Reland of "[heap] Divide available memory upon compaction tasks"

src/heap/mark-compact.cc

 // Copyright 2012 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/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 548 matching lines @@
   }
 
   if (heap()->concurrent_sweeping_enabled()) {
     pending_sweeper_tasks_semaphore_.Wait();
     pending_sweeper_tasks_semaphore_.Wait();
     pending_sweeper_tasks_semaphore_.Wait();
   }
 
   ParallelSweepSpacesComplete();
   sweeping_in_progress_ = false;
-  RefillFreeList(heap()->paged_space(OLD_SPACE));
-  RefillFreeList(heap()->paged_space(CODE_SPACE));
-  RefillFreeList(heap()->paged_space(MAP_SPACE));
+  heap()->old_space()->RefillFreeList();
+  heap()->code_space()->RefillFreeList();
+  heap()->map_space()->RefillFreeList();
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap && !evacuation()) {
     VerifyEvacuation(heap_);
   }
 #endif
 }
 
 
 bool MarkCompactCollector::IsSweepingCompleted() {
   if (!pending_sweeper_tasks_semaphore_.WaitFor(
           base::TimeDelta::FromSeconds(0))) {
     return false;
   }
   pending_sweeper_tasks_semaphore_.Signal();
   return true;
 }
 
 
-void MarkCompactCollector::RefillFreeList(PagedSpace* space) {
-  FreeList* free_list;
-
-  if (space == heap()->old_space()) {
-    free_list = free_list_old_space_.get();
-  } else if (space == heap()->code_space()) {
-    free_list = free_list_code_space_.get();
-  } else if (space == heap()->map_space()) {
-    free_list = free_list_map_space_.get();
-  } else {
-    // Any PagedSpace might invoke RefillFreeLists, so we need to make sure
-    // to only refill them for the old space.
-    return;
-  }
-
-  intptr_t added = space->free_list()->Concatenate(free_list);
-  space->accounting_stats_.IncreaseCapacity(added);
-}
-
-
 void Marking::TransferMark(Heap* heap, Address old_start, Address new_start) {
   // This is only used when resizing an object.
   DCHECK(MemoryChunk::FromAddress(old_start) ==
          MemoryChunk::FromAddress(new_start));
 
   if (!heap->incremental_marking()->IsMarking()) return;
 
   // If the mark doesn't move, we don't check the color of the object.
   // It doesn't matter whether the object is black, since it hasn't changed
   // size, so the adjustment to the live data count will be zero anyway.
@@ skipping 2770 matching lines @@
 
   const int num_tasks = NumberOfParallelCompactionTasks();
 
   // Set up compaction spaces.
   CompactionSpaceCollection** compaction_spaces_for_tasks =
       new CompactionSpaceCollection*[num_tasks];
   for (int i = 0; i < num_tasks; i++) {
     compaction_spaces_for_tasks[i] = new CompactionSpaceCollection(heap());
   }
 
-  compaction_spaces_for_tasks[0]->Get(OLD_SPACE)->MoveOverFreeMemory(
-      heap()->old_space());
-  compaction_spaces_for_tasks[0]
-      ->Get(CODE_SPACE)
-      ->MoveOverFreeMemory(heap()->code_space());
+  heap()->old_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
+                                                  num_tasks);
+  heap()->code_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
+                                                   num_tasks);
 
   compaction_in_progress_ = true;
   // Kick off parallel tasks.
   for (int i = 1; i < num_tasks; i++) {
     concurrent_compaction_tasks_active_++;
     V8::GetCurrentPlatform()->CallOnBackgroundThread(
         new CompactionTask(heap(), compaction_spaces_for_tasks[i]),
         v8::Platform::kShortRunningTask);
   }
 
   // Contribute in main thread. Counter and signal are in principal not needed.
-  concurrent_compaction_tasks_active_++;
   EvacuatePages(compaction_spaces_for_tasks[0], &migration_slots_buffer_);
-  pending_compaction_tasks_semaphore_.Signal();
 
   WaitUntilCompactionCompleted();
 
   // Merge back memory (compacted and unused) from compaction spaces.
   for (int i = 0; i < num_tasks; i++) {
     heap()->old_space()->MergeCompactionSpace(
         compaction_spaces_for_tasks[i]->Get(OLD_SPACE));
     heap()->code_space()->MergeCompactionSpace(
         compaction_spaces_for_tasks[i]->Get(CODE_SPACE));
     delete compaction_spaces_for_tasks[i];
@@ skipping 1172 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(host);
     if (Marking::IsBlack(mark_bit)) {
       RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
       RecordRelocSlot(&rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8