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/oat_file.h"
26
27 namespace art HIDDEN {
28 namespace gc {
29 namespace collector {
30
Reset()31 void ImmuneSpaces::Reset() {
32 spaces_.clear();
33 largest_immune_region_.Reset();
34 }
35
CreateLargestImmuneRegion()36 void 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()),
54 kElfSegmentAlignment);
55 // For the app image case, GetOatFileBegin is where the oat file was mapped during image
56 // creation, the actual oat file could be somewhere else.
57 const OatFile* const image_oat_file = image_space->GetOatFile();
58 if (image_oat_file != nullptr) {
59 intervals.push_back(Interval(reinterpret_cast<uintptr_t>(image_oat_file->Begin()),
60 reinterpret_cast<uintptr_t>(image_oat_file->End()),
61 /*image=*/false));
62 }
63 }
64 intervals.push_back(Interval(space_begin, space_end, /*is_heap*/true));
65 }
66 std::sort(intervals.begin(), intervals.end());
67 // Intervals are already sorted by begin, if a new interval begins at the end of the current
68 // region then we append, otherwise we restart the current interval. To prevent starting an
69 // interval on an oat file, ignore oat files that are not extending an existing interval.
70 // If the total number of image bytes in the current interval is larger than the current best
71 // one, then we set the best one to be the current one.
72 for (const Interval& interval : intervals) {
73 const uintptr_t begin = std::get<0>(interval);
74 const uintptr_t end = std::get<1>(interval);
75 const bool is_heap = std::get<2>(interval);
76 VLOG(collector) << "Interval " << reinterpret_cast<const void*>(begin) << "-"
77 << reinterpret_cast<const void*>(end) << " is_heap=" << is_heap;
78 DCHECK_GE(end, begin);
79 DCHECK_GE(begin, cur_end);
80 // New interval is not at the end of the current one, start a new interval if we are a heap
81 // interval. Otherwise continue since we never start a new region with non image intervals.
82 if (begin != cur_end) {
83 if (!is_heap) {
84 continue;
85 }
86 // Not extending, reset the region.
87 cur_begin = begin;
88 cur_heap_size = 0;
89 }
90 cur_end = end;
91 if (is_heap) {
92 // Only update if the total number of image bytes is greater than the current best one.
93 // We don't want to count the oat file bytes since these contain no java objects.
94 cur_heap_size += end - begin;
95 if (cur_heap_size > best_heap_size) {
96 best_begin = cur_begin;
97 best_end = cur_end;
98 best_heap_size = cur_heap_size;
99 }
100 }
101 }
102 largest_immune_region_.SetBegin(reinterpret_cast<mirror::Object*>(best_begin));
103 largest_immune_region_.SetEnd(reinterpret_cast<mirror::Object*>(best_end));
104 VLOG(collector) << "Immune region " << largest_immune_region_.Begin() << "-"
105 << largest_immune_region_.End();
106 }
107
AddSpace(space::ContinuousSpace * space)108 void ImmuneSpaces::AddSpace(space::ContinuousSpace* space) {
109 DCHECK(spaces_.find(space) == spaces_.end()) << *space;
110 // Bind live to mark bitmap if necessary.
111 if (space->GetLiveBitmap() != nullptr && !space->HasBoundBitmaps()) {
112 CHECK(space->IsContinuousMemMapAllocSpace());
113 space->AsContinuousMemMapAllocSpace()->BindLiveToMarkBitmap();
114 }
115 spaces_.insert(space);
116 CreateLargestImmuneRegion();
117 }
118
operator ()(space::ContinuousSpace * a,space::ContinuousSpace * b) const119 bool ImmuneSpaces::CompareByBegin::operator()(space::ContinuousSpace* a, space::ContinuousSpace* b)
120 const {
121 return a->Begin() < b->Begin();
122 }
123
ContainsSpace(space::ContinuousSpace * space) const124 bool ImmuneSpaces::ContainsSpace(space::ContinuousSpace* space) const {
125 return spaces_.find(space) != spaces_.end();
126 }
127
128 } // namespace collector
129 } // namespace gc
130 } // namespace art
131