Ryan Macnak
d965998d1c
Improves the space overhead of compaction from O(size of live objects) to O(number of live objects). Future work includes: - a smaller, faster representation the forwarding table via a bitmap of used allocation units - sorting class sizes off-heap to allow sliding classes - running forwarding in parallel Removes unnecessary sweep from evacuating compactor. Change-Id: If0991bfb75573201c6e8feed142ca0cc69fccab4 Bug: https://github.com/dart-lang/sdk/issues/30978 Reviewed-on: https://dart-review.googlesource.com/15988 Commit-Queue: Ryan Macnak <rmacnak@google.com> Reviewed-by: Erik Corry <erikcorry@google.com>
33 lines
1.2 KiB
Dart
33 lines
1.2 KiB
Dart
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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// Deliberately fragment the heap and test that GC peformance does not
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// break down. See https://github.com/dart-lang/sdk/issues/29588
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// Normally runs in about 6-7 seconds on an x64 machine, using about 2.5Gbytes
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// of memory.
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//
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// This test is deliberately CPU-light and so it can make a lot of
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// progress before the concurrent sweepers are done sweeping the heap.
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// In that time there is no freelist and so the issue does not arise.
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// VMOptions=--no_concurrent_sweep
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// VMOptions=--use_compactor_evacuating
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// VMOptions=--use_compactor_sliding
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main() {
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final List<List> arrays = [];
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// Fill up heap with alternate large-small items.
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for (int i = 0; i < 500000; i++) {
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arrays.add(new List(260));
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arrays.add(new List(1));
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}
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// Clear the large items so that the heap is full of 260-word gaps.
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for (int i = 0; i < arrays.length; i += 2) {
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arrays[i] = null;
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}
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// Allocate a lot of 300-word objects that don't fit in the gaps.
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for (int i = 0; i < 600000; i++) {
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arrays.add(new List(300));
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}
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}
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