Introducing phased profiling framework.

TrackingSynchronizer can send a "phase completed" message to all processes. Their ThreadData's make a snapshot of task deaths and store it in a static map, associating with the number of the completed phase. They also clean the death data.

When requested to return a tasks snapshot, ThreadData returns that saved map, adding a snapshot of current task deaths as a separate "current" phase.

The rest of code was transformed to work with the map of snapshots instead of a single snapshot.

BUG=456354

Review URL: https://codereview.chromium.org/985773002

Cr-Commit-Position: refs/heads/master@{#323151}

1 files changed, 56 insertions, 45 deletions

diff --git a/base/tracked_objects.cc b/base/tracked_objects.cc
index 5359d89..32ec75c 100644
--- a/base/tracked_objects.cc
+++ b/base/tracked_objects.cc
@@ -390,23 +390,9 @@ void ThreadData::OnThreadTerminationCleanup() {
 }
 
 // static
-void ThreadData::Snapshot(ProcessDataSnapshot* process_data) {
-  // Add births that have run to completion to |collected_data|.
-  // |birth_counts| tracks the total number of births recorded at each location
-  // for which we have not seen a death count.
-  BirthCountMap birth_counts;
-  ThreadData::SnapshotAllExecutedTasks(process_data, &birth_counts);
-
-  // Add births that are still active -- i.e. objects that have tallied a birth,
-  // but have not yet tallied a matching death, and hence must be either
-  // running, queued up, or being held in limbo for future posting.
-  for (BirthCountMap::const_iterator it = birth_counts.begin();
-       it != birth_counts.end(); ++it) {
-    if (it->second > 0) {
-      process_data->tasks.push_back(
-          TaskSnapshot(*it->first, DeathData(it->second), "Still_Alive"));
-    }
-  }
+void ThreadData::Snapshot(ProcessDataSnapshot* process_data_snapshot) {
+  ThreadData::SnapshotCurrentPhase(
+      &process_data_snapshot->phased_process_data_snapshots[0]);
 }
 
 Births* ThreadData::TallyABirth(const Location& location) {
@@ -578,8 +564,9 @@ void ThreadData::TallyRunInAScopedRegionIfTracking(
 }
 
 // static
-void ThreadData::SnapshotAllExecutedTasks(ProcessDataSnapshot* process_data,
-                                          BirthCountMap* birth_counts) {
+void ThreadData::SnapshotAllExecutedTasks(
+    ProcessDataPhaseSnapshot* process_data_phase,
+    BirthCountMap* birth_counts) {
   if (!kTrackAllTaskObjects)
     return;  // Not compiled in.
 
@@ -595,12 +582,33 @@ void ThreadData::SnapshotAllExecutedTasks(ProcessDataSnapshot* process_data,
   for (ThreadData* thread_data = my_list;
        thread_data;
        thread_data = thread_data->next()) {
-    thread_data->SnapshotExecutedTasks(process_data, birth_counts);
+    thread_data->SnapshotExecutedTasks(process_data_phase, birth_counts);
+  }
+}
+
+// static
+void ThreadData::SnapshotCurrentPhase(
+    ProcessDataPhaseSnapshot* process_data_phase) {
+  // Add births that have run to completion to |collected_data|.
+  // |birth_counts| tracks the total number of births recorded at each location
+  // for which we have not seen a death count.
+  BirthCountMap birth_counts;
+  ThreadData::SnapshotAllExecutedTasks(process_data_phase, &birth_counts);
+
+  // Add births that are still active -- i.e. objects that have tallied a birth,
+  // but have not yet tallied a matching death, and hence must be either
+  // running, queued up, or being held in limbo for future posting.
+  for (const auto& birth_count : birth_counts) {
+    if (birth_count.second > 0) {
+      process_data_phase->tasks.push_back(TaskSnapshot(
+          *birth_count.first, DeathData(birth_count.second), "Still_Alive"));
+    }
   }
 }
 
-void ThreadData::SnapshotExecutedTasks(ProcessDataSnapshot* process_data,
-                                       BirthCountMap* birth_counts) {
+void ThreadData::SnapshotExecutedTasks(
+    ProcessDataPhaseSnapshot* process_data_phase,
+    BirthCountMap* birth_counts) {
   // Get copy of data, so that the data will not change during the iterations
   // and processing.
   ThreadData::BirthMap birth_map;
@@ -608,24 +616,22 @@ void ThreadData::SnapshotExecutedTasks(ProcessDataSnapshot* process_data,
   ThreadData::ParentChildSet parent_child_set;
   SnapshotMaps(&birth_map, &death_map, &parent_child_set);
 
-  for (ThreadData::DeathMap::const_iterator it = death_map.begin();
-       it != death_map.end(); ++it) {
-    process_data->tasks.push_back(
-        TaskSnapshot(*it->first, it->second, thread_name()));
-    (*birth_counts)[it->first] -= it->first->birth_count();
+  for (const auto& death : death_map) {
+    process_data_phase->tasks.push_back(
+        TaskSnapshot(*death.first, death.second, thread_name()));
+    (*birth_counts)[death.first] -= death.first->birth_count();
   }
 
-  for (ThreadData::BirthMap::const_iterator it = birth_map.begin();
-       it != birth_map.end(); ++it) {
-    (*birth_counts)[it->second] += it->second->birth_count();
+  for (const auto& birth : birth_map) {
+    (*birth_counts)[birth.second] += birth.second->birth_count();
   }
 
   if (!kTrackParentChildLinks)
     return;
 
-  for (ThreadData::ParentChildSet::const_iterator it = parent_child_set.begin();
-       it != parent_child_set.end(); ++it) {
-    process_data->descendants.push_back(ParentChildPairSnapshot(*it));
+  for (const auto& parent_child : parent_child_set) {
+    process_data_phase->descendants.push_back(
+        ParentChildPairSnapshot(parent_child));
   }
 }
 
@@ -634,20 +640,16 @@ void ThreadData::SnapshotMaps(BirthMap* birth_map,
                               DeathMap* death_map,
                               ParentChildSet* parent_child_set) {
   base::AutoLock lock(map_lock_);
-  for (BirthMap::const_iterator it = birth_map_.begin();
-       it != birth_map_.end(); ++it)
-    (*birth_map)[it->first] = it->second;
-  for (DeathMap::iterator it = death_map_.begin();
-       it != death_map_.end(); ++it) {
-    (*death_map)[it->first] = it->second;
-  }
+  for (const auto& birth : birth_map_)
+    (*birth_map)[birth.first] = birth.second;
+  for (const auto& death : death_map_)
+    (*death_map)[death.first] = death.second;
 
   if (!kTrackParentChildLinks)
     return;
 
-  for (ParentChildSet::iterator it = parent_child_set_.begin();
-       it != parent_child_set_.end(); ++it)
-    parent_child_set->insert(*it);
+  for (const auto& parent_child : parent_child_set_)
+    parent_child_set->insert(parent_child);
 }
 
 static void OptionallyInitializeAlternateTimer() {
@@ -959,13 +961,22 @@ ParentChildPairSnapshot::~ParentChildPairSnapshot() {
 }
 
 //------------------------------------------------------------------------------
-// ProcessDataSnapshot
+// ProcessDataPhaseSnapshot
+
+ProcessDataPhaseSnapshot::ProcessDataPhaseSnapshot() {
+}
+
+ProcessDataPhaseSnapshot::~ProcessDataPhaseSnapshot() {
+}
+
+//------------------------------------------------------------------------------
+// ProcessDataPhaseSnapshot
 
 ProcessDataSnapshot::ProcessDataSnapshot()
 #if !defined(OS_NACL)
     : process_id(base::GetCurrentProcId()) {
 #else
-    : process_id(0) {
+    : process_id(base::kNullProcessId) {
 #endif
 }