Support for extracting user-data from activity tracking.

base/debug/activity_analyzer.cc

Index: base/debug/activity_analyzer.cc
diff --git a/base/debug/activity_analyzer.cc b/base/debug/activity_analyzer.cc
index 0c30d8d0c213c2e973dec707cc439d97e58e3fe7..90714bdd0f871e55759bfea90ea101faa5319265 100644
--- a/base/debug/activity_analyzer.cc
+++ b/base/debug/activity_analyzer.cc
@@ -15,9 +15,12 @@
 namespace base {
 namespace debug {
 
+ThreadActivityAnalyzer::Snapshot::Snapshot() {}
+ThreadActivityAnalyzer::Snapshot::~Snapshot() {}
+
 ThreadActivityAnalyzer::ThreadActivityAnalyzer(
     const ThreadActivityTracker& tracker)
-    : activity_snapshot_valid_(tracker.Snapshot(&activity_snapshot_)) {}
+    : activity_snapshot_valid_(tracker.CreateSnapshot(&activity_snapshot_)) {}
 
 ThreadActivityAnalyzer::ThreadActivityAnalyzer(void* base, size_t size)
     : ThreadActivityAnalyzer(ThreadActivityTracker(base, size)) {}
@@ -33,6 +36,22 @@ ThreadActivityAnalyzer::ThreadActivityAnalyzer(
 
 ThreadActivityAnalyzer::~ThreadActivityAnalyzer() {}
 
+void ThreadActivityAnalyzer::AddGlobalInformation(
+    GlobalActivityAnalyzer* global) {
+  if (!IsValid())
+    return;
+
+  // User-data is held at the global scope even though it's referenced an the

[manzagop (departed), 2016/12/02 22:13:33]

typo: referenced an -> at

[bcwhite, 2016/12/08 21:30:56]

Done.

+  // thread scope.
+  activity_snapshot_.user_data_stack.clear();
+  for (auto& activity : activity_snapshot_.activity_stack) {
+    // The global GetUserDataSnapshot will return an empty snapshot if the ref
+    // or id is not valid.
+    activity_snapshot_.user_data_stack.push_back(global->GetUserDataSnapshot(
+        activity.user_data_ref, activity.user_data_id));
+  }
+}
+
 GlobalActivityAnalyzer::GlobalActivityAnalyzer(
     std::unique_ptr<PersistentMemoryAllocator> allocator)
     : allocator_(std::move(allocator)), allocator_iterator_(allocator_.get()) {}
@@ -83,6 +102,46 @@ ThreadActivityAnalyzer* GlobalActivityAnalyzer::GetAnalyzerForThread(
   return found->second.get();
 }
 
+ActivityUserData::Snapshot GlobalActivityAnalyzer::GetUserDataSnapshot(
+    uint32_t ref,
+    uint32_t id) {
+  ActivityUserData::Snapshot snapshot;
+
+  void* memory = allocator_->GetAsArray<char>(
+      ref, GlobalActivityTracker::kTypeIdUserDataRecord,
+      PersistentMemoryAllocator::kSizeAny);
+  if (memory) {
+    size_t size = allocator_->GetAllocSize(ref);
+    const ActivityUserData user_data(memory, size);
+    user_data.CreateSnapshot(&snapshot);
+    if (user_data.id() != id) {
+      // This allocation has been overwritten since it was created. Return an
+      // empty snapshot because whatever was captured is incorrect.
+      snapshot.clear();
+    }
+  }
+
+  return snapshot;
+}
+
+ActivityUserData::Snapshot GlobalActivityAnalyzer::GetGlobalUserDataSnapshot() {
+  ActivityUserData::Snapshot snapshot;
+
+  PersistentMemoryAllocator::Reference ref =
+      PersistentMemoryAllocator::Iterator(allocator_.get())
+          .GetNextOfType(GlobalActivityTracker::kTypeIdGlobalDataRecord);
+  void* memory = allocator_->GetAsArray<char>(
+      ref, GlobalActivityTracker::kTypeIdGlobalDataRecord,
+      PersistentMemoryAllocator::kSizeAny);
+  if (memory) {
+    size_t size = allocator_->GetAllocSize(ref);
+    const ActivityUserData global_data(memory, size);
+    global_data.CreateSnapshot(&snapshot);
+  }
+
+  return snapshot;
+}
+
 GlobalActivityAnalyzer::ProgramLocation
 GlobalActivityAnalyzer::GetProgramLocationFromAddress(uint64_t address) {
   // TODO(bcwhite): Implement this.
@@ -123,6 +182,7 @@ void GlobalActivityAnalyzer::PrepareAllAnalyzers() {
         base, allocator_->GetAllocSize(tracker_ref)));
     if (!analyzer->IsValid())
       continue;
+    analyzer->AddGlobalInformation(this);
 
     // Add this analyzer to the map of known ones, indexed by a unique thread
     // identifier.