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 <tuple>
20#include <vector>
21
22#include "base/logging.h"  // For VLOG.
23#include "gc/space/space-inl.h"
24#include "mirror/object.h"
25#include "oat_file.h"
26
27namespace art {
28namespace gc {
29namespace collector {
30
31void ImmuneSpaces::Reset() {
32  spaces_.clear();
33  largest_immune_region_.Reset();
34}
35
36void ImmuneSpaces::CreateLargestImmuneRegion() {
37  uintptr_t best_begin = 0u;
38  uintptr_t best_end = 0u;
39  uintptr_t best_heap_size = 0u;
40  uintptr_t cur_begin = 0u;
41  uintptr_t cur_end = 0u;
42  uintptr_t cur_heap_size = 0u;
43  using Interval = std::tuple</*start*/uintptr_t, /*end*/uintptr_t, /*is_heap*/bool>;
44  std::vector<Interval> intervals;
45  for (space::ContinuousSpace* space : GetSpaces()) {
46    uintptr_t space_begin = reinterpret_cast<uintptr_t>(space->Begin());
47    uintptr_t space_end = reinterpret_cast<uintptr_t>(space->Limit());
48    if (space->IsImageSpace()) {
49      // For the boot image, the boot oat file is always directly after. For app images it may not
50      // be if the app image was mapped at a random address.
51      space::ImageSpace* image_space = space->AsImageSpace();
52      // Update the end to include the other non-heap sections.
53      space_end = RoundUp(reinterpret_cast<uintptr_t>(image_space->GetImageEnd()), kPageSize);
54      // For the app image case, GetOatFileBegin is where the oat file was mapped during image
55      // creation, the actual oat file could be somewhere else.
56      const OatFile* const image_oat_file = image_space->GetOatFile();
57      if (image_oat_file != nullptr) {
58        intervals.push_back(Interval(reinterpret_cast<uintptr_t>(image_oat_file->Begin()),
59                                     reinterpret_cast<uintptr_t>(image_oat_file->End()),
60                                     /*image*/false));
61      }
62    }
63    intervals.push_back(Interval(space_begin, space_end, /*is_heap*/true));
64  }
65  std::sort(intervals.begin(), intervals.end());
66  // Intervals are already sorted by begin, if a new interval begins at the end of the current
67  // region then we append, otherwise we restart the current interval. To prevent starting an
68  // interval on an oat file, ignore oat files that are not extending an existing interval.
69  // If the total number of image bytes in the current interval is larger than the current best
70  // one, then we set the best one to be the current one.
71  for (const Interval& interval : intervals) {
72    const uintptr_t begin = std::get<0>(interval);
73    const uintptr_t end = std::get<1>(interval);
74    const bool is_heap = std::get<2>(interval);
75    VLOG(collector) << "Interval " << reinterpret_cast<const void*>(begin) << "-"
76                    << reinterpret_cast<const void*>(end) << " is_heap=" << is_heap;
77    DCHECK_GE(end, begin);
78    DCHECK_GE(begin, cur_end);
79    // New interval is not at the end of the current one, start a new interval if we are a heap
80    // interval. Otherwise continue since we never start a new region with non image intervals.
81    if (begin != cur_end) {
82      if (!is_heap) {
83        continue;
84      }
85      // Not extending, reset the region.
86      cur_begin = begin;
87      cur_heap_size = 0;
88    }
89    cur_end = end;
90    if (is_heap) {
91      // Only update if the total number of image bytes is greater than the current best one.
92      // We don't want to count the oat file bytes since these contain no java objects.
93      cur_heap_size += end - begin;
94      if (cur_heap_size > best_heap_size) {
95        best_begin = cur_begin;
96        best_end = cur_end;
97        best_heap_size = cur_heap_size;
98      }
99    }
100  }
101  largest_immune_region_.SetBegin(reinterpret_cast<mirror::Object*>(best_begin));
102  largest_immune_region_.SetEnd(reinterpret_cast<mirror::Object*>(best_end));
103  VLOG(collector) << "Immune region " << largest_immune_region_.Begin() << "-"
104                  << largest_immune_region_.End();
105}
106
107void ImmuneSpaces::AddSpace(space::ContinuousSpace* space) {
108  DCHECK(spaces_.find(space) == spaces_.end()) << *space;
109  // Bind live to mark bitmap if necessary.
110  if (space->GetLiveBitmap() != space->GetMarkBitmap()) {
111    CHECK(space->IsContinuousMemMapAllocSpace());
112    space->AsContinuousMemMapAllocSpace()->BindLiveToMarkBitmap();
113  }
114  spaces_.insert(space);
115  CreateLargestImmuneRegion();
116}
117
118bool ImmuneSpaces::CompareByBegin::operator()(space::ContinuousSpace* a, space::ContinuousSpace* b)
119    const {
120  return a->Begin() < b->Begin();
121}
122
123bool ImmuneSpaces::ContainsSpace(space::ContinuousSpace* space) const {
124  return spaces_.find(space) != spaces_.end();
125}
126
127}  // namespace collector
128}  // namespace gc
129}  // namespace art
130