[test] AllocationObserver for stress marking.

Observer that increases frequency of checking if we reached
marking limit. Works only with --stress-marking.

Bug: v8:6972
Change-Id: I13544fdd8bb33738d78adbac96feb70222b5b634
Reviewed-on: https://chromium-review.googlesource.com/802434
Commit-Queue: Michał Majewski <majeski@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49907}

BUILD.gn

@@ -1690,6 +1690,8 @@ v8_source_set("v8_base") {
     "src/heap/spaces.h",
     "src/heap/store-buffer.cc",
     "src/heap/store-buffer.h",
+    "src/heap/stress-marking-observer.cc",
+    "src/heap/stress-marking-observer.h",
     "src/heap/sweeper.cc",
     "src/heap/sweeper.h",
     "src/heap/worklist.h",

src/heap/heap.cc

@@ -43,6 +43,7 @@
 #include "src/heap/scavenge-job.h"
 #include "src/heap/scavenger-inl.h"
 #include "src/heap/store-buffer.h"
+#include "src/heap/stress-marking-observer.h"
 #include "src/heap/sweeper.h"
 #include "src/interpreter/interpreter.h"
 #include "src/objects/object-macros.h"
@@ -172,6 +173,7 @@ Heap::Heap()
       gc_post_processing_depth_(0),
       allocations_count_(0),
       raw_allocations_hash_(0),
+      stress_marking_observer_(nullptr),
       ms_count_(0),
       gc_count_(0),
       mmap_region_base_(0),
@@ -5658,6 +5660,10 @@ bool Heap::SetUp() {
 
   if (FLAG_stress_marking > 0) {
     stress_marking_percentage_ = NextStressMarkingLimit();
+
+    stress_marking_observer_ = new StressMarkingObserver(*this);
+    AddAllocationObserversToAllSpaces(stress_marking_observer_,
+                                      stress_marking_observer_);
   }
 
   write_protect_code_memory_ = FLAG_write_protect_code_memory;
@@ -5768,6 +5774,13 @@ void Heap::TearDown() {
   delete idle_scavenge_observer_;
   idle_scavenge_observer_ = nullptr;
 
+  if (FLAG_stress_marking > 0) {
+    RemoveAllocationObserversFromAllSpaces(stress_marking_observer_,
+                                           stress_marking_observer_);
+    delete stress_marking_observer_;
+    stress_marking_observer_ = nullptr;
+  }
+
   if (mark_compact_collector_ != nullptr) {
     mark_compact_collector_->TearDown();
     delete mark_compact_collector_;

src/heap/heap.h

@@ -2403,6 +2403,10 @@ class Heap {
   // is reached.
   int stress_marking_percentage_;
 
+  // Observer that causes more frequent checks for reached incremental marking
+  // limit.
+  AllocationObserver* stress_marking_observer_;
+
   // How many mark-sweep collections happened.
   unsigned int ms_count_;
 

src/heap/stress-marking-observer.cc

@@ -0,0 +1,21 @@
+// Copyright 2017 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/stress-marking-observer.h"
+
+namespace v8 {
+namespace internal {
+
+// TODO(majeski): meaningful step_size
+StressMarkingObserver::StressMarkingObserver(Heap& heap)
+    : AllocationObserver(64), heap_(heap) {}
+
+void StressMarkingObserver::Step(int bytes_allocated, Address soon_object,
+                                 size_t size) {
+  heap_.StartIncrementalMarkingIfAllocationLimitIsReached(Heap::kNoGCFlags,
+                                                          kNoGCCallbackFlags);
+}
+
+}  // namespace internal
+}  // namespace v8

src/heap/stress-marking-observer.h

@@ -0,0 +1,26 @@
+// Copyright 2017 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.
+
+#ifndef V8_HEAP_STRESS_MARKING_OBSERVER_H_
+#define V8_HEAP_STRESS_MARKING_OBSERVER_H_
+
+#include "src/heap/heap.h"
+
+namespace v8 {
+namespace internal {
+
+class StressMarkingObserver : public AllocationObserver {
+ public:
+  explicit StressMarkingObserver(Heap& heap);
+
+  void Step(int bytes_allocated, Address soon_object, size_t size) override;
+
+ private:
+  Heap& heap_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif

src/v8.gyp

@@ -1044,6 +1044,8 @@
         'heap/spaces.h',
         'heap/store-buffer.cc',
         'heap/store-buffer.h',
+        'heap/stress-marking-observer.cc',
+        'heap/stress-marking-observer.h',
         'heap/sweeper.cc',
         'heap/sweeper.h',
         'heap/worklist.h',