Wait for sweeper threads only if we have to.

src/spaces.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 "src/v8.h"
 
 #include "src/base/platform/platform.h"
 #include "src/full-codegen.h"
 #include "src/macro-assembler.h"
 #include "src/mark-compact.h"
@@ skipping 49 matching lines @@
              size_func);
   ASSERT(page->WasSweptPrecisely());
 }
 
 
 void HeapObjectIterator::Initialize(PagedSpace* space,
                                     Address cur, Address end,
                                     HeapObjectIterator::PageMode mode,
                                     HeapObjectCallback size_f) {
   // Check that we actually can iterate this space.
-  ASSERT(!space->was_swept_conservatively());
+  ASSERT(space->is_iterable());
 
   space_ = space;
   cur_addr_ = cur;
   cur_end_ = end;
   page_mode_ = mode;
   size_func_ = size_f;
 }
 
 
 // We have hit the end of the page and should advance to the next block of
@@ skipping 847 matching lines @@
 
 // -----------------------------------------------------------------------------
 // PagedSpace implementation
 
 PagedSpace::PagedSpace(Heap* heap,
                        intptr_t max_capacity,
                        AllocationSpace id,
                        Executability executable)
     : Space(heap, id, executable),
       free_list_(this),
-      was_swept_conservatively_(false),
+      is_iterable_(true),
+      is_swept_concurrently_(false),
       unswept_free_bytes_(0),
       end_of_unswept_pages_(NULL) {
   if (id == CODE_SPACE) {
     area_size_ = heap->isolate()->memory_allocator()->
         CodePageAreaSize();
   } else {
     area_size_ = Page::kPageSize - Page::kObjectStartOffset;
   }
   max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize)
       * AreaSize();
@@ skipping 201 matching lines @@
 }
 
 
 #ifdef DEBUG
 void PagedSpace::Print() { }
 #endif
 
 #ifdef VERIFY_HEAP
 void PagedSpace::Verify(ObjectVisitor* visitor) {
   // We can only iterate over the pages if they were swept precisely.
-  if (was_swept_conservatively_) return;
+  if (!is_iterable_) return;
 
   bool allocation_pointer_found_in_space =
       (allocation_info_.top() == allocation_info_.limit());
   PageIterator page_iterator(this);
   while (page_iterator.has_next()) {
     Page* page = page_iterator.next();
     CHECK(page->owner() == this);
     if (page == Page::FromAllocationTop(allocation_info_.top())) {
       allocation_pointer_found_in_space = true;
     }
@@ skipping 1368 matching lines @@
   // This counter will be increased for pages which will be swept by the
   // sweeper threads.
   unswept_free_bytes_ = 0;
 
   // Clear the free list before a full GC---it will be rebuilt afterward.
   free_list_.Reset();
 }
 
 
 intptr_t PagedSpace::SizeOfObjects() {
-  ASSERT(heap()->mark_compact_collector()->IsConcurrentSweepingInProgress() ||
-         (unswept_free_bytes_ == 0));
+  ASSERT(heap()->mark_compact_collector()->
+      IsConcurrentSweepingInProgress(this) || (unswept_free_bytes_ == 0));
   return Size() - unswept_free_bytes_ - (limit() - top());
 }
 
 
 // After we have booted, we have created a map which represents free space
 // on the heap.  If there was already a free list then the elements on it
 // were created with the wrong FreeSpaceMap (normally NULL), so we need to
 // fix them.
 void PagedSpace::RepairFreeListsAfterBoot() {
   free_list_.RepairLists(heap());
@@ skipping 14 matching lines @@
     allocation_info_.set_limit(NULL);
   }
 }
 
 
 HeapObject* PagedSpace::WaitForSweeperThreadsAndRetryAllocation(
     int size_in_bytes) {
   MarkCompactCollector* collector = heap()->mark_compact_collector();
 
   // If sweeper threads are still running, wait for them.
-  if (collector->IsConcurrentSweepingInProgress()) {
+  if (collector->IsConcurrentSweepingInProgress(this)) {
     collector->WaitUntilSweepingCompleted();
 
     // After waiting for the sweeper threads, there may be new free-list
     // entries.
     return free_list_.Allocate(size_in_bytes);
   }
   return NULL;
 }
 
 
 HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
   // Allocation in this space has failed.
 
   // If sweeper threads are active, try to re-fill the free-lists.
   MarkCompactCollector* collector = heap()->mark_compact_collector();
-  if (collector->IsConcurrentSweepingInProgress()) {
+  if (collector->IsConcurrentSweepingInProgress(this)) {
     collector->RefillFreeList(this);
 
     // Retry the free list allocation.
     HeapObject* object = free_list_.Allocate(size_in_bytes);
     if (object != NULL) return object;
   }
 
   // Free list allocation failed and there is no next page.  Fail if we have
   // hit the old generation size limit that should cause a garbage
   // collection.
@@ skipping 143 matching lines @@
 }
 
 
 void PagedSpace::ReportStatistics() {
   int pct = static_cast<int>(Available() * 100 / Capacity());
   PrintF("  capacity: %" V8_PTR_PREFIX "d"
              ", waste: %" V8_PTR_PREFIX "d"
              ", available: %" V8_PTR_PREFIX "d, %%%d\n",
          Capacity(), Waste(), Available(), pct);
 
-  if (was_swept_conservatively_) return;
+  if (!is_iterable_) return;
   ClearHistograms(heap()->isolate());
   HeapObjectIterator obj_it(this);
   for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next())
     CollectHistogramInfo(obj);
   ReportHistogram(heap()->isolate(), true);
 }
 #endif
 
 
 // -----------------------------------------------------------------------------
@@ skipping 360 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal