Don't create redundant ThreadData for Worker Threads

base/tracked_objects.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_TRACKED_OBJECTS_H_
 #define BASE_TRACKED_OBJECTS_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 430 matching lines @@
     UNINITIALIZED,         // Pristine, link-time state before running.
     DORMANT_DURING_TESTS,  // Only used during testing.
     DEACTIVATED,           // No longer recording profiling.
     PROFILING_ACTIVE,      // Recording profiles.
     STATUS_LAST = PROFILING_ACTIVE
   };
 
   typedef base::hash_map<Location, Births*, Location::Hash> BirthMap;
   typedef std::map<const Births*, DeathData> DeathMap;
 
-  // Initialize the current thread context with a new instance of ThreadData.
+  // If is_worker_thread, do partial initialization of the thread context,
+  // and wait for just-in-time initilization using potentially recycled

[Lei Zhang, 2016/05/12 19:47:40]

typo

[Zhenyu Shan, 2016/05/16 02:05:35]

Restored the comment here because we moved is_worker_thread checking before
calling InitializeThreadContext

+  // context. Otherwise, Initialize the current thread context with a new
+  // instance of ThreadData.
   // This is used by all threads that have names, and should be explicitly
   // set *before* any births on the threads have taken place.  It is generally
   // only used by the message loop, which has a well defined thread name.
-  static void InitializeThreadContext(const std::string& suggested_name);
+  static void InitializeThreadContext(const std::string& suggested_name,
+                                      bool is_worker_thread = false);
 
   // Using Thread Local Store, find the current instance for collecting data.
   // If an instance does not exist, construct one (and remember it for use on
   // this thread.
   // This may return NULL if the system is disabled for any reason.
   static ThreadData* Get();
 
   // Fills |process_data_snapshot| with phased snapshots of all profiling
   // phases, including the current one, identified by |current_profiling_phase|.
   // |current_profiling_phase| is necessary because a child process can start
@@ skipping 41 matching lines @@
 
   // Record the end of execution in region, generally corresponding to a scope
   // being exited.
   static void TallyRunInAScopedRegionIfTracking(const Births* births,
                                                 const TaskStopwatch& stopwatch);
 
   const std::string& thread_name() const { return thread_name_; }
 
   // Initializes all statics if needed (this initialization call should be made
   // while we are single threaded).
-  static void Initialize();
+  static void EnsureTlsInitialization();
 
   // Sets internal status_.
   // If |status| is false, then status_ is set to DEACTIVATED.
   // If |status| is true, then status_ is set to PROFILING_ACTIVE.
   static void InitializeAndSetTrackingStatus(Status status);
 
   static Status status();
 
   // Indicate if any sort of profiling is being done (i.e., we are more than
   // DEACTIVATED).
@@ skipping 283 matching lines @@
   ProcessDataSnapshot(const ProcessDataSnapshot& other);
   ~ProcessDataSnapshot();
 
   PhasedProcessDataSnapshotMap phased_snapshots;
   base::ProcessId process_id;
 };
 
 }  // namespace tracked_objects
 
 #endif  // BASE_TRACKED_OBJECTS_H_