Safepointing in GC

runtime/vm/thread.cc

Index: runtime/vm/thread.cc
diff --git a/runtime/vm/thread.cc b/runtime/vm/thread.cc
index 3b3eb3308d30b292147168449f670ba1f62033f5..dff8b1db7f831607ff64fe68181255bbc4fb0d71 100644
--- a/runtime/vm/thread.cc
+++ b/runtime/vm/thread.cc
@@ -75,7 +75,8 @@ void Thread::CleanUp() {
 
 Thread::Thread(bool init_vm_constants)
     : isolate_(NULL),
-      store_buffer_block_(NULL) {
+      store_buffer_block_(NULL),
+      pass_safepoint_(kNoSafepointId) {
   ClearState();
 #define DEFAULT_INIT(type_name, member_name, init_expr, default_init_value)    \
   member_name = default_init_value;
@@ -168,11 +169,13 @@ void Thread::ExitIsolate() {
 }
 
 
-void Thread::EnterIsolateAsHelper(Isolate* isolate) {
+void Thread::EnterIsolateAsHelper(Isolate* isolate,
+                                  SafepointId pass_safepoint) {
   Thread* thread = Thread::Current();
   ASSERT(thread != NULL);
   ASSERT(thread->isolate() == NULL);
   thread->isolate_ = isolate;
+  thread->pass_safepoint_ = pass_safepoint;
   ASSERT(isolate->heap() != NULL);
   thread->heap_ = isolate->heap();
   ASSERT(thread->thread_state() == NULL);
@@ -192,6 +195,7 @@ void Thread::ExitIsolateAsHelper() {
   ASSERT(isolate != NULL);
   thread->Unschedule();
   thread->set_thread_state(NULL);
+  thread->pass_safepoint_ = kNoSafepointId;
   thread->isolate_ = NULL;
   thread->heap_ = NULL;
   ASSERT(!isolate->MutatorThreadIsCurrentThread());