Sane asynchronous debugging and stack traces

runtime/vm/thread.cc

Index: runtime/vm/thread.cc
diff --git a/runtime/vm/thread.cc b/runtime/vm/thread.cc
index 620e542d209bec406d2116221d63c4c1a3d72e1a..d39b26d9c9657b5dc686fb1ac42de23b9a0053d9 100644
--- a/runtime/vm/thread.cc
+++ b/runtime/vm/thread.cc
@@ -101,6 +101,7 @@ Thread::Thread(Isolate* isolate)
       active_stacktrace_(Object::null()),
       resume_pc_(0),
       sticky_error_(Error::null()),
+      async_stack_trace_(StackTrace::null()),
       compiler_stats_(NULL),
       REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_INITIALIZERS)
           REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_SCOPE_INIT) safepoint_state_(0),
@@ -292,6 +293,22 @@ const char* Thread::TaskKindToCString(TaskKind kind) {
 }
 
 
+RawStackTrace* Thread::async_stack_trace() const {
+  return async_stack_trace_;
+}
+
+
+void Thread::set_async_stack_trace(const StackTrace& stack_trace) {
+  ASSERT(!stack_trace.IsNull());
+  async_stack_trace_ = stack_trace.raw();
+}
+
+
+void Thread::clear_async_stack_trace() {
+  async_stack_trace_ = StackTrace::null();
+}
+
+
 bool Thread::EnterIsolate(Isolate* isolate) {
   const bool kIsMutatorThread = true;
   Thread* thread = isolate->ScheduleThread(kIsMutatorThread);
@@ -670,6 +687,7 @@ void Thread::VisitObjectPointers(ObjectPointerVisitor* visitor,
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&active_exception_));
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&active_stacktrace_));
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&sticky_error_));
+  visitor->VisitPointer(reinterpret_cast<RawObject**>(&async_stack_trace_));
 
   // Visit the api local scope as it has all the api local handles.
   ApiLocalScope* scope = api_top_scope_;