Make GlobalHandle::NodeBlock deletable

test/cctest/test-global-handles.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
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+#include <map>
+#include <vector>
+
 #include "global-handles.h"
 
 #include "cctest.h"
 
 using namespace v8::internal;
 using v8::UniqueId;
 
 
 static List<Object*> skippable_objects;
 static List<Object*> can_skip_called_objects;
@@ skipping 270 matching lines @@
   ASSERT(implicit_refs->at(0)->parent ==
          reinterpret_cast<HeapObject**>(g1s1.location()));
   ASSERT(implicit_refs->at(0)->length == 2);
   ASSERT(implicit_refs->at(0)->children[0] == g1c1.location());
   ASSERT(implicit_refs->at(0)->children[1] == g1c2.location());
   ASSERT(implicit_refs->at(1)->parent ==
          reinterpret_cast<HeapObject**>(g2s1.location()));
   ASSERT(implicit_refs->at(1)->length == 1);
   ASSERT(implicit_refs->at(1)->children[0] == g2c1.location());
 }
+
+
+static const int kBlockSize = 256;
+
+
+TEST(BlockCollection) {
+  v8::V8::Initialize();
+  Isolate* isolate = Isolate::Current();
+  GlobalHandles* global_handles = isolate->global_handles();
+  CHECK_EQ(0, global_handles->block_count());
+  CHECK_EQ(0, global_handles->global_handles_count());
+  Object* object = isolate->heap()->undefined_value();
+  const int kNumberOfBlocks = 5;
+  typedef Handle<Object> Block[kBlockSize];
+  for (int round = 0; round < 3; round++) {
+    Block blocks[kNumberOfBlocks];
+    for (int i = 0; i < kNumberOfBlocks; i++) {
+      for (int j = 0; j < kBlockSize; j++) {
+        blocks[i][j] = global_handles->Create(object);
+      }
+    }
+    CHECK_EQ(kNumberOfBlocks, global_handles->block_count());
+    for (int i = 0; i < kNumberOfBlocks; i++) {
+      for (int j = 0; j < kBlockSize; j++) {
+        global_handles->Destroy(blocks[i][j].location());
+      }
+    }
+    isolate->heap()->CollectAllAvailableGarbage("BlockCollection");
+    CHECK_EQ(0, global_handles->global_handles_count());
+    CHECK_EQ(1, global_handles->block_count());
+  }
+}
+
+
+class RandomMutationData {
+ public:
+  explicit RandomMutationData(Isolate* isolate)
+      : isolate_(isolate), weak_offset_(0) {}
+
+  void Mutate(double strong_growth_tendency,
+              double weak_growth_tendency = 0.05) {
+    for (int i = 0; i < kBlockSize * 100; i++) {
+      if (rng_.next(strong_growth_tendency)) {
+        AddStrong();
+      } else if (strong_nodes_.size() != 0) {
+        size_t to_remove = rng_.next(static_cast<int>(strong_nodes_.size()));
+        RemoveStrong(to_remove);
+      }
+      if (rng_.next(weak_growth_tendency)) AddWeak();
+      if (rng_.next(0.05)) {
+#ifdef DEBUG
+        isolate_->global_handles()->VerifyBlockInvariants();
+#endif
+      }
+      if (rng_.next(0.0001)) {
+        isolate_->heap()->PerformScavenge();
+      } else if (rng_.next(0.00003)) {
+        isolate_->heap()->CollectAllAvailableGarbage();
+      }
+      CheckSizes();
+    }
+  }
+
+  void RemoveAll() {
+    while (strong_nodes_.size() != 0) {
+      RemoveStrong(strong_nodes_.size() - 1);
+    }
+    isolate_->heap()->PerformScavenge();
+    isolate_->heap()->CollectAllAvailableGarbage();
+    CheckSizes();
+  }
+
+ private:
+  typedef std::vector<Object**> NodeVector;
+  typedef std::map<int32_t, Object**> NodeMap;
+
+  void CheckSizes() {
+    int stored_sizes =
+        static_cast<int>(strong_nodes_.size() + weak_nodes_.size());
+    CHECK_EQ(isolate_->global_handles()->global_handles_count(), stored_sizes);
+  }
+
+  void AddStrong() {
+    Object* object = isolate_->heap()->undefined_value();
+    Object** location = isolate_->global_handles()->Create(object).location();
+    strong_nodes_.push_back(location);
+  }
+
+  void RemoveStrong(size_t offset) {
+    isolate_->global_handles()->Destroy(strong_nodes_.at(offset));
+    strong_nodes_.erase(strong_nodes_.begin() + offset);
+  }
+
+  void AddWeak() {
+    v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(isolate_);
+    v8::HandleScope scope(isolate);
+    v8::Local<v8::Object> object = v8::Object::New();
+    int32_t offset = ++weak_offset_;
+    object->Set(7, v8::Integer::New(offset, isolate));
+    v8::Persistent<v8::Object> persistent(isolate, object);
+    persistent.MakeWeak(isolate, this, WeakCallback);
+    persistent.MarkIndependent();
+    Object** location = v8::Utils::OpenPersistent(persistent).location();
+    bool inserted =
+        weak_nodes_.insert(std::make_pair(offset, location)).second;
+    CHECK(inserted);
+  }
+
+  static void WeakCallback(v8::Isolate* isolate,
+                           v8::Persistent<v8::Object>* persistent,
+                           RandomMutationData* data) {
+    v8::Local<v8::Object> object =
+        v8::Local<v8::Object>::New(isolate, *persistent);
+    int32_t offset =
+        v8::Local<v8::Integer>::Cast(object->Get(7))->Int32Value();
+    Object** location = v8::Utils::OpenPersistent(persistent).location();
+    NodeMap& weak_nodes = data->weak_nodes_;
+    NodeMap::iterator it = weak_nodes.find(offset);
+    CHECK(it != weak_nodes.end());
+    CHECK(it->second == location);
+    weak_nodes.erase(it);
+    persistent->Dispose();
+  }
+
+  Isolate* isolate_;
+  RandomNumberGenerator rng_;
+  NodeVector strong_nodes_;
+  NodeMap weak_nodes_;
+  int32_t weak_offset_;
+};
+
+
+TEST(RandomMutation) {
+  v8::V8::Initialize();
+  Isolate* isolate = Isolate::Current();
+  CHECK_EQ(0, isolate->global_handles()->block_count());
+  HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(
+      v8::Context::New(reinterpret_cast<v8::Isolate*>(isolate)));
+  RandomMutationData data(isolate);
+  // grow some
+  data.Mutate(0.65);
+  data.Mutate(0.55);
+  // balanced mutation
+  for (int i = 0; i < 3; i++) data.Mutate(0.50);
+  // shrink some
+  data.Mutate(0.45);
+  data.Mutate(0.35);
+  // clear everything
+  data.RemoveAll();
+}