The Tor Browser / file comparison
comparison: js/src/gc/Nursery-inl.h
js/src/gc/Nursery-inl.h
- changeset 0
- 6474c204b198
equal
deleted
inserted
replaced
| -1:000000000000 | 0:01228dc08ad4 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * vim: set ts=4 sw=4 et tw=79 ft=cpp: | |
| 3 * | |
| 4 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 5 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 6 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 7 | |
| 8 #ifndef gc_Nursery_inl_h | |
| 9 #define gc_Nursery_inl_h | |
| 10 | |
| 11 #ifdef JSGC_GENERATIONAL | |
| 12 | |
| 13 #include "gc/Nursery.h" | |
| 14 | |
| 15 #include "gc/Heap.h" | |
| 16 | |
| 17 namespace js { | |
| 18 namespace gc { | |
| 19 | |
| 20 /* | |
| 21 * This structure overlays a Cell in the Nursery and re-purposes its memory | |
| 22 * for managing the Nursery collection process. | |
| 23 */ | |
| 24 class RelocationOverlay | |
| 25 { | |
| 26 friend class MinorCollectionTracer; | |
| 27 | |
| 28 /* The low bit is set so this should never equal a normal pointer. */ | |
| 29 static const uintptr_t Relocated = uintptr_t(0xbad0bad1); | |
| 30 | |
| 31 /* Set to Relocated when moved. */ | |
| 32 uintptr_t magic_; | |
| 33 | |
| 34 /* The location |this| was moved to. */ | |
| 35 Cell *newLocation_; | |
| 36 | |
| 37 /* A list entry to track all relocated things. */ | |
| 38 RelocationOverlay *next_; | |
| 39 | |
| 40 public: | |
| 41 static RelocationOverlay *fromCell(Cell *cell) { | |
| 42 JS_ASSERT(!cell->isTenured()); | |
| 43 return reinterpret_cast<RelocationOverlay *>(cell); | |
| 44 } | |
| 45 | |
| 46 bool isForwarded() const { | |
| 47 return magic_ == Relocated; | |
| 48 } | |
| 49 | |
| 50 Cell *forwardingAddress() const { | |
| 51 JS_ASSERT(isForwarded()); | |
| 52 return newLocation_; | |
| 53 } | |
| 54 | |
| 55 void forwardTo(Cell *cell) { | |
| 56 JS_ASSERT(!isForwarded()); | |
| 57 magic_ = Relocated; | |
| 58 newLocation_ = cell; | |
| 59 next_ = nullptr; | |
| 60 } | |
| 61 | |
| 62 RelocationOverlay *next() const { | |
| 63 return next_; | |
| 64 } | |
| 65 }; | |
| 66 | |
| 67 } /* namespace gc */ | |
| 68 } /* namespace js */ | |
| 69 | |
| 70 template <typename T> | |
| 71 MOZ_ALWAYS_INLINE bool | |
| 72 js::Nursery::getForwardedPointer(T **ref) | |
| 73 { | |
| 74 JS_ASSERT(ref); | |
| 75 JS_ASSERT(isInside(*ref)); | |
| 76 const gc::RelocationOverlay *overlay = reinterpret_cast<const gc::RelocationOverlay *>(*ref); | |
| 77 if (!overlay->isForwarded()) | |
| 78 return false; | |
| 79 /* This static cast from Cell* restricts T to valid (GC thing) types. */ | |
| 80 *ref = static_cast<T *>(overlay->forwardingAddress()); | |
| 81 return true; | |
| 82 } | |
| 83 | |
| 84 #endif /* JSGC_GENERATIONAL */ | |
| 85 | |
| 86 #endif /* gc_Nursery_inl_h */ |
