bug 216112, "add ability to disable object tracking in jsd"

r=caillon, sr=brendan, a=asa

adds the ability to turn off the object tracking without having to disable the debugger.  should make a dormant venkman less of a performance impact.

js/jsd/idl/jsdIDebuggerService.idl

@@ -182,6 +182,11 @@ interface jsdIDebuggerService : nsISupports
      * If HIDE_DISABLED_FRAMES is set, this is effectively set as well.
      */
     const unsigned long MASK_TOP_FRAME_ONLY     = 0x20;
+    /**
+     * When this flag is set, object creation will not be tracked.  This will
+     * reduce the performance price you pay by enabling the debugger.
+     */
+    const unsigned long DISABLE_OBJECT_TRACE = 0x40;
     
     /**
      * Debugger service flags.

js/jsd/jsd_obj.c

@@ -122,15 +122,18 @@ _createJSDObject(JSDContext* jsdc, JSContext *cx, JSObject *obj)
     JS_ASSERT(JSD_OBJECTS_LOCKED(jsdc));
 
     jsdobj = (JSDObject*) calloc(1, sizeof(JSDObject));
-    if( jsdobj )
+    if (jsdobj)
     {
         JS_INIT_CLIST(&jsdobj->links);
         JS_APPEND_LINK(&jsdobj->links, &jsdc->objectsList);
         jsdobj->obj = obj;
         JS_HashTableAdd(jsdc->objectsTable, obj, jsdobj);
 
+        if (jsdc->flags & JSD_DISABLE_OBJECT_TRACE)
+            return jsdobj;
+        
         /* walk the stack to find js frame (if any) causing creation */
-        while( NULL != (fp = JS_FrameIterator(cx, &iter)) )
+        while (NULL != (fp = JS_FrameIterator(cx, &iter)))
         {
             if( !JS_IsNativeFrame(cx, fp) )
             {

js/jsd/jsd_step.c

@@ -118,6 +118,16 @@ _callHook(JSDContext *jsdc, JSContext *cx, JSStackFrame *fp, JSBool before,
     
     if (!jsdc || !jsdc->inited)
         return JS_FALSE;
+
+    if (!hook && !(jsdc->flags & JSD_COLLECT_PROFILE_DATA) &&
+        jsdc->flags & JSD_DISABLE_OBJECT_TRACE)
+    {
+        /* no hook to call, no profile data needs to be collected, and
+         * the client has object tracing disabled, so there is nothing
+         * to do here.
+         */
+        return hookresult;
+    }
     
     if (before && JS_IsConstructorFrame(cx, fp))
         jsd_Constructing(jsdc, cx, JS_GetFrameThis(cx, fp), fp);

js/jsd/jsd_xpc.cpp

@@ -96,7 +96,7 @@
 }
 
 #define JSDS_MAJOR_VERSION 1
-#define JSDS_MINOR_VERSION 1
+#define JSDS_MINOR_VERSION 2
 
 #define NS_CATMAN_CTRID   "@mozilla.org/categorymanager;1"
 #define NS_JSRT_CTRID     "@mozilla.org/js/xpc/RuntimeService;1"
@@ -3235,9 +3235,7 @@ class jsdASObserver : public nsIObserver
     NS_DECL_ISUPPORTS
     NS_DECL_NSIOBSERVER
 
-    jsdASObserver ()
-    {
-    }    
+    jsdASObserver () {}    
 };
 
 NS_IMPL_THREADSAFE_ISUPPORTS1(jsdASObserver, nsIObserver); 
@@ -3267,15 +3265,17 @@ jsdASObserver::Observe (nsISupports *aSubject, const char *aTopic,
         return rv;
 
     rv = jsds->OnForRuntime(rt);
+    if (NS_FAILED(rv))
+        return rv;
     
-    return rv;
+    return jsds->SetFlags(JSD_DISABLE_OBJECT_TRACE);
 }
 
 NS_GENERIC_FACTORY_CONSTRUCTOR(jsdASObserver);
 
 static const nsModuleComponentInfo components[] = {
-    {"JSDService", JSDSERVICE_CID,     jsdServiceCtrID, jsdServiceConstructor},
-    {"JSDASObserver",  JSDASO_CID,  jsdASObserverCtrID, jsdASObserverConstructor}
+    {"JSDService", JSDSERVICE_CID,    jsdServiceCtrID, jsdServiceConstructor},
+    {"JSDASObserver",  JSDASO_CID, jsdASObserverCtrID, jsdASObserverConstructor}
 };
 
 NS_IMPL_NSGETMODULE(JavaScript_Debugger, components);

js/jsd/jsdebug.h

@@ -230,6 +230,11 @@ JSD_ClearAllProfileData(JSDContext* jsdc);
 * If JSD_HIDE_DISABLED_FRAMES is set, this is effectively set as well.
 */
 #define JSD_MASK_TOP_FRAME_ONLY   0x20
+/*
+* When this flag is set, object creation will not be tracked.  This will
+* reduce the performance price you pay by enabling the debugger.
+*/
+#define JSD_DISABLE_OBJECT_TRACE  0x40
 
 extern JSD_PUBLIC_API(void)
 JSD_SetContextFlags (JSDContext* jsdc, uint32 flags);