[GC] Change behavior when reaching external allocation limit

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6866 matching lines @@
   if (fits_into_int32_t) {
     return Integer::New(isolate, static_cast<int32_t>(value));
   }
   ENTER_V8(internal_isolate);
   i::Handle<i::Object> result = internal_isolate->factory()->NewNumber(value);
   return Utils::IntegerToLocal(result);
 }
 
 
 void Isolate::CollectAllGarbage(const char* gc_reason) {
-  reinterpret_cast<i::Isolate*>(this)->heap()->CollectAllGarbage(
-      i::Heap::kNoGCFlags, gc_reason, v8::kGCCallbackFlagForced);
+  using IM = i::IncrementalMarking;
+  using Heap = i::Heap;

[jochen (gone - plz use gerrit), 2015/08/05 12:22:27]

please don't use using.

[Michael Lippautz, 2015/08/05 12:55:58]

Done.

+  double kIncrementalMarkingIntervalInMs = 3;

[Michael Lippautz, 2015/08/05 12:08:26]

keep local?

[jochen (gone - plz use gerrit), 2015/08/05 12:22:27]

maybe make it a flag?

[Hannes Payer (out of office), 2015/08/05 12:39:36]

I would prefer 1 instead of 3. The smaller the better.

It would be nice to calculate the value, based on memory pressure. More ms for
higher memory pressure. That could be a TODO.

[Michael Lippautz, 2015/08/05 12:55:58]

1ms it is. Works on N9. 

Agree that it would be better to dynamically adjust the 
time slices.

[Michael Lippautz, 2015/08/05 12:55:58]

Done.

+
+  Heap* heap = reinterpret_cast<i::Isolate*>(this)->heap();
+  if (heap->incremental_marking()->IsStopped()) {
+    heap->StartIncrementalMarking(Heap::kNoGCFlags, kGCCallbackFlagForced,
+                                  gc_reason);
+  }
+  double deadline =
+      heap->MonotonicallyIncreasingTimeInMs() + kIncrementalMarkingIntervalInMs;
+  heap->AdvanceIncrementalMarking(
+      0, deadline, IM::StepActions(IM::GC_VIA_STACK_GUARD, IM::FORCE_MARKING,
+                                   IM::FORCE_COMPLETION));
 }
 
 
 HeapProfiler* Isolate::GetHeapProfiler() {
   i::HeapProfiler* heap_profiler =
       reinterpret_cast<i::Isolate*>(this)->heap_profiler();
   return reinterpret_cast<HeapProfiler*>(heap_profiler);
 }
 
 
@@ skipping 1504 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8