Sweep map space concurrently.

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/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 209 matching lines @@
 
   VerifyEvacuationVisitor visitor;
   heap->IterateStrongRoots(&visitor, VISIT_ALL);
 }
 #endif  // VERIFY_HEAP
 
 
 void MarkCompactCollector::SetUp() {
   free_list_old_space_.Reset(new FreeList(heap_->old_space()));
   free_list_code_space_.Reset(new FreeList(heap_->code_space()));
+  free_list_map_space_.Reset(new FreeList(heap_->map_space()));
   EnsureMarkingDequeIsReserved();
   EnsureMarkingDequeIsCommitted(kMinMarkingDequeSize);
 }
 
 
 void MarkCompactCollector::TearDown() {
   AbortCompaction();
   delete marking_deque_memory_;
 }
 
@@ skipping 249 matching lines @@
   Heap* heap_;
   PagedSpace* space_;
 
   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);
   V8::GetCurrentPlatform()->CallOnBackgroundThread(
       new SweeperTask(heap(), heap()->code_space()),
       v8::Platform::kShortRunningTask);
+  V8::GetCurrentPlatform()->CallOnBackgroundThread(
+      new SweeperTask(heap(), heap()->map_space()),
+      v8::Platform::kShortRunningTask);
 }
 
 
 void MarkCompactCollector::SweepOrWaitUntilSweepingCompleted(Page* page) {
   PagedSpace* owner = reinterpret_cast<PagedSpace*>(page->owner());
   if (!page->SweepingCompleted()) {
     SweepInParallel(page, owner);
     if (!page->SweepingCompleted()) {
       // We were not able to sweep that page, i.e., a concurrent
       // sweeper thread currently owns this page. Wait for the sweeper
       // thread to be done with this page.
       page->WaitUntilSweepingCompleted();
     }
   }
 }
 
 
 void MarkCompactCollector::EnsureSweepingCompleted() {
   DCHECK(sweeping_in_progress_ == true);
 
   // If sweeping is not completed or not running at all, we try to complete it
   // here.
   if (!heap()->concurrent_sweeping_enabled() || !IsSweepingCompleted()) {
     SweepInParallel(heap()->paged_space(OLD_SPACE), 0);
     SweepInParallel(heap()->paged_space(CODE_SPACE), 0);
+    SweepInParallel(heap()->paged_space(MAP_SPACE), 0);
   }
   // Wait twice for both jobs.
   if (heap()->concurrent_sweeping_enabled()) {
     pending_sweeper_jobs_semaphore_.Wait();
     pending_sweeper_jobs_semaphore_.Wait();
+    pending_sweeper_jobs_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()->paged_space(OLD_SPACE)->ResetUnsweptFreeBytes();
   heap()->paged_space(CODE_SPACE)->ResetUnsweptFreeBytes();
+  heap()->paged_space(MAP_SPACE)->ResetUnsweptFreeBytes();
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap && !evacuation()) {
     VerifyEvacuation(heap_);
   }
 #endif
 }
 
 
 bool MarkCompactCollector::IsSweepingCompleted() {
   if (!pending_sweeper_jobs_semaphore_.WaitFor(
           base::TimeDelta::FromSeconds(0))) {
     return false;
   }
   pending_sweeper_jobs_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 freed_bytes = space->free_list()->Concatenate(free_list);
   space->AddToAccountingStats(freed_bytes);
   space->DecrementUnsweptFreeBytes(freed_bytes);
 }
@@ skipping 3650 matching lines @@
   int max_freed = 0;
   if (page->TryLock()) {
     // If this page was already swept in the meantime, we can return here.
     if (page->parallel_sweeping() != MemoryChunk::SWEEPING_PENDING) {
       page->mutex()->Unlock();
       return 0;
     }
     page->set_parallel_sweeping(MemoryChunk::SWEEPING_IN_PROGRESS);
     FreeList* free_list;
     FreeList private_free_list(space);
-    if (space->identity() == CODE_SPACE) {
+    if (space->identity() == OLD_SPACE) {
+      free_list = free_list_old_space_.get();
+      max_freed =
+          Sweep<SWEEP_ONLY, SWEEP_IN_PARALLEL, IGNORE_SKIP_LIST,
+                IGNORE_FREE_SPACE>(space, &private_free_list, page, NULL);
+    } else if (space->identity() == CODE_SPACE) {
       free_list = free_list_code_space_.get();
       max_freed =
           Sweep<SWEEP_ONLY, SWEEP_IN_PARALLEL, REBUILD_SKIP_LIST,
                 IGNORE_FREE_SPACE>(space, &private_free_list, page, NULL);
     } else {
-      free_list = free_list_old_space_.get();
+      free_list = free_list_map_space_.get();
       max_freed =
           Sweep<SWEEP_ONLY, SWEEP_IN_PARALLEL, IGNORE_SKIP_LIST,
                 IGNORE_FREE_SPACE>(space, &private_free_list, page, NULL);
     }
     free_list->Concatenate(&private_free_list);
     page->mutex()->Unlock();
   }
   return max_freed;
 }
 
@@ skipping 50 matching lines @@
           }
           if (space->identity() == CODE_SPACE) {
             if (FLAG_zap_code_space) {
               Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, REBUILD_SKIP_LIST,
                     ZAP_FREE_SPACE>(space, NULL, p, NULL);
             } else {
               Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, REBUILD_SKIP_LIST,
                     IGNORE_FREE_SPACE>(space, NULL, p, NULL);
             }
           } else {
-            DCHECK(space->identity() == OLD_SPACE);
             Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, IGNORE_SKIP_LIST,
                   IGNORE_FREE_SPACE>(space, NULL, p, NULL);
           }
           pages_swept++;
           parallel_sweeping_active = true;
         } else {
           if (FLAG_gc_verbose) {
             PrintF("Sweeping 0x%" V8PRIxPTR " in parallel.\n",
                    reinterpret_cast<intptr_t>(p));
           }
           p->set_parallel_sweeping(MemoryChunk::SWEEPING_PENDING);
           space->IncreaseUnsweptFreeBytes(p);
         }
         space->set_end_of_unswept_pages(p);
         break;
       case SEQUENTIAL_SWEEPING: {
         if (FLAG_gc_verbose) {
           PrintF("Sweeping 0x%" V8PRIxPTR ".\n", reinterpret_cast<intptr_t>(p));
         }
         if (space->identity() == CODE_SPACE) {
           if (FLAG_zap_code_space) {
             Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, REBUILD_SKIP_LIST,
                   ZAP_FREE_SPACE>(space, NULL, p, NULL);
           } else {
             Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, REBUILD_SKIP_LIST,
                   IGNORE_FREE_SPACE>(space, NULL, p, NULL);
           }
         } else {
-          DCHECK(space->identity() == OLD_SPACE ||
-                 space->identity() == MAP_SPACE);
           Sweep<SWEEP_ONLY, SWEEP_ON_MAIN_THREAD, IGNORE_SKIP_LIST,
                 IGNORE_FREE_SPACE>(space, NULL, p, NULL);
         }
         pages_swept++;
         break;
       }
       default: { UNREACHABLE(); }
     }
   }
 
@@ skipping 29 matching lines @@
     {
       GCTracer::Scope sweep_scope(heap()->tracer(),
                                   GCTracer::Scope::MC_SWEEP_OLDSPACE);
       SweepSpace(heap()->old_space(), CONCURRENT_SWEEPING);
     }
     {
       GCTracer::Scope sweep_scope(heap()->tracer(),
                                   GCTracer::Scope::MC_SWEEP_CODE);
       SweepSpace(heap()->code_space(), CONCURRENT_SWEEPING);
     }
-
+    {
+      GCTracer::Scope sweep_scope(heap()->tracer(),
+                                  GCTracer::Scope::MC_SWEEP_MAP);
+      SweepSpace(heap()->map_space(), CONCURRENT_SWEEPING);
+    }
     sweeping_in_progress_ = true;
     if (heap()->concurrent_sweeping_enabled()) {
       StartSweeperThreads();
     }
   }
 
   RemoveDeadInvalidatedCode();
 
   EvacuateNewSpaceAndCandidates();
 
   heap()->FreeDeadArrayBuffers(false);
 
-  // ClearNonLiveReferences depends on precise sweeping of map space to
-  // detect whether unmarked map became dead in this collection or in one
-  // of the previous ones.
-  {
-    GCTracer::Scope sweep_scope(heap()->tracer(),
-                                GCTracer::Scope::MC_SWEEP_MAP);
-    SweepSpace(heap()->map_space(), SEQUENTIAL_SWEEPING);
-  }
-
   // Deallocate unmarked objects and clear marked bits for marked objects.
   heap_->lo_space()->FreeUnmarkedObjects();
 
   // Deallocate evacuated candidate pages.
   ReleaseEvacuationCandidates();
   CodeRange* code_range = heap()->isolate()->code_range();
   if (code_range != NULL && code_range->valid()) {
     code_range->ReserveEmergencyBlock();
   }
 
@@ skipping 19 matching lines @@
       p->SetWasSwept();
     }
     DCHECK(p->parallel_sweeping() == MemoryChunk::SWEEPING_DONE);
   }
 }
 
 
 void MarkCompactCollector::ParallelSweepSpacesComplete() {
   ParallelSweepSpaceComplete(heap()->old_space());
   ParallelSweepSpaceComplete(heap()->code_space());
+  ParallelSweepSpaceComplete(heap()->map_space());
 }
 
 
 void MarkCompactCollector::EnableCodeFlushing(bool enable) {
   if (isolate()->debug()->is_active()) enable = false;
 
   if (enable) {
     if (code_flusher_ != NULL) return;
     code_flusher_ = new CodeFlusher(isolate());
   } else {
@@ skipping 300 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8