Support use of third party time function to profiler

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_
 #pragma once
 
 #include <map>
 #include <set>
 #include <stack>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/gtest_prod_util.h"
 #include "base/lazy_instance.h"
 #include "base/location.h"
+#include "base/profiler/alternate_timer.h"
 #include "base/profiler/tracked_time.h"
 #include "base/time.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/tracking_info.h"
 #include "base/values.h"
 
 // TrackedObjects provides a database of stats about objects (generally Tasks)
 // that are tracked.  Tracking means their birth, death, duration, birth thread,
 // death thread, and birth place are recorded.  This data is carefully spread
@@ skipping 432 matching lines @@
   // relationships can be (optionally) calculated.
   static TrackedTime NowForStartOfRun(const Births* parent);
   static TrackedTime NowForEndOfRun();
 
   // Provide a time function that does nothing (runs fast) when we don't have
   // the profiler enabled.  It will generally be optimized away when it is
   // ifdef'ed to be small enough (allowing the profiler to be "compiled out" of
   // the code).
   static TrackedTime Now();
 
+  // Use the function |now| to provide current times, instead of calling the
+  // TrackedTime::Now() function.  Since this alternate function is being used,
+  // the other time arguments (used for calculating queueing delay) will be
+  // ignored.
+  static void SetAlternateTimeSource(NowFunction* now);
+
   // This function can be called at process termination to validate that thread
   // cleanup routines have been called for at least some number of named
   // threads.
   static void EnsureCleanupWasCalled(int major_threads_shutdown_count);
 
  private:
   // Allow only tests to call ShutdownSingleThreadedCleanup.  We NEVER call it
   // in production code.
   // TODO(jar): Make this a friend in DEBUG only, so that the optimizer has a
   // better change of optimizing (inlining? etc.) private methods (knowing that
@@ skipping 56 matching lines @@
   // uninitialized) state.  If there is any chance that other threads are still
   // using the data structures, then the |leak| argument should be passed in as
   // true, and the data structures (birth maps, death maps, ThreadData
   // insntances, etc.) will be leaked and not deleted.  If you have joined all
   // threads since the time that InitializeAndSetTrackingStatus() was called,
   // then you can pass in a |leak| value of false, and this function will
   // delete recursively all data structures, starting with the list of
   // ThreadData instances.
   static void ShutdownSingleThreadedCleanup(bool leak);
 
+  // When non-null, this specifies an external function that supplies monotone
+  // increasing time functcion.
+  static NowFunction* now_function_;
+
   // We use thread local store to identify which ThreadData to interact with.
   static base::ThreadLocalStorage::StaticSlot tls_index_;
 
   // List of ThreadData instances for use with worker threads. When a worker
   // thread is done (terminated), we push it onto this llist.  When a new worker
   // thread is created, we first try to re-use a ThreadData instance from the
   // list, and if none are available, construct a new one.
   // This is only accessed while list_lock_ is held.
   static ThreadData* first_retired_worker_;
 
@@ skipping 143 matching lines @@
 
   // The complete list of parent-child relationships among tasks.
   ThreadData::ParentChildSet parent_child_set_;
 
   DISALLOW_COPY_AND_ASSIGN(DataCollector);
 };
 
 }  // namespace tracked_objects
 
 #endif  // BASE_TRACKED_OBJECTS_H_