Added tracking of memory usage within ApiNativeScopes. Usage to be displayed within Observatory.

BUG=
R=asiva@google.com

Review-Url: https://codereview.chromium.org/2650583014 .

runtime/vm/dart_api_state.cc

@@ -14,6 +14,8 @@
 
 namespace dart {
 
+intptr_t ApiNativeScope::current_memory_usage_ = 0;
+
 BackgroundFinalizer::BackgroundFinalizer(Isolate* isolate,
                                          FinalizationQueue* queue)
     : isolate_(isolate), queue_(queue) {

runtime/vm/dart_api_state.h

@@ -674,11 +674,18 @@ class ApiNativeScope {
     ASSERT(Current() == NULL);
     OSThread::SetThreadLocal(Api::api_native_key_,
                              reinterpret_cast<uword>(this));
+    // We manually increment the memory usage counter since there is memory
+    // initially allocated within the zone on creation.
+    IncrementNativeScopeMemoryUsage(zone_.GetZone()->CapacityInBytes());
   }
 
   ~ApiNativeScope() {
     ASSERT(Current() == this);
     OSThread::SetThreadLocal(Api::api_native_key_, 0);
+    // We must also manually decrement the memory usage counter since the native
+    // is still holding it's initial memory and ~Zone() won't be able to
+    // determine which memory usage counter to decrement.
+    DecrementNativeScopeMemoryUsage(zone_.GetZone()->CapacityInBytes());
   }
 
   static inline ApiNativeScope* Current() {
@@ -686,6 +693,16 @@ class ApiNativeScope {
         OSThread::GetThreadLocal(Api::api_native_key_));
   }
 
+  static intptr_t current_memory_usage() { return current_memory_usage_; }
+
+  static void IncrementNativeScopeMemoryUsage(intptr_t size) {
+    AtomicOperations::IncrementBy(&current_memory_usage_, size);
+  }
+
+  static void DecrementNativeScopeMemoryUsage(intptr_t size) {
+    AtomicOperations::DecrementBy(&current_memory_usage_, size);
+  }
+
   Zone* zone() {
     Zone* result = zone_.GetZone();
     ASSERT(result->handles()->CountScopedHandles() == 0);
@@ -694,6 +711,9 @@ class ApiNativeScope {
   }
 
  private:
+  // The current total memory usage within ApiNativeScopes.
+  static intptr_t current_memory_usage_;
+
   ApiZone zone_;
 };
 

runtime/vm/zone.cc

@@ -6,6 +6,7 @@
 
 #include "platform/assert.h"
 #include "platform/utils.h"
+#include "vm/dart_api_state.h"
 #include "vm/flags.h"
 #include "vm/handles_impl.h"
 #include "vm/heap.h"
@@ -46,9 +47,10 @@ void Zone::Segment::DeleteSegmentList(Segment* head) {
   Thread* current_thread = Thread::Current();
   while (current != NULL) {
     if (current_thread != NULL) {
-      // TODO(bkonyi) Handle special case of segment deletion within native
-      // isolate.
       current_thread->DecrementMemoryUsage(current->size());
+    } else if (ApiNativeScope::Current() != NULL) {
+      // If there is no current thread, we might be inside of a native scope.
+      ApiNativeScope::DecrementNativeScopeMemoryUsage(current->size());
     }
     Segment* next = current->next();
 #ifdef DEBUG
@@ -74,15 +76,19 @@ Zone::Segment* Zone::Segment::New(intptr_t size, Zone::Segment* next) {
 #endif
   result->next_ = next;
   result->size_ = size;
-  if (Thread::Current() != NULL) {
-    // TODO(bkonyi) Handle special case of segment creation within native
-    // isolate.
-    Thread::Current()->IncrementMemoryUsage(size);
+  Thread* current = Thread::Current();
+  if (current != NULL) {
+    current->IncrementMemoryUsage(size);
+  } else if (ApiNativeScope::Current() != NULL) {
+    // If there is no current thread, we might be inside of a native scope.
+    ApiNativeScope::IncrementNativeScopeMemoryUsage(size);
   }
   return result;
 }
 
-
+// TODO(bkonyi): We need to account for the initial chunk size when a new zone
+// is created within a new thread or ApiNativeScope when calculating high
+// watermarks or memory consumption.
 Zone::Zone()
     : initial_buffer_(buffer_, kInitialChunkSize),
       position_(initial_buffer_.start()),
@@ -117,7 +123,6 @@ void Zone::DeleteAll() {
   if (large_segments_ != NULL) {
     Segment::DeleteSegmentList(large_segments_);
   }
-
 // Reset zone state.
 #ifdef DEBUG
   memset(initial_buffer_.pointer(), kZapDeletedByte, initial_buffer_.size());

runtime/vm/zone_test.cc

@@ -228,4 +228,20 @@ UNIT_TEST_CASE(PrintZoneMemoryInfoToJSON) {
 }
 #endif
 
+
+UNIT_TEST_CASE(NativeScopeZoneAllocation) {
+  ASSERT(ApiNativeScope::Current() == NULL);
+  ASSERT(Thread::Current() == NULL);
+  EXPECT_EQ(0, ApiNativeScope::current_memory_usage());
+  {
+    ApiNativeScope scope;
+    EXPECT_EQ(scope.zone()->CapacityInBytes(),
+              ApiNativeScope::current_memory_usage());
+    (void)Dart_ScopeAllocate(2048);
+    EXPECT_EQ(scope.zone()->CapacityInBytes(),
+              ApiNativeScope::current_memory_usage());
+  }
+  EXPECT_EQ(0, ApiNativeScope::current_memory_usage());
+}
+
 }  // namespace dart