update v8 to 9.1.269 for mac/ios/android/ohos

2021-09-09 19:48:05 +08:00
parent 91ced4772c
commit b9d9873d98
487 changed files with 81409 additions and 9546 deletions
@@ -0,0 +1,232 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_ALLOCATION_H_
+#define INCLUDE_CPPGC_ALLOCATION_H_
+
+#include <stdint.h>
+
+#include <atomic>
+
+#include "cppgc/custom-space.h"
+#include "cppgc/garbage-collected.h"
+#include "cppgc/internal/api-constants.h"
+#include "cppgc/internal/gc-info.h"
+
+namespace cppgc {
+
+template <typename T>
+class MakeGarbageCollectedTraitBase;
+
+namespace internal {
+class ObjectAllocator;
+}  // namespace internal
+
+/**
+ * AllocationHandle is used to allocate garbage-collected objects.
+ */
+class AllocationHandle;
+
+namespace internal {
+
+class V8_EXPORT MakeGarbageCollectedTraitInternal {
+ protected:
+  static inline void MarkObjectAsFullyConstructed(const void* payload) {
+    // See api_constants for an explanation of the constants.
+    std::atomic<uint16_t>* atomic_mutable_bitfield =
+        reinterpret_cast<std::atomic<uint16_t>*>(
+            const_cast<uint16_t*>(reinterpret_cast<const uint16_t*>(
+                reinterpret_cast<const uint8_t*>(payload) -
+                api_constants::kFullyConstructedBitFieldOffsetFromPayload)));
+    atomic_mutable_bitfield->fetch_or(api_constants::kFullyConstructedBitMask,
+                                      std::memory_order_release);
+  }
+
+  template <typename U, typename CustomSpace>
+  struct SpacePolicy {
+    static void* Allocate(AllocationHandle& handle, size_t size) {
+      // Custom space.
+      static_assert(std::is_base_of<CustomSpaceBase, CustomSpace>::value,
+                    "Custom space must inherit from CustomSpaceBase.");
+      return MakeGarbageCollectedTraitInternal::Allocate(
+          handle, size, internal::GCInfoTrait<U>::Index(),
+          CustomSpace::kSpaceIndex);
+    }
+  };
+
+  template <typename U>
+  struct SpacePolicy<U, void> {
+    static void* Allocate(AllocationHandle& handle, size_t size) {
+      // Default space.
+      return MakeGarbageCollectedTraitInternal::Allocate(
+          handle, size, internal::GCInfoTrait<U>::Index());
+    }
+  };
+
+ private:
+  static void* Allocate(cppgc::AllocationHandle& handle, size_t size,
+                        GCInfoIndex index);
+  static void* Allocate(cppgc::AllocationHandle& handle, size_t size,
+                        GCInfoIndex index, CustomSpaceIndex space_index);
+
+  friend class HeapObjectHeader;
+};
+
+}  // namespace internal
+
+/**
+ * Base trait that provides utilities for advancers users that have custom
+ * allocation needs (e.g., overriding size). It's expected that users override
+ * MakeGarbageCollectedTrait (see below) and inherit from
+ * MakeGarbageCollectedTraitBase and make use of the low-level primitives
+ * offered to allocate and construct an object.
+ */
+template <typename T>
+class MakeGarbageCollectedTraitBase
+    : private internal::MakeGarbageCollectedTraitInternal {
+ private:
+  static_assert(internal::IsGarbageCollectedType<T>::value,
+                "T needs to be a garbage collected object");
+  static_assert(!IsGarbageCollectedWithMixinTypeV<T> ||
+                    sizeof(T) <=
+                        internal::api_constants::kLargeObjectSizeThreshold,
+                "GarbageCollectedMixin may not be a large object");
+
+ protected:
+  /**
+   * Allocates memory for an object of type T.
+   *
+   * \param handle AllocationHandle identifying the heap to allocate the object
+   *   on.
+   * \param size The size that should be reserved for the object.
+   * \returns the memory to construct an object of type T on.
+   */
+  V8_INLINE static void* Allocate(AllocationHandle& handle, size_t size) {
+    return SpacePolicy<
+        typename internal::GCInfoFolding<
+            T, typename T::ParentMostGarbageCollectedType>::ResultType,
+        typename SpaceTrait<T>::Space>::Allocate(handle, size);
+  }
+
+  /**
+   * Marks an object as fully constructed, resulting in precise handling by the
+   * garbage collector.
+   *
+   * \param payload The base pointer the object is allocated at.
+   */
+  V8_INLINE static void MarkObjectAsFullyConstructed(const void* payload) {
+    internal::MakeGarbageCollectedTraitInternal::MarkObjectAsFullyConstructed(
+        payload);
+  }
+};
+
+/**
+ * Passed to MakeGarbageCollected to specify how many bytes should be appended
+ * to the allocated object.
+ *
+ * Example:
+ * \code
+ * class InlinedArray final : public GarbageCollected<InlinedArray> {
+ *  public:
+ *   explicit InlinedArray(size_t bytes) : size(bytes), byte_array(this + 1) {}
+ *   void Trace(Visitor*) const {}
+
+ *   size_t size;
+ *   char* byte_array;
+ * };
+ *
+ * auto* inlined_array = MakeGarbageCollected<InlinedArray(
+ *    GetAllocationHandle(), AdditionalBytes(4), 4);
+ * for (size_t i = 0; i < 4; i++) {
+ *   Process(inlined_array->byte_array[i]);
+ * }
+ * \endcode
+ */
+struct AdditionalBytes {
+  constexpr explicit AdditionalBytes(size_t bytes) : value(bytes) {}
+  const size_t value;
+};
+
+/**
+ * Default trait class that specifies how to construct an object of type T.
+ * Advanced users may override how an object is constructed using the utilities
+ * that are provided through MakeGarbageCollectedTraitBase.
+ *
+ * Any trait overriding construction must
+ * - allocate through `MakeGarbageCollectedTraitBase<T>::Allocate`;
+ * - mark the object as fully constructed using
+ *   `MakeGarbageCollectedTraitBase<T>::MarkObjectAsFullyConstructed`;
+ */
+template <typename T>
+class MakeGarbageCollectedTrait : public MakeGarbageCollectedTraitBase<T> {
+ public:
+  template <typename... Args>
+  static T* Call(AllocationHandle& handle, Args&&... args) {
+    void* memory =
+        MakeGarbageCollectedTraitBase<T>::Allocate(handle, sizeof(T));
+    T* object = ::new (memory) T(std::forward<Args>(args)...);
+    MakeGarbageCollectedTraitBase<T>::MarkObjectAsFullyConstructed(object);
+    return object;
+  }
+
+  template <typename... Args>
+  static T* Call(AllocationHandle& handle, AdditionalBytes additional_bytes,
+                 Args&&... args) {
+    void* memory = MakeGarbageCollectedTraitBase<T>::Allocate(
+        handle, sizeof(T) + additional_bytes.value);
+    T* object = ::new (memory) T(std::forward<Args>(args)...);
+    MakeGarbageCollectedTraitBase<T>::MarkObjectAsFullyConstructed(object);
+    return object;
+  }
+};
+
+/**
+ * Allows users to specify a post-construction callback for specific types. The
+ * callback is invoked on the instance of type T right after it has been
+ * constructed. This can be useful when the callback requires a
+ * fully-constructed object to be able to dispatch to virtual methods.
+ */
+template <typename T, typename = void>
+struct PostConstructionCallbackTrait {
+  static void Call(T*) {}
+};
+
+/**
+ * Constructs a managed object of type T where T transitively inherits from
+ * GarbageCollected.
+ *
+ * \param args List of arguments with which an instance of T will be
+ *   constructed.
+ * \returns an instance of type T.
+ */
+template <typename T, typename... Args>
+T* MakeGarbageCollected(AllocationHandle& handle, Args&&... args) {
+  T* object =
+      MakeGarbageCollectedTrait<T>::Call(handle, std::forward<Args>(args)...);
+  PostConstructionCallbackTrait<T>::Call(object);
+  return object;
+}
+
+/**
+ * Constructs a managed object of type T where T transitively inherits from
+ * GarbageCollected. Created objects will have additional bytes appended to
+ * it. Allocated memory would suffice for `sizeof(T) + additional_bytes`.
+ *
+ * \param additional_bytes Denotes how many bytes to append to T.
+ * \param args List of arguments with which an instance of T will be
+ *   constructed.
+ * \returns an instance of type T.
+ */
+template <typename T, typename... Args>
+T* MakeGarbageCollected(AllocationHandle& handle,
+                        AdditionalBytes additional_bytes, Args&&... args) {
+  T* object = MakeGarbageCollectedTrait<T>::Call(handle, additional_bytes,
+                                                 std::forward<Args>(args)...);
+  PostConstructionCallbackTrait<T>::Call(object);
+  return object;
+}
+
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_ALLOCATION_H_