Record allocation stack traces

src/allocation-tracker.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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// 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 "allocation-tracker.h"
+
+#include "heap-snapshot-generator.h"
+#include "frames-inl.h"
+
+namespace v8 {
+namespace internal {
+
+AllocationTraceNode::AllocationTraceNode(
+    AllocationTraceTree* tree, SnapshotObjectId shared_function_info_id)
+    : tree_(tree),
+      function_id_(shared_function_info_id),
+      total_size_(0),
+      allocation_count_(0),
+      id_(tree->next_node_id()) {
+}
+
+
+AllocationTraceNode::~AllocationTraceNode() {
+}
+
+
+AllocationTraceNode* AllocationTraceNode::FindChild(SnapshotObjectId id) {
+  for (int i = 0; i < children_.length(); i++) {
+    AllocationTraceNode* node = children_[i];

[loislo, 2013/10/18 08:30:38]

what are you expectations about the average number of children.
Especially in case of the highe stacks (more than 64)?

[yurys, 2013/10/18 09:04:32]

I'd expect it to be <10, if we see some nodes with a great number of children
passing some threshold we can switch to a hashmap instead of the list. It think
plain list is fine for now.

+    if (node->function_id() == id) return node;
+  }
+  return NULL;
+}
+
+
+AllocationTraceNode* AllocationTraceNode::FindOrAddChild(SnapshotObjectId id) {
+  AllocationTraceNode* child = FindChild(id);
+  if (child == NULL) {
+    child = new AllocationTraceNode(tree_, id);
+    children_.Add(child);
+  }
+  return child;
+}
+
+
+void AllocationTraceNode::AddAllocation(unsigned size) {
+  total_size_ += size;
+  ++allocation_count_;
+}
+
+
+void AllocationTraceNode::Print(int indent, AllocationTracker* tracker) {
+  OS::Print("%10u %10u %*c",
+            total_size_, allocation_count_,
+            indent, ' ');
+  if (tracker != NULL) {
+    const char* name = "<unknown function>";
+    if (function_id_ != 0) {
+      AllocationTracker::FunctionInfo* info =
+          tracker->GetFunctionInfo(function_id_);
+      if (info != NULL) {
+        name = info->name;
+      }
+    }
+    OS::Print("%s #%u", name, id_);
+  } else {
+    OS::Print("%u #%u", function_id_, id_);
+  }
+  OS::Print("\n");
+  indent += 2;
+  for (int i = 0; i < children_.length(); i++) {
+    children_[i]->Print(indent, tracker);
+  }
+}
+
+
+AllocationTraceTree::AllocationTraceTree()
+    : next_node_id_(1),
+      root_(this, 0) {
+}
+
+
+AllocationTraceTree::~AllocationTraceTree() {
+}
+
+
+AllocationTraceNode* AllocationTraceTree::AddPathFromEnd(
+    const Vector<SnapshotObjectId>& path) {
+  AllocationTraceNode* node = root();
+  for (SnapshotObjectId* entry = path.start() + path.length() - 1;
+       entry != path.start() - 1;
+       --entry) {
+    node = node->FindOrAddChild(*entry);
+  }
+  return node;
+}
+
+
+void AllocationTraceTree::Print(AllocationTracker* tracker) {
+  OS::Print("[AllocationTraceTree:]\n");
+  OS::Print("Total size | Allocation count | Function id | id\n");
+  root()->Print(0, tracker);
+}
+
+void AllocationTracker::DeleteUnresolvedLocation(
+    UnresolvedLocation** location) {
+  delete *location;
+}
+
+
+AllocationTracker::FunctionInfo::FunctionInfo()
+    : name(""),
+      script_name(""),
+      script_id(0),
+      line(-1),
+      column(-1) {
+}
+
+
+static bool AddressesMatch(void* key1, void* key2) {
+  return key1 == key2;
+}
+
+
+AllocationTracker::AllocationTracker(
+    HeapObjectsMap* ids, StringsStorage* names)
+    : ids_(ids),
+      names_(names),
+      id_to_function_info_(AddressesMatch) {
+}
+
+
+AllocationTracker::~AllocationTracker() {
+  unresolved_locations_.Iterate(DeleteUnresolvedLocation);
+}
+
+
+void AllocationTracker::PrepareForSerialization() {
+  List<UnresolvedLocation*> copy(unresolved_locations_.length());
+  copy.AddAll(unresolved_locations_);
+  unresolved_locations_.Clear();
+  for (int i = 0; i < copy.length(); i++) {
+    copy[i]->Resolve();
+    delete copy[i];
+  }
+}
+
+
+void AllocationTracker::NewObjectEvent(Address addr, int size) {
+  DisallowHeapAllocation no_allocation;
+  Isolate* isolate = ids_->heap()->isolate();
+  int length = 0;
+  StackTraceFrameIterator it(isolate);
+  while (!it.done() && length < kMaxAllocationTraceLength) {
+    JavaScriptFrame* frame = it.frame();
+    SharedFunctionInfo* shared = frame->function()->shared();
+    SnapshotObjectId id = ids_->FindEntry(shared->address());
+    allocation_trace_buffer_[length++] = id;
+    AddFunctionInfo(shared, id);
+    it.Advance();
+  }
+  AllocationTraceNode* top_node = allocation_traces_.AddPathFromEnd(
+      Vector<SnapshotObjectId>(allocation_trace_buffer_, length));
+  top_node->AddAllocation(size);
+}
+
+
+static uint32_t SnapshotObjectIdHash(SnapshotObjectId id) {
+  return ComputeIntegerHash(static_cast<uint32_t>(id),
+                            v8::internal::kZeroHashSeed);
+}
+
+
+AllocationTracker::FunctionInfo* AllocationTracker::GetFunctionInfo(
+    SnapshotObjectId id) {
+  HashMap::Entry* entry = id_to_function_info_.Lookup(
+      reinterpret_cast<void*>(id), SnapshotObjectIdHash(id), false);
+  if (entry == NULL) {
+    return NULL;
+  }
+  return reinterpret_cast<FunctionInfo*>(entry->value);
+}
+
+
+void AllocationTracker::AddFunctionInfo(SharedFunctionInfo* shared,
+                                        SnapshotObjectId id) {
+  HashMap::Entry* entry = id_to_function_info_.Lookup(
+      reinterpret_cast<void*>(id), SnapshotObjectIdHash(id), true);
+  if (entry->value == NULL) {
+    FunctionInfo* info = new FunctionInfo();
+    info->name = names_->GetFunctionName(shared->DebugName());
+    if (shared->script()->IsScript()) {
+      Script* script = Script::cast(shared->script());
+      if (script->name()->IsName()) {
+        Name* name = Name::cast(script->name());
+        info->script_name = names_->GetName(name);
+      }
+      info->script_id = script->id()->value();
+      // Converting start offset into line and column may cause heap
+      // allocations so we postpone them until snapshot serialization.
+      unresolved_locations_.Add(new UnresolvedLocation(
+          script,
+          shared->start_position(),
+          info));
+    }
+    entry->value = info;
+  }
+}
+
+
+AllocationTracker::UnresolvedLocation::UnresolvedLocation(
+    Script* script, int start, FunctionInfo* info)
+    : start_position_(start),
+      info_(info) {
+  script_ = Handle<Script>::cast(
+      script->GetIsolate()->global_handles()->Create(script));
+  GlobalHandles::MakeWeak(
+      reinterpret_cast<Object**>(script_.location()),
+      this, &HandleWeakScript);
+}
+
+
+AllocationTracker::UnresolvedLocation::~UnresolvedLocation() {
+  if (!script_.is_null()) {
+    script_->GetIsolate()->global_handles()->Destroy(
+        reinterpret_cast<Object**>(script_.location()));
+  }
+}
+
+
+void AllocationTracker::UnresolvedLocation::Resolve() {
+  if (script_.is_null()) return;
+  info_->line = GetScriptLineNumber(script_, start_position_);
+  info_->column = GetScriptColumnNumber(script_, start_position_);
+}
+
+
+void AllocationTracker::UnresolvedLocation::HandleWeakScript(
+    v8::Isolate* isolate,
+    v8::Persistent<v8::Value>* obj,
+    void* data) {
+  UnresolvedLocation* location = reinterpret_cast<UnresolvedLocation*>(data);
+  location->script_ = Handle<Script>::null();
+  obj->Dispose();
+}
+
+
+} }  // namespace v8::internal