Index: tests/standalone/fragmentation_test.dart |
diff --git a/tests/standalone/fragmentation_test.dart b/tests/standalone/fragmentation_test.dart |
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+// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file |
+// for details. All rights reserved. Use of this source code is governed by a |
+// BSD-style license that can be found in the LICENSE file. |
+ |
+// Deliberately fragment the heap and test that GC peformance does not |
+// break down. See https://github.com/dart-lang/sdk/issues/29588 |
+// Normally runs in about 6-7 seconds on an x64 machine, using about 2.5Gbytes |
+// of memory. |
+// |
+// This test is deliberately CPU-light and so it can make a lot of |
+// progress before the concurrent sweepers are done sweeping the heap. |
+// In that time there is no freelist and so the issue does not arise. |
+// VMOptions=--no-concurrent-sweep |
+ |
+main() { |
+ final List<List> arrays = []; |
+ // Fill up heap with alternate large-small items. |
+ for (int i = 0; i < 500000; i++) { |
+ arrays.add(new List(260)); |
+ arrays.add(new List(1)); |
+ } |
+ // Clear the large items so that the heap is full of 260-word gaps. |
+ for (int i = 0; i < arrays.length; i += 2) { |
+ arrays[i] = null; |
+ } |
+ // Allocate a lot of 300-word objects that don't fit in the gaps. |
+ for (int i = 0; i < 600000; i++) { |
+ arrays.add(new List(300)); |
+ } |
+} |