Wait for sweeper threads and finalize sweeping only if parallel/concurrent sweeping was in progress.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 532 matching lines @@
 
 void MarkCompactCollector::StartSweeperThreads() {
   sweeping_pending_ = true;
   for (int i = 0; i < FLAG_sweeper_threads; i++) {
     heap()->isolate()->sweeper_threads()[i]->StartSweeping();
   }
 }
 
 
 void MarkCompactCollector::WaitUntilSweepingCompleted() {
-  if (sweeping_pending_) {
-    for (int i = 0; i < FLAG_sweeper_threads; i++) {
-      heap()->isolate()->sweeper_threads()[i]->WaitForSweeperThread();
-    }
-    sweeping_pending_ = false;
-    StealMemoryFromSweeperThreads(heap()->paged_space(OLD_DATA_SPACE));
-    StealMemoryFromSweeperThreads(heap()->paged_space(OLD_POINTER_SPACE));
-    heap()->paged_space(OLD_DATA_SPACE)->ResetUnsweptFreeBytes();
-    heap()->paged_space(OLD_POINTER_SPACE)->ResetUnsweptFreeBytes();
+  ASSERT(sweeping_pending_ == true);
+  for (int i = 0; i < FLAG_sweeper_threads; i++) {
+    heap()->isolate()->sweeper_threads()[i]->WaitForSweeperThread();
   }
+  sweeping_pending_ = false;
+  StealMemoryFromSweeperThreads(heap()->paged_space(OLD_DATA_SPACE));
+  StealMemoryFromSweeperThreads(heap()->paged_space(OLD_POINTER_SPACE));
+  heap()->paged_space(OLD_DATA_SPACE)->ResetUnsweptFreeBytes();
+  heap()->paged_space(OLD_POINTER_SPACE)->ResetUnsweptFreeBytes();
 }
 
 
 intptr_t MarkCompactCollector::
              StealMemoryFromSweeperThreads(PagedSpace* space) {
   intptr_t freed_bytes = 0;
   for (int i = 0; i < FLAG_sweeper_threads; i++) {
     freed_bytes += heap()->isolate()->sweeper_threads()[i]->StealMemory(space);
   }
   space->AddToAccountingStats(freed_bytes);
@@ skipping 328 matching lines @@
   // variable.
   tracer_ = tracer;
 
 #ifdef DEBUG
   ASSERT(state_ == IDLE);
   state_ = PREPARE_GC;
 #endif
 
   ASSERT(!FLAG_never_compact || !FLAG_always_compact);
 
-  if (AreSweeperThreadsActivated() && FLAG_concurrent_sweeping) {
+  if (IsConcurrentSweepingInProgress()) {
     // Instead of waiting we could also abort the sweeper threads here.
     WaitUntilSweepingCompleted();
     FinalizeSweeping();
   }
 
   // Clear marking bits if incremental marking is aborted.
   if (was_marked_incrementally_ && abort_incremental_marking_) {
     heap()->incremental_marking()->Abort();
     ClearMarkbits();
     AbortCompaction();
@@ skipping 3199 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal