void HandleSet::writeBarrier(HandleSlot slot, const JSValue& value)
{
// Forbid assignment to handles during the finalization phase, since it would violate many GC invariants.
// File a bug with stack trace if you hit this.
if (m_nextToFinalize)
CRASH();
if (!value == !*slot && slot->isCell() == value.isCell())
return;
Node* node = toNode(slot);
#if ENABLE(GC_VALIDATION)
if (!isLiveNode(node))
CRASH();
#endif
SentinelLinkedList<Node>::remove(node);
if (!value || !value.isCell()) {
m_immediateList.push(node);
return;
}
m_strongList.push(node);
#if ENABLE(GC_VALIDATION)
if (!isLiveNode(node))
CRASH();
#endif
}
void HandleHeap::finalizeWeakHandles()
{
Node* end = m_weakList.end();
for (Node* node = m_weakList.begin(); node != end; node = m_nextToFinalize) {
m_nextToFinalize = node->next();
#if ENABLE(GC_VALIDATION)
if (!isValidWeakNode(node))
CRASH();
#endif
JSCell* cell = node->slot()->asCell();
if (Heap::isMarked(cell))
continue;
if (WeakHandleOwner* weakOwner = node->weakOwner()) {
weakOwner->finalize(Handle<Unknown>::wrapSlot(node->slot()), node->weakOwnerContext());
if (m_nextToFinalize != node->next()) // Owner deallocated node.
continue;
}
#if ENABLE(GC_VALIDATION)
if (!isLiveNode(node))
CRASH();
#endif
*node->slot() = JSValue();
SentinelLinkedList<Node>::remove(node);
m_immediateList.push(node);
}
m_nextToFinalize = 0;
}
void HandleSet::visitStrongHandles(HeapRootVisitor& heapRootVisitor)
{
Node* end = m_strongList.end();
for (Node* node = m_strongList.begin(); node != end; node = node->next()) {
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
heapRootVisitor.visit(node->slot());
}
}
void HandleSet::visitStrongHandles(SlotVisitor& visitor)
{
Node* end = m_strongList.end();
for (Node* node = m_strongList.begin(); node != end; node = node->next()) {
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
visitor.appendUnbarriered(*node->slot());
}
}
void HandleSet::writeBarrier(HandleSlot slot, const JSValue& value)
{
if (!value == !*slot && slot->isCell() == value.isCell())
return;
Node* node = toNode(slot);
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
SentinelLinkedList<Node>::remove(node);
if (!value || !value.isCell()) {
m_immediateList.push(node);
return;
}
m_strongList.push(node);
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
}
bool HandleHeap::isValidWeakNode(Node* node)
{
if (!isLiveNode(node))
return false;
if (!node->isWeak())
return false;
JSValue value = *node->slot();
if (!value || !value.isCell())
return false;
JSCell* cell = value.asCell();
if (!cell || !cell->structure())
return false;
return true;
}