Chunk-wise marking stack processing.

runtime/vm/store_buffer.cc

Index: runtime/vm/store_buffer.cc
diff --git a/runtime/vm/store_buffer.cc b/runtime/vm/store_buffer.cc
index f4fbad79f51c17274c5eb471934b049a79ec2675..7fe58c74290511b3938a448735e28b89494a8940 100644
--- a/runtime/vm/store_buffer.cc
+++ b/runtime/vm/store_buffer.cc
@@ -90,7 +90,7 @@ void StoreBuffer::PushBlock(StoreBufferBlock* block, bool check_threshold) {
 }
 
 
-StoreBufferBlock* StoreBuffer::PopBlock() {
+StoreBufferBlock* StoreBuffer::PopNonFullBlock() {
   {
     MutexLocker ml(mutex_);
     if (!partial_.IsEmpty()) {
@@ -112,6 +112,24 @@ StoreBufferBlock* StoreBuffer::PopEmptyBlock() {
 }
 
 
+StoreBufferBlock* StoreBuffer::PopNonEmptyBlock() {
+  MutexLocker ml(mutex_);
+  if (!full_.IsEmpty()) {
+    return full_.Pop();
+  } else if (!partial_.IsEmpty()) {
+    return partial_.Pop();
+  } else {
+    return NULL;
+  }
+}
+
+
+bool StoreBuffer::IsEmpty() {
+  MutexLocker ml(global_mutex_);
+  return full_.IsEmpty() && partial_.IsEmpty();
+}
+
+
 StoreBuffer::List::~List() {
   while (!IsEmpty()) {
     delete Pop();