[heap] Parallel newspace evacuation, semispace copy, and compaction \o/

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 90d252abb592a46a051864883c30c6bd44b436b3..3ff354a64591c057a90d0dc25ae050f46882aaf5 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -2837,21 +2837,23 @@ HeapObject* CompactionSpace::SweepAndRetryAllocation(int size_in_bytes) {
 
 
 HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
+  const int kMaxPagesToSweep = 10;
   // Allocation in this space has failed.
-
+  HeapObject* object = nullptr;
   MarkCompactCollector* collector = heap()->mark_compact_collector();
   // Sweeping is still in progress.
   if (collector->sweeping_in_progress()) {
     // First try to refill the free-list, concurrent sweeper threads
     // may have freed some objects in the meantime.
     RefillFreeList();
-
     // Retry the free list allocation.
-    HeapObject* object = free_list_.Allocate(size_in_bytes);
-    if (object != NULL) return object;
+    object = free_list_.Allocate(size_in_bytes);
+    if (object != nullptr) return object;
 
-    // If sweeping is still in progress try to sweep pages on the main thread.
-    collector->SweepInParallel(heap()->paged_space(identity()), size_in_bytes);
+    // If sweeping is still in progress and we are currently not compacting
+    // try to sweep pages on the main thread.
+    collector->SweepInParallel(heap()->paged_space(identity()), size_in_bytes,
+                               kMaxPagesToSweep);
     RefillFreeList();
     object = free_list_.Allocate(size_in_bytes);
     if (object != nullptr) return object;
@@ -2864,8 +2866,7 @@ HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
       heap()->OldGenerationAllocationLimitReached()) {
     // If sweeper threads are active, wait for them at that point and steal
     // elements form their free-lists.
-    HeapObject* object = SweepAndRetryAllocation(size_in_bytes);
-    return object;
+    return SweepAndRetryAllocation(size_in_bytes);
   }
 
   // Try to expand the space and allocate in the new next page.