Propogate status setting for profiler to track parents

[Reland: https://src.chromium.org/viewvc/chrome?view=rev&revision=120789
with minor change to avoid race on status change.]

This allows child processes to track ancestry, and report
it to the browser process.

Parent tracking is only turned on based on an 
environment variable.

r=rtenneti
Review URL: https://chromiumcodereview.appspot.com/9363007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@121491 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 58 insertions, 39 deletions

diff --git a/base/profiler/tracked_time_unittest.cc b/base/profiler/tracked_time_unittest.cc
index 6491a2f..b85411d 100644
--- a/base/profiler/tracked_time_unittest.cc
+++ b/base/profiler/tracked_time_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -76,7 +76,7 @@ TEST(TrackedTimeTest, TrackedTimerVsTimeTicks) {
 TEST(TrackedTimeTest, TrackedTimerDisabled) {
   // Check to be sure disabling the collection of data induces a null time
   // (which we know will return much faster).
-  if (!ThreadData::InitializeAndSetTrackingStatus(false))
+  if (!ThreadData::InitializeAndSetTrackingStatus(ThreadData::DEACTIVATED))
     return;
   // Since we disabled tracking, we should get a null response.
   TrackedTime track_now = ThreadData::Now();
@@ -88,7 +88,8 @@ TEST(TrackedTimeTest, TrackedTimerDisabled) {
 }
 
 TEST(TrackedTimeTest, TrackedTimerEnabled) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
   // Make sure that when we enable tracking, we get a real timer result.
 
diff --git a/base/tracked_objects.cc b/base/tracked_objects.cc
index e7d7bd1..87af8dc 100644
--- a/base/tracked_objects.cc
+++ b/base/tracked_objects.cc
@@ -393,7 +393,7 @@ Births* ThreadData::TallyABirthIfActive(const Location& location) {
   if (!kTrackAllTaskObjects)
     return NULL;  // Not compiled in.
 
-  if (!tracking_status())
+  if (!TrackingStatus())
     return NULL;
   ThreadData* current_thread_data = Get();
   if (!current_thread_data)
@@ -622,28 +622,31 @@ bool ThreadData::Initialize() {
 }
 
 // static
-bool ThreadData::InitializeAndSetTrackingStatus(bool status) {
+bool ThreadData::InitializeAndSetTrackingStatus(Status status) {
+  DCHECK_GE(status, DEACTIVATED);
+  DCHECK_LE(status, PROFILING_CHILDREN_ACTIVE);
+
   if (!Initialize())  // No-op if already initialized.
     return false;  // Not compiled in.
 
-  if (!status) {
-    status_ = DEACTIVATED;
-  } else {
-    if (kTrackParentChildLinks)
-      status_ = PROFILING_CHILDREN_ACTIVE;
-    else
-      status_ = PROFILING_ACTIVE;
-  }
+  if (!kTrackParentChildLinks && status > DEACTIVATED)
+    status = PROFILING_ACTIVE;
+  status_ = status;
   return true;
 }
 
 // static
-bool ThreadData::tracking_status() {
+ThreadData::Status ThreadData::status() {
+  return status_;
+}
+
+// static
+bool ThreadData::TrackingStatus() {
   return status_ > DEACTIVATED;
 }
 
 // static
-bool ThreadData::tracking_parent_child_status() {
+bool ThreadData::TrackingParentChildStatus() {
   return status_ >= PROFILING_CHILDREN_ACTIVE;
 }
 
@@ -664,7 +667,7 @@ TrackedTime ThreadData::NowForEndOfRun() {
 
 // static
 TrackedTime ThreadData::Now() {
-  if (kTrackAllTaskObjects && tracking_status())
+  if (kTrackAllTaskObjects && TrackingStatus())
     return TrackedTime::Now();
   return TrackedTime();  // Super fast when disabled, or not compiled.
 }
@@ -686,7 +689,7 @@ void ThreadData::ShutdownSingleThreadedCleanup(bool leak) {
   // This is only called from test code, where we need to cleanup so that
   // additional tests can be run.
   // We must be single threaded... but be careful anyway.
-  if (!InitializeAndSetTrackingStatus(false))
+  if (!InitializeAndSetTrackingStatus(DEACTIVATED))
     return;
   ThreadData* thread_data_list;
   {
diff --git a/base/tracked_objects.h b/base/tracked_objects.h
index 9b7f111..c0674cc 100644
--- a/base/tracked_objects.h
+++ b/base/tracked_objects.h
@@ -442,15 +442,17 @@ class BASE_EXPORT ThreadData {
   // PROFILING_ACTIVE (i.e., it can't be set to a higher level than what is
   // compiled into the binary, and parent-child tracking at the
   // PROFILING_CHILDREN_ACTIVE level might not be compiled in).
-  static bool InitializeAndSetTrackingStatus(bool status);
+  static bool InitializeAndSetTrackingStatus(Status status);
+
+  static Status status();
 
   // Indicate if any sort of profiling is being done (i.e., we are more than
   // DEACTIVATED).
-  static bool tracking_status();
+  static bool TrackingStatus();
 
   // For testing only, indicate if the status of parent-child tracking is turned
-  // on.  This is currently a compiled option, atop tracking_status().
-  static bool tracking_parent_child_status();
+  // on.  This is currently a compiled option, atop TrackingStatus().
+  static bool TrackingParentChildStatus();
 
   // Special versions of Now() for getting times at start and end of a tracked
   // run.  They are super fast when tracking is disabled, and have some internal
diff --git a/base/tracked_objects_unittest.cc b/base/tracked_objects_unittest.cc
index 68911bb..d57ddee 100644
--- a/base/tracked_objects_unittest.cc
+++ b/base/tracked_objects_unittest.cc
@@ -35,7 +35,8 @@ class TrackedObjectsTest : public testing::Test {
 
 TEST_F(TrackedObjectsTest, MinimalStartupShutdown) {
   // Minimal test doesn't even create any tasks.
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   EXPECT_FALSE(ThreadData::first());  // No activity even on this thread.
@@ -55,7 +56,8 @@ TEST_F(TrackedObjectsTest, MinimalStartupShutdown) {
   ShutdownSingleThreadedCleanup(false);
 
   // Do it again, just to be sure we reset state completely.
-  ThreadData::InitializeAndSetTrackingStatus(true);
+  ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE);
   EXPECT_FALSE(ThreadData::first());  // No activity even on this thread.
   data = ThreadData::Get();
   EXPECT_TRUE(ThreadData::first());  // Now class was constructed.
@@ -71,7 +73,8 @@ TEST_F(TrackedObjectsTest, MinimalStartupShutdown) {
 }
 
 TEST_F(TrackedObjectsTest, TinyStartupShutdown) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Instigate tracking on a single tracked object, on our thread.
@@ -113,7 +116,7 @@ TEST_F(TrackedObjectsTest, TinyStartupShutdown) {
   EXPECT_EQ(2, birth_map.begin()->second->birth_count());  // 2 births.
   EXPECT_EQ(1u, death_map.size());                         // 1 location.
   EXPECT_EQ(1, death_map.begin()->second.count());         // 1 death.
-  if (ThreadData::tracking_parent_child_status()) {
+  if (ThreadData::TrackingParentChildStatus()) {
     EXPECT_EQ(1u, parent_child_set.size());                  // 1 child.
     EXPECT_EQ(parent_child_set.begin()->first,
               parent_child_set.begin()->second);
@@ -126,9 +129,10 @@ TEST_F(TrackedObjectsTest, TinyStartupShutdown) {
 }
 
 TEST_F(TrackedObjectsTest, ParentChildTest) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
-  if (!ThreadData::tracking_parent_child_status())
+  if (!ThreadData::TrackingParentChildStatus())
     return;   // Feature not compiled in.
 
   // Instigate tracking on a single tracked object, on our thread.
@@ -211,7 +215,8 @@ TEST_F(TrackedObjectsTest, ParentChildTest) {
 }
 
 TEST_F(TrackedObjectsTest, DeathDataTest) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   scoped_ptr<DeathData> data(new DeathData());
@@ -270,7 +275,7 @@ TEST_F(TrackedObjectsTest, DeathDataTest) {
 
 TEST_F(TrackedObjectsTest, DeactivatedBirthOnlyToValueWorkerThread) {
   // Transition to Deactivated state before doing anything.
-  if (!ThreadData::InitializeAndSetTrackingStatus(false))
+  if (!ThreadData::InitializeAndSetTrackingStatus(ThreadData::DEACTIVATED))
     return;
   // We don't initialize system with a thread name, so we're viewed as a worker
   // thread.
@@ -296,7 +301,7 @@ TEST_F(TrackedObjectsTest, DeactivatedBirthOnlyToValueWorkerThread) {
 
 TEST_F(TrackedObjectsTest, DeactivatedBirthOnlyToValueMainThread) {
   // Start in the deactivated state.
-  if (!ThreadData::InitializeAndSetTrackingStatus(false))
+  if (!ThreadData::InitializeAndSetTrackingStatus(ThreadData::DEACTIVATED))
     return;
 
   // Use a well named thread.
@@ -323,7 +328,8 @@ TEST_F(TrackedObjectsTest, DeactivatedBirthOnlyToValueMainThread) {
 }
 
 TEST_F(TrackedObjectsTest, BirthOnlyToValueWorkerThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
   // We don't initialize system with a thread name, so we're viewed as a worker
   // thread.
@@ -365,7 +371,8 @@ TEST_F(TrackedObjectsTest, BirthOnlyToValueWorkerThread) {
 }
 
 TEST_F(TrackedObjectsTest, BirthOnlyToValueMainThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Use a well named thread.
@@ -409,7 +416,8 @@ TEST_F(TrackedObjectsTest, BirthOnlyToValueMainThread) {
 }
 
 TEST_F(TrackedObjectsTest, LifeCycleToValueMainThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Use a well named thread.
@@ -470,7 +478,8 @@ TEST_F(TrackedObjectsTest, LifeCycleToValueMainThread) {
 // our tallied births are matched by tallied deaths (except for when the
 // task is still running, or is queued).
 TEST_F(TrackedObjectsTest, LifeCycleMidDeactivatedToValueMainThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Use a well named thread.
@@ -491,7 +500,8 @@ TEST_F(TrackedObjectsTest, LifeCycleMidDeactivatedToValueMainThread) {
   pending_task.time_posted = kTimePosted;  // Overwrite implied Now().
 
   // Turn off tracking now that we have births.
-  EXPECT_TRUE(ThreadData::InitializeAndSetTrackingStatus(false));
+  EXPECT_TRUE(ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::DEACTIVATED));
 
   const TrackedTime kStartOfRun = TrackedTime() +
       Duration::FromMilliseconds(5);
@@ -532,7 +542,7 @@ TEST_F(TrackedObjectsTest, LifeCycleMidDeactivatedToValueMainThread) {
 // We will deactivate tracking before starting a life cycle, and neither
 // the birth nor the death will be recorded.
 TEST_F(TrackedObjectsTest, LifeCyclePreDeactivatedToValueMainThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(false))
+  if (!ThreadData::InitializeAndSetTrackingStatus(ThreadData::DEACTIVATED))
     return;
 
   // Use a well named thread.
@@ -571,7 +581,8 @@ TEST_F(TrackedObjectsTest, LifeCyclePreDeactivatedToValueMainThread) {
 }
 
 TEST_F(TrackedObjectsTest, LifeCycleToValueWorkerThread) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Don't initialize thread, so that we appear as a worker thread.
@@ -662,7 +673,8 @@ TEST_F(TrackedObjectsTest, LifeCycleToValueWorkerThread) {
 }
 
 TEST_F(TrackedObjectsTest, TwoLives) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Use a well named thread.
@@ -727,7 +739,8 @@ TEST_F(TrackedObjectsTest, TwoLives) {
 }
 
 TEST_F(TrackedObjectsTest, DifferentLives) {
-  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+  if (!ThreadData::InitializeAndSetTrackingStatus(
+      ThreadData::PROFILING_CHILDREN_ACTIVE))
     return;
 
   // Use a well named thread.