| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "platform/assert.h" |
| #include "vm/object_graph.h" |
| #include "vm/unit_test.h" |
| |
| namespace dart { |
| |
| class CounterVisitor : public ObjectGraph::Visitor { |
| public: |
| // Records the number of objects and total size visited, excluding 'skip' |
| // and any objects only reachable through 'skip'. |
| CounterVisitor(RawObject* skip, RawObject* expected_parent) |
| : count_(0), size_(0), skip_(skip), expected_parent_(expected_parent) { } |
| |
| virtual Direction VisitObject(ObjectGraph::StackIterator* it) { |
| RawObject* obj = it->Get(); |
| if (obj == skip_) { |
| EXPECT(it->MoveToParent()); |
| EXPECT_EQ(expected_parent_, it->Get()); |
| return kBacktrack; |
| } |
| ++count_; |
| size_ += obj->Size(); |
| return kProceed; |
| } |
| |
| int count() const { return count_; } |
| int size() const { return size_; } |
| |
| private: |
| int count_; |
| intptr_t size_; |
| RawObject* skip_; |
| RawObject* expected_parent_; |
| }; |
| |
| |
| TEST_CASE(ObjectGraph) { |
| Isolate* isolate = thread->isolate(); |
| // Create a simple object graph with objects a, b, c, d: |
| // a+->b+->c |
| // + + |
| // | v |
| // +-->d |
| Array& a = Array::Handle(Array::New(12, Heap::kNew)); |
| Array& b = Array::Handle(Array::New(2, Heap::kOld)); |
| Array& c = Array::Handle(Array::New(0, Heap::kOld)); |
| Array& d = Array::Handle(Array::New(0, Heap::kOld)); |
| a.SetAt(10, b); |
| b.SetAt(0, c); |
| b.SetAt(1, d); |
| a.SetAt(11, d); |
| intptr_t a_size = a.raw()->Size(); |
| intptr_t b_size = b.raw()->Size(); |
| intptr_t c_size = c.raw()->Size(); |
| intptr_t d_size = d.raw()->Size(); |
| { |
| // No more allocation; raw pointers ahead. |
| NoSafepointScope no_safepoint_scope; |
| RawObject* b_raw = b.raw(); |
| // Clear handles to cut unintended retained paths. |
| b = Array::null(); |
| c = Array::null(); |
| d = Array::null(); |
| ObjectGraph graph(thread); |
| { |
| // Compare count and size when 'b' is/isn't skipped. |
| CounterVisitor with(Object::null(), Object::null()); |
| graph.IterateObjectsFrom(a, &with); |
| CounterVisitor without(b_raw, a.raw()); |
| graph.IterateObjectsFrom(a, &without); |
| // Only 'b' and 'c' were cut off. |
| EXPECT_EQ(2, with.count() - without.count()); |
| EXPECT_EQ(b_size + c_size, |
| with.size() - without.size()); |
| } |
| { |
| // Like above, but iterate over the entire isolate. The counts and sizes |
| // are thus larger, but the difference should still be just 'b' and 'c'. |
| CounterVisitor with(Object::null(), Object::null()); |
| graph.IterateObjects(&with); |
| CounterVisitor without(b_raw, a.raw()); |
| graph.IterateObjects(&without); |
| EXPECT_EQ(2, with.count() - without.count()); |
| EXPECT_EQ(b_size + c_size, |
| with.size() - without.size()); |
| } |
| EXPECT_EQ(a_size + b_size + c_size + d_size, |
| graph.SizeRetainedByInstance(a)); |
| } |
| { |
| // Get hold of c again. |
| b ^= a.At(10); |
| c ^= b.At(0); |
| b = Array::null(); |
| ObjectGraph graph(thread); |
| // A retaining path should end like this: c <- b <- a <- ... |
| { |
| HANDLESCOPE(thread); |
| // Test null, empty, and length 1 array. |
| intptr_t null_length = graph.RetainingPath(&c, Object::null_array()); |
| intptr_t empty_length = graph.RetainingPath(&c, Object::empty_array()); |
| Array& path = Array::Handle(Array::New(1, Heap::kNew)); |
| intptr_t one_length = graph.RetainingPath(&c, path); |
| EXPECT_EQ(null_length, empty_length); |
| EXPECT_EQ(null_length, one_length); |
| EXPECT_LE(3, null_length); |
| } |
| { |
| HANDLESCOPE(thread); |
| Array& path = Array::Handle(Array::New(6, Heap::kNew)); |
| // Trigger a full GC to increase probability of concurrent tasks. |
| isolate->heap()->CollectAllGarbage(); |
| intptr_t length = graph.RetainingPath(&c, path); |
| EXPECT_LE(3, length); |
| Array& expected_c = Array::Handle(); |
| expected_c ^= path.At(0); |
| // c is the first element in b. |
| Smi& offset_from_parent = Smi::Handle(); |
| offset_from_parent ^= path.At(1); |
| EXPECT_EQ(Array::element_offset(0), |
| offset_from_parent.Value() * kWordSize); |
| Array& expected_b = Array::Handle(); |
| expected_b ^= path.At(2); |
| // b is the element with index 10 in a. |
| offset_from_parent ^= path.At(3); |
| EXPECT_EQ(Array::element_offset(10), |
| offset_from_parent.Value() * kWordSize); |
| Array& expected_a = Array::Handle(); |
| expected_a ^= path.At(4); |
| EXPECT(expected_c.raw() == c.raw()); |
| EXPECT(expected_b.raw() == a.At(10)); |
| EXPECT(expected_a.raw() == a.raw()); |
| } |
| } |
| } |
| |
| } // namespace dart |