Introduce object visitor to estimate the size of a native context.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <stdlib.h>
 #include <utility>
 
 #include "src/v8.h"
 
 #include "src/compilation-cache.h"
+#include "src/context-measure.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
 #include "src/factory.h"
 #include "src/global-handles.h"
 #include "src/ic/ic.h"
 #include "src/macro-assembler.h"
 #include "src/snapshot/snapshot.h"
 #include "test/cctest/cctest.h"
 
 using namespace v8::internal;
@@ skipping 6217 matching lines @@
                                  array->address(),
                                  array->address() + array->Size());
   CHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
         HeapObject::RawField(heap->empty_fixed_array(),
                              FixedArrayBase::kLengthOffset));
   CHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
         HeapObject::RawField(heap->empty_fixed_array(),
                              FixedArrayBase::kLengthOffset));
   delete buffer;
 }
+
+
+TEST(ContextMeasure) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  LocalContext context;
+
+  int size_upper_limit = 0;
+  int count_upper_limit = 0;
+  HeapIterator it(CcTest::heap());
+  for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
+    size_upper_limit += obj->Size();
+    count_upper_limit++;
+  }
+
+  ContextMeasure measure(*isolate->native_context());
+
+  PrintF("Context size        : %d bytes\n", measure.Size());
+  PrintF("Context object count: %d\n", measure.Count());
+
+  CHECK_LE(1000, measure.Count());
+  CHECK_LE(50000, measure.Size());
+
+  CHECK_LE(measure.Count(), count_upper_limit);
+  CHECK_LE(measure.Size(), size_upper_limit);
+}