Start incremental marking on idle notification.

src/heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 122 matching lines @@
       previous_survival_rate_trend_(Heap::STABLE),
       survival_rate_trend_(Heap::STABLE),
       max_gc_pause_(0),
       max_alive_after_gc_(0),
       min_in_mutator_(kMaxInt),
       alive_after_last_gc_(0),
       last_gc_end_timestamp_(0.0),
       store_buffer_(this),
       marking_(this),
       incremental_marking_(this),
+      idle_work_(IDLE_INCREMENTAL_MARKING),
       number_idle_notifications_(0),
       last_idle_notification_gc_count_(0),
       last_idle_notification_gc_count_init_(false),
       configured_(false),
       chunks_queued_for_free_(NULL) {
   // Allow build-time customization of the max semispace size. Building
   // V8 with snapshots and a non-default max semispace size is much
   // easier if you can define it as part of the build environment.
 #if defined(V8_MAX_SEMISPACE_SIZE)
   max_semispace_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
@@ skipping 4355 matching lines @@
 void Heap::EnsureHeapIsIterable() {
   ASSERT(IsAllocationAllowed());
   if (!IsHeapIterable()) {
     CollectAllGarbage(kMakeHeapIterableMask);
   }
   ASSERT(IsHeapIterable());
 }
 
 
 bool Heap::IdleNotification() {
+  switch (idle_work_) {
+    case IDLE_INCREMENTAL_MARKING:
+      if (IdleIncrementalMarking()) {
+        idle_work_ = IDLE_GLOBAL_GC;
+      }
+      break;
+    case IDLE_GLOBAL_GC:
+      if (IdleGlobalGC()) {
+        idle_work_ = IDLE_INCREMENTAL_MARKING;
+        return true;
+      }
+      break;
+    default:
+      UNREACHABLE();
+  }
+  return false;
+}
+
+bool Heap::IdleIncrementalMarking() {
+  if (incremental_marking()->IsStopped()) {
+    if (!incremental_marking()->WorthActivating()) {
+      return true;
+    }
+    incremental_marking()->Start();
+  }
+  incremental_marking()->Step(IncrementalMarking::kStepFakeAllocatedBytes);
+  return incremental_marking()->IsComplete();

[Vyacheslav Egorov (Chromium), 2011/10/12 07:41:00]

when it's complete it makes sense to do a finishing GC immediately without
giving JS chance to mutate anything.

+}
+
+bool Heap::IdleGlobalGC() {
   static const int kIdlesBeforeScavenge = 4;
   static const int kIdlesBeforeMarkSweep = 7;
   static const int kIdlesBeforeMarkCompact = 8;
   static const int kMaxIdleCount = kIdlesBeforeMarkCompact + 1;
   static const unsigned int kGCsBetweenCleanup = 4;
 
   if (!last_idle_notification_gc_count_init_) {
     last_idle_notification_gc_count_ = gc_count_;
     last_idle_notification_gc_count_init_ = true;
   }
@@ skipping 1942 matching lines @@
   isolate_->heap()->store_buffer()->Compact();
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal