[heap] Implement simple concurrent marking deque.

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 2217 matching lines @@
       Code* code = it.frame()->LookupCode();
       if (!code->CanDeoptAt(it.frame()->pc())) {
         Code::BodyDescriptor::IterateBody(code, visitor);
       }
       ProcessMarkingDeque();
       return;
     }
   }
 }
 
-void MarkingDeque::SetUp() {

[ulan, 2017/04/27 17:49:39]

This is moved to sequential-marking-deque.cc

-  backing_store_ = new base::VirtualMemory(kMaxSize);
-  backing_store_committed_size_ = 0;
-  if (backing_store_ == nullptr) {
-    V8::FatalProcessOutOfMemory("MarkingDeque::SetUp");
-  }
-}
-
-void MarkingDeque::TearDown() {
-  delete backing_store_;
-}
-
-void MarkingDeque::StartUsing() {
-  base::LockGuard<base::Mutex> guard(&mutex_);
-  if (in_use_) {
-    // This can happen in mark-compact GC if the incremental marker already
-    // started using the marking deque.
-    return;
-  }
-  in_use_ = true;
-  EnsureCommitted();
-  array_ = reinterpret_cast<HeapObject**>(backing_store_->address());
-  size_t size = FLAG_force_marking_deque_overflows
-                    ? 64 * kPointerSize
-                    : backing_store_committed_size_;
-  DCHECK(
-      base::bits::IsPowerOfTwo32(static_cast<uint32_t>(size / kPointerSize)));
-  mask_ = static_cast<int>((size / kPointerSize) - 1);
-  top_ = bottom_ = 0;
-  overflowed_ = false;
-}
-
-void MarkingDeque::StopUsing() {
-  base::LockGuard<base::Mutex> guard(&mutex_);
-  if (!in_use_) return;
-  DCHECK(IsEmpty());
-  DCHECK(!overflowed_);
-  top_ = bottom_ = mask_ = 0;
-  in_use_ = false;
-  if (FLAG_concurrent_sweeping) {
-    StartUncommitTask();
-  } else {
-    Uncommit();
-  }
-}
-
-void MarkingDeque::Clear() {
-  DCHECK(in_use_);
-  top_ = bottom_ = 0;
-  overflowed_ = false;
-}
-
-void MarkingDeque::Uncommit() {
-  DCHECK(!in_use_);
-  bool success = backing_store_->Uncommit(backing_store_->address(),
-                                          backing_store_committed_size_);
-  backing_store_committed_size_ = 0;
-  CHECK(success);
-}
-
-void MarkingDeque::EnsureCommitted() {
-  DCHECK(in_use_);
-  if (backing_store_committed_size_ > 0) return;
-
-  for (size_t size = kMaxSize; size >= kMinSize; size /= 2) {
-    if (backing_store_->Commit(backing_store_->address(), size, false)) {
-      backing_store_committed_size_ = size;
-      break;
-    }
-  }
-  if (backing_store_committed_size_ == 0) {
-    V8::FatalProcessOutOfMemory("MarkingDeque::EnsureCommitted");
-  }
-}
-
-void MarkingDeque::StartUncommitTask() {
-  if (!uncommit_task_pending_) {
-    uncommit_task_pending_ = true;
-    UncommitTask* task = new UncommitTask(heap_->isolate(), this);
-    V8::GetCurrentPlatform()->CallOnBackgroundThread(
-        task, v8::Platform::kShortRunningTask);
-  }
-}
-
 class ObjectStatsVisitor : public HeapObjectVisitor {
  public:
   ObjectStatsVisitor(Heap* heap, ObjectStats* live_stats,
                      ObjectStats* dead_stats)
       : live_collector_(heap, live_stats), dead_collector_(heap, dead_stats) {
     DCHECK_NOT_NULL(live_stats);
     DCHECK_NOT_NULL(dead_stats);
     // Global objects are roots and thus recorded as live.
     live_collector_.CollectGlobalStatistics();
   }
@@ skipping 1869 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8