1/*
2 * Copyright (C) 2014-2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "FullGCActivityCallback.h"
28
29#include "VM.h"
30
31namespace JSC {
32
33#if !PLATFORM(IOS_FAMILY)
34const constexpr Seconds pagingTimeOut { 100_ms }; // Time in seconds to allow opportunistic timer to iterate over all blocks to see if the Heap is paged out.
35#endif
36
37FullGCActivityCallback::FullGCActivityCallback(Heap* heap)
38 : GCActivityCallback(heap)
39{
40}
41
42void FullGCActivityCallback::doCollection(VM& vm)
43{
44 Heap& heap = vm.heap;
45 m_didGCRecently = false;
46
47#if !PLATFORM(IOS_FAMILY)
48 MonotonicTime startTime = MonotonicTime::now();
49 if (heap.isPagedOut(startTime + pagingTimeOut)) {
50 cancel();
51 heap.increaseLastFullGCLength(pagingTimeOut);
52 return;
53 }
54#endif
55
56 heap.collectAsync(CollectionScope::Full);
57}
58
59Seconds FullGCActivityCallback::lastGCLength(Heap& heap)
60{
61 return heap.lastFullGCLength();
62}
63
64double FullGCActivityCallback::deathRate(Heap& heap)
65{
66 size_t sizeBefore = heap.sizeBeforeLastFullCollection();
67 size_t sizeAfter = heap.sizeAfterLastFullCollection();
68 if (!sizeBefore)
69 return 1.0;
70 if (sizeAfter > sizeBefore) {
71 // GC caused the heap to grow(!)
72 // This could happen if the we visited more extra memory than was reported allocated.
73 // We don't return a negative death rate, since that would schedule the next GC in the past.
74 return 0;
75 }
76 return static_cast<double>(sizeBefore - sizeAfter) / static_cast<double>(sizeBefore);
77}
78
79double FullGCActivityCallback::gcTimeSlice(size_t bytes)
80{
81 return std::min((static_cast<double>(bytes) / MB) * Options::percentCPUPerMBForFullTimer(), Options::collectionTimerMaxPercentCPU());
82}
83
84} // namespace JSC
85