Changeset 32819 in webkit for trunk/JavaScriptCore/kjs

Timestamp:

May 2, 2008, 11:10:33 AM (17 years ago)

Author:

[email protected]

Message:

Reviewed by Darin.

Move call stack depth counter to global object.

• kjs/ExecState.h: (KJS::ExecState::functionCallDepth): Added a recursion depth counter to per-thread data.
• kjs/JSGlobalObject.cpp: (KJS::JSGlobalObject::init): Initialize PerThreadData.functionCallDepth.
• kjs/JSGlobalObject.h: (KJS::JSGlobalObject::perThreadData): Made the result non-const.

• kjs/object.cpp: (KJS::throwStackSizeExceededError): Moved throwError to a separate function, since it is now the only thing in JSObject::call that needs a PIC branch. (KJS::JSObject::call): Use a per-thread variable instead of local static for recursion depth tracking.

Location:

trunk/JavaScriptCore/kjs

Files:

• ExecState.h (modified) (3 diffs)
• JSGlobalObject.cpp (modified) (1 diff)
• JSGlobalObject.h (modified) (1 diff)
• object.cpp (modified) (3 diffs)

trunk/JavaScriptCore/kjs/ExecState.h

@@ -61 +61 @@
         
         Heap* heap;
+
+        unsigned functionCallDepth;
     };
 
@@ -125 +127 @@
         Heap* heap() const { return m_perThreadData->heap; }
 
+        unsigned& functionCallDepth() { return m_perThreadData->functionCallDepth; }
+
         LocalStorage& localStorage() { return *m_localStorage; }
         void setLocalStorage(LocalStorage* s) { m_localStorage = s; }
@@ -205 +209 @@
         ExecState* m_callingExec;
 
-        const PerThreadData* m_perThreadData;
+        PerThreadData* m_perThreadData;
 
         ScopeNode* m_scopeNode;

trunk/JavaScriptCore/kjs/JSGlobalObject.cpp

@@ -231 +231 @@
     d()->perThreadData.propertyNames = CommonIdentifiers::shared();
     d()->perThreadData.heap = Heap::threadHeap();
+    d()->perThreadData.functionCallDepth = 0;
 
     d()->globalExec.set(new GlobalExecState(this, thisValue));

trunk/JavaScriptCore/kjs/JSGlobalObject.h

@@ -251 +251 @@
 
         // Per-thread hash tables, cached on the global object for faster access.
-        const PerThreadData* perThreadData() const { return &d()->perThreadData; }
+        PerThreadData* perThreadData() { return &d()->perThreadData; }
 
         // Initialize and/or retrieve per-thread hash tables - use perThreadData() for faster access instead.

trunk/JavaScriptCore/kjs/object.cpp

@@ -64 +64 @@
 // ------------------------------ Object ---------------------------------------
 
+JSValue* NEVER_INLINE throwStackSizeExceededError(ExecState* exec)
+{
+    // This function takes a PIC branch to access a string literal, so moving it out of JSObject::call() improves performance.
+    return throwError(exec, RangeError, "Maximum call stack size exceeded.");
+}
+
 JSValue *JSObject::call(ExecState *exec, JSObject *thisObj, const List &args)
 {
@@ -69 +75 @@
 
 #if KJS_MAX_STACK > 0
-  static int depth = 0; // sum of all extant function calls
-
 #if JAVASCRIPT_CALL_TRACING
     static bool tracing = false;
@@ -87 +91 @@
 #endif
 
+  unsigned& depth = exec->functionCallDepth();
   if (++depth > KJS_MAX_STACK) {
+    // FIXME: secondary threads probably need a different limit than main thread.
+    // Ideally, the limit should be calculated from available stack space, and not just hardcoded.
     --depth;
-    return throwError(exec, RangeError, "Maximum call stack size exceeded.");
+    return throwStackSizeExceededError(exec);
   }
 #endif