Check if there is still time before finalizing an incremental collection.

test/cctest/test-heap.cc

 // Copyright 2012 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 2165 matching lines @@
   const int kLongIdlePauseInMs = 1000;
   CcTest::isolate()->ContextDisposedNotification();
   CcTest::isolate()->IdleNotification(kLongIdlePauseInMs);
 
   CHECK_EQ(CcTest::heap()->global_ic_age(), f->shared()->ic_age());
   CHECK_EQ(0, f->shared()->opt_count());
   CHECK_EQ(0, f->shared()->code()->profiler_ticks());
 }
 
 
+TEST(IdleNotificationFinishMarking) {
+  i::FLAG_allow_natives_syntax = true;
+  CcTest::InitializeVM();
+  SimulateFullSpace(CcTest::heap()->old_pointer_space());
+  IncrementalMarking* marking = CcTest::heap()->incremental_marking();
+  marking->Abort();
+  marking->Start();
+
+  CHECK_EQ(CcTest::heap()->gc_count(), 0);
+
+  // TODO(hpayer): We cannot write proper unit test right now for heap.
+  // The ideal test would call kMaxIdleMarkingDelayCounter to test the
+  // marking delay counter.
+
+  // Perform a huge incremental marking step but don't complete marking.
+  marking->Step(100 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD,

[ulan, 2014/10/13 13:40:04]

"100 * MB" looks fragile, but I guess it is sufficient. One possible solution
would be to make Step() return number of marked bytes and do "while (Step() >
0)";

[Hannes Payer (out of office), 2014/10/13 13:53:32]

Done.

+                IncrementalMarking::FORCE_MARKING,
+                IncrementalMarking::DO_NOT_FORCE_COMPLETION);
+  CHECK(!marking->IsIdleMarkingDelayCounterLimitReached());
+
+  // The next invocations of incremental marking are not going to complete
+  // marking
+  // since the completion threshold is not reached
+  for (size_t i = 0; i < IncrementalMarking::kMaxIdleMarkingDelayCounter - 1;
+       i++) {
+    marking->Step(100 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  IncrementalMarking::FORCE_MARKING,
+                  IncrementalMarking::DO_NOT_FORCE_COMPLETION);
+    CHECK(!marking->IsIdleMarkingDelayCounterLimitReached());
+  }
+
+  // The next idle notification has to finish incremental marking.
+  const int kShortIdleTimeInMs = 1;
+  CcTest::isolate()->IdleNotification(kShortIdleTimeInMs);
+  CHECK_EQ(CcTest::heap()->gc_count(), kShortIdleTimeInMs);

[ulan, 2014/10/13 13:40:04]

Did you mean CHECK_EQ(CcTest::heap()->gc_count(), 1) ?

[Hannes Payer (out of office), 2014/10/13 13:53:32]

lol, yes. Done.

+}
+
+
 // Test that HAllocateObject will always return an object in new-space.
 TEST(OptimizedAllocationAlwaysInNewSpace) {
   i::FLAG_allow_natives_syntax = true;
   CcTest::InitializeVM();
   if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
   if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
   v8::HandleScope scope(CcTest::isolate());
 
   SimulateFullSpace(CcTest::heap()->new_space());
   AlwaysAllocateScope always_allocate(CcTest::i_isolate());
@@ skipping 2309 matching lines @@
 #ifdef DEBUG
 TEST(PathTracer) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
 
   v8::Local<v8::Value> result = CompileRun("'abc'");
   Handle<Object> o = v8::Utils::OpenHandle(*result);
   CcTest::i_isolate()->heap()->TracePathToObject(*o);
 }
 #endif  // DEBUG