зеркало из https://github.com/mozilla/gecko-dev.git
111 строки
3.3 KiB
C++
111 строки
3.3 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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* vim: set ts=8 sts=2 et sw=2 tw=80:
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef js_SweepingAPI_h
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#define js_SweepingAPI_h
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#include "js/HeapAPI.h"
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namespace js {
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namespace gc {
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class StoreBuffer;
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JS_PUBLIC_API void LockStoreBuffer(StoreBuffer* sb);
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JS_PUBLIC_API void UnlockStoreBuffer(StoreBuffer* sb);
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class AutoLockStoreBuffer {
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StoreBuffer* sb;
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public:
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explicit AutoLockStoreBuffer(StoreBuffer* sb) : sb(sb) {
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LockStoreBuffer(sb);
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}
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~AutoLockStoreBuffer() { UnlockStoreBuffer(sb); }
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};
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} // namespace gc
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} // namespace js
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namespace JS {
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namespace detail {
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class WeakCacheBase;
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} // namespace detail
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namespace shadow {
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JS_PUBLIC_API void RegisterWeakCache(JS::Zone* zone,
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JS::detail::WeakCacheBase* cachep);
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JS_PUBLIC_API void RegisterWeakCache(JSRuntime* rt,
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JS::detail::WeakCacheBase* cachep);
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} // namespace shadow
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namespace detail {
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class WeakCacheBase : public mozilla::LinkedListElement<WeakCacheBase> {
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WeakCacheBase() = delete;
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explicit WeakCacheBase(const WeakCacheBase&) = delete;
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public:
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explicit WeakCacheBase(Zone* zone) { shadow::RegisterWeakCache(zone, this); }
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explicit WeakCacheBase(JSRuntime* rt) { shadow::RegisterWeakCache(rt, this); }
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WeakCacheBase(WeakCacheBase&& other) = default;
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virtual ~WeakCacheBase() = default;
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virtual size_t sweep(js::gc::StoreBuffer* sbToLock) = 0;
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virtual bool needsSweep() = 0;
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virtual bool setNeedsIncrementalBarrier(bool needs) {
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// Derived classes do not support incremental barriers by default.
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return false;
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}
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virtual bool needsIncrementalBarrier() const {
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// Derived classes do not support incremental barriers by default.
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return false;
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}
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};
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} // namespace detail
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// A WeakCache stores the given Sweepable container and links itself into a
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// list of such caches that are swept during each GC. A WeakCache can be
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// specific to a zone, or across a whole runtime, depending on which
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// constructor is used.
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template <typename T>
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class WeakCache : protected detail::WeakCacheBase,
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public js::MutableWrappedPtrOperations<T, WeakCache<T>> {
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T cache;
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public:
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using Type = T;
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template <typename... Args>
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explicit WeakCache(Zone* zone, Args&&... args)
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: WeakCacheBase(zone), cache(std::forward<Args>(args)...) {}
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template <typename... Args>
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explicit WeakCache(JSRuntime* rt, Args&&... args)
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: WeakCacheBase(rt), cache(std::forward<Args>(args)...) {}
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const T& get() const { return cache; }
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T& get() { return cache; }
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size_t sweep(js::gc::StoreBuffer* sbToLock) override {
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// Take the store buffer lock in case sweeping triggers any generational
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// post barriers. This is not always required and WeakCache specializations
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// may delay or skip taking the lock as appropriate.
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mozilla::Maybe<js::gc::AutoLockStoreBuffer> lock;
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if (sbToLock) {
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lock.emplace(sbToLock);
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}
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GCPolicy<T>::sweep(&cache);
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return 0;
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}
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bool needsSweep() override { return cache.needsSweep(); }
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} JS_HAZ_NON_GC_POINTER;
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} // namespace JS
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#endif // js_SweepingAPI_h
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