[heap] Add more tasks for parallel compaction

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index b8fc9b7efe0845d4852b6660c8465abdda18f115..58c619029d61b8092f874f20cd8cd107df069c50 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -1631,6 +1631,11 @@ class FreeList {
 
   intptr_t Concatenate(FreeList* free_list);
 
+  // Divide {this} free lists up among {other_free_lists} up to some certain
+  // {limit} of bytes. Note that this operation needs to iterate over nodes
+  // one-by-one, making it a potentially slow operation.
+  void Divide(FreeList** other_free_lists, int num, intptr_t limit);
+
   // Clear the free list.
   void Reset();
 
@@ -1997,6 +2002,14 @@ class PagedSpace : public Space {
 
   virtual bool is_local() { return false; }
 
+  // Adds external memory starting at {start} of {size_in_bytes} to the space.
+  void AddExternalMemory(Address start, int size_in_bytes) {

[Hannes Payer (out of office), 2015/09/23 08:47:22]

Call it AddMemory, to get the naming in sync with RemoveMemory.

+    IncreaseCapacity(size_in_bytes);
+    Free(start, size_in_bytes);
+  }
+
+  void RemoveMemory(int size) { accounting_stats_.DecreaseCapacity(size); }

[Hannes Payer (out of office), 2015/09/23 08:47:22]

To make this one dual with AddMemory, it should actually also remove memory from
the free list. WDYT?

[Michael Lippautz, 2015/09/23 11:49:01]

Done.

+
  protected:
   // PagedSpaces that should be included in snapshots have different, i.e.,
   // smaller, initial pages.
@@ -2744,12 +2757,6 @@ class CompactionSpace : public PagedSpace {
   CompactionSpace(Heap* heap, AllocationSpace id, Executability executable)
       : PagedSpace(heap, id, executable) {}
 
-  // Adds external memory starting at {start} of {size_in_bytes} to the space.
-  void AddExternalMemory(Address start, int size_in_bytes) {
-    IncreaseCapacity(size_in_bytes);
-    Free(start, size_in_bytes);
-  }
-
   virtual bool is_local() { return true; }
 
  protected: