[heap] Collaborating sweeper 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 461 matching lines @@
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
     Marking::MarkWhite(Marking::MarkBitFrom(obj));
     Page::FromAddress(obj->address())->ResetProgressBar();
     Page::FromAddress(obj->address())->ResetLiveBytes();
   }
 }
 
 
 class MarkCompactCollector::SweeperTask : public v8::Task {
  public:
-  SweeperTask(Heap* heap, PagedSpace* space) : heap_(heap), space_(space) {}
+  SweeperTask(Heap* heap, AllocationSpace space_to_start)
+      : heap_(heap), space_to_start_(space_to_start) {}
 
   virtual ~SweeperTask() {}
 
  private:
   // v8::Task overrides.
   void Run() override {
-    heap_->mark_compact_collector()->SweepInParallel(space_, 0);
+    DCHECK_GE(space_to_start_, FIRST_PAGED_SPACE);
+    DCHECK_LE(space_to_start_, LAST_PAGED_SPACE);
+    const int offset = space_to_start_ - FIRST_PAGED_SPACE;
+    const int num_spaces = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
+    for (int i = 0; i < num_spaces; i++) {
+      const int space_id = FIRST_PAGED_SPACE + ((i + offset) % num_spaces);
+      DCHECK_GE(space_id, FIRST_PAGED_SPACE);
+      DCHECK_LE(space_id, LAST_PAGED_SPACE);
+      heap_->mark_compact_collector()->SweepInParallel(
+          heap_->paged_space(space_id), 0);
+    }
     heap_->mark_compact_collector()->pending_sweeper_tasks_semaphore_.Signal();
   }
 
   Heap* heap_;
-  PagedSpace* space_;
+  AllocationSpace space_to_start_;
 
   DISALLOW_COPY_AND_ASSIGN(SweeperTask);
 };
 
 
 void MarkCompactCollector::StartSweeperThreads() {
   DCHECK(free_list_old_space_.get()->IsEmpty());
   DCHECK(free_list_code_space_.get()->IsEmpty());
   DCHECK(free_list_map_space_.get()->IsEmpty());
   V8::GetCurrentPlatform()->CallOnBackgroundThread(
-      new SweeperTask(heap(), heap()->old_space()),
-      v8::Platform::kShortRunningTask);
+      new SweeperTask(heap(), OLD_SPACE), v8::Platform::kShortRunningTask);
   V8::GetCurrentPlatform()->CallOnBackgroundThread(
-      new SweeperTask(heap(), heap()->code_space()),
-      v8::Platform::kShortRunningTask);
+      new SweeperTask(heap(), CODE_SPACE), v8::Platform::kShortRunningTask);
   V8::GetCurrentPlatform()->CallOnBackgroundThread(
-      new SweeperTask(heap(), heap()->map_space()),
-      v8::Platform::kShortRunningTask);
+      new SweeperTask(heap(), MAP_SPACE), v8::Platform::kShortRunningTask);
 }
 
 
 void MarkCompactCollector::SweepOrWaitUntilSweepingCompleted(Page* page) {
   PagedSpace* owner = reinterpret_cast<PagedSpace*>(page->owner());
   if (!page->SweepingDone()) {
     SweepInParallel(page, owner);
     if (!page->SweepingDone()) {
       // We were not able to sweep that page, i.e., a concurrent
       // sweeper thread currently owns this page. Wait for the sweeper
@@ skipping 3533 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(host);
     if (Marking::IsBlack(mark_bit)) {
       RelocInfo rinfo(isolate(), pc, RelocInfo::CODE_TARGET, 0, host);
       RecordRelocSlot(&rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8