Move CompilerStats from isolate to thread. Aggregate stats.

runtime/vm/timer.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_TIMER_H_
 #define VM_TIMER_H_
 
 #include "platform/utils.h"
 #include "vm/allocation.h"
+#include "vm/atomic.h"
 #include "vm/flags.h"
 #include "vm/os.h"
 
 namespace dart {
 
 // Timer class allows timing of specific operations in the VM.
 class Timer : public ValueObject {
  public:
   Timer(bool report, const char* message)
       : report_(report), message_(message) {
     Reset();
   }
   ~Timer() {}
 
   // Start timer.
   void Start() {
     start_ = OS::GetCurrentTimeMicros();
     running_ = true;
   }
 
   // Stop timer.
   void Stop() {
     ASSERT(start_ != 0);
     ASSERT(running());
     stop_ = OS::GetCurrentTimeMicros();
     int64_t elapsed = ElapsedMicros();
     max_contiguous_ = Utils::Maximum(max_contiguous_, elapsed);
     total_ += elapsed;

[hausner, 2016/03/30 19:49:20]

What if another thread does AddTotal at the same time this addition is performed
in the mutator thread?

[srdjan, 2016/03/30 20:14:04]

Using Atomic increment.

     running_ = false;
   }
 
   // Get total cummulative elapsed time in micros.
   int64_t TotalElapsedTime() const {
     int64_t result = total_;
     if (running_) {
       int64_t now = OS::GetCurrentTimeMicros();
       result += (now - start_);
     }
@@ skipping 10 matching lines @@
   }
 
   void Reset() {
     start_ = 0;
     stop_ = 0;
     total_ = 0;
     max_contiguous_ = 0;
     running_ = false;
   }
 
+  bool IsReset() const {
+    return (start_ == 0) && (stop_ == 0) && (total_ == 0) &&
+        (max_contiguous_ == 0) && !running_;
+  }
+
+  void AddTotal(const Timer& other) {
+    AtomicOperations::IncrementInt64By(&total_, other.total_);
+  }
+
   // Accessors.
   bool report() const { return report_; }
   bool running() const { return running_; }
   const char* message() const { return message_; }
 
  private:
   int64_t ElapsedMicros() const {
     ASSERT(start_ != 0);
     ASSERT(stop_ != 0);
     return stop_ - start_;
@@ skipping 82 matching lines @@
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(PauseTimerScope);
 };
 
 
 
 }  // namespace dart
 
 #endif  // VM_TIMER_H_