Record allocation stack traces

src/heap-snapshot-generator.cc

 // Copyright 2013 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 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // 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 "v8.h"
 
 #include "heap-snapshot-generator-inl.h"
 
+#include "allocation-tracker.h"
 #include "heap-profiler.h"
 #include "debug.h"
 #include "types.h"
 
 namespace v8 {
 namespace internal {
 
 
 HeapGraphEdge::HeapGraphEdge(Type type, const char* name, int from, int to)
     : type_(type),
@@ skipping 585 matching lines @@
       ids_(heap) {
 }
 
 
 static void DeleteHeapSnapshot(HeapSnapshot** snapshot_ptr) {
   delete *snapshot_ptr;
 }
 
 
 HeapSnapshotsCollection::~HeapSnapshotsCollection() {
+  delete allocation_tracker_;
   snapshots_.Iterate(DeleteHeapSnapshot);
 }
 
 
+void HeapSnapshotsCollection::StartHeapObjectsTracking() {
+  ids_.UpdateHeapObjectsMap();
+  if (allocation_tracker_ == NULL) {
+    allocation_tracker_ = new AllocationTracker(&ids_, names());
+  }
+  is_tracking_objects_ = true;
+}
+
+
+void HeapSnapshotsCollection::StopHeapObjectsTracking() {
+  ids_.StopHeapObjectsTracking();
+  if (allocation_tracker_ != NULL) {
+    delete allocation_tracker_;
+    allocation_tracker_ = NULL;
+  }
+}
+
+
 HeapSnapshot* HeapSnapshotsCollection::NewSnapshot(const char* name,
                                                    unsigned uid) {
   is_tracking_objects_ = true;  // Start watching for heap objects moves.
   return new HeapSnapshot(this, name, uid);
 }
 
 
 void HeapSnapshotsCollection::SnapshotGenerationFinished(
     HeapSnapshot* snapshot) {
   ids_.SnapshotGenerationFinished();
@@ skipping 23 matching lines @@
     if (ids_.FindEntry(obj->address()) == id) {
       ASSERT(object == NULL);
       object = obj;
       // Can't break -- kFilterUnreachable requires full heap traversal.
     }
   }
   return object != NULL ? Handle<HeapObject>(object) : Handle<HeapObject>();
 }
 
 
+void HeapSnapshotsCollection::NewObjectEvent(Address addr, int size) {
+  DisallowHeapAllocation no_allocation;
+  ids_.NewObject(addr, size);
+  if (allocation_tracker_ != NULL) {
+    allocation_tracker_->NewObjectEvent(addr, size);
+  }
+}
+
+
 size_t HeapSnapshotsCollection::GetUsedMemorySize() const {
   size_t size = sizeof(*this);
   size += names_.GetUsedMemorySize();
   size += ids_.GetUsedMemorySize();
   size += GetMemoryUsedByList(snapshots_);
   for (int i = 0; i < snapshots_.length(); ++i) {
     size += snapshots_[i]->RawSnapshotSize();
   }
   return size;
 }
@@ skipping 1778 matching lines @@
   bool aborted_;
 };
 
 
 // type, name|index, to_node.
 const int HeapSnapshotJSONSerializer::kEdgeFieldsCount = 3;
 // type, name, id, self_size, children_index.
 const int HeapSnapshotJSONSerializer::kNodeFieldsCount = 5;
 
 void HeapSnapshotJSONSerializer::Serialize(v8::OutputStream* stream) {
+  if (AllocationTracker* allocation_tracker =
+      snapshot_->collection()->allocation_tracker()) {
+    allocation_tracker->PrepareForSerialization();
+  }
   ASSERT(writer_ == NULL);
   writer_ = new OutputStreamWriter(stream);
   SerializeImpl();
   delete writer_;
   writer_ = NULL;
 }
 
 
 void HeapSnapshotJSONSerializer::SerializeImpl() {
   ASSERT(0 == snapshot_->root()->index());
   writer_->AddCharacter('{');
   writer_->AddString("\"snapshot\":{");
   SerializeSnapshot();
   if (writer_->aborted()) return;
   writer_->AddString("},\n");
   writer_->AddString("\"nodes\":[");
   SerializeNodes();
   if (writer_->aborted()) return;
   writer_->AddString("],\n");
   writer_->AddString("\"edges\":[");
   SerializeEdges();
   if (writer_->aborted()) return;
   writer_->AddString("],\n");
+
+  writer_->AddString("\"trace_function_infos\":[");
+  SerializeTraceNodeInfos();
+  if (writer_->aborted()) return;
+  writer_->AddString("],\n");
+  writer_->AddString("\"trace_tree\":[");
+  SerializeTraceTree();
+  if (writer_->aborted()) return;
+  writer_->AddString("],\n");
+
   writer_->AddString("\"strings\":[");
   SerializeStrings();
   if (writer_->aborted()) return;
   writer_->AddCharacter(']');
   writer_->AddCharacter('}');
   writer_->Finalize();
 }
 
 
 int HeapSnapshotJSONSerializer::GetStringId(const char* s) {
@@ skipping 140 matching lines @@
     JSON_S("edge_types") ":" JSON_A(
         JSON_A(
             JSON_S("context") ","
             JSON_S("element") ","
             JSON_S("property") ","
             JSON_S("internal") ","
             JSON_S("hidden") ","
             JSON_S("shortcut") ","
             JSON_S("weak")) ","
         JSON_S("string_or_number") ","
-        JSON_S("node"))));
+        JSON_S("node")) ","
+    JSON_S("trace_function_info_fields") ":" JSON_A(
+        JSON_S("function_id") ","
+        JSON_S("name") ","
+        JSON_S("script_name") ","
+        JSON_S("script_id") ","
+        JSON_S("line") ","
+        JSON_S("column")) ","
+    JSON_S("trace_node_fields") ":" JSON_A(
+        JSON_S("id") ","
+        JSON_S("function_id") ","
+        JSON_S("count") ","
+        JSON_S("size") ","
+        JSON_S("children"))));
 #undef JSON_S
 #undef JSON_O
 #undef JSON_A
   writer_->AddString(",\"node_count\":");
   writer_->AddNumber(snapshot_->entries().length());
   writer_->AddString(",\"edge_count\":");
   writer_->AddNumber(snapshot_->edges().length());
+  writer_->AddString(",\"trace_function_count\":");
+  uint32_t count = 0;
+  AllocationTracker* tracker = snapshot_->collection()->allocation_tracker();
+  if (tracker) {
+    count = tracker->id_to_function_info()->occupancy();
+  }
+  writer_->AddNumber(count);
 }
 
 
 static void WriteUChar(OutputStreamWriter* w, unibrow::uchar u) {
   static const char hex_chars[] = "0123456789ABCDEF";
   w->AddString("\\u");
   w->AddCharacter(hex_chars[(u >> 12) & 0xf]);
   w->AddCharacter(hex_chars[(u >> 8) & 0xf]);
   w->AddCharacter(hex_chars[(u >> 4) & 0xf]);
   w->AddCharacter(hex_chars[u & 0xf]);
 }
 
 
+void HeapSnapshotJSONSerializer::SerializeTraceTree() {
+  AllocationTracker* tracker = snapshot_->collection()->allocation_tracker();
+  if (!tracker) return;
+  AllocationTraceTree* traces = tracker->trace_tree();
+  SerializeTraceNode(traces->root());
+}
+
+
+void HeapSnapshotJSONSerializer::SerializeTraceNode(AllocationTraceNode* node) {
+  // The buffer needs space for 4 unsigned ints, 4 commas, [ and \0
+  const int kBufferSize =
+      4 * MaxDecimalDigitsIn<sizeof(unsigned)>::kUnsigned  // NOLINT
+      + 4 + 1 + 1;

[Hannes Payer (out of office), 2013/10/21 09:57:22]

Why don't you define this constant in the header and initialize it in the
constructor?

[yurys, 2013/10/21 15:07:56]

Not sure I follow you here, this constant is used as the template parameter here
(similar to the other methods in this file) and it is an implementation detail
of this particular method. What's the point in moving the constant into the
header?

+  EmbeddedVector<char, kBufferSize> buffer;
+  int buffer_pos = 0;
+  buffer_pos = utoa(node->id(), buffer, buffer_pos);
+  buffer[buffer_pos++] = ',';
+  buffer_pos = utoa(node->function_id(), buffer, buffer_pos);
+  buffer[buffer_pos++] = ',';
+  buffer_pos = utoa(node->allocation_count(), buffer, buffer_pos);
+  buffer[buffer_pos++] = ',';
+  buffer_pos = utoa(node->allocation_size(), buffer, buffer_pos);
+  buffer[buffer_pos++] = ',';
+  buffer[buffer_pos++] = '[';
+  buffer[buffer_pos++] = '\0';
+  writer_->AddString(buffer.start());
+
+  Vector<AllocationTraceNode*> children = node->children();
+  for (int i = 0; i < children.length(); i++) {
+    if (i > 0) {
+      writer_->AddCharacter(',');
+    }
+    SerializeTraceNode(children[i]);
+  }
+  writer_->AddCharacter(']');
+}
+
+
+// 0-based position is converted to 1-based during the serialization.
+static int SerializePosition(int position, const Vector<char>& buffer,
+                             int buffer_pos) {
+  if (position == -1) {
+    buffer[buffer_pos++] = '0';
+  } else {
+    ASSERT(position >= 0);
+    buffer_pos = utoa(static_cast<unsigned>(position + 1), buffer, buffer_pos);
+  }
+  return buffer_pos;
+}
+
+
+void HeapSnapshotJSONSerializer::SerializeTraceNodeInfos() {
+  AllocationTracker* tracker = snapshot_->collection()->allocation_tracker();
+  if (!tracker) return;
+  // The buffer needs space for 6 unsigned ints, 6 commas, \n and \0
+  const int kBufferSize =
+      6 * MaxDecimalDigitsIn<sizeof(unsigned)>::kUnsigned  // NOLINT
+      + 6 + 1 + 1;

[Hannes Payer (out of office), 2013/10/21 09:57:22]

Same here.

+  EmbeddedVector<char, kBufferSize> buffer;
+  HashMap* id_to_function_info = tracker->id_to_function_info();
+  bool first_entry = true;
+  for (HashMap::Entry* p = id_to_function_info->Start();
+       p != NULL;
+       p = id_to_function_info->Next(p)) {
+    SnapshotObjectId id =
+        static_cast<SnapshotObjectId>(reinterpret_cast<intptr_t>(p->key));
+    AllocationTracker::FunctionInfo* info =
+        reinterpret_cast<AllocationTracker::FunctionInfo* >(p->value);
+    int buffer_pos = 0;
+    if (first_entry) {
+      first_entry = false;
+    } else {
+      buffer[buffer_pos++] = ',';
+    }
+    buffer_pos = utoa(id, buffer, buffer_pos);
+    buffer[buffer_pos++] = ',';
+    buffer_pos = utoa(GetStringId(info->name), buffer, buffer_pos);
+    buffer[buffer_pos++] = ',';
+    buffer_pos = utoa(GetStringId(info->script_name), buffer, buffer_pos);
+    buffer[buffer_pos++] = ',';
+    // The cast is safe because script id is a non-negative Smi.
+    buffer_pos = utoa(static_cast<unsigned>(info->script_id), buffer,
+        buffer_pos);
+    buffer[buffer_pos++] = ',';
+    buffer_pos = SerializePosition(info->line, buffer, buffer_pos);
+    buffer[buffer_pos++] = ',';
+    buffer_pos = SerializePosition(info->column, buffer, buffer_pos);
+    buffer[buffer_pos++] = '\n';
+    buffer[buffer_pos++] = '\0';
+    writer_->AddString(buffer.start());
+  }
+}
+
+
 void HeapSnapshotJSONSerializer::SerializeString(const unsigned char* s) {
   writer_->AddCharacter('\n');
   writer_->AddCharacter('\"');
   for ( ; *s != '\0'; ++s) {
     switch (*s) {
       case '\b':
         writer_->AddString("\\b");
         continue;
       case '\f':
         writer_->AddString("\\f");
@@ skipping 49 matching lines @@
   writer_->AddString("\"<dummy>\"");
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 } }  // namespace v8::internal