Heap profiler: implement diffing of snapshots.

test/cctest/test-heap-profiler.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 //
 // Tests for heap profiler
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 #include "v8.h"
 #include "heap-profiler.h"
 #include "snapshot.h"
 #include "string-stream.h"
@@ skipping 38 matching lines @@
  private:
   i::Handle<i::String> f_name_;
   int f_count_;
 };
 
 }  // namespace
 
 
 TEST(ConstructorProfile) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   CompileAndRunScript(
       "function F() {}  // A constructor\n"
       "var f1 = new F();\n"
       "var f2 = new F();\n");
 
   ConstructorHeapProfileTestHelper cons_profile;
   i::AssertNoAllocation no_alloc;
   i::HeapIterator iterator;
   for (i::HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next())
@@ skipping 66 matching lines @@
     value.DebugPrint(&stream);
     V8_Fatal(file, line, "CHECK_NE(%s, %s) failed\n%s",
              expected_source, value_source,
              *stream.ToCString());
   }
 }
 
 
 TEST(ClustersCoarserSimple) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   i::ZoneScope zn_scope(i::DELETE_ON_EXIT);
 
   JSObjectsRetainerTree tree;
   JSObjectsCluster function(i::Heap::function_class_symbol());
   JSObjectsCluster a(*i::Factory::NewStringFromAscii(i::CStrVector("A")));
   JSObjectsCluster b(*i::Factory::NewStringFromAscii(i::CStrVector("B")));
 
   // o1 <- Function
   JSObjectsCluster o1 =
@@ skipping 17 matching lines @@
 
   CHECK_EQ(coarser.GetCoarseEquivalent(o1), coarser.GetCoarseEquivalent(o2));
   CHECK_EQ(coarser.GetCoarseEquivalent(o3), coarser.GetCoarseEquivalent(o4));
   CHECK_NE(coarser.GetCoarseEquivalent(o1), coarser.GetCoarseEquivalent(o3));
   CHECK_EQ(JSObjectsCluster(), coarser.GetCoarseEquivalent(o5));
 }
 
 
 TEST(ClustersCoarserMultipleConstructors) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   i::ZoneScope zn_scope(i::DELETE_ON_EXIT);
 
   JSObjectsRetainerTree tree;
   JSObjectsCluster function(i::Heap::function_class_symbol());
 
   // o1 <- Function
   JSObjectsCluster o1 =
       AddHeapObjectToTree(&tree, i::Heap::Object_symbol(), 0x100, &function);
   // a1 <- Function
   JSObjectsCluster a1 =
       AddHeapObjectToTree(&tree, i::Heap::Array_symbol(), 0x1000, &function);
   // o2 <- Function
   JSObjectsCluster o2 =
       AddHeapObjectToTree(&tree, i::Heap::Object_symbol(), 0x200, &function);
   // a2 <- Function
   JSObjectsCluster a2 =
       AddHeapObjectToTree(&tree, i::Heap::Array_symbol(), 0x2000, &function);
 
   ClustersCoarser coarser;
   coarser.Process(&tree);
 
   CHECK_EQ(coarser.GetCoarseEquivalent(o1), coarser.GetCoarseEquivalent(o2));
   CHECK_EQ(coarser.GetCoarseEquivalent(a1), coarser.GetCoarseEquivalent(a2));
 }
 
 
 TEST(ClustersCoarserPathsTraversal) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   i::ZoneScope zn_scope(i::DELETE_ON_EXIT);
 
   JSObjectsRetainerTree tree;
 
   // On the following graph:
   //
   // p
   //   <- o21 <- o11 <-
   // q                  o
@@ skipping 31 matching lines @@
   CHECK_NE(JSObjectsCluster(), coarser.GetCoarseEquivalent(p));
   CHECK_EQ(coarser.GetCoarseEquivalent(p), coarser.GetCoarseEquivalent(q));
   CHECK_EQ(coarser.GetCoarseEquivalent(q), coarser.GetCoarseEquivalent(r));
   CHECK_NE(coarser.GetCoarseEquivalent(o11), coarser.GetCoarseEquivalent(p));
   CHECK_NE(coarser.GetCoarseEquivalent(o21), coarser.GetCoarseEquivalent(p));
 }
 
 
 TEST(ClustersCoarserSelf) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   i::ZoneScope zn_scope(i::DELETE_ON_EXIT);
 
   JSObjectsRetainerTree tree;
 
   // On the following graph:
   //
   // p (self-referencing)
   //          <- o1     <-
   // q (self-referencing)   o
@@ skipping 73 matching lines @@
   i::StringStream stream_;
   i::SmartPointer<const char> stream_str_;
   i::List<const char*> lines_;
 };
 
 }  // namespace
 
 
 TEST(RetainerProfile) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   CompileAndRunScript(
       "function A() {}\n"
       "function B(x) { this.x = x; }\n"
       "function C(x) { this.x1 = x; this.x2 = x; }\n"
       "var a = new A();\n"
       "var b1 = new B(a), b2 = new B(a);\n"
       "var c = new C(a);");
 
   RetainerHeapProfile ret_profile;
@@ skipping 47 matching lines @@
   bool has_A2;
   bool has_B2;
   bool has_C2;
 };
 
 }  // namespace
 
 
 static const v8::HeapGraphNode* GetGlobalObject(
     const v8::HeapSnapshot* snapshot) {
-  CHECK_EQ(1, snapshot->GetHead()->GetChildrenCount());
-  return snapshot->GetHead()->GetChild(0)->GetToNode();
+  CHECK_EQ(1, snapshot->GetRoot()->GetChildrenCount());
+  return snapshot->GetRoot()->GetChild(0)->GetToNode();
 }
 
 
 static const v8::HeapGraphNode* GetProperty(const v8::HeapGraphNode* node,
                                             v8::HeapGraphEdge::Type type,
                                             const char* name) {
   for (int i = 0, count = node->GetChildrenCount(); i < count; ++i) {
     const v8::HeapGraphEdge* prop = node->GetChild(i);
     v8::String::AsciiValue prop_name(prop->GetName());
     if (prop->GetType() == type && strcmp(name, *prop_name) == 0)
       return prop->GetToNode();
   }
   return NULL;
 }
 
 
+static bool IsNodeRetainedAs(const v8::HeapGraphNode* node,
+                             v8::HeapGraphEdge::Type type,
+                             const char* name) {
+  for (int i = 0, count = node->GetRetainersCount(); i < count; ++i) {
+    const v8::HeapGraphEdge* prop = node->GetRetainer(i);
+    v8::String::AsciiValue prop_name(prop->GetName());
+    if (prop->GetType() == type && strcmp(name, *prop_name) == 0)
+      return true;
+  }
+  return false;
+}
+
+
 static bool HasString(const v8::HeapGraphNode* node, const char* contents) {
   for (int i = 0, count = node->GetChildrenCount(); i < count; ++i) {
     const v8::HeapGraphEdge* prop = node->GetChild(i);
     const v8::HeapGraphNode* node = prop->GetToNode();
     if (node->GetType() == v8::HeapGraphNode::STRING) {
       v8::String::AsciiValue node_name(node->GetName());
       if (strcmp(contents, *node_name) == 0) return true;
     }
   }
   return false;
 }
 
 
 TEST(HeapSnapshot) {
   v8::HandleScope scope;
-
   v8::Handle<v8::String> token1 = v8::String::New("token1");
-  v8::Handle<v8::Context> env1 = v8::Context::New();
+  LocalContext env1;
   env1->SetSecurityToken(token1);
-  env1->Enter();
 
   CompileAndRunScript(
       "function A1() {}\n"
       "function B1(x) { this.x = x; }\n"
       "function C1(x) { this.x1 = x; this.x2 = x; }\n"
       "var a1 = new A1();\n"
       "var b1_1 = new B1(a1), b1_2 = new B1(a1);\n"
       "var c1 = new C1(a1);");
 
   v8::Handle<v8::String> token2 = v8::String::New("token2");
-  v8::Handle<v8::Context> env2 = v8::Context::New();
+  LocalContext env2;
   env2->SetSecurityToken(token2);
-  env2->Enter();
 
   CompileAndRunScript(
       "function A2() {}\n"
       "function B2(x) { return function() { return typeof x; }; }\n"
       "function C2(x) { this.x1 = x; this.x2 = x; this[1] = x; }\n"
       "var a2 = new A2();\n"
       "var b2_1 = new B2(a2), b2_2 = new B2(a2);\n"
       "var c2 = new C2(a2);");
   const v8::HeapSnapshot* snapshot_env2 =
       v8::HeapProfiler::TakeSnapshot(v8::String::New("env2"));
@@ skipping 67 matching lines @@
   CHECK(has_c2_x1_ref);
   CHECK(has_c2_x2_ref);
   CHECK(has_c2_1_ref);
   CHECK(has_b2_1_x_ref);
   CHECK(has_b2_2_x_ref);
 }
 
 
 TEST(HeapSnapshotCodeObjects) {
   v8::HandleScope scope;
-  v8::Handle<v8::Context> env = v8::Context::New();
-  env->Enter();
+  LocalContext env;
 
   CompileAndRunScript(
       "function lazy(x) { return x - 1; }\n"
       "function compiled(x) { return x + 1; }\n"
       "compiled(1)");
   const v8::HeapSnapshot* snapshot =
       v8::HeapProfiler::TakeSnapshot(v8::String::New("code"));
 
   const v8::HeapGraphNode* global = GetGlobalObject(snapshot);
   const v8::HeapGraphNode* compiled =
@@ skipping 34 matching lines @@
       if (HasString(node, "x")) {
         lazy_references_x = true;
         break;
       }
     }
   }
   CHECK(compiled_references_x);
   CHECK(!lazy_references_x);
 }
 
+
+TEST(HeapEntryIdsAndGC) {
+  v8::HandleScope scope;
+  LocalContext env;
+
+  CompileAndRunScript(
+      "function A() {}\n"
+      "function B(x) { this.x = x; }\n"
+      "var a = new A();\n"
+      "var b = new B(a);");
+  const v8::HeapSnapshot* snapshot1 =
+      v8::HeapProfiler::TakeSnapshot(v8::String::New("s1"));
+
+  i::Heap::CollectAllGarbage(true);  // Enforce compaction.
+
+  const v8::HeapSnapshot* snapshot2 =
+      v8::HeapProfiler::TakeSnapshot(v8::String::New("s2"));
+
+  const v8::HeapGraphNode* global1 = GetGlobalObject(snapshot1);
+  const v8::HeapGraphNode* global2 = GetGlobalObject(snapshot2);
+  CHECK_NE(0, global1->GetId());
+  CHECK_EQ(global1->GetId(), global2->GetId());
+  const v8::HeapGraphNode* A1 =
+      GetProperty(global1, v8::HeapGraphEdge::PROPERTY, "A");
+  const v8::HeapGraphNode* A2 =
+      GetProperty(global2, v8::HeapGraphEdge::PROPERTY, "A");
+  CHECK_NE(0, A1->GetId());
+  CHECK_EQ(A1->GetId(), A2->GetId());
+  const v8::HeapGraphNode* B1 =
+      GetProperty(global1, v8::HeapGraphEdge::PROPERTY, "B");
+  const v8::HeapGraphNode* B2 =
+      GetProperty(global2, v8::HeapGraphEdge::PROPERTY, "B");
+  CHECK_NE(0, B1->GetId());
+  CHECK_EQ(B1->GetId(), B2->GetId());
+  const v8::HeapGraphNode* a1 =
+      GetProperty(global1, v8::HeapGraphEdge::PROPERTY, "a");
+  const v8::HeapGraphNode* a2 =
+      GetProperty(global2, v8::HeapGraphEdge::PROPERTY, "a");
+  CHECK_NE(0, a1->GetId());
+  CHECK_EQ(a1->GetId(), a2->GetId());
+  const v8::HeapGraphNode* b1 =
+      GetProperty(global1, v8::HeapGraphEdge::PROPERTY, "b");
+  const v8::HeapGraphNode* b2 =
+      GetProperty(global2, v8::HeapGraphEdge::PROPERTY, "b");
+  CHECK_NE(0, b1->GetId());
+  CHECK_EQ(b1->GetId(), b2->GetId());
+}
+
+
+TEST(HeapSnapshotsDiff) {
+  v8::HandleScope scope;
+  LocalContext env;
+
+  CompileAndRunScript(
+      "function A() {}\n"
+      "function B(x) { this.x = x; }\n"
+      "var a = new A();\n"
+      "var b = new B(a);");
+  const v8::HeapSnapshot* snapshot1 =
+      v8::HeapProfiler::TakeSnapshot(v8::String::New("s1"));
+
+  CompileAndRunScript(
+      "delete a;\n"
+      "b.x = null;\n"
+      "var a = new A();\n"
+      "var b2 = new B(a);");
+  const v8::HeapSnapshot* snapshot2 =
+      v8::HeapProfiler::TakeSnapshot(v8::String::New("s2"));
+
+  const v8::HeapSnapshotsDiff* diff = snapshot1->CompareWith(snapshot2);
+
+  // Verify additions: ensure that addition of A and B was detected.
+  const v8::HeapGraphNode* additions_root = diff->GetAdditionsRoot();
+  bool found_A = false, found_B = false;
+  uint64_t s1_A_id = 0;
+  for (int i = 0, count = additions_root->GetChildrenCount(); i < count; ++i) {
+    const v8::HeapGraphEdge* prop = additions_root->GetChild(i);
+    const v8::HeapGraphNode* node = prop->GetToNode();
+    if (node->GetType() == v8::HeapGraphNode::OBJECT) {
+      v8::String::AsciiValue node_name(node->GetName());
+      if (strcmp(*node_name, "A") == 0) {
+        CHECK(IsNodeRetainedAs(node, v8::HeapGraphEdge::PROPERTY, "a"));
+        CHECK(!found_A);
+        found_A = true;
+        s1_A_id = node->GetId();
+      } else if (strcmp(*node_name, "B") == 0) {
+        CHECK(IsNodeRetainedAs(node, v8::HeapGraphEdge::PROPERTY, "b2"));
+        CHECK(!found_B);
+        found_B = true;
+      }
+    }
+  }
+  CHECK(found_A);
+  CHECK(found_B);
+
+  // Verify deletions: ensure that deletion of A was detected.
+  const v8::HeapGraphNode* deletions_root = diff->GetDeletionsRoot();
+  bool found_A_del = false;
+  uint64_t s2_A_id = 0;
+  for (int i = 0, count = deletions_root->GetChildrenCount(); i < count; ++i) {
+    const v8::HeapGraphEdge* prop = deletions_root->GetChild(i);
+    const v8::HeapGraphNode* node = prop->GetToNode();
+    if (node->GetType() == v8::HeapGraphNode::OBJECT) {
+      v8::String::AsciiValue node_name(node->GetName());
+      if (strcmp(*node_name, "A") == 0) {
+        CHECK(IsNodeRetainedAs(node, v8::HeapGraphEdge::PROPERTY, "a"));
+        CHECK(!found_A_del);
+        found_A_del = true;
+        s2_A_id = node->GetId();
+      }
+    }
+  }
+  CHECK(found_A_del);
+  CHECK_NE(0, s1_A_id);
+  CHECK(s1_A_id != s2_A_id);
+}
+
 #endif  // ENABLE_LOGGING_AND_PROFILING