1 files changed, 69 insertions, 12 deletions
diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/parser/ParserArena.cpp b/src/3rdparty/javascriptcore/JavaScriptCore/parser/ParserArena.cpp
index 78c5196a92..6a2af8335c 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/parser/ParserArena.cpp
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/parser/ParserArena.cpp
@@ -31,9 +31,39 @@
 
 namespace JSC {
 
+ParserArena::ParserArena()
+    : m_freeableMemory(0)
+    , m_freeablePoolEnd(0)
+    , m_identifierArena(new IdentifierArena)
+{
+}
+
+inline void* ParserArena::freeablePool()
+{
+    ASSERT(m_freeablePoolEnd);
+    return m_freeablePoolEnd - freeablePoolSize;
+}
+
+inline void ParserArena::deallocateObjects()
+{
+    if (m_freeablePoolEnd)
+        fastFree(freeablePool());
+
+    size_t size = m_freeablePools.size();
+    for (size_t i = 0; i < size; ++i)
+        fastFree(m_freeablePools[i]);
+
+    size = m_deletableObjects.size();
+    for (size_t i = 0; i < size; ++i) {
+        ParserArenaDeletable* object = m_deletableObjects[i];
+        object->~ParserArenaDeletable();
+        fastFree(object);
+    }
+}
+
 ParserArena::~ParserArena()
 {
-    deleteAllValues(m_deletableObjects);
+    deallocateObjects();
 }
 
 bool ParserArena::contains(ParserArenaRefCounted* object) const
@@ -53,26 +83,53 @@ void ParserArena::removeLast()
 
 void ParserArena::reset()
 {
-    deleteAllValues(m_deletableObjects);
-    m_deletableObjects.shrink(0);
-    m_refCountedObjects.shrink(0);
+    // Since this code path is used only when parsing fails, it's not bothering to reuse
+    // any of the memory the arena allocated. We could improve that later if we want to
+    // efficiently reuse the same arena.
+
+    deallocateObjects();
+
+    m_freeableMemory = 0;
+    m_freeablePoolEnd = 0;
+    m_identifierArena->clear();
+    m_freeablePools.clear();
+    m_deletableObjects.clear();
+    m_refCountedObjects.clear();
 }
 
-void* ParserArenaDeletable::operator new(size_t size, JSGlobalData* globalData)
+void ParserArena::allocateFreeablePool()
 {
-    ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(fastMalloc(size));
-    globalData->parser->arena().deleteWithArena(deletable);
-    return deletable;
+    if (m_freeablePoolEnd)
+        m_freeablePools.append(freeablePool());
+
+    char* pool = static_cast<char*>(fastMalloc(freeablePoolSize));
+    m_freeableMemory = pool;
+    m_freeablePoolEnd = pool + freeablePoolSize;
+    ASSERT(freeablePool() == pool);
 }
 
-void* ParserArenaDeletable::operator new(size_t size)
+bool ParserArena::isEmpty() const
 {
-    return fastMalloc(size);
+    return !m_freeablePoolEnd
+        && m_identifierArena->isEmpty()
+        && m_freeablePools.isEmpty()
+        && m_deletableObjects.isEmpty()
+        && m_refCountedObjects.isEmpty();
 }
 
-void ParserArenaDeletable::operator delete(void* p)
+void ParserArena::derefWithArena(PassRefPtr<ParserArenaRefCounted> object)
+{
+    m_refCountedObjects.append(object);
+}
+
+void* ParserArenaFreeable::operator new(size_t size, JSGlobalData* globalData)
+{
+    return globalData->parser->arena().allocateFreeable(size);
+}
+
+void* ParserArenaDeletable::operator new(size_t size, JSGlobalData* globalData)
 {
-    fastFree(p);
+    return globalData->parser->arena().allocateDeletable(size);
 }
 
 }