1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "immune_spaces.h"
18
19#include <vector>
20#include <tuple>
21
22#include "gc/space/space-inl.h"
23#include "mirror/object.h"
24#include "oat_file.h"
25
26namespace art {
27namespace gc {
28namespace collector {
29
30void ImmuneSpaces::Reset() {
31  spaces_.clear();
32  largest_immune_region_.Reset();
33}
34
35void ImmuneSpaces::CreateLargestImmuneRegion() {
36  uintptr_t best_begin = 0u;
37  uintptr_t best_end = 0u;
38  uintptr_t best_heap_size = 0u;
39  uintptr_t cur_begin = 0u;
40  uintptr_t cur_end = 0u;
41  uintptr_t cur_heap_size = 0u;
42  using Interval = std::tuple</*start*/uintptr_t, /*end*/uintptr_t, /*is_heap*/bool>;
43  std::vector<Interval> intervals;
44  for (space::ContinuousSpace* space : GetSpaces()) {
45    uintptr_t space_begin = reinterpret_cast<uintptr_t>(space->Begin());
46    uintptr_t space_end = reinterpret_cast<uintptr_t>(space->Limit());
47    if (space->IsImageSpace()) {
48      // For the boot image, the boot oat file is always directly after. For app images it may not
49      // be if the app image was mapped at a random address.
50      space::ImageSpace* image_space = space->AsImageSpace();
51      // Update the end to include the other non-heap sections.
52      space_end = RoundUp(reinterpret_cast<uintptr_t>(image_space->GetImageEnd()), kPageSize);
53      // For the app image case, GetOatFileBegin is where the oat file was mapped during image
54      // creation, the actual oat file could be somewhere else.
55      const OatFile* const image_oat_file = image_space->GetOatFile();
56      if (image_oat_file != nullptr) {
57        intervals.push_back(Interval(reinterpret_cast<uintptr_t>(image_oat_file->Begin()),
58                                     reinterpret_cast<uintptr_t>(image_oat_file->End()),
59                                     /*image*/false));
60      }
61    }
62    intervals.push_back(Interval(space_begin, space_end, /*is_heap*/true));
63  }
64  std::sort(intervals.begin(), intervals.end());
65  // Intervals are already sorted by begin, if a new interval begins at the end of the current
66  // region then we append, otherwise we restart the current interval. To prevent starting an
67  // interval on an oat file, ignore oat files that are not extending an existing interval.
68  // If the total number of image bytes in the current interval is larger than the current best
69  // one, then we set the best one to be the current one.
70  for (const Interval& interval : intervals) {
71    const uintptr_t begin = std::get<0>(interval);
72    const uintptr_t end = std::get<1>(interval);
73    const bool is_heap = std::get<2>(interval);
74    VLOG(collector) << "Interval " << reinterpret_cast<const void*>(begin) << "-"
75                    << reinterpret_cast<const void*>(end) << " is_heap=" << is_heap;
76    DCHECK_GE(end, begin);
77    DCHECK_GE(begin, cur_end);
78    // New interval is not at the end of the current one, start a new interval if we are a heap
79    // interval. Otherwise continue since we never start a new region with non image intervals.
80    if (begin != cur_end) {
81      if (!is_heap) {
82        continue;
83      }
84      // Not extending, reset the region.
85      cur_begin = begin;
86      cur_heap_size = 0;
87    }
88    cur_end = end;
89    if (is_heap) {
90      // Only update if the total number of image bytes is greater than the current best one.
91      // We don't want to count the oat file bytes since these contain no java objects.
92      cur_heap_size += end - begin;
93      if (cur_heap_size > best_heap_size) {
94        best_begin = cur_begin;
95        best_end = cur_end;
96        best_heap_size = cur_heap_size;
97      }
98    }
99  }
100  largest_immune_region_.SetBegin(reinterpret_cast<mirror::Object*>(best_begin));
101  largest_immune_region_.SetEnd(reinterpret_cast<mirror::Object*>(best_end));
102  VLOG(collector) << "Immune region " << largest_immune_region_.Begin() << "-"
103                  << largest_immune_region_.End();
104}
105
106void ImmuneSpaces::AddSpace(space::ContinuousSpace* space) {
107  DCHECK(spaces_.find(space) == spaces_.end()) << *space;
108  // Bind live to mark bitmap if necessary.
109  if (space->GetLiveBitmap() != space->GetMarkBitmap()) {
110    CHECK(space->IsContinuousMemMapAllocSpace());
111    space->AsContinuousMemMapAllocSpace()->BindLiveToMarkBitmap();
112  }
113  spaces_.insert(space);
114  CreateLargestImmuneRegion();
115}
116
117bool ImmuneSpaces::CompareByBegin::operator()(space::ContinuousSpace* a, space::ContinuousSpace* b)
118    const {
119  return a->Begin() < b->Begin();
120}
121
122bool ImmuneSpaces::ContainsSpace(space::ContinuousSpace* space) const {
123  return spaces_.find(space) != spaces_.end();
124}
125
126}  // namespace collector
127}  // namespace gc
128}  // namespace art
129