Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class.

src/optimizing-compiler-thread.cc

 // Copyright 2012 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 30 matching lines @@
 #ifdef DEBUG
   { ScopedLock lock(thread_id_mutex_);
     thread_id_ = ThreadId::Current().ToInteger();
   }
 #endif
   Isolate::SetIsolateThreadLocals(isolate_, NULL);
   DisallowHeapAllocation no_allocation;
   DisallowHandleAllocation no_handles;
   DisallowHandleDereference no_deref;
 
-  int64_t epoch = 0;
-  if (FLAG_trace_concurrent_recompilation) epoch = OS::Ticks();
+  ElapsedTimer total_timer;
+  if (FLAG_trace_concurrent_recompilation) total_timer.Start();
 
   while (true) {
     input_queue_semaphore_->Wait();
     Logger::TimerEventScope timer(
         isolate_, Logger::TimerEventScope::v8_recompile_concurrent);
 
     if (FLAG_concurrent_recompilation_delay != 0) {
       OS::Sleep(FLAG_concurrent_recompilation_delay);
     }
 
     switch (static_cast<StopFlag>(Acquire_Load(&stop_thread_))) {
       case CONTINUE:
         break;
       case STOP:
         if (FLAG_trace_concurrent_recompilation) {
-          time_spent_total_ = OS::Ticks() - epoch;
+          time_spent_total_ = total_timer.Elapsed();
         }
         stop_semaphore_->Signal();
         return;
       case FLUSH:
         // The main thread is blocked, waiting for the stop semaphore.
         { AllowHandleDereference allow_handle_dereference;
           FlushInputQueue(true);
         }
         Release_Store(&queue_length_, static_cast<AtomicWord>(0));
         Release_Store(&stop_thread_, static_cast<AtomicWord>(CONTINUE));
         stop_semaphore_->Signal();
         // Return to start of consumer loop.
         continue;
     }
 
-    int64_t compiling_start = 0;
-    if (FLAG_trace_concurrent_recompilation) compiling_start = OS::Ticks();
+    ElapsedTimer compiling_timer;
+    if (FLAG_trace_concurrent_recompilation) compiling_timer.Start();
 
     CompileNext();
 
     if (FLAG_trace_concurrent_recompilation) {
-      time_spent_compiling_ += OS::Ticks() - compiling_start;
+      time_spent_compiling_ += compiling_timer.Elapsed();
     }
   }
 }
 
 
 void OptimizingCompilerThread::CompileNext() {
   OptimizingCompiler* optimizing_compiler = NULL;
   bool result = input_queue_.Dequeue(&optimizing_compiler);
   USE(result);
   ASSERT(result);
@@ skipping 67 matching lines @@
     // happens in CompileNext on the same thread.
     // This is used only for testing.
     while (NoBarrier_Load(&queue_length_) > 0) CompileNext();
     InstallOptimizedFunctions();
   } else {
     FlushInputQueue(false);
     FlushOutputQueue(false);
   }
 
   if (FLAG_trace_concurrent_recompilation) {
-    double compile_time = static_cast<double>(time_spent_compiling_);
-    double total_time = static_cast<double>(time_spent_total_);
-    double percentage = (compile_time * 100) / total_time;
+    double percentage = time_spent_compiling_.PercentOf(time_spent_total_);
     PrintF("  ** Compiler thread did %.2f%% useful work\n", percentage);
   }
 
   Join();
 }
 
 
 void OptimizingCompilerThread::InstallOptimizedFunctions() {
   ASSERT(!IsOptimizerThread());
   HandleScope handle_scope(isolate_);
@@ skipping 22 matching lines @@
 #ifdef DEBUG
 bool OptimizingCompilerThread::IsOptimizerThread() {
   if (!FLAG_concurrent_recompilation) return false;
   ScopedLock lock(thread_id_mutex_);
   return ThreadId::Current().ToInteger() == thread_id_;
 }
 #endif
 
 
 } }  // namespace v8::internal