Start incremental marking on idle notification.

test/cctest/test-heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "execution.h"
 #include "factory.h"
 #include "macro-assembler.h"
 #include "global-handles.h"
@@ skipping 1254 matching lines @@
   CHECK(old_capacity == 2 * new_capacity);
 
   // Consecutive shrinking should not affect space capacity.
   old_capacity = new_space->Capacity();
   new_space->Shrink();
   new_space->Shrink();
   new_space->Shrink();
   new_capacity = new_space->Capacity();
   CHECK(old_capacity == new_capacity);
 }
+
+TEST(IdleNotificationAdvancesIncrementalMarking) {
+  if (!FLAG_incremental_marking || !FLAG_incremental_marking_steps) return;
+  InitializeVM();
+  v8::HandleScope scope;
+  const char* source = "function binom(n, m) {"
+                       "  var C = [[1]];"
+                       "  for (var i = 1; i <= n; ++i) {"
+                       "    C[i] = [1];"
+                       "    for (var j = 1; j < i; ++j) {"
+                       "      C[i][j] = C[i-1][j-1] + C[i-1][j];"
+                       "    }"
+                       "    C[i][i] = 1;"
+                       "  }"
+                       "  return C[n][m];"
+                       "};"
+                       "binom(1000, 500)";
+  {
+    AlwaysAllocateScope aa_scope;
+    CompileRun(source);
+  }
+  intptr_t old_size = HEAP->SizeOfObjects();
+  int old_steps = HEAP->incremental_marking()->steps_count();
+  HEAP->IdleNotification();
+  int new_steps = HEAP->incremental_marking()->steps_count();
+  CHECK(new_steps > old_steps);
+  while (!HEAP->IdleNotification());
+  intptr_t new_size = HEAP->SizeOfObjects();
+  CHECK(new_size < old_size);
+}
+