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Diffstat (limited to '')
-rw-r--r-- | js/src/gc/AtomMarking.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/js/src/gc/AtomMarking.h b/js/src/gc/AtomMarking.h new file mode 100644 index 0000000000..d9186c7c8b --- /dev/null +++ b/js/src/gc/AtomMarking.h @@ -0,0 +1,88 @@ +/* -*- 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 gc_AtomMarking_h +#define gc_AtomMarking_h + +#include "NamespaceImports.h" +#include "ds/Bitmap.h" +#include "threading/ProtectedData.h" + +namespace js { + +class AutoLockGC; + +namespace gc { + +class Arena; + +// This class manages state used for marking atoms during GCs. +// See AtomMarking.cpp for details. +class AtomMarkingRuntime { + // Unused arena atom bitmap indexes. Protected by the GC lock. + js::GCLockData<Vector<size_t, 0, SystemAllocPolicy>> freeArenaIndexes; + + inline void markChildren(JSContext* cx, JSAtom*); + inline void markChildren(JSContext* cx, JS::Symbol* symbol); + + public: + // The extent of all allocated and free words in atom mark bitmaps. + // This monotonically increases and may be read from without locking. + mozilla::Atomic<size_t, mozilla::SequentiallyConsistent> allocatedWords; + + AtomMarkingRuntime() : allocatedWords(0) {} + + // Mark an arena as holding things in the atoms zone. + void registerArena(Arena* arena, const AutoLockGC& lock); + + // Mark an arena as no longer holding things in the atoms zone. + void unregisterArena(Arena* arena, const AutoLockGC& lock); + + // Fill |bitmap| with an atom marking bitmap based on the things that are + // currently marked in the chunks used by atoms zone arenas. This returns + // false on an allocation failure (but does not report an exception). + bool computeBitmapFromChunkMarkBits(JSRuntime* runtime, DenseBitmap& bitmap); + + // Update the atom marking bitmap in |zone| according to another + // overapproximation of the reachable atoms in |bitmap|. + void refineZoneBitmapForCollectedZone(Zone* zone, const DenseBitmap& bitmap); + + // Set any bits in the chunk mark bitmaps for atoms which are marked in any + // uncollected zone in the runtime. + void markAtomsUsedByUncollectedZones(JSRuntime* runtime); + + // Mark an atom or id as being newly reachable by the context's zone. + template <typename T> + void markAtom(JSContext* cx, T* thing); + + // Version of markAtom that's always inlined, for performance-sensitive + // callers. + template <typename T, bool Fallible> + MOZ_ALWAYS_INLINE bool inlinedMarkAtomInternal(JSContext* cx, T* thing); + template <typename T> + MOZ_ALWAYS_INLINE void inlinedMarkAtom(JSContext* cx, T* thing); + template <typename T> + MOZ_ALWAYS_INLINE bool inlinedMarkAtomFallible(JSContext* cx, T* thing); + + void markId(JSContext* cx, jsid id); + void markAtomValue(JSContext* cx, const Value& value); + + // Mark all atoms in |source| as being reachable within |target|. + void adoptMarkedAtoms(Zone* target, Zone* source); + +#ifdef DEBUG + // Return whether |thing/id| is in the atom marking bitmap for |zone|. + template <typename T> + bool atomIsMarked(Zone* zone, T* thing); + bool idIsMarked(Zone* zone, jsid id); + bool valueIsMarked(Zone* zone, const Value& value); +#endif +}; + +} // namespace gc +} // namespace js + +#endif // gc_AtomMarking_h |