From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- js/public/SweepingAPI.h | 121 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 js/public/SweepingAPI.h (limited to 'js/public/SweepingAPI.h') diff --git a/js/public/SweepingAPI.h b/js/public/SweepingAPI.h new file mode 100644 index 0000000000..7833d65b7a --- /dev/null +++ b/js/public/SweepingAPI.h @@ -0,0 +1,121 @@ +/* -*- 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 js_SweepingAPI_h +#define js_SweepingAPI_h + +#include "mozilla/LinkedList.h" +#include "mozilla/Maybe.h" + +#include "jstypes.h" + +#include "js/GCAnnotations.h" +#include "js/GCPolicyAPI.h" +#include "js/RootingAPI.h" + +namespace js { +namespace gc { + +class StoreBuffer; + +JS_PUBLIC_API void LockStoreBuffer(StoreBuffer* sb); +JS_PUBLIC_API void UnlockStoreBuffer(StoreBuffer* sb); + +class AutoLockStoreBuffer { + StoreBuffer* sb; + + public: + explicit AutoLockStoreBuffer(StoreBuffer* sb) : sb(sb) { + LockStoreBuffer(sb); + } + ~AutoLockStoreBuffer() { UnlockStoreBuffer(sb); } +}; + +} // namespace gc +} // namespace js + +namespace JS { +namespace detail { +class WeakCacheBase; +} // namespace detail + +namespace shadow { +JS_PUBLIC_API void RegisterWeakCache(JS::Zone* zone, + JS::detail::WeakCacheBase* cachep); +JS_PUBLIC_API void RegisterWeakCache(JSRuntime* rt, + JS::detail::WeakCacheBase* cachep); +} // namespace shadow + +namespace detail { +class WeakCacheBase : public mozilla::LinkedListElement { + WeakCacheBase() = delete; + explicit WeakCacheBase(const WeakCacheBase&) = delete; + + public: + explicit WeakCacheBase(Zone* zone) { shadow::RegisterWeakCache(zone, this); } + explicit WeakCacheBase(JSRuntime* rt) { shadow::RegisterWeakCache(rt, this); } + WeakCacheBase(WeakCacheBase&& other) = default; + virtual ~WeakCacheBase() = default; + + virtual size_t traceWeak(JSTracer* trc, js::gc::StoreBuffer* sbToLock) = 0; + + // Sweeping will be skipped if the cache is empty already. + virtual bool empty() = 0; + + // Enable/disable read barrier during incremental sweeping and set the tracer + // to use. + virtual bool setIncrementalBarrierTracer(JSTracer* trc) { + // Derived classes do not support incremental barriers by default. + return false; + } + virtual bool needsIncrementalBarrier() const { + // Derived classes do not support incremental barriers by default. + return false; + } +}; +} // namespace detail + +// A WeakCache stores the given Sweepable container and links itself into a +// list of such caches that are swept during each GC. A WeakCache can be +// specific to a zone, or across a whole runtime, depending on which +// constructor is used. +template +class WeakCache : protected detail::WeakCacheBase, + public js::MutableWrappedPtrOperations> { + T cache; + + public: + using Type = T; + + template + explicit WeakCache(Zone* zone, Args&&... args) + : WeakCacheBase(zone), cache(std::forward(args)...) {} + template + explicit WeakCache(JSRuntime* rt, Args&&... args) + : WeakCacheBase(rt), cache(std::forward(args)...) {} + + const T& get() const { return cache; } + T& get() { return cache; } + + size_t traceWeak(JSTracer* trc, js::gc::StoreBuffer* sbToLock) override { + // Take the store buffer lock in case sweeping triggers any generational + // post barriers. This is not always required and WeakCache specializations + // may delay or skip taking the lock as appropriate. + mozilla::Maybe lock; + if (sbToLock) { + lock.emplace(sbToLock); + } + + GCPolicy::traceWeak(trc, &cache); + return 0; + } + + bool empty() override { return cache.empty(); } +} JS_HAZ_NON_GC_POINTER; + +} // namespace JS + +#endif // js_SweepingAPI_h -- cgit v1.2.3