expose counter in d8

src/d8.cc

 // Copyright 2011 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 580 matching lines @@
 
 #ifdef LIVE_OBJECT_LIST
   global_template->Set(String::New("lol_is_enabled"), Boolean::New(true));
 #else
   global_template->Set(String::New("lol_is_enabled"), Boolean::New(false));
 #endif
 
   Handle<ObjectTemplate> os_templ = ObjectTemplate::New();
   AddOSMethods(os_templ);
   global_template->Set(String::New("os"), os_templ);
 

[Yang, 2011/06/29 12:02:20]

Add new object "counter".

+  Handle<ObjectTemplate> counter_templ = ObjectTemplate::New();
+  counter_templ->Set(String::New("get"),
+                     FunctionTemplate::New(GetCounterValue));
+  counter_templ->Set(String::New("names"),
+                       FunctionTemplate::New(GetCounterNames));
+  global_template->Set(String::New("counter"), counter_templ);
+
   return global_template;
 }
 
 

[Yang, 2011/06/29 12:02:20]

counter.get() returns the counter by the name provided.
e.g.
counter.get("c:V8.TotalCompiledCodeSize")

+Handle<Value> Shell::GetCounterValue(const Arguments& args) {
+  if (args.Length() != 1) {
+    return ThrowException(String::New("get() takes one argument"));
+  }
+  if (args[0]->IsString()) {
+    String::AsciiValue name(args[0]);
+    Counter* counter = counter_map_->Lookup(*name);
+    if (!counter) {
+      return ThrowException(String::New("invalid counter name"));
+    }
+    return Handle<Integer>::Cast(Integer::New(counter->count()));
+  }
+  return ThrowException(String::New("counter name must be a string"));
+}
+
+

[Yang, 2011/06/29 12:02:20]

counter.names() returns counter names as an array of strings.

+Handle<Value> Shell::GetCounterNames(const Arguments& args) {
+  if (args.Length() != 0) {
+    return ThrowException(String::New("names() takes no arguments"));
+  }
+  Handle<Array> results = Handle<Array>::Cast(Array::New(0));
+  int j = 0;
+  for (CounterMap::Iterator i(counter_map_); i.More(); i.Next()) {
+    results->Set(j++, Handle<String>::Cast(String::New(i.CurrentKey())));
+  }
+  return results;
+}
+
+
 void Shell::Initialize(bool test_shell) {
 #ifdef COMPRESS_STARTUP_DATA_BZ2
   BZip2Decompressor startup_data_decompressor;
   int bz2_result = startup_data_decompressor.Decompress();
   if (bz2_result != BZ_OK) {
     fprintf(stderr, "bzip error code: %d\n", bz2_result);
     exit(1);
   }
 #endif
 
   Shell::counter_map_ = new CounterMap();
   // Set up counters
   if (i::StrLength(i::FLAG_map_counters) != 0)
     MapCounters(i::FLAG_map_counters);

[Yang, 2011/06/29 12:02:20]

Init counter in any case (not only upon --dump-counters). This makes unit tests
take less than half a second longer in total, so I think this is acceptable.

-  if (i::FLAG_dump_counters) {
-    V8::SetCounterFunction(LookupCounter);
-    V8::SetCreateHistogramFunction(CreateHistogram);
-    V8::SetAddHistogramSampleFunction(AddHistogramSample);
-  }
+  V8::SetCounterFunction(LookupCounter);
+  V8::SetCreateHistogramFunction(CreateHistogram);
+  V8::SetAddHistogramSampleFunction(AddHistogramSample);
 
   if (test_shell) return;
 
   Locker lock;
   HandleScope scope;
   Handle<ObjectTemplate> global_template = CreateGlobalTemplate();
   utility_context_ = Context::New(NULL, global_template);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Start the debugger agent if requested.
@@ skipping 357 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif