Make it easier to run an optimized build, turn the GC timings back on, and remove some unnecessary code.

The Class* field is a regular instance field now, so no need to scan it twice.
We do our null checking in ScanObject, so we don't need to duplicate the checks
in each child.

Also count the number of class, array, and other objects we scan.

Change-Id: I9034708d5e0e1edffaccf3cad4785c5fccf3b38e

4 files changed, 31 insertions, 18 deletions

diff --git a/src/heap.cc b/src/heap.cc
index 40bc673..d87c79c 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -61,7 +61,7 @@ void Heap::Init(bool is_verbose_heap, bool is_verbose_gc,
   is_verbose_gc_ = is_verbose_gc;
 
   const Runtime* runtime = Runtime::Current();
-  if (is_verbose_heap_ || runtime->IsVerboseStartup()) {
+  if (Heap::IsVerboseHeap() || runtime->IsVerboseStartup()) {
     LOG(INFO) << "Heap::Init entering";
   }
 
@@ -133,7 +133,7 @@ void Heap::Init(bool is_verbose_heap, bool is_verbose_gc,
   // make it clear that you can't use locks during heap initialization.
   lock_ = new Mutex("Heap lock");
 
-  if (is_verbose_heap_ || runtime->IsVerboseStartup()) {
+  if (Heap::IsVerboseHeap() || runtime->IsVerboseStartup()) {
     LOG(INFO) << "Heap::Init exiting";
   }
 }
@@ -289,7 +289,7 @@ void Heap::RecordFreeLocked(size_t freed_objects, size_t freed_bytes) {
 
 void Heap::RecordImageAllocations(Space* space) {
   const Runtime* runtime = Runtime::Current();
-  if (is_verbose_heap_ || runtime->IsVerboseStartup()) {
+  if (Heap::IsVerboseHeap() || runtime->IsVerboseStartup()) {
     LOG(INFO) << "Heap::RecordImageAllocations entering";
   }
   DCHECK(!Runtime::Current()->IsStarted());
@@ -302,7 +302,7 @@ void Heap::RecordImageAllocations(Space* space) {
     live_bitmap_->Set(obj);
     current += RoundUp(obj->SizeOf(), kObjectAlignment);
   }
-  if (is_verbose_heap_ || runtime->IsVerboseStartup()) {
+  if (Heap::IsVerboseHeap() || runtime->IsVerboseStartup()) {
     LOG(INFO) << "Heap::RecordImageAllocations exiting";
   }
 }
@@ -369,7 +369,7 @@ Object* Heap::AllocateLocked(Space* space, size_t size) {
     // OLD-TODO: may want to grow a little bit more so that the amount of
     //       free space is equal to the old free space + the
     //       utilization slop for the new allocation.
-    if (is_verbose_gc_) {
+    if (Heap::IsVerboseGc()) {
       LOG(INFO) << "Grow heap (frag case) to " << new_footprint / MB
                 << " for " << size << "-byte allocation";
     }
@@ -383,7 +383,7 @@ Object* Heap::AllocateLocked(Space* space, size_t size) {
   // cleared before throwing an OOME.
 
   // OLD-TODO: wait for the finalizers from the previous GC to finish
-  if (is_verbose_gc_) {
+  if (Heap::IsVerboseGc()) {
     LOG(INFO) << "Forcing collection of SoftReferences for "
               << size << "-byte allocation";
   }
@@ -521,14 +521,14 @@ void Heap::CollectGarbageInternal() {
   size_t percentFree = 100 - static_cast<size_t>(100.0f * float(num_bytes_allocated_) / total);
 
   uint32_t duration = (t1 - t0)/1000/1000;
-  if (is_verbose_gc_) {
+  if (Heap::IsVerboseGc()) {
     LOG(INFO) << "GC freed " << (is_small ? "<" : "") << kib_freed << "KiB, "
               << percentFree << "% free "
               << (num_bytes_allocated_/1024) << "KiB/" << (total/1024) << "KiB, "
               << "paused " << duration << "ms";
   }
   Dbg::GcDidFinish();
-  if (is_verbose_heap_) {
+  if (Heap::IsVerboseHeap()) {
     timings.Dump();
   }
 }
@@ -568,7 +568,7 @@ void Heap::WalkHeap(void(*callback)(const void*, size_t, const void*, size_t, vo
 void Heap::SetIdealFootprint(size_t max_allowed_footprint)
 {
   if (max_allowed_footprint > Heap::growth_size_) {
-    if (is_verbose_gc_) {
+    if (Heap::IsVerboseGc()) {
       LOG(INFO) << "Clamp target GC heap from " << max_allowed_footprint
                 << " to " << Heap::growth_size_;
     }
diff --git a/src/heap.h b/src/heap.h
index 829bbb2..932d490 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -52,7 +52,7 @@ class Heap {
   static void Destroy();
 
   static bool IsVerboseHeap() {
-    return is_verbose_heap_;
+    return is_verbose_heap_ || is_verbose_gc_ /* TODO: remove when pause times are down */;
   }
 
   static bool IsVerboseGc() {
diff --git a/src/mark_sweep.cc b/src/mark_sweep.cc
index 4cc6b22..6b565a1 100644
--- a/src/mark_sweep.cc
+++ b/src/mark_sweep.cc
@@ -218,6 +218,9 @@ inline void MarkSweep::ScanFields(const Object* obj, uint32_t ref_offsets, bool
 // Scans the header, static field references, and interface pointers
 // of a class object.
 inline void MarkSweep::ScanClass(const Object* obj) {
+#ifndef NDEBUG
+  ++class_count_;
+#endif
   ScanInstanceFields(obj);
   ScanStaticFields(obj->AsClass());
 }
@@ -225,8 +228,9 @@ inline void MarkSweep::ScanClass(const Object* obj) {
 // Scans the header of all array objects.  If the array object is
 // specialized to a reference type, scans the array data as well.
 inline void MarkSweep::ScanArray(const Object* obj) {
-  DCHECK(obj != NULL);
-  DCHECK(obj->GetClass() != NULL);
+#ifndef NDEBUG
+  ++array_count_;
+#endif
   MarkObject(obj->GetClass());
   if (obj->IsObjectArray()) {
     const ObjectArray<Object>* array = obj->AsObjectArray<Object>();
@@ -267,12 +271,11 @@ void MarkSweep::DelayReferenceReferent(Object* obj) {
 // scanned object is a reference subclass, it is scheduled for later
 // processing.
 inline void MarkSweep::ScanOther(const Object* obj) {
-  DCHECK(obj != NULL);
-  Class* klass = obj->GetClass();
-  DCHECK(klass != NULL);
-  MarkObject(klass);
+#ifndef NDEBUG
+  ++other_count_;
+#endif
   ScanInstanceFields(obj);
-  if (klass->IsReferenceClass()) {
+  if (obj->GetClass()->IsReferenceClass()) {
     DelayReferenceReferent(const_cast<Object*>(obj));
   }
 }
@@ -423,6 +426,11 @@ void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft,
 }
 
 MarkSweep::~MarkSweep() {
+#ifndef NDEBUG
+  if (Heap::IsVerboseHeap()) {
+    LOG(INFO) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_ << " other=" << other_count_;
+  }
+#endif
   delete mark_stack_;
   mark_bitmap_->Clear();
 }
diff --git a/src/mark_sweep.h b/src/mark_sweep.h
index 8c37456..22aad15 100644
--- a/src/mark_sweep.h
+++ b/src/mark_sweep.h
@@ -22,7 +22,8 @@ class MarkSweep {
       weak_reference_list_(NULL),
       finalizer_reference_list_(NULL),
       phantom_reference_list_(NULL),
-      cleared_reference_list_(NULL) {
+      cleared_reference_list_(NULL),
+      class_count_(0), array_count_(0), other_count_(0) {
   }
 
   ~MarkSweep();
@@ -138,6 +139,10 @@ class MarkSweep {
 
   Object* cleared_reference_list_;
 
+  size_t class_count_;
+  size_t array_count_;
+  size_t other_count_;
+
   friend class InternTableEntryIsUnmarked;
 
   DISALLOW_COPY_AND_ASSIGN(MarkSweep);