shape->numFixedSlots();
+  }
+};
+using InitialShapeSet =
+    WeakCache<JS::GCHashSet<WeakHeapPtr<SharedShape*>, InitialShapeHasher,
+                            SystemAllocPolicy>>;
+
+// Hash policy for the per-zone propMapShapes set storing shared shapes with
+// shared property maps.
+struct PropMapShapeHasher {
+  struct Lookup {
+    BaseShape* base;
+    SharedPropMap* map;
+    uint32_t mapLength;
+    uint32_t nfixed;
+    ObjectFlags objectFlags;
+
+    Lookup(BaseShape* base, uint32_t nfixed, SharedPropMap* map,
+           uint32_t mapLength, ObjectFlags objectFlags)
+        : base(base),
+          map(map),
+          mapLength(mapLength),
+          nfixed(nfixed),
+          objectFlags(objectFlags) {}
+  };
+
+  static HashNumber hash(const Lookup& lookup) {
+    return mozilla::HashGeneric(lookup.base, lookup.map, lookup.mapLength,
+                                lookup.nfixed, lookup.objectFlags.toRaw());
+  }
+  static bool match(const WeakHeapPtr<SharedShape*>& key,
+                    const Lookup& lookup) {
+    const SharedShape* shape = key.unbarrieredGet();
+    return lookup.base == shape->base() &&
+           lookup.nfixed == shape->numFixedSlots() &&
+           lookup.map == shape->propMap() &&
+           lookup.mapLength == shape->propMapLength() &&
+           lookup.objectFlags == shape->objectFlags();
+  }
+  static void rekey(WeakHeapPtr<SharedShape*>& k,
+                    const WeakHeapPtr<SharedShape*>& newKey) {
+    k = newKey;
+  }
+};
+using PropMapShapeSet =
+    WeakCache<JS::GCHashSet<WeakHeapPtr<SharedShape*>, PropMapShapeHasher,
+                            SystemAllocPolicy>>;
+
+// Hash policy for the per-zone proxyShapes set storing shapes for proxy objects
+// in the zone.
+struct ProxyShapeHasher : public ShapeBaseHasher {
+  static bool match(const WeakHeapPtr<ProxyShape*>& key, const Lookup& lookup) {
+    const ProxyShape* shape = key.unbarrieredGet();
+    return ShapeBaseHasher::match(shape, lookup);
+  }
+};
+using ProxyShapeSet =
+    WeakCache<JS::GCHashSet<WeakHeapPtr<ProxyShape*>, ProxyShapeHasher,
+                            SystemAllocPolicy>>;
+
+// Hash policy for the per-zone wasmGCShapes set storing shapes for Wasm GC
+// objects in the zone.
+struct WasmGCShapeHasher : public ShapeBaseHasher {
+  struct Lookup : public ShapeBaseHasher::Lookup {
+    const wasm::RecGroup* recGroup;
+
+    Lookup(const JSClass* clasp, JS::Realm* realm, const TaggedProto& proto,
+           const wasm::RecGroup* recGroup, ObjectFlags objectFlags)
+        : ShapeBaseHasher::Lookup(clasp, realm, proto, objectFlags),
+          recGroup(recGroup) {}
+  };
+
+  static HashNumber hash(const Lookup& lookup) {
+    HashNumber hash = ShapeBaseHasher::hash(lookup);
+    hash = mozilla::AddToHash(hash, lookup.recGroup);
+    return hash;
+  }
+
+  static bool match(const WeakHeapPtr<WasmGCShape*>& key,
+                    const Lookup& lookup) {
+    const WasmGCShape* shape = key.unbarrieredGet();
+    return ShapeBaseHasher::match(shape, lookup) &&
+           shape->recGroup() == lookup.recGroup;
+  }
+};
+using WasmGCShapeSet =
+    WeakCache<JS::GCHashSet<WeakHeapPtr<WasmGCShape*>, WasmGCShapeHasher,
+                            SystemAllocPolicy>>;
+
+struct ShapeZone {
+  // Set of all base shapes in the Zone.
+  BaseShapeSet baseShapes;
+
+  // Set used to look up a shared property map based on the first property's
+  // PropertyKey and PropertyInfo.
+  InitialPropMapSet initialPropMaps;
+
+  // Set of initial shapes in the Zone.
+  InitialShapeSet initialShapes;
+
+  // Set of SharedPropMapShapes in the Zone.
+  PropMapShapeSet propMapShapes;
+
+  // Set of ProxyShapes in the Zone.
+  ProxyShapeSet proxyShapes;
+
+  // Set of WasmGCShapes in the Zone.
+  WasmGCShapeSet wasmGCShapes;
+
+  using ShapeWithCacheVector = js::Vector<js::Shape*, 0, js::SystemAllocPolicy>;
+  ShapeWithCacheVector shapesWithCache;
+
+  explicit ShapeZone(Zone* zone);
+
+  void purgeShapeCaches(JS::GCContext* gcx);
+
+  void addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf,
+                              size_t* initialPropMapTable, size_t* shapeTables);
+
+  void fixupPropMapShapeTableAfterMovingGC();
+
+#ifdef JSGC_HASH_TABLE_CHECKS
+  void checkTablesAfterMovingGC();
+#endif
+};
+
+}  // namespace js
+
+#endif /* vm_ShapeZone_h */