Implement sampling profiler (chromium side change)

base/debug/trace_event_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifndef BASE_DEBUG_TRACE_EVENT_IMPL_H_
 #define BASE_DEBUG_TRACE_EVENT_IMPL_H_
 
 #include <stack>
 #include <string>
@@ skipping 336 matching lines @@
 
   StringList included_;
   StringList disabled_;
   StringList excluded_;
 };
 
 class TraceSamplingThread;
 
 class BASE_EXPORT TraceLog {
  public:
+  enum Mode {
+    DISABLED = 0,
+    RECORDING_MODE,
+    MONITORING_MODE,
+  };
+
   // Options determines how the trace buffer stores data.
   enum Options {
     // Record until the trace buffer is full.
     RECORD_UNTIL_FULL = 1 << 0,
 
     // Record until the user ends the trace. The trace buffer is a fixed size
     // and we use it as a ring buffer during recording.
     RECORD_CONTINUOUSLY = 1 << 1,
 
     // Enable the sampling profiler in the recording mode.
     ENABLE_SAMPLING = 1 << 2,
 
-    // Enable the sampling profiler in the monitoring mode.
-    MONITOR_SAMPLING = 1 << 3,
-
     // Echo to console. Events are discarded.
-    ECHO_TO_CONSOLE = 1 << 4,
+    ECHO_TO_CONSOLE = 1 << 3,
   };
 
   // The pointer returned from GetCategoryGroupEnabledInternal() points to a
   // value with zero or more of the following bits. Used in this class only.
   // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in TraceEvent.h in Blink.
   enum CategoryGroupEnabledFlags {
-    // Normal enabled flag for category groups enabled by SetEnabled().
+    // Category group enabled for the recording mode.
     ENABLED_FOR_RECORDING = 1 << 0,
+    // Category group enabled for the monitoring mode.
+    ENABLED_FOR_MONITORING = 1 << 1,
     // Category group enabled by SetEventCallbackEnabled().
-    ENABLED_FOR_EVENT_CALLBACK = 1 << 1,
+    ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
   };
 
   static TraceLog* GetInstance();
 
   // Get set of known category groups. This can change as new code paths are
   // reached. The known category groups are inserted into |category_groups|.
   void GetKnownCategoryGroups(std::vector<std::string>* category_groups);
 
   // Retrieves a copy (for thread-safety) of the current CategoryFilter.
   CategoryFilter GetCurrentCategoryFilter();
 
   Options trace_options() const {
     return static_cast<Options>(subtle::NoBarrier_Load(&trace_options_));
   }
 
   // Enables normal tracing (recording trace events in the trace buffer).
   // See CategoryFilter comments for details on how to control what categories
   // will be traced. If tracing has already been enabled, |category_filter| will
   // be merged into the current category filter.
-  void SetEnabled(const CategoryFilter& category_filter, Options options);
+  void SetEnabled(const CategoryFilter& category_filter,
+                  Mode mode, Options options);
 
   // Disables normal tracing for all categories.
   void SetDisabled();
 
-  bool IsEnabled() { return enabled_; }
+  bool IsEnabled() { return mode_ != DISABLED; }
 
   // The number of times we have begun recording traces. If tracing is off,
   // returns -1. If tracing is on, then it returns the number of times we have
   // recorded a trace. By watching for this number to increment, you can
   // passively discover when a new trace has begun. This is then used to
   // implement the TRACE_EVENT_IS_NEW_TRACE() primitive.
   int GetNumTracesRecorded();
 
 #if defined(OS_ANDROID)
   void StartATrace();
   void StopATrace();
   void AddClockSyncMetadataEvent();
 #endif
 
   // Enabled state listeners give a callback when tracing is enabled or
   // disabled. This can be used to tie into other library's tracing systems
   // on-demand.
   class EnabledStateObserver {
    public:
     // Called just after the tracing system becomes enabled, outside of the
-    // |lock_|.  TraceLog::IsEnabled() is true at this point.
+    // |lock_|. TraceLog::IsEnabled() is true at this point.
     virtual void OnTraceLogEnabled() = 0;
 
     // Called just after the tracing system disables, outside of the |lock_|.
     // TraceLog::IsEnabled() is false at this point.
     virtual void OnTraceLogDisabled() = 0;
   };
   void AddEnabledStateObserver(EnabledStateObserver* listener);
   void RemoveEnabledStateObserver(EnabledStateObserver* listener);
   bool HasEnabledStateObserver(EnabledStateObserver* listener) const;
 
@@ skipping 144 matching lines @@
                            TraceBufferRingBufferGetReturnChunk);
   FRIEND_TEST_ALL_PREFIXES(TraceEventTestFixture,
                            TraceBufferRingBufferHalfIteration);
   FRIEND_TEST_ALL_PREFIXES(TraceEventTestFixture,
                            TraceBufferRingBufferFullIteration);
 
   // This allows constructor and destructor to be private and usable only
   // by the Singleton class.
   friend struct DefaultSingletonTraits<TraceLog>;
 
-  // Enable/disable each category group based on the current enabled_,
+  // Enable/disable each category group based on the current mode_,
   // category_filter_, event_callback_ and event_callback_category_filter_.
-  // Enable the category group if enabled_ is true and category_filter_ matches
+  // Enable the category group in the enabled mode if category_filter_ matches
   // the category group, or event_callback_ is not null and
   // event_callback_category_filter_ matches the category group.
   void UpdateCategoryGroupEnabledFlags();
   void UpdateCategoryGroupEnabledFlag(int category_index);
 
   class ThreadLocalEventBuffer;
   class OptionalAutoLock;
 
   TraceLog();
   ~TraceLog();
@@ skipping 38 matching lines @@
     return timestamp - time_offset_;
   }
 
   // This lock protects TraceLog member accesses (except for members protected
   // by thread_info_lock_) from arbitrary threads.
   mutable Lock lock_;
   // This lock protects accesses to thread_names_, thread_event_start_times_
   // and thread_colors_.
   Lock thread_info_lock_;
   int locked_line_;
-  bool enabled_;
+  Mode mode_;
   int num_traces_recorded_;
   scoped_ptr<TraceBuffer> logged_events_;
   subtle::AtomicWord /* EventCallback */ event_callback_;
   bool dispatching_to_observer_list_;
   std::vector<EnabledStateObserver*> enabled_state_observer_list_;
 
   std::string process_name_;
   base::hash_map<int, std::string> process_labels_;
   int process_sort_index_;
   base::hash_map<int, int> thread_sort_indices_;
@@ skipping 43 matching lines @@
   scoped_refptr<MessageLoopProxy> flush_message_loop_proxy_;
   subtle::AtomicWord generation_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceLog);
 };
 
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_TRACE_EVENT_IMPL_H_