Don't lookup the cache for the result of Function::New

src/apinatives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 48 matching lines @@
     default:
       throw 'Unknown API tag <' + tag + '>';
   }
 }
 
 
 function InstantiateFunction(data, name) {
   // We need a reference to kApiFunctionCache in the stack frame
   // if we need to bail out from a stack overflow.
   var cache = kApiFunctionCache;
+  var flags = %GetTemplateField(data, kApiFlagOffset);
+  var doNotCache = flags & (1 << kDoNotCacheBit);
   var serialNumber = %GetTemplateField(data, kApiSerialNumberOffset);
   var isFunctionCached =
-   (serialNumber in cache) && (cache[serialNumber] != kUninitialized);
+   !doNotCache && (serialNumber in cache) && (cache[serialNumber] != kUninitialized);

[yhirano, 2013/09/13 05:54:56]

Let's wrap this line.

[yusukesuzuki, 2013/09/13 06:03:06]

Done.

   if (!isFunctionCached) {
     try {
       cache[serialNumber] = null;

[yusukesuzuki, 2013/09/13 05:52:00]

Because of this, `(serialNumber in cache) && (cache[serialNumber] !=
kUninitialized)` becomes true even if doNotCache is true. So isFunctionCached
should check `!doNotCache` at the same time.

       var fun = %CreateApiFunction(data);
       if (name) %FunctionSetName(fun, name);
-      var flags = %GetTemplateField(data, kApiFlagOffset);
-      var doNotCache = flags & (1 << kDoNotCacheBit);
       if (!doNotCache) cache[serialNumber] = fun;
       if (flags & (1 << kRemovePrototypeBit)) {
         %FunctionRemovePrototype(fun);
       } else {
         var prototype = %GetTemplateField(data, kApiPrototypeTemplateOffset);
         // Note: Do not directly use an object template as a condition, our
         // internal ToBoolean doesn't handle that!
         fun.prototype = typeof prototype === 'undefined' ?
             {} : Instantiate(prototype);
         if (flags & (1 << kReadOnlyPrototypeBit)) {
@@ skipping 43 matching lines @@
             obj, name, getter, setter, attribute, access_control);
       } else {
         throw "Bad properties array";
       }
       i += length + 1;
     }
   } finally {
     if (requires_access_checks) %EnableAccessChecks(obj);
   }
 }