Title: [295036] trunk/Source/_javascript_Core/heap
- Revision
- 295036
- Author
- ysuz...@apple.com
- Date
- 2022-05-30 16:41:10 -0700 (Mon, 30 May 2022)
Log Message
[JSC] Make Strong::set cheap
https://bugs.webkit.org/show_bug.cgi?id=241090
Reviewed by Mark Lam.
HandleSet::writeBarrier is frequently called because it is called every time we set a value in Strong<>.
This patch optimizes it,
1. We should make it inline function since it has a super fast path major use can be covered. And this function is small.
2. We should not always remove a node from the list first. We should insert / remove it only when necessary.
3. Remove m_immediateList since it is not necessary.
4. Make HandleNode as a derived class of BasicRawSentinelNode to make implementation simpler.
This change improves promise benchmarks score since promise uses microtasks which hold values via Strong<>.
ToT
Time(doxbee-async-bluebird): 42.8 ms.
Time(doxbee-async-es2017-babel): 36.4 ms.
Time(doxbee-async-es2017-native): 28.3 ms.
Time(doxbee-promises-bluebird): 514.2 ms.
Time(doxbee-promises-es2015-native): 44.8 ms.
Time(fibonacci-async-es2017-babel): 380.5 ms.
Time(fibonacci-async-es2017-native): 218.2 ms.
Time(parallel-async-bluebird): 648.8 ms.
Time(parallel-async-es2017-babel): 116.9 ms.
Time(parallel-async-es2017-native): 115.6 ms.
Time(parallel-promises-bluebird): 638 ms.
Time(parallel-promises-es2015-native): 82 ms.
Patched
Time(doxbee-async-bluebird): 38 ms.
Time(doxbee-async-es2017-babel): 27 ms.
Time(doxbee-async-es2017-native): 19.5 ms.
Time(doxbee-promises-bluebird): 508.3 ms.
Time(doxbee-promises-es2015-native): 33.3 ms.
Time(fibonacci-async-es2017-babel): 349.1 ms.
Time(fibonacci-async-es2017-native): 151 ms.
Time(parallel-async-bluebird): 639.6 ms.
Time(parallel-async-es2017-babel): 100.9 ms.
Time(parallel-async-es2017-native): 101.9 ms.
Time(parallel-promises-bluebird): 614 ms.
Time(parallel-promises-es2015-native): 70.9 ms.
* Source/_javascript_Core/heap/HandleSet.cpp:
(JSC::HandleSet::writeBarrier): Deleted.
* Source/_javascript_Core/heap/HandleSet.h:
(JSC::HandleSet::heapFor):
(JSC::HandleSet::allocate):
(JSC::HandleSet::deallocate):
(JSC::HandleSet::writeBarrier):
(JSC::HandleSet::toHandle): Deleted.
(JSC::HandleSet::toNode): Deleted.
(JSC::HandleNode::HandleNode): Deleted.
(JSC::HandleNode::setPrev): Deleted.
(JSC::HandleNode::prev): Deleted.
(JSC::HandleNode::setNext): Deleted.
(JSC::HandleNode::next): Deleted.
* Source/_javascript_Core/heap/Strong.h:
(JSC::Strong::set):
Canonical link: https://commits.webkit.org/251131@main
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/heap/HandleSet.cpp (295035 => 295036)
--- trunk/Source/_javascript_Core/heap/HandleSet.cpp 2022-05-30 22:10:58 UTC (rev 295035)
+++ trunk/Source/_javascript_Core/heap/HandleSet.cpp 2022-05-30 23:41:10 UTC (rev 295036)
@@ -70,27 +70,6 @@
template void HandleSet::visitStrongHandles(AbstractSlotVisitor&);
template void HandleSet::visitStrongHandles(SlotVisitor&);
-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
-}
-
unsigned HandleSet::protectedGlobalObjectCount()
{
unsigned count = 0;
Modified: trunk/Source/_javascript_Core/heap/HandleSet.h (295035 => 295036)
--- trunk/Source/_javascript_Core/heap/HandleSet.h 2022-05-30 22:10:58 UTC (rev 295035)
+++ trunk/Source/_javascript_Core/heap/HandleSet.h 2022-05-30 23:41:10 UTC (rev 295036)
@@ -39,24 +39,20 @@
class VM;
class JSValue;
-class HandleNode {
+class HandleNode final : public BasicRawSentinelNode<HandleNode> {
public:
- HandleNode(WTF::SentinelTag);
- HandleNode();
+ HandleNode() = default;
HandleSlot slot();
HandleSet* handleSet();
- void setPrev(HandleNode*);
- HandleNode* prev();
+ static HandleNode* toHandleNode(HandleSlot slot)
+ {
+ return bitwise_cast<HandleNode*>(bitwise_cast<uintptr_t>(slot) - OBJECT_OFFSETOF(HandleNode, m_value));
+ }
- void setNext(HandleNode*);
- HandleNode* next();
-
private:
- JSValue m_value;
- HandleNode* m_prev;
- HandleNode* m_next;
+ JSValue m_value { };
};
class HandleSet {
@@ -74,7 +70,8 @@
template<typename Visitor> void visitStrongHandles(Visitor&);
- JS_EXPORT_PRIVATE void writeBarrier(HandleSlot, const JSValue&);
+ template<bool isCellOnly>
+ void writeBarrier(HandleSlot, JSValue);
unsigned protectedGlobalObjectCount();
@@ -82,26 +79,24 @@
private:
typedef HandleNode Node;
- static HandleSlot toHandle(Node*);
- static Node* toNode(HandleSlot);
JS_EXPORT_PRIVATE void grow();
#if ENABLE(GC_VALIDATION) || ASSERT_ENABLED
- bool isLiveNode(Node*);
+ JS_EXPORT_PRIVATE bool isLiveNode(Node*);
#endif
VM& m_vm;
DoublyLinkedList<HandleBlock> m_blockList;
- SentinelLinkedList<Node> m_strongList;
- SentinelLinkedList<Node> m_immediateList;
+ using NodeList = SentinelLinkedList<Node, BasicRawSentinelNode<Node>>;
+ NodeList m_strongList;
SinglyLinkedList<Node> m_freeList;
};
inline HandleSet* HandleSet::heapFor(HandleSlot handle)
{
- return toNode(handle)->handleSet();
+ return HandleNode::toHandleNode(handle)->handleSet();
}
inline VM& HandleSet::vm()
@@ -109,16 +104,6 @@
return m_vm;
}
-inline HandleSlot HandleSet::toHandle(HandleSet::Node* node)
-{
- return reinterpret_cast<HandleSlot>(node);
-}
-
-inline HandleSet::Node* HandleSet::toNode(HandleSlot handle)
-{
- return reinterpret_cast<HandleSet::Node*>(handle);
-}
-
inline HandleSlot HandleSet::allocate()
{
if (m_freeList.isEmpty())
@@ -126,29 +111,17 @@
HandleSet::Node* node = m_freeList.pop();
new (NotNull, node) HandleSet::Node();
- m_immediateList.push(node);
- return toHandle(node);
+ return node->slot();
}
inline void HandleSet::deallocate(HandleSlot handle)
{
- HandleSet::Node* node = toNode(handle);
- SentinelLinkedList<HandleSet::Node>::remove(node);
+ HandleSet::Node* node = HandleNode::toHandleNode(handle);
+ if (node->isOnList())
+ NodeList::remove(node);
m_freeList.push(node);
}
-inline HandleNode::HandleNode()
- : m_prev(nullptr)
- , m_next(nullptr)
-{
-}
-
-inline HandleNode::HandleNode(WTF::SentinelTag)
- : m_prev(nullptr)
- , m_next(nullptr)
-{
-}
-
inline HandleSlot HandleNode::slot()
{
return &m_value;
@@ -159,26 +132,6 @@
return HandleBlock::blockFor(this)->handleSet();
}
-inline void HandleNode::setPrev(HandleNode* prev)
-{
- m_prev = prev;
-}
-
-inline HandleNode* HandleNode::prev()
-{
- return m_prev;
-}
-
-inline void HandleNode::setNext(HandleNode* next)
-{
- m_next = next;
-}
-
-inline HandleNode* HandleNode::next()
-{
- return m_next;
-}
-
template<typename Functor> void HandleSet::forEachStrongHandle(const Functor& functor, const HashCountedSet<JSCell*>& skipSet)
{
for (Node& node : m_strongList) {
@@ -191,4 +144,33 @@
}
}
+template<bool isCellOnly>
+inline void HandleSet::writeBarrier(HandleSlot slot, JSValue value)
+{
+ bool valueIsNonEmptyCell = value && (isCellOnly || value.isCell());
+ bool slotIsNonEmptyCell = *slot && (isCellOnly || slot->isCell());
+ if (valueIsNonEmptyCell == slotIsNonEmptyCell)
+ return;
+
+ Node* node = HandleNode::toHandleNode(slot);
+#if ENABLE(GC_VALIDATION)
+ if (node->isOnList())
+ RELEASE_ASSERT(isLiveNode(node));
+#endif
+ if (!valueIsNonEmptyCell) {
+ ASSERT(slotIsNonEmptyCell);
+ ASSERT(node->isOnList());
+ NodeList::remove(node);
+ return;
+ }
+
+ ASSERT(!slotIsNonEmptyCell);
+ ASSERT(!node->isOnList());
+ m_strongList.push(node);
+
+#if ENABLE(GC_VALIDATION)
+ RELEASE_ASSERT(isLiveNode(node));
+#endif
+}
+
} // namespace JSC
Modified: trunk/Source/_javascript_Core/heap/Strong.h (295035 => 295036)
--- trunk/Source/_javascript_Core/heap/Strong.h 2022-05-30 22:10:58 UTC (rev 295035)
+++ trunk/Source/_javascript_Core/heap/Strong.h 2022-05-30 23:41:10 UTC (rev 295036)
@@ -141,7 +141,7 @@
{
ASSERT(slot());
JSValue value = HandleTypes<T>::toJSValue(externalType);
- HandleSet::heapFor(slot())->writeBarrier(slot(), value);
+ HandleSet::heapFor(slot())->template writeBarrier<std::is_base_of_v<JSCell, T>>(slot(), value);
*slot() = value;
}
};
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