Changeset 29425 in webkit for trunk/JavaScriptCore/kjs/JSGlobalObject.cpp

Timestamp:

Jan 11, 2008, 6:08:50 PM (17 years ago)

Author:

[email protected]

Message:

JavaScriptCore:

Reviewed by Maciej.

Optimized ActivationImp allocation, so that activation records are now
first allocated on an explicitly managed stack and only heap allocated
when necessary. Roughly a 5% improvement on SunSpider, and a larger
improvement on benchmarks that use more function calls.

• JavaScriptCore.xcodeproj/project.pbxproj:
• kjs/Activation.h: Added. (KJS::ActivationImp::ActivationData::ActivationData): (KJS::ActivationImp::ActivationImp): (KJS::ActivationImp::classInfo): (KJS::ActivationImp::isActivationObject): (KJS::ActivationImp::isOnStack): (KJS::ActivationImp::d): (KJS::StackActivation::StackActivation):
• kjs/ExecState.cpp: (KJS::ExecState::ExecState): (KJS::ExecState::~ExecState):
• kjs/ExecState.h: (KJS::ExecState::replaceScopeChainTop): (KJS::ExecState::setActivationObject): (KJS::ExecState::setLocalStorage):
• kjs/JSGlobalObject.cpp: (KJS::JSGlobalObject::reset): (KJS::JSGlobalObject::pushActivation): (KJS::JSGlobalObject::checkActivationCount): (KJS::JSGlobalObject::popActivationHelper): (KJS::JSGlobalObject::popActivation): (KJS::JSGlobalObject::tearOffActivation):
• kjs/JSGlobalObject.h:
• kjs/JSVariableObject.h: (KJS::JSVariableObject::JSVariableObjectData::JSVariableObjectData): (KJS::JSVariableObject::JSVariableObject):
• kjs/function.cpp: (KJS::FunctionImp::argumentsGetter): (KJS::ActivationImp::ActivationImp): (KJS::ActivationImp::~ActivationImp): (KJS::ActivationImp::init): (KJS::ActivationImp::getOwnPropertySlot): (KJS::ActivationImp::markHelper): (KJS::ActivationImp::mark): (KJS::ActivationImp::ActivationData::ActivationData): (KJS::GlobalFuncImp::callAsFunction):
• kjs/function.h:
• kjs/nodes.cpp: (KJS::PostIncResolveNode::evaluate): (KJS::PostDecResolveNode::evaluate): (KJS::PreIncResolveNode::evaluate): (KJS::PreDecResolveNode::evaluate): (KJS::ReadModifyResolveNode::evaluate): (KJS::AssignResolveNode::evaluate): (KJS::WithNode::execute): (KJS::TryNode::execute): (KJS::FunctionBodyNode::processDeclarations): (KJS::FuncExprNode::evaluate):
• kjs/object.h:
• kjs/scope_chain.h: (KJS::ScopeChain::replace):
• kjs/scope_chain_mark.h: Added. (KJS::ScopeChain::mark):

WebCore:

Reviewed by Maciej.

Added a new forwarding header, because Activation.h has been separated
from function.h

• ForwardingHeaders/kjs/Activation.h: Added.

LayoutTests:

Reviewed by Maciej.

Added a test case that came up when developing the ActivationImp tear-off.

• fast/js/resources/vardecl-preserve-arguments.js:
• fast/js/vardecl-preserve-arguments-expected.txt:

File:

• trunk/JavaScriptCore/kjs/JSGlobalObject.cpp (modified) (5 diffs)

trunk/JavaScriptCore/kjs/JSGlobalObject.cpp

@@ -1 +1 @@
 /*
  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich ([email protected])
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30 +31 @@
 #include "JSGlobalObject.h"
 
-#include "SavedBuiltins.h"
+#include "Activation.h"
 #include "array_object.h"
 #include "bool_object.h"
@@ -41 +42 @@
 #include "object_object.h"
 #include "regexp_object.h"
+#include "SavedBuiltins.h"
 #include "string_object.h"
 
@@ -201 +203 @@
     ExecState* exec = &d()->globalExec;
 
+    d()->activations = new ActivationStackNode;
+    d()->activationCount = 0;
+
     // Prototypes
     d()->functionPrototype = new FunctionPrototype(exec);
@@ -495 +500 @@
 }
 
+ActivationImp* JSGlobalObject::pushActivation(ExecState* exec)
+{
+    if (d()->activationCount == activationStackNodeSize) {
+        ActivationStackNode* newNode = new ActivationStackNode;
+        newNode->prev = d()->activations;
+        d()->activations = newNode;
+        d()->activationCount = 0;
+    }
+    
+    StackActivation* stackEntry = &d()->activations->data[d()->activationCount++];
+    stackEntry->activationStorage.init(exec);
+    
+    return &(stackEntry->activationStorage);
+}
+
+inline void JSGlobalObject::checkActivationCount()
+{
+    if (!d()->activationCount) {
+        ActivationStackNode* prev = d()->activations->prev;
+        delete d()->activations;
+        d()->activations = prev;
+        d()->activationCount = activationStackNodeSize;
+    }
+}
+
+void JSGlobalObject::popActivation()
+{
+    checkActivationCount();
+    d()->activations->data[--d()->activationCount].activationDataStorage.localStorage.shrink(0);    
+}
+
+void JSGlobalObject::tearOffActivation(ExecState* exec, bool leaveRelic)
+{
+    if (exec->codeType() == FunctionCode && static_cast<ActivationImp*>(exec->activationObject())->isOnStack()) {
+        ActivationImp* oldActivation = static_cast<ActivationImp*>(exec->activationObject());
+        ActivationImp* newActivation = new ActivationImp(*oldActivation->d(), leaveRelic);
+        
+        if (!leaveRelic) {
+            checkActivationCount();
+            d()->activationCount--;
+        }
+        
+        oldActivation->d()->localStorage.shrink(0);
+        
+        exec->setActivationObject(newActivation);
+        exec->setVariableObject(newActivation);
+        exec->setLocalStorage(&(newActivation->localStorage()));
+        exec->replaceScopeChainTop(newActivation);
+    }
+}
+
 } // namespace KJS