Revert "Background finalization."

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 1534 matching lines @@
 
 
 class FinalizeWeakPersistentHandlesVisitor : public HandleVisitor {
  public:
   FinalizeWeakPersistentHandlesVisitor() : HandleVisitor(Thread::Current()) {
   }
 
   void VisitHandle(uword addr) {
     FinalizablePersistentHandle* handle =
         reinterpret_cast<FinalizablePersistentHandle*>(addr);
-    FinalizationQueue* queue = NULL;  // Finalize in the foreground.
-    handle->UpdateUnreachable(thread()->isolate(), queue);
+    handle->UpdateUnreachable(thread()->isolate());
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FinalizeWeakPersistentHandlesVisitor);
 };
 
 
 void Isolate::LowLevelShutdown() {
   // Ensure we have a zone and handle scope so that we can call VM functions,
   // but we no longer allocate new heap objects.
@@ skipping 102 matching lines @@
     }
   }
 
   // Remove this isolate from the list *before* we start tearing it down, to
   // avoid exposing it in a state of decay.
   RemoveIsolateFromList(this);
 
   if (heap_ != NULL) {
     // Wait for any concurrent GC tasks to finish before shutting down.
     // TODO(koda): Support faster sweeper shutdown (e.g., after current page).
-    {
-      PageSpace* old_space = heap_->old_space();
-      MonitorLocker ml(old_space->tasks_lock());
-      while (old_space->tasks() > 0) {
-        ml.Wait();
-      }
-    }
-
-    // Wait for background finalization to finish before shutting down.
-    {
-      MonitorLocker ml(heap_->finalization_tasks_lock());
-      while (heap_->finalization_tasks() > 0) {
-        ml.Wait();
-      }
+    PageSpace* old_space = heap_->old_space();
+    MonitorLocker ml(old_space->tasks_lock());
+    while (old_space->tasks() > 0) {
+      ml.Wait();
     }
   }
 
   // Then, proceed with low-level teardown.
   LowLevelShutdown();
 
 #if defined(DEBUG)
   // No concurrent sweeper tasks should be running at this point.
   if (heap_ != NULL) {
     PageSpace* old_space = heap_->old_space();
@@ skipping 1100 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart