зеркало из https://github.com/mozilla/pjs.git
bug 665354 - page-independent free span. r=wmccloskey
This commit is contained in:
Igor Bukanov
Родитель
2b2ff5f8b1
Коммит
602f05f2d4
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@ -176,7 +176,7 @@ ArenaHeader::checkSynchronizedWithFreeList() const
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if (!compartment->rt->gcRunning)
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return;
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FreeSpan firstSpan(address() + firstFreeSpanStart, address() + firstFreeSpanEnd);
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FreeSpan firstSpan = FreeSpan::decodeOffsets(arenaAddress(), firstFreeSpanOffsets);
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if (firstSpan.isEmpty())
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return;
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FreeSpan *list = &compartment->freeLists.lists[getThingKind()];
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@ -187,8 +187,7 @@ ArenaHeader::checkSynchronizedWithFreeList() const
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* Here this arena has free things, FreeList::lists[thingKind] is not
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* empty and also points to this arena. Thus they must the same.
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*/
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JS_ASSERT(firstSpan.start == list->start);
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JS_ASSERT(firstSpan.end == list->end);
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JS_ASSERT(firstSpan.isSameNonEmptySpan(list));
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}
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#endif
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@ -200,7 +199,7 @@ Arena::finalize(JSContext *cx)
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JS_ASSERT(!aheader.getMarkingDelay()->link);
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uintptr_t thing = thingsStart(sizeof(T));
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uintptr_t end = thingsEnd();
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uintptr_t lastByte = thingsEnd() - 1;
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FreeSpan nextFree(aheader.getFirstFreeSpan());
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nextFree.checkSpan();
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@ -213,15 +212,15 @@ Arena::finalize(JSContext *cx)
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size_t nmarked = 0;
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#endif
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for (;; thing += sizeof(T)) {
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JS_ASSERT(thing <= end);
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if (thing == nextFree.start) {
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JS_ASSERT(nextFree.end <= end);
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if (nextFree.end == end)
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JS_ASSERT(thing <= lastByte + 1);
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if (thing == nextFree.first) {
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JS_ASSERT(nextFree.last <= lastByte);
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if (nextFree.last == lastByte)
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break;
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JS_ASSERT(Arena::isAligned(nextFree.end, sizeof(T)));
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JS_ASSERT(Arena::isAligned(nextFree.last, sizeof(T)));
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if (!newFreeSpanStart)
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newFreeSpanStart = thing;
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thing = nextFree.end;
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thing = nextFree.last;
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nextFree = *nextFree.nextSpan();
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nextFree.checkSpan();
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} else {
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@ -233,10 +232,10 @@ Arena::finalize(JSContext *cx)
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#endif
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if (newFreeSpanStart) {
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JS_ASSERT(thing >= thingsStart(sizeof(T)) + sizeof(T));
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newListTail->start = newFreeSpanStart;
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newListTail->end = thing - sizeof(T);
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newListTail = newListTail->nextSpanUnchecked();
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newFreeSpanStart = 0;
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newListTail->first = newFreeSpanStart;
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newListTail->last = thing - sizeof(T);
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newListTail = newListTail->nextSpanUnchecked(sizeof(T));
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newFreeSpanStart = NULL;
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}
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} else {
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if (!newFreeSpanStart)
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@ -253,20 +252,20 @@ Arena::finalize(JSContext *cx)
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return true;
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}
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newListTail->start = newFreeSpanStart ? newFreeSpanStart : nextFree.start;
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JS_ASSERT(Arena::isAligned(newListTail->start, sizeof(T)));
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newListTail->end = end;
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newListTail->first = newFreeSpanStart ? newFreeSpanStart : nextFree.first;
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JS_ASSERT(Arena::isAligned(newListTail->first, sizeof(T)));
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newListTail->last = lastByte;
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#ifdef DEBUG
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size_t nfree = 0;
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for (FreeSpan *span = &newListHead; span != newListTail; span = span->nextSpan()) {
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for (const FreeSpan *span = &newListHead; span != newListTail; span = span->nextSpan()) {
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span->checkSpan();
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JS_ASSERT(Arena::isAligned(span->start, sizeof(T)));
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JS_ASSERT(Arena::isAligned(span->end, sizeof(T)));
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nfree += (span->end - span->start) / sizeof(T) + 1;
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JS_ASSERT(Arena::isAligned(span->first, sizeof(T)));
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JS_ASSERT(Arena::isAligned(span->last, sizeof(T)));
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nfree += (span->last - span->first) / sizeof(T) + 1;
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JS_ASSERT(nfree + nmarked <= thingsPerArena(sizeof(T)));
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}
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nfree += (newListTail->end - newListTail->start) / sizeof(T);
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nfree += (newListTail->last + 1 - newListTail->first) / sizeof(T);
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JS_ASSERT(nfree + nmarked == thingsPerArena(sizeof(T)));
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#endif
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aheader.setFirstFreeSpan(&newListHead);
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@ -629,9 +628,9 @@ InFreeList(ArenaHeader *aheader, uintptr_t addr)
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FreeSpan firstSpan(aheader->getFirstFreeSpan());
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for (FreeSpan *span = &firstSpan;;) {
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for (const FreeSpan *span = &firstSpan;;) {
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/* If the thing comes fore the current span, it's not free. */
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if (addr < span->start)
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if (addr < span->first)
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return false;
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/*
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@ -639,7 +638,7 @@ InFreeList(ArenaHeader *aheader, uintptr_t addr)
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* "<" even for the last span as we know that thing is inside the
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* arena. Thus for the last span thing < span->end.
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*/
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if (addr <= span->end)
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if (addr <= span->last)
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return true;
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/*
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@ -1364,7 +1363,7 @@ IsGCAllowed(JSContext *cx)
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}
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template <typename T>
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inline Cell *
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inline void *
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RefillTypedFreeList(JSContext *cx, unsigned thingKind)
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{
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JS_ASSERT(!cx->runtime->gcRunning);
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@ -1391,7 +1390,7 @@ RefillTypedFreeList(JSContext *cx, unsigned thingKind)
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* things and populate the free list. If that happens, just
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* return that list head.
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*/
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if (Cell *thing = compartment->freeLists.getNext(thingKind, sizeof(T)))
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if (void *thing = compartment->freeLists.getNext(thingKind, sizeof(T)))
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return thing;
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}
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ArenaHeader *aheader =
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@ -1414,7 +1413,7 @@ RefillTypedFreeList(JSContext *cx, unsigned thingKind)
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return NULL;
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}
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Cell *
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void *
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RefillFinalizableFreeList(JSContext *cx, unsigned thingKind)
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{
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switch (thingKind) {
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@ -1452,7 +1451,7 @@ RefillFinalizableFreeList(JSContext *cx, unsigned thingKind)
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#endif
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default:
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JS_NOT_REACHED("bad finalize kind");
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return NULL;
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return 0;
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}
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}
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@ -2320,7 +2319,7 @@ MarkAndSweep(JSContext *cx, JSCompartment *comp, JSGCInvocationKind gckind GCTIM
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WatchpointMap::sweepAll(rt);
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/*
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* We finalize objects before other GC things to ensure that object's finalizer
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* We finalize objects before other GC things to ensure that object's finalizer
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* can access them even if they will be freed. Sweep the runtime's property trees
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* after finalizing objects, in case any had watchpoints referencing tree nodes.
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* Do this before sweeping compartments, so that we sweep all shapes in
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@ -2832,18 +2831,18 @@ IterateCompartmentsArenasCells(JSContext *cx, void *data,
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Arena *arena = aheader->getArena();
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(*arenaCallback)(cx, data, arena, traceKind, thingSize);
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FreeSpan firstSpan(aheader->getFirstFreeSpan());
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FreeSpan *span = &firstSpan;
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const FreeSpan *span = &firstSpan;
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for (uintptr_t thing = arena->thingsStart(thingSize); ; thing += thingSize) {
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JS_ASSERT(thing <= arena->thingsEnd());
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if (thing == span->start) {
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if (thing == span->first) {
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if (!span->hasNext())
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break;
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thing = span->end;
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thing = span->last;
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span = span->nextSpan();
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} else {
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(*cellCallback)(cx, data, reinterpret_cast<void *>(thing), traceKind,
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thingSize);
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void *t = reinterpret_cast<void *>(thing);
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(*cellCallback)(cx, data, t, traceKind, thingSize);
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}
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}
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}
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295
js/src/jsgc.h
295
js/src/jsgc.h
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@ -126,100 +126,221 @@ const size_t ArenaBitmapWords = ArenaBitmapBits / JS_BITS_PER_WORD;
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/*
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* A FreeSpan represents a contiguous sequence of free cells in an Arena.
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* |start| is the address of the first free cell in the span. |end| is the
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* address of the last free cell in the span. The last cell (starting at
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* |end|) holds a FreeSpan data structure for the next span. However, the last
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* FreeSpan in an Arena is special: |end| points to the end of the Arena (an
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* unusable address), and no next FreeSpan is stored there.
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* |first| is the address of the first free cell in the span. |last| is the
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* address of the last free cell in the span. This last cell holds a FreeSpan
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* data structure for the next span unless this is the last span on the list
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* of spans in the arena. For this last span |last| points to the last byte of
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* the last thing in the arena and no linkage is stored there, so
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* |last| == arenaStart + ArenaSize - 1. If the space at the arena end is
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* fully used this last span is empty and |first| == |last + 1|.
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*
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* As things in the arena ends on its boundary that is aligned on ArenaSize,
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* end & ArenaMask is zero if and only if the span is last. Also, since the
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* first thing in the arena comes after the header, start & ArenaSize is zero
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* if and only if the span is the empty span at the end of the arena.
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* Thus |first| < |last| implies that we have either the last span with at least
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* one element or that the span is not the last and contains at least 2
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* elements. In both cases to allocate a thing from this span we need simply
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* to increment |first| by the allocation size.
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*
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* The type of the start and end fields is uintptr_t, not a pointer type, to
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* minimize the amount of casting when doing mask operations.
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* |first| == |last| implies that we have a one element span that records the
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* next span. So to allocate from it we need to update the span list head
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* with a copy of the span stored at |last| address so the following
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* allocations will use that span.
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*
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* |first| > |last| implies that we have an empty last span and the arena is
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* fully used.
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*
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* Also only for the last span (|last| & 1)! = 0 as all allocation sizes are
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* multiples of Cell::CellSize.
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*/
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struct FreeSpan {
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uintptr_t start;
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uintptr_t end;
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uintptr_t first;
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uintptr_t last;
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public:
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FreeSpan() { }
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FreeSpan() {}
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FreeSpan(uintptr_t start, uintptr_t end)
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: start(start), end(end) {
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FreeSpan(uintptr_t first, uintptr_t last)
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: first(first), last(last) {
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checkSpan();
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}
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/*
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* To minimize the size of the arena header the first span is encoded
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* there as offsets from the arena start.
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*/
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static size_t encodeOffsets(size_t firstOffset, size_t lastOffset = ArenaSize - 1) {
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/* Check that we can pack the offsets into uint16. */
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JS_STATIC_ASSERT(ArenaShift < 16);
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JS_ASSERT(firstOffset <= ArenaSize);
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JS_ASSERT(lastOffset < ArenaSize);
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JS_ASSERT(firstOffset <= ((lastOffset + 1) & ~size_t(1)));
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return firstOffset | (lastOffset << 16);
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}
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static const size_t EmptyOffsets = ArenaSize | ((ArenaSize - 1) << 16);
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static FreeSpan decodeOffsets(uintptr_t arenaAddr, size_t offsets) {
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JS_ASSERT(!(arenaAddr & ArenaMask));
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size_t firstOffset = offsets & 0xFFFF;
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size_t lastOffset = offsets >> 16;
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JS_ASSERT(firstOffset <= ArenaSize);
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JS_ASSERT(lastOffset < ArenaSize);
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/*
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* We must not use | when calculating first as firstOffset is
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* ArenaMask + 1 for the empty span.
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*/
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return FreeSpan(arenaAddr + firstOffset, arenaAddr | lastOffset);
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}
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void initAsEmpty(uintptr_t arenaAddr = 0) {
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JS_ASSERT(!(arenaAddr & ArenaMask));
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first = arenaAddr + ArenaSize;
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last = arenaAddr | (ArenaSize - 1);
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JS_ASSERT(isEmpty());
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}
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bool isEmpty() const {
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checkSpan();
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return !(start & ArenaMask);
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return first > last;
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}
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bool hasNext() const {
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checkSpan();
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return !!(end & ArenaMask);
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return !(last & uintptr_t(1));
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}
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FreeSpan *nextSpan() const {
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const FreeSpan *nextSpan() const {
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JS_ASSERT(hasNext());
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return reinterpret_cast<FreeSpan *>(end);
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return reinterpret_cast<FreeSpan *>(last);
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}
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FreeSpan *nextSpanUnchecked() const {
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JS_ASSERT(end & ArenaMask);
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return reinterpret_cast<FreeSpan *>(end);
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FreeSpan *nextSpanUnchecked(size_t thingSize) const {
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#ifdef DEBUG
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uintptr_t lastOffset = last & ArenaMask;
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JS_ASSERT(!(lastOffset & 1));
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JS_ASSERT((ArenaSize - lastOffset) % thingSize == 0);
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#endif
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return reinterpret_cast<FreeSpan *>(last);
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}
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uintptr_t arenaAddressUnchecked() const {
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return last & ~ArenaMask;
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}
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uintptr_t arenaAddress() const {
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checkSpan();
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return arenaAddressUnchecked();
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}
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ArenaHeader *arenaHeader() const {
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return reinterpret_cast<ArenaHeader *>(arenaAddress());
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}
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bool isSameNonEmptySpan(const FreeSpan *another) const {
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JS_ASSERT(!isEmpty());
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return start & ~ArenaMask;
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JS_ASSERT(!another->isEmpty());
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return first == another->first && last == another->last;
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}
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bool isWithinArena(uintptr_t arenaAddr) const {
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JS_ASSERT(!(arenaAddr & ArenaMask));
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/* Return true for the last empty span as well. */
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return arenaAddress() == arenaAddr;
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}
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size_t encodeAsOffsets() const {
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/*
|
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* We must use first - arenaAddress(), not first & ArenaMask as
|
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* first == ArenaMask + 1 for an empty span.
|
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*/
|
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uintptr_t arenaAddr = arenaAddress();
|
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return encodeOffsets(first - arenaAddr, last & ArenaMask);
|
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}
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|
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/* See comments before FreeSpan for details. */
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JS_ALWAYS_INLINE void *allocate(size_t thingSize) {
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JS_ASSERT(thingSize % Cell::CellSize == 0);
|
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checkSpan();
|
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uintptr_t thing = first;
|
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if (thing < last) {
|
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/* Bump-allocate from the current span. */
|
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first = thing + thingSize;
|
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} else if (JS_LIKELY(thing == last)) {
|
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/*
|
||||
* Move to the next span. We use JS_LIKELY as without PGO
|
||||
* compilers mis-predict == here as unlikely to succeed.
|
||||
*/
|
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*this = *reinterpret_cast<FreeSpan *>(thing);
|
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} else {
|
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return NULL;
|
||||
}
|
||||
checkSpan();
|
||||
return reinterpret_cast<void *>(thing);
|
||||
}
|
||||
|
||||
void checkSpan() const {
|
||||
#ifdef DEBUG
|
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JS_ASSERT(start <= end);
|
||||
JS_ASSERT(end - start <= ArenaSize);
|
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if (!(start & ArenaMask)) {
|
||||
/* The span is last and empty. */
|
||||
JS_ASSERT(start == end);
|
||||
/* We do not allow spans at the end of the address space. */
|
||||
JS_ASSERT(last != uintptr_t(-1));
|
||||
JS_ASSERT(first);
|
||||
JS_ASSERT(last);
|
||||
JS_ASSERT(first - 1 <= last);
|
||||
uintptr_t arenaAddr = arenaAddressUnchecked();
|
||||
if (last & 1) {
|
||||
/* The span is the last. */
|
||||
JS_ASSERT((last & ArenaMask) == ArenaMask);
|
||||
|
||||
if (first - 1 == last) {
|
||||
/* The span is last and empty. The above start != 0 check
|
||||
* implies that we are not at the end of the address space.
|
||||
*/
|
||||
return;
|
||||
}
|
||||
size_t spanLength = last - first + 1;
|
||||
JS_ASSERT(spanLength % Cell::CellSize == 0);
|
||||
|
||||
/* Start and end must belong to the same arena. */
|
||||
JS_ASSERT((first & ~ArenaMask) == arenaAddr);
|
||||
return;
|
||||
}
|
||||
|
||||
JS_ASSERT(start);
|
||||
JS_ASSERT(end);
|
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uintptr_t arena = start & ~ArenaMask;
|
||||
if (!(end & ArenaMask)) {
|
||||
/* The last span with few free things at the end of the arena. */
|
||||
JS_ASSERT(arena + ArenaSize == end);
|
||||
return;
|
||||
}
|
||||
/* The span is not the last and we have more spans to follow. */
|
||||
JS_ASSERT(first <= last);
|
||||
size_t spanLengthWithoutOneThing = last - first;
|
||||
JS_ASSERT(spanLengthWithoutOneThing % Cell::CellSize == 0);
|
||||
|
||||
/* The span is not last and we have at least one span that follows it.*/
|
||||
JS_ASSERT(arena == (end & ~ArenaMask));
|
||||
FreeSpan *next = reinterpret_cast<FreeSpan *>(end);
|
||||
JS_ASSERT((first & ~ArenaMask) == arenaAddr);
|
||||
|
||||
/*
|
||||
* If there is not enough space before the arena end to allocate one
|
||||
* more thing, then the span must be marked as the last one to avoid
|
||||
* storing useless empty span reference.
|
||||
*/
|
||||
size_t beforeTail = ArenaSize - (last & ArenaMask);
|
||||
JS_ASSERT(beforeTail >= sizeof(FreeSpan) + Cell::CellSize);
|
||||
|
||||
FreeSpan *next = reinterpret_cast<FreeSpan *>(last);
|
||||
|
||||
/*
|
||||
* The GC things on the list of free spans come from one arena
|
||||
* and the spans are linked in ascending address order with
|
||||
* at least one non-free thing between spans.
|
||||
*/
|
||||
JS_ASSERT(end < next->start);
|
||||
JS_ASSERT(last < next->first);
|
||||
JS_ASSERT(arenaAddr == next->arenaAddressUnchecked());
|
||||
|
||||
if (!(next->start & ArenaMask)) {
|
||||
if (next->first > next->last) {
|
||||
/*
|
||||
* The next span is the empty span that terminates the list for
|
||||
* arenas that do not have any free things at the end.
|
||||
*/
|
||||
JS_ASSERT(next->start == next->end);
|
||||
JS_ASSERT(arena + ArenaSize == next->start);
|
||||
} else {
|
||||
/* The next spans is not empty and must starts inside the arena. */
|
||||
JS_ASSERT(arena == (next->start & ~ArenaMask));
|
||||
JS_ASSERT(next->first - 1 == next->last);
|
||||
JS_ASSERT(arenaAddr + ArenaSize == next->first);
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
};
|
||||
|
||||
/* Every arena has a header. */
|
||||
|
|
@ -231,12 +352,9 @@ struct ArenaHeader {
|
|||
/*
|
||||
* The first span of free things in the arena. We encode it as the start
|
||||
* and end offsets within the arena, not as FreeSpan structure, to
|
||||
* minimize the header size. When the arena has no free things, the span
|
||||
* must be the empty one pointing to the arena's end. For such a span the
|
||||
* start and end offsets must be ArenaSize.
|
||||
* minimize the header size.
|
||||
*/
|
||||
uint16_t firstFreeSpanStart;
|
||||
uint16_t firstFreeSpanEnd;
|
||||
size_t firstFreeSpanOffsets;
|
||||
|
||||
/*
|
||||
* One of FinalizeKind constants or FINALIZE_LIMIT when the arena does not
|
||||
|
|
@ -263,8 +381,12 @@ struct ArenaHeader {
|
|||
|
||||
inline void init(JSCompartment *comp, unsigned thingKind, size_t thingSize);
|
||||
|
||||
uintptr_t arenaAddress() const {
|
||||
return address();
|
||||
}
|
||||
|
||||
Arena *getArena() {
|
||||
return reinterpret_cast<Arena *>(address());
|
||||
return reinterpret_cast<Arena *>(arenaAddress());
|
||||
}
|
||||
|
||||
unsigned getThingKind() const {
|
||||
|
|
@ -273,26 +395,23 @@ struct ArenaHeader {
|
|||
}
|
||||
|
||||
bool hasFreeThings() const {
|
||||
return firstFreeSpanStart != ArenaSize;
|
||||
return firstFreeSpanOffsets != FreeSpan::EmptyOffsets;
|
||||
}
|
||||
|
||||
void setAsFullyUsed() {
|
||||
firstFreeSpanStart = firstFreeSpanEnd = uint16_t(ArenaSize);
|
||||
firstFreeSpanOffsets = FreeSpan::EmptyOffsets;
|
||||
}
|
||||
|
||||
FreeSpan getFirstFreeSpan() const {
|
||||
#ifdef DEBUG
|
||||
checkSynchronizedWithFreeList();
|
||||
#endif
|
||||
return FreeSpan(address() + firstFreeSpanStart, address() + firstFreeSpanEnd);
|
||||
return FreeSpan::decodeOffsets(arenaAddress(), firstFreeSpanOffsets);
|
||||
}
|
||||
|
||||
void setFirstFreeSpan(const FreeSpan *span) {
|
||||
span->checkSpan();
|
||||
JS_ASSERT(span->start - address() <= ArenaSize);
|
||||
JS_ASSERT(span->end - address() <= ArenaSize);
|
||||
firstFreeSpanStart = uint16_t(span->start - address());
|
||||
firstFreeSpanEnd = uint16_t(span->end - address());
|
||||
JS_ASSERT(span->isWithinArena(arenaAddress()));
|
||||
firstFreeSpanOffsets = span->encodeAsOffsets();
|
||||
}
|
||||
|
||||
inline MarkingDelay *getMarkingDelay() const;
|
||||
|
|
@ -549,8 +668,7 @@ ArenaHeader::init(JSCompartment *comp, unsigned kind, size_t thingSize)
|
|||
JS_ASSERT(!getMarkingDelay()->link);
|
||||
compartment = comp;
|
||||
thingKind = kind;
|
||||
firstFreeSpanStart = uint16_t(Arena::thingsStartOffset(thingSize));
|
||||
firstFreeSpanEnd = uint16_t(ArenaSize);
|
||||
firstFreeSpanOffsets = FreeSpan::encodeOffsets(Arena::thingsStartOffset(thingSize));
|
||||
}
|
||||
|
||||
inline uintptr_t
|
||||
|
|
@ -806,7 +924,7 @@ struct FreeLists {
|
|||
|
||||
void init() {
|
||||
for (size_t i = 0; i != JS_ARRAY_LENGTH(lists); ++i)
|
||||
lists[i].start = lists[i].end = 0;
|
||||
lists[i].initAsEmpty();
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -817,10 +935,10 @@ struct FreeLists {
|
|||
for (size_t i = 0; i != size_t(FINALIZE_LIMIT); ++i) {
|
||||
FreeSpan *list = &lists[i];
|
||||
if (!list->isEmpty()) {
|
||||
ArenaHeader *aheader = reinterpret_cast<Cell *>(list->start)->arenaHeader();
|
||||
ArenaHeader *aheader = list->arenaHeader();
|
||||
JS_ASSERT(!aheader->hasFreeThings());
|
||||
aheader->setFirstFreeSpan(list);
|
||||
list->start = list->end = 0;
|
||||
list->initAsEmpty();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -834,7 +952,7 @@ struct FreeLists {
|
|||
for (size_t i = 0; i != size_t(FINALIZE_LIMIT); ++i) {
|
||||
FreeSpan *list = &lists[i];
|
||||
if (!list->isEmpty()) {
|
||||
ArenaHeader *aheader = reinterpret_cast<Cell *>(list->start)->arenaHeader();
|
||||
ArenaHeader *aheader = list->arenaHeader();
|
||||
JS_ASSERT(!aheader->hasFreeThings());
|
||||
aheader->setFirstFreeSpan(list);
|
||||
}
|
||||
|
|
@ -849,47 +967,22 @@ struct FreeLists {
|
|||
for (size_t i = 0; i != size_t(FINALIZE_LIMIT); ++i) {
|
||||
FreeSpan *list = &lists[i];
|
||||
if (!list->isEmpty()) {
|
||||
ArenaHeader *aheader = reinterpret_cast<Cell *>(list->start)->arenaHeader();
|
||||
#ifdef DEBUG
|
||||
FreeSpan span(aheader->getFirstFreeSpan());
|
||||
JS_ASSERT(span.start == list->start);
|
||||
JS_ASSERT(span.end == list->end);
|
||||
#endif
|
||||
ArenaHeader *aheader = list->arenaHeader();
|
||||
JS_ASSERT(aheader->getFirstFreeSpan().isSameNonEmptySpan(list));
|
||||
aheader->setAsFullyUsed();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
JS_ALWAYS_INLINE Cell *getNext(unsigned thingKind, size_t thingSize) {
|
||||
FreeSpan *list = &lists[thingKind];
|
||||
list->checkSpan();
|
||||
uintptr_t thing = list->start;
|
||||
if (thing != list->end) {
|
||||
/*
|
||||
* We either have at least one thing in the span that ends the
|
||||
* arena list or we have at least two things in the non-last span.
|
||||
* In both cases we just need to bump the start pointer to account
|
||||
* for the allocation.
|
||||
*/
|
||||
list->start += thingSize;
|
||||
JS_ASSERT(list->start <= list->end);
|
||||
} else if (thing & ArenaMask) {
|
||||
/*
|
||||
* The thing points to the last thing in the span that has at
|
||||
* least one more span to follow. Return the thing and update
|
||||
* the list with that next span.
|
||||
*/
|
||||
*list = *list->nextSpan();
|
||||
} else {
|
||||
return NULL;
|
||||
}
|
||||
return reinterpret_cast<Cell *>(thing);
|
||||
JS_ALWAYS_INLINE void *getNext(unsigned thingKind, size_t thingSize) {
|
||||
return lists[thingKind].allocate(thingSize);
|
||||
}
|
||||
|
||||
Cell *populate(ArenaHeader *aheader, unsigned thingKind, size_t thingSize) {
|
||||
lists[thingKind] = aheader->getFirstFreeSpan();
|
||||
void *populate(ArenaHeader *aheader, unsigned thingKind, size_t thingSize) {
|
||||
FreeSpan *list = &lists[thingKind];
|
||||
*list = aheader->getFirstFreeSpan();
|
||||
aheader->setAsFullyUsed();
|
||||
Cell *t = getNext(thingKind, thingSize);
|
||||
void *t = list->allocate(thingSize);
|
||||
JS_ASSERT(t);
|
||||
return t;
|
||||
}
|
||||
|
|
@ -902,7 +995,7 @@ struct FreeLists {
|
|||
}
|
||||
};
|
||||
|
||||
extern Cell *
|
||||
extern void *
|
||||
RefillFinalizableFreeList(JSContext *cx, unsigned thingKind);
|
||||
|
||||
} /* namespace gc */
|
||||
|
|
|
|||
|
|
@ -203,8 +203,8 @@ NewGCThing(JSContext *cx, unsigned thingKind, size_t thingSize)
|
|||
js::gc::RunDebugGC(cx);
|
||||
#endif
|
||||
|
||||
js::gc::Cell *cell = cx->compartment->freeLists.getNext(thingKind, thingSize);
|
||||
return static_cast<T *>(cell ? cell : js::gc::RefillFinalizableFreeList(cx, thingKind));
|
||||
void *t = cx->compartment->freeLists.getNext(thingKind, thingSize);
|
||||
return static_cast<T *>(t ? t : js::gc::RefillFinalizableFreeList(cx, thingKind));
|
||||
}
|
||||
|
||||
inline JSObject *
|
||||
|
|
|
|||
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