void
js::Nursery::collect(JSRuntime *rt, JS::gcreason::Reason reason)
{
JS_AbortIfWrongThread(rt);
if (rt->mainThread.suppressGC)
return;
if (!isEnabled())
return;
if (position() == start())
return;
rt->gcHelperThread.waitBackgroundSweepEnd();
AutoStopVerifyingBarriers av(rt, false);
/* Move objects pointed to by roots from the nursery to the major heap. */
MinorCollectionTracer trc(rt, this);
MarkRuntime(&trc);
Debugger::markAll(&trc);
for (CompartmentsIter comp(rt); !comp.done(); comp.next()) {
comp->markAllCrossCompartmentWrappers(&trc);
comp->markAllInitialShapeTableEntries(&trc);
}
markStoreBuffer(&trc);
rt->newObjectCache.clearNurseryObjects(rt);
/*
* Most of the work is done here. This loop iterates over objects that have
* been moved to the major heap. If these objects have any outgoing pointers
* to the nursery, then those nursery objects get moved as well, until no
* objects are left to move. That is, we iterate to a fixed point.
*/
for (RelocationOverlay *p = trc.head; p; p = p->next()) {
JSObject *obj = static_cast<JSObject*>(p->forwardingAddress());
JS_TraceChildren(&trc, obj, MapAllocToTraceKind(obj->tenuredGetAllocKind()));
}
/* Resize the nursery. */
double promotionRate = trc.tenuredSize / double(allocationEnd() - start());
if (promotionRate > 0.5)
growAllocableSpace();
else if (promotionRate < 0.1)
shrinkAllocableSpace();
/* Sweep. */
sweep(rt->defaultFreeOp());
rt->gcStoreBuffer.clear();
/*
* We ignore gcMaxBytes when allocating for minor collection. However, if we
* overflowed, we disable the nursery. The next time we allocate, we'll fail
* because gcBytes >= gcMaxBytes.
*/
if (rt->gcBytes >= rt->gcMaxBytes)
disable();
}
void
js::Nursery::collectToFixedPoint(MinorCollectionTracer *trc)
{
for (RelocationOverlay *p = trc->head; p; p = p->next()) {
JSObject *obj = static_cast<JSObject*>(p->forwardingAddress());
traceObject(trc, obj);
}
}
void
js::Nursery::collectToFixedPoint(MinorCollectionTracer *trc, TenureCountCache &tenureCounts)
{
for (RelocationOverlay *p = trc->head; p; p = p->next()) {
JSObject *obj = static_cast<JSObject*>(p->forwardingAddress());
traceObject(trc, obj);
TenureCount &entry = tenureCounts.findEntry(obj->type());
if (entry.type == obj->type()) {
entry.count++;
} else if (!entry.type) {
entry.type = obj->type();
entry.count = 1;
}
}
}
void *
ForkJoinNursery::moveObjectToTospace(JSObject *src)
{
AllocKind dstKind = getObjectAllocKind(src);
JSObject *dst = static_cast<JSObject *>(allocateInTospace(dstKind));
if (!dst)
CrashAtUnhandlableOOM("Failed to allocate object while moving object.");
movedSize_ += copyObjectToTospace(dst, src, dstKind);
RelocationOverlay *overlay = reinterpret_cast<RelocationOverlay *>(src);
overlay->forwardTo(dst);
insertIntoFixupList(overlay);
return static_cast<void *>(dst);
}
void *
js::Nursery::moveToTenured(MinorCollectionTracer *trc, JSObject *src)
{
Zone *zone = src->zone();
AllocKind dstKind = GetObjectAllocKindForCopy(trc->runtime(), src);
JSObject *dst = static_cast<JSObject *>(allocateFromTenured(zone, dstKind));
if (!dst)
CrashAtUnhandlableOOM("Failed to allocate object while tenuring.");
trc->tenuredSize += moveObjectToTenured(dst, src, dstKind);
RelocationOverlay *overlay = reinterpret_cast<RelocationOverlay *>(src);
overlay->forwardTo(dst);
trc->insertIntoFixupList(overlay);
return static_cast<void *>(dst);
}
void *
js::Nursery::moveToTenured(MinorCollectionTracer *trc, JSObject *src)
{
Zone *zone = src->zone();
AllocKind dstKind = GetObjectAllocKindForCopy(src);
JSObject *dst = static_cast<JSObject *>(allocateFromTenured(zone, dstKind));
if (!dst)
MOZ_CRASH();
moveObjectToTenured(dst, src, dstKind);
RelocationOverlay *overlay = reinterpret_cast<RelocationOverlay *>(src);
overlay->forwardTo(dst);
trc->insertIntoFixupList(overlay);
return static_cast<void *>(dst);
}
void
js::Nursery::collectToFixedPoint(MinorCollectionTracer *trc)
{
for (RelocationOverlay *p = trc->head; p; p = p->next()) {
JSObject *obj = static_cast<JSObject*>(p->forwardingAddress());
traceObject(trc, obj);
/*
* Increment tenure count and recompile the script for pre-tenuring if
* long-lived. Attempt to distinguish between tenuring because the
* object is long lived and tenuring while the nursery is still
* smaller than the working set size.
*/
if (isFullyGrown() && !obj->hasLazyType() && obj->type()->hasNewScript() &&
obj->type()->incrementTenureCount())
{
MaybeInvalidateScriptUsedWithNew(trc->runtime, obj->type());
}
}
}
void
ForkJoinNursery::collectToFixedPoint(ForkJoinNurseryCollectionTracer *trc)
{
for (RelocationOverlay *p = head_; p; p = p->next())
traceObject(trc, static_cast<JSObject *>(p->forwardingAddress()));
}
