[heap] inline allocation steps refactor

src/heap/incremental-marking.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/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/objects-visiting.h"
 #include "src/heap/objects-visiting-inl.h"
 #include "src/v8.h"
 
 namespace v8 {
 namespace internal {
 
+class IncrementalMarkingObserver : public InlineAllocationObserver {
+ public:
+  IncrementalMarkingObserver(IncrementalMarking& incremental_marking,
+                             intptr_t step_size)
+      : InlineAllocationObserver(step_size),
+        incremental_marking_(incremental_marking) {}
+
+  virtual void Step(int bytes_allocated) {
+    incremental_marking_.Step(bytes_allocated,
+                              IncrementalMarking::GC_VIA_STACK_GUARD);
+  }
+
+ private:
+  IncrementalMarking& incremental_marking_;
+};
+
 
 IncrementalMarking::StepActions IncrementalMarking::IdleStepActions() {
   return StepActions(IncrementalMarking::NO_GC_VIA_STACK_GUARD,
                      IncrementalMarking::FORCE_MARKING,
                      IncrementalMarking::DO_NOT_FORCE_COMPLETION);
 }
 
 
 IncrementalMarking::IncrementalMarking(Heap* heap)
     : heap_(heap),
+      observer_(nullptr),
       state_(STOPPED),
       is_compacting_(false),
       steps_count_(0),
       old_generation_space_available_at_start_of_incremental_(0),
       old_generation_space_used_at_start_of_incremental_(0),
       bytes_rescanned_(0),
       should_hurry_(false),
       marking_speed_(0),
       bytes_scanned_(0),
       allocated_(0),
@@ skipping 522 matching lines @@
 
   if (!heap_->mark_compact_collector()->sweeping_in_progress()) {
     StartMarking();
   } else {
     if (FLAG_trace_incremental_marking) {
       PrintF("[IncrementalMarking] Start sweeping.\n");
     }
     state_ = SWEEPING;
   }
 
-  heap_->LowerInlineAllocationLimit(kAllocatedThreshold);
+  observer_ = new IncrementalMarkingObserver(*this, kAllocatedThreshold);

[ulan, 2015/10/22 09:02:22]

I think we can bind the lifetime of the observer to the lifetime of the
IncrementalMarking object, i.e. create one observer at the beginning and reuse
it.

[ofrobots, 2015/10/26 21:55:01]

Done.

+  heap_->new_space()->AddInlineAllocationObserver(observer_);
+
   incremental_marking_job()->Start(heap_);
 }
 
 
 void IncrementalMarking::StartMarking() {
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Start marking\n");
   }
 
   is_compacting_ = !FLAG_never_compact &&
@@ skipping 231 matching lines @@
     context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
   }
 }
 
 
 void IncrementalMarking::Stop() {
   if (IsStopped()) return;
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Stopping.\n");
   }
-  heap_->ResetInlineAllocationLimit();
+
+  if (observer_) {
+    heap_->new_space()->RemoveInlineAllocationObserver(observer_);
+    delete observer_;

[Hannes Payer (out of office), 2015/10/22 09:14:14]

Let's allocate/delete the observer at heap setup/shutdown.

[ofrobots, 2015/10/26 21:55:01]

Done as per Ulan's suggestion above.

+    observer_ = nullptr;
+  }
+
   IncrementalMarking::set_should_hurry(false);
   ResetStepCounters();
   if (IsMarking()) {
     PatchIncrementalMarkingRecordWriteStubs(heap_,
                                             RecordWriteStub::STORE_BUFFER_ONLY);
     DeactivateIncrementalWriteBarrier();
 
     if (is_compacting_) {
       LargeObjectIterator it(heap_->lo_space());
       for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
         Page* p = Page::FromAddress(obj->address());
         if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
           p->ClearFlag(Page::RESCAN_ON_EVACUATION);
         }
       }
     }
   }
   heap_->isolate()->stack_guard()->ClearGC();
   state_ = STOPPED;
   is_compacting_ = false;
 }
 
 
 void IncrementalMarking::Finalize() {
   Hurry();
   state_ = STOPPED;
   is_compacting_ = false;
-  heap_->ResetInlineAllocationLimit();
+
+  if (observer_) {
+    heap_->new_space()->RemoveInlineAllocationObserver(observer_);
+    delete observer_;
+    observer_ = nullptr;
+  }
   IncrementalMarking::set_should_hurry(false);
   ResetStepCounters();
   PatchIncrementalMarkingRecordWriteStubs(heap_,
                                           RecordWriteStub::STORE_BUFFER_ONLY);
   DeactivateIncrementalWriteBarrier();
   DCHECK(heap_->mark_compact_collector()->marking_deque()->IsEmpty());
   heap_->isolate()->stack_guard()->ClearGC();
 }
 
 
@@ skipping 264 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }  // namespace internal
 }  // namespace v8