Reland concurrent sweeping of code space.

src/heap/store-buffer.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/v8.h"
 
 #include "src/counters.h"
 #include "src/heap/store-buffer-inl.h"
@@ skipping 450 matching lines @@
               // We skip free space objects.
               if (!heap_object->IsFiller()) {
                 DCHECK(heap_object->IsMap());
                 FindPointersToNewSpaceInRegion(
                     heap_object->address() + Map::kPointerFieldsBeginOffset,
                     heap_object->address() + Map::kPointerFieldsEndOffset,
                     slot_callback);
               }
             }
           } else {
-            if (!page->SweepingCompleted()) {
-              heap_->mark_compact_collector()->SweepInParallel(page, owner);
-              if (!page->SweepingCompleted()) {
-                // We were not able to sweep that page, i.e., a concurrent
-                // sweeper thread currently owns this page.
-                // TODO(hpayer): This may introduce a huge pause here. We
-                // just care about finish sweeping of the scan on scavenge page.
-                heap_->mark_compact_collector()->EnsureSweepingCompleted();
-              }
-            }
             CHECK(page->owner() == heap_->old_space());
+            heap_->mark_compact_collector()->EnsureSweepingCompleted(page,
+                                                                     owner);
             HeapObjectIterator iterator(page, NULL);
             for (HeapObject* heap_object = iterator.Next(); heap_object != NULL;
                  heap_object = iterator.Next()) {
               // We iterate over objects that contain new space pointers only.
               Address obj_address = heap_object->address();
               const int start_offset = HeapObject::kHeaderSize;
               const int end_offset = heap_object->Size();
 
               switch (heap_object->ContentType()) {
                 case HeapObjectContents::kTaggedValues: {
@@ skipping 93 matching lines @@
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     DCHECK(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
 }
 }  // namespace internal
 }  // namespace v8