The Tor Browser: js/src/gc/StoreBuffer.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2  * vim: set ts=8 sts=4 et sw=4 tw=99:

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifdef JSGC_GENERATIONAL

     9 #include "gc/StoreBuffer.h"

    11 #include "mozilla/Assertions.h"

    13 #include "vm/ArgumentsObject.h"

    14 #include "vm/ForkJoin.h"

    16 #include "jsgcinlines.h"

    18 using namespace js;

    19 using namespace js::gc;

    20 using mozilla::ReentrancyGuard;

    22 /*** Edges ***/

    24 void

    25 StoreBuffer::SlotsEdge::mark(JSTracer *trc)

    26 {

    27     JSObject *obj = object();

    29     if (trc->runtime()->gcNursery.isInside(obj))

    30         return;

    32     if (!obj->isNative()) {

    33         const Class *clasp = obj->getClass();

    34         if (clasp)

    35             clasp->trace(trc, obj);

    36         return;

    37     }

    39     if (kind() == ElementKind) {

    40         int32_t initLen = obj->getDenseInitializedLength();

    41         int32_t clampedStart = Min(start_, initLen);

    42         int32_t clampedEnd = Min(start_ + count_, initLen);

    43         gc::MarkArraySlots(trc, clampedEnd - clampedStart,

    44                            obj->getDenseElements() + clampedStart, "element");

    45     } else {

    46         int32_t start = Min(uint32_t(start_), obj->slotSpan());

    47         int32_t end = Min(uint32_t(start_) + count_, obj->slotSpan());

    48         MOZ_ASSERT(end >= start);

    49         MarkObjectSlots(trc, obj, start, end - start);

    50     }

    51 }

    53 void

    54 StoreBuffer::WholeCellEdges::mark(JSTracer *trc)

    55 {

    56     JS_ASSERT(edge->isTenured());

    57     JSGCTraceKind kind = GetGCThingTraceKind(edge);

    58     if (kind <= JSTRACE_OBJECT) {

    59         JSObject *object = static_cast<JSObject *>(edge);

    60         if (object->is<ArgumentsObject>())

    61             ArgumentsObject::trace(trc, object);

    62         MarkChildren(trc, object);

    63         return;

    64     }

    65 #ifdef JS_ION

    66     JS_ASSERT(kind == JSTRACE_JITCODE);

    67     static_cast<jit::JitCode *>(edge)->trace(trc);

    68 #else

    69     MOZ_ASSUME_UNREACHABLE("Only objects can be in the wholeCellBuffer if IonMonkey is disabled.");

    70 #endif

    71 }

    73 void

    74 StoreBuffer::CellPtrEdge::mark(JSTracer *trc)

    75 {

    76     if (!*edge)

    77         return;

    79     JS_ASSERT(GetGCThingTraceKind(*edge) == JSTRACE_OBJECT);

    80     MarkObjectRoot(trc, reinterpret_cast<JSObject**>(edge), "store buffer edge");

    81 }

    83 void

    84 StoreBuffer::ValueEdge::mark(JSTracer *trc)

    85 {

    86     if (!deref())

    87         return;

    89     MarkValueRoot(trc, edge, "store buffer edge");

    90 }

    92 /*** MonoTypeBuffer ***/

    94 template <typename T>

    95 void

    96 StoreBuffer::MonoTypeBuffer<T>::handleOverflow(StoreBuffer *owner)

    97 {

    98     if (!owner->isAboutToOverflow()) {

    99         /*

   100          * Compact the buffer now, and if that fails to free enough space then

   101          * trigger a minor collection.

   102          */

   103         compact(owner);

   104         if (isAboutToOverflow())

   105             owner->setAboutToOverflow();

   106     } else {

   107          /*

   108           * A minor GC has already been triggered, so there's no point

   109           * compacting unless the buffer is totally full.

   110           */

   111         if (storage_->availableInCurrentChunk() < sizeof(T))

   112             maybeCompact(owner);

   113     }

   114 }

   116 template <typename T>

   117 void

   118 StoreBuffer::MonoTypeBuffer<T>::compactRemoveDuplicates(StoreBuffer *owner)

   119 {

   120     typedef HashSet<T, typename T::Hasher, SystemAllocPolicy> DedupSet;

   122     DedupSet duplicates;

   123     if (!duplicates.init())

   124         return; /* Failure to de-dup is acceptable. */

   126     LifoAlloc::Enum insert(*storage_);

   127     for (LifoAlloc::Enum e(*storage_); !e.empty(); e.popFront<T>()) {

   128         T *edge = e.get<T>();

   129         if (!duplicates.has(*edge)) {

   130             insert.updateFront<T>(*edge);

   131             insert.popFront<T>();

   133             /* Failure to insert will leave the set with duplicates. Oh well. */

   134             duplicates.put(*edge);

   135         }

   136     }

   137     storage_->release(insert.mark());

   139     duplicates.clear();

   140 }

   142 template <typename T>

   143 void

   144 StoreBuffer::MonoTypeBuffer<T>::compact(StoreBuffer *owner)

   145 {

   146     JS_ASSERT(storage_);

   147     compactRemoveDuplicates(owner);

   148     usedAtLastCompact_ = storage_->used();

   149 }

   151 template <typename T>

   152 void

   153 StoreBuffer::MonoTypeBuffer<T>::maybeCompact(StoreBuffer *owner)

   154 {

   155     JS_ASSERT(storage_);

   156     if (storage_->used() != usedAtLastCompact_)

   157         compact(owner);

   158 }

   160 template <typename T>

   161 void

   162 StoreBuffer::MonoTypeBuffer<T>::mark(StoreBuffer *owner, JSTracer *trc)

   163 {

   164     JS_ASSERT(owner->isEnabled());

   165     ReentrancyGuard g(*owner);

   166     if (!storage_)

   167         return;

   169     maybeCompact(owner);

   170     for (LifoAlloc::Enum e(*storage_); !e.empty(); e.popFront<T>()) {

   171         T *edge = e.get<T>();

   172         edge->mark(trc);

   173     }

   174 }

   176 /*** RelocatableMonoTypeBuffer ***/

   178 template <typename T>

   179 void

   180 StoreBuffer::RelocatableMonoTypeBuffer<T>::compactMoved(StoreBuffer *owner)

   181 {

   182     LifoAlloc &storage = *this->storage_;

   183     EdgeSet invalidated;

   184     if (!invalidated.init())

   185         CrashAtUnhandlableOOM("RelocatableMonoTypeBuffer::compactMoved: Failed to init table.");

   187     /* Collect the set of entries which are currently invalid. */

   188     for (LifoAlloc::Enum e(storage); !e.empty(); e.popFront<T>()) {

   189         T *edge = e.get<T>();

   190         if (edge->isTagged()) {

   191             if (!invalidated.put(edge->untagged().edge))

   192                 CrashAtUnhandlableOOM("RelocatableMonoTypeBuffer::compactMoved: Failed to put removal.");

   193         } else {

   194             invalidated.remove(edge->untagged().edge);

   195         }

   196     }

   198     /* Remove all entries which are in the invalidated set. */

   199     LifoAlloc::Enum insert(storage);

   200     for (LifoAlloc::Enum e(storage); !e.empty(); e.popFront<T>()) {

   201         T *edge = e.get<T>();

   202         if (!edge->isTagged() && !invalidated.has(edge->untagged().edge)) {

   203             insert.updateFront<T>(*edge);

   204             insert.popFront<T>();

   205         }

   206     }

   207     storage.release(insert.mark());

   209     invalidated.clear();

   211 #ifdef DEBUG

   212     for (LifoAlloc::Enum e(storage); !e.empty(); e.popFront<T>())

   213         JS_ASSERT(!e.get<T>()->isTagged());

   214 #endif

   215 }

   217 template <typename T>

   218 void

   219 StoreBuffer::RelocatableMonoTypeBuffer<T>::compact(StoreBuffer *owner)

   220 {

   221     compactMoved(owner);

   222     StoreBuffer::MonoTypeBuffer<T>::compact(owner);

   223 }

   225 /*** GenericBuffer ***/

   227 void

   228 StoreBuffer::GenericBuffer::mark(StoreBuffer *owner, JSTracer *trc)

   229 {

   230     JS_ASSERT(owner->isEnabled());

   231     ReentrancyGuard g(*owner);

   232     if (!storage_)

   233         return;

   235     for (LifoAlloc::Enum e(*storage_); !e.empty();) {

   236         unsigned size = *e.get<unsigned>();

   237         e.popFront<unsigned>();

   238         BufferableRef *edge = e.get<BufferableRef>(size);

   239         edge->mark(trc);

   240         e.popFront(size);

   241     }

   242 }

   244 /*** StoreBuffer ***/

   246 bool

   247 StoreBuffer::enable()

   248 {

   249     if (enabled_)

   250         return true;

   252     if (!bufferVal.init() ||

   253         !bufferCell.init() ||

   254         !bufferSlot.init() ||

   255         !bufferWholeCell.init() ||

   256         !bufferRelocVal.init() ||

   257         !bufferRelocCell.init() ||

   258         !bufferGeneric.init())

   259     {

   260         return false;

   261     }

   263     enabled_ = true;

   264     return true;

   265 }

   267 void

   268 StoreBuffer::disable()

   269 {

   270     if (!enabled_)

   271         return;

   273     aboutToOverflow_ = false;

   275     enabled_ = false;

   276 }

   278 bool

   279 StoreBuffer::clear()

   280 {

   281     if (!enabled_)

   282         return true;

   284     aboutToOverflow_ = false;

   286     bufferVal.clear();

   287     bufferCell.clear();

   288     bufferSlot.clear();

   289     bufferWholeCell.clear();

   290     bufferRelocVal.clear();

   291     bufferRelocCell.clear();

   292     bufferGeneric.clear();

   294     return true;

   295 }

   297 void

   298 StoreBuffer::markAll(JSTracer *trc)

   299 {

   300     bufferVal.mark(this, trc);

   301     bufferCell.mark(this, trc);

   302     bufferSlot.mark(this, trc);

   303     bufferWholeCell.mark(this, trc);

   304     bufferRelocVal.mark(this, trc);

   305     bufferRelocCell.mark(this, trc);

   306     bufferGeneric.mark(this, trc);

   307 }

   309 void

   310 StoreBuffer::setAboutToOverflow()

   311 {

   312     aboutToOverflow_ = true;

   313     runtime_->requestInterrupt(JSRuntime::RequestInterruptMainThread);

   314 }

   316 bool

   317 StoreBuffer::inParallelSection() const

   318 {

   319     return InParallelSection();

   320 }

   322 void

   323 StoreBuffer::addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::GCSizes

   324 *sizes)

   325 {

   326     sizes->storeBufferVals       += bufferVal.sizeOfExcludingThis(mallocSizeOf);

   327     sizes->storeBufferCells      += bufferCell.sizeOfExcludingThis(mallocSizeOf);

   328     sizes->storeBufferSlots      += bufferSlot.sizeOfExcludingThis(mallocSizeOf);

   329     sizes->storeBufferWholeCells += bufferWholeCell.sizeOfExcludingThis(mallocSizeOf);

   330     sizes->storeBufferRelocVals  += bufferRelocVal.sizeOfExcludingThis(mallocSizeOf);

   331     sizes->storeBufferRelocCells += bufferRelocCell.sizeOfExcludingThis(mallocSizeOf);

   332     sizes->storeBufferGenerics   += bufferGeneric.sizeOfExcludingThis(mallocSizeOf);

   333 }

   335 JS_PUBLIC_API(void)

   336 JS::HeapCellPostBarrier(js::gc::Cell **cellp)

   337 {

   338     JS_ASSERT(*cellp);

   339     JSRuntime *runtime = (*cellp)->runtimeFromMainThread();

   340     runtime->gcStoreBuffer.putRelocatableCell(cellp);

   341 }

   343 JS_PUBLIC_API(void)

   344 JS::HeapCellRelocate(js::gc::Cell **cellp)

   345 {

   346     /* Called with old contents of *pp before overwriting. */

   347     JS_ASSERT(*cellp);

   348     JSRuntime *runtime = (*cellp)->runtimeFromMainThread();

   349     runtime->gcStoreBuffer.removeRelocatableCell(cellp);

   350 }

   352 JS_PUBLIC_API(void)

   353 JS::HeapValuePostBarrier(JS::Value *valuep)

   354 {

   355     JS_ASSERT(valuep->isMarkable());

   356     if (valuep->isString() && StringIsPermanentAtom(valuep->toString()))

   357         return;

   358     JSRuntime *runtime = static_cast<js::gc::Cell *>(valuep->toGCThing())->runtimeFromMainThread();

   359     runtime->gcStoreBuffer.putRelocatableValue(valuep);

   360 }

   362 JS_PUBLIC_API(void)

   363 JS::HeapValueRelocate(JS::Value *valuep)

   364 {

   365     /* Called with old contents of *valuep before overwriting. */

   366     JS_ASSERT(valuep->isMarkable());

   367     if (valuep->isString() && StringIsPermanentAtom(valuep->toString()))

   368         return;

   369     JSRuntime *runtime = static_cast<js::gc::Cell *>(valuep->toGCThing())->runtimeFromMainThread();

   370     runtime->gcStoreBuffer.removeRelocatableValue(valuep);

   371 }

   373 template class StoreBuffer::MonoTypeBuffer<StoreBuffer::ValueEdge>;

   374 template class StoreBuffer::MonoTypeBuffer<StoreBuffer::CellPtrEdge>;

   375 template class StoreBuffer::MonoTypeBuffer<StoreBuffer::SlotsEdge>;

   376 template class StoreBuffer::MonoTypeBuffer<StoreBuffer::WholeCellEdges>;

   377 template class StoreBuffer::RelocatableMonoTypeBuffer<StoreBuffer::ValueEdge>;

   378 template class StoreBuffer::RelocatableMonoTypeBuffer<StoreBuffer::CellPtrEdge>;

   380 #endif /* JSGC_GENERATIONAL */

The Tor Browser / file revision

js/src/gc/StoreBuffer.cpp@6474c204b198

js/src/gc/StoreBuffer.cpp