c02258f01d
This change comprises a few tiny changes wrt Member: 1) Move member policies to a separate file so that some of them (CheckingPolicy) can be reused by Persistent; 2) SFINAE out incompatible pointers from heterogeneous ctor/asgnmt; 3) Rename kMemberSentinel to kSentinelPointer. Bug: chromium:1056170 Change-Id: I4482998e6ba61005a5d0861dcae9fab2aa43702c Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2139587 Reviewed-by: Omer Katz <omerkatz@chromium.org> Reviewed-by: Michael Lippautz <mlippautz@chromium.org> Commit-Queue: Anton Bikineev <bikineev@chromium.org> Cr-Commit-Position: refs/heads/master@{#67061}
75 lines
2.0 KiB
C++
75 lines
2.0 KiB
C++
// Copyright 2020 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef INCLUDE_CPPGC_INTERNAL_POINTER_POLICIES_H_
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#define INCLUDE_CPPGC_INTERNAL_POINTER_POLICIES_H_
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#include <cstdint>
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#include "include/v8config.h"
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namespace cppgc {
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namespace internal {
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// Tags to distinguish between strong and weak member types.
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class StrongMemberTag;
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class WeakMemberTag;
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class UntracedMemberTag;
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struct DijkstraWriteBarrierPolicy {
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static void InitializingBarrier(const void*, const void*) {
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// Since in initializing writes the source object is always white, having no
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// barrier doesn't break the tri-color invariant.
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}
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static void AssigningBarrier(const void*, const void*) {
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// TODO(chromium:1056170): Add actual implementation.
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}
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};
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struct NoWriteBarrierPolicy {
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static void InitializingBarrier(const void*, const void*) {}
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static void AssigningBarrier(const void*, const void*) {}
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};
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class V8_EXPORT EnabledCheckingPolicy {
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protected:
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EnabledCheckingPolicy();
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void CheckPointer(const void* ptr);
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private:
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void* impl_;
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};
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class DisabledCheckingPolicy {
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protected:
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void CheckPointer(const void* raw) {}
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};
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#if V8_ENABLE_CHECKS
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using DefaultCheckingPolicy = EnabledCheckingPolicy;
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#else
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using DefaultCheckingPolicy = DisabledCheckingPolicy;
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#endif
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// Special tag type used to denote some sentinel member. The semantics of the
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// sentinel is defined by the embedder.
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struct SentinelPointer {
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template <typename T>
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operator T*() const { // NOLINT
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static constexpr intptr_t kSentinelValue = -1;
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return reinterpret_cast<T*>(kSentinelValue);
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}
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// Hidden friends.
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friend bool operator==(SentinelPointer, SentinelPointer) { return true; }
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friend bool operator!=(SentinelPointer, SentinelPointer) { return false; }
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};
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} // namespace internal
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constexpr internal::SentinelPointer kSentinelPointer;
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} // namespace cppgc
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#endif // INCLUDE_CPPGC_INTERNAL_POINTER_POLICIES_H_
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