1 /*
2 * Copyright (C) 2012 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 "large_object_space.h"
18
19 #include <sys/mman.h>
20
21 #include <memory>
22
23 #include <android-base/logging.h>
24
25 #include "base/macros.h"
26 #include "base/memory_tool.h"
27 #include "base/mutex-inl.h"
28 #include "base/os.h"
29 #include "base/stl_util.h"
30 #include "gc/accounting/heap_bitmap-inl.h"
31 #include "gc/accounting/space_bitmap-inl.h"
32 #include "gc/heap.h"
33 #include "image.h"
34 #include "scoped_thread_state_change-inl.h"
35 #include "space-inl.h"
36 #include "thread-current-inl.h"
37
38 namespace art {
39 namespace gc {
40 namespace space {
41
42 class MemoryToolLargeObjectMapSpace final : public LargeObjectMapSpace {
43 public:
MemoryToolLargeObjectMapSpace(const std::string & name)44 explicit MemoryToolLargeObjectMapSpace(const std::string& name) : LargeObjectMapSpace(name) {
45 }
46
~MemoryToolLargeObjectMapSpace()47 ~MemoryToolLargeObjectMapSpace() override {
48 // Historical note: We were deleting large objects to keep Valgrind happy if there were
49 // any large objects such as Dex cache arrays which aren't freed since they are held live
50 // by the class linker.
51 }
52
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)53 mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
54 size_t* usable_size, size_t* bytes_tl_bulk_allocated)
55 override {
56 mirror::Object* obj =
57 LargeObjectMapSpace::Alloc(self, num_bytes + kMemoryToolRedZoneBytes * 2, bytes_allocated,
58 usable_size, bytes_tl_bulk_allocated);
59 mirror::Object* object_without_rdz = reinterpret_cast<mirror::Object*>(
60 reinterpret_cast<uintptr_t>(obj) + kMemoryToolRedZoneBytes);
61 MEMORY_TOOL_MAKE_NOACCESS(reinterpret_cast<void*>(obj), kMemoryToolRedZoneBytes);
62 MEMORY_TOOL_MAKE_NOACCESS(
63 reinterpret_cast<uint8_t*>(object_without_rdz) + num_bytes,
64 kMemoryToolRedZoneBytes);
65 if (usable_size != nullptr) {
66 *usable_size = num_bytes; // Since we have redzones, shrink the usable size.
67 }
68 return object_without_rdz;
69 }
70
AllocationSize(mirror::Object * obj,size_t * usable_size)71 size_t AllocationSize(mirror::Object* obj, size_t* usable_size) override {
72 return LargeObjectMapSpace::AllocationSize(ObjectWithRedzone(obj), usable_size);
73 }
74
IsZygoteLargeObject(Thread * self,mirror::Object * obj) const75 bool IsZygoteLargeObject(Thread* self, mirror::Object* obj) const override {
76 return LargeObjectMapSpace::IsZygoteLargeObject(self, ObjectWithRedzone(obj));
77 }
78
Free(Thread * self,mirror::Object * obj)79 size_t Free(Thread* self, mirror::Object* obj) override {
80 mirror::Object* object_with_rdz = ObjectWithRedzone(obj);
81 MEMORY_TOOL_MAKE_UNDEFINED(object_with_rdz, AllocationSize(obj, nullptr));
82 return LargeObjectMapSpace::Free(self, object_with_rdz);
83 }
84
Contains(const mirror::Object * obj) const85 bool Contains(const mirror::Object* obj) const override {
86 return LargeObjectMapSpace::Contains(ObjectWithRedzone(obj));
87 }
88
89 private:
ObjectWithRedzone(const mirror::Object * obj)90 static const mirror::Object* ObjectWithRedzone(const mirror::Object* obj) {
91 return reinterpret_cast<const mirror::Object*>(
92 reinterpret_cast<uintptr_t>(obj) - kMemoryToolRedZoneBytes);
93 }
94
ObjectWithRedzone(mirror::Object * obj)95 static mirror::Object* ObjectWithRedzone(mirror::Object* obj) {
96 return reinterpret_cast<mirror::Object*>(
97 reinterpret_cast<uintptr_t>(obj) - kMemoryToolRedZoneBytes);
98 }
99
100 static constexpr size_t kMemoryToolRedZoneBytes = kPageSize;
101 };
102
SwapBitmaps()103 void LargeObjectSpace::SwapBitmaps() {
104 live_bitmap_.swap(mark_bitmap_);
105 // Swap names to get more descriptive diagnostics.
106 std::string temp_name = live_bitmap_->GetName();
107 live_bitmap_->SetName(mark_bitmap_->GetName());
108 mark_bitmap_->SetName(temp_name);
109 }
110
LargeObjectSpace(const std::string & name,uint8_t * begin,uint8_t * end,const char * lock_name)111 LargeObjectSpace::LargeObjectSpace(const std::string& name, uint8_t* begin, uint8_t* end,
112 const char* lock_name)
113 : DiscontinuousSpace(name, kGcRetentionPolicyAlwaysCollect),
114 lock_(lock_name, kAllocSpaceLock),
115 num_bytes_allocated_(0), num_objects_allocated_(0), total_bytes_allocated_(0),
116 total_objects_allocated_(0), begin_(begin), end_(end) {
117 }
118
119
CopyLiveToMarked()120 void LargeObjectSpace::CopyLiveToMarked() {
121 mark_bitmap_->CopyFrom(live_bitmap_.get());
122 }
123
LargeObjectMapSpace(const std::string & name)124 LargeObjectMapSpace::LargeObjectMapSpace(const std::string& name)
125 : LargeObjectSpace(name, nullptr, nullptr, "large object map space lock") {}
126
Create(const std::string & name)127 LargeObjectMapSpace* LargeObjectMapSpace::Create(const std::string& name) {
128 if (Runtime::Current()->IsRunningOnMemoryTool()) {
129 return new MemoryToolLargeObjectMapSpace(name);
130 } else {
131 return new LargeObjectMapSpace(name);
132 }
133 }
134
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)135 mirror::Object* LargeObjectMapSpace::Alloc(Thread* self, size_t num_bytes,
136 size_t* bytes_allocated, size_t* usable_size,
137 size_t* bytes_tl_bulk_allocated) {
138 std::string error_msg;
139 MemMap mem_map = MemMap::MapAnonymous("large object space allocation",
140 num_bytes,
141 PROT_READ | PROT_WRITE,
142 /*low_4gb=*/ true,
143 &error_msg);
144 if (UNLIKELY(!mem_map.IsValid())) {
145 LOG(WARNING) << "Large object allocation failed: " << error_msg;
146 return nullptr;
147 }
148 mirror::Object* const obj = reinterpret_cast<mirror::Object*>(mem_map.Begin());
149 const size_t allocation_size = mem_map.BaseSize();
150 MutexLock mu(self, lock_);
151 large_objects_.Put(obj, LargeObject {std::move(mem_map), false /* not zygote */});
152 DCHECK(bytes_allocated != nullptr);
153
154 if (begin_ == nullptr || begin_ > reinterpret_cast<uint8_t*>(obj)) {
155 begin_ = reinterpret_cast<uint8_t*>(obj);
156 }
157 end_ = std::max(end_, reinterpret_cast<uint8_t*>(obj) + allocation_size);
158
159 *bytes_allocated = allocation_size;
160 if (usable_size != nullptr) {
161 *usable_size = allocation_size;
162 }
163 DCHECK(bytes_tl_bulk_allocated != nullptr);
164 *bytes_tl_bulk_allocated = allocation_size;
165 num_bytes_allocated_ += allocation_size;
166 total_bytes_allocated_ += allocation_size;
167 ++num_objects_allocated_;
168 ++total_objects_allocated_;
169 return obj;
170 }
171
IsZygoteLargeObject(Thread * self,mirror::Object * obj) const172 bool LargeObjectMapSpace::IsZygoteLargeObject(Thread* self, mirror::Object* obj) const {
173 MutexLock mu(self, lock_);
174 auto it = large_objects_.find(obj);
175 CHECK(it != large_objects_.end());
176 return it->second.is_zygote;
177 }
178
SetAllLargeObjectsAsZygoteObjects(Thread * self)179 void LargeObjectMapSpace::SetAllLargeObjectsAsZygoteObjects(Thread* self) {
180 MutexLock mu(self, lock_);
181 for (auto& pair : large_objects_) {
182 pair.second.is_zygote = true;
183 }
184 }
185
Free(Thread * self,mirror::Object * ptr)186 size_t LargeObjectMapSpace::Free(Thread* self, mirror::Object* ptr) {
187 MutexLock mu(self, lock_);
188 auto it = large_objects_.find(ptr);
189 if (UNLIKELY(it == large_objects_.end())) {
190 ScopedObjectAccess soa(self);
191 Runtime::Current()->GetHeap()->DumpSpaces(LOG_STREAM(FATAL_WITHOUT_ABORT));
192 LOG(FATAL) << "Attempted to free large object " << ptr << " which was not live";
193 }
194 const size_t map_size = it->second.mem_map.BaseSize();
195 DCHECK_GE(num_bytes_allocated_, map_size);
196 size_t allocation_size = map_size;
197 num_bytes_allocated_ -= allocation_size;
198 --num_objects_allocated_;
199 large_objects_.erase(it);
200 return allocation_size;
201 }
202
AllocationSize(mirror::Object * obj,size_t * usable_size)203 size_t LargeObjectMapSpace::AllocationSize(mirror::Object* obj, size_t* usable_size) {
204 MutexLock mu(Thread::Current(), lock_);
205 auto it = large_objects_.find(obj);
206 CHECK(it != large_objects_.end()) << "Attempted to get size of a large object which is not live";
207 size_t alloc_size = it->second.mem_map.BaseSize();
208 if (usable_size != nullptr) {
209 *usable_size = alloc_size;
210 }
211 return alloc_size;
212 }
213
FreeList(Thread * self,size_t num_ptrs,mirror::Object ** ptrs)214 size_t LargeObjectSpace::FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs) {
215 size_t total = 0;
216 for (size_t i = 0; i < num_ptrs; ++i) {
217 if (kDebugSpaces) {
218 CHECK(Contains(ptrs[i]));
219 }
220 total += Free(self, ptrs[i]);
221 }
222 return total;
223 }
224
Walk(DlMallocSpace::WalkCallback callback,void * arg)225 void LargeObjectMapSpace::Walk(DlMallocSpace::WalkCallback callback, void* arg) {
226 MutexLock mu(Thread::Current(), lock_);
227 for (auto& pair : large_objects_) {
228 MemMap* mem_map = &pair.second.mem_map;
229 callback(mem_map->Begin(), mem_map->End(), mem_map->Size(), arg);
230 callback(nullptr, nullptr, 0, arg);
231 }
232 }
233
ForEachMemMap(std::function<void (const MemMap &)> func) const234 void LargeObjectMapSpace::ForEachMemMap(std::function<void(const MemMap&)> func) const {
235 MutexLock mu(Thread::Current(), lock_);
236 for (auto& pair : large_objects_) {
237 func(pair.second.mem_map);
238 }
239 }
240
Contains(const mirror::Object * obj) const241 bool LargeObjectMapSpace::Contains(const mirror::Object* obj) const {
242 Thread* self = Thread::Current();
243 if (lock_.IsExclusiveHeld(self)) {
244 // We hold lock_ so do the check.
245 return large_objects_.find(const_cast<mirror::Object*>(obj)) != large_objects_.end();
246 } else {
247 MutexLock mu(self, lock_);
248 return large_objects_.find(const_cast<mirror::Object*>(obj)) != large_objects_.end();
249 }
250 }
251
252 // Keeps track of allocation sizes + whether or not the previous allocation is free.
253 // Used to coalesce free blocks and find the best fit block for an allocation for best fit object
254 // allocation. Each allocation has an AllocationInfo which contains the size of the previous free
255 // block preceding it. Implemented in such a way that we can also find the iterator for any
256 // allocation info pointer.
257 class AllocationInfo {
258 public:
AllocationInfo()259 AllocationInfo() : prev_free_(0), alloc_size_(0) {
260 }
261 // Return the number of pages that the allocation info covers.
AlignSize() const262 size_t AlignSize() const {
263 return alloc_size_ & kFlagsMask;
264 }
265 // Returns the allocation size in bytes.
ByteSize() const266 size_t ByteSize() const {
267 return AlignSize() * FreeListSpace::kAlignment;
268 }
269 // Updates the allocation size and whether or not it is free.
SetByteSize(size_t size,bool free)270 void SetByteSize(size_t size, bool free) {
271 DCHECK_EQ(size & ~kFlagsMask, 0u);
272 DCHECK_ALIGNED(size, FreeListSpace::kAlignment);
273 alloc_size_ = (size / FreeListSpace::kAlignment) | (free ? kFlagFree : 0u);
274 }
275 // Returns true if the block is free.
IsFree() const276 bool IsFree() const {
277 return (alloc_size_ & kFlagFree) != 0;
278 }
279 // Return true if the large object is a zygote object.
IsZygoteObject() const280 bool IsZygoteObject() const {
281 return (alloc_size_ & kFlagZygote) != 0;
282 }
283 // Change the object to be a zygote object.
SetZygoteObject()284 void SetZygoteObject() {
285 alloc_size_ |= kFlagZygote;
286 }
287 // Return true if this is a zygote large object.
288 // Finds and returns the next non free allocation info after ourself.
GetNextInfo()289 AllocationInfo* GetNextInfo() {
290 return this + AlignSize();
291 }
GetNextInfo() const292 const AllocationInfo* GetNextInfo() const {
293 return this + AlignSize();
294 }
295 // Returns the previous free allocation info by using the prev_free_ member to figure out
296 // where it is. This is only used for coalescing so we only need to be able to do it if the
297 // previous allocation info is free.
GetPrevFreeInfo()298 AllocationInfo* GetPrevFreeInfo() {
299 DCHECK_NE(prev_free_, 0U);
300 return this - prev_free_;
301 }
302 // Returns the address of the object associated with this allocation info.
GetObjectAddress()303 mirror::Object* GetObjectAddress() {
304 return reinterpret_cast<mirror::Object*>(reinterpret_cast<uintptr_t>(this) + sizeof(*this));
305 }
306 // Return how many kAlignment units there are before the free block.
GetPrevFree() const307 size_t GetPrevFree() const {
308 return prev_free_;
309 }
310 // Returns how many free bytes there is before the block.
GetPrevFreeBytes() const311 size_t GetPrevFreeBytes() const {
312 return GetPrevFree() * FreeListSpace::kAlignment;
313 }
314 // Update the size of the free block prior to the allocation.
SetPrevFreeBytes(size_t bytes)315 void SetPrevFreeBytes(size_t bytes) {
316 DCHECK_ALIGNED(bytes, FreeListSpace::kAlignment);
317 prev_free_ = bytes / FreeListSpace::kAlignment;
318 }
319
320 private:
321 static constexpr uint32_t kFlagFree = 0x80000000; // If block is free.
322 static constexpr uint32_t kFlagZygote = 0x40000000; // If the large object is a zygote object.
323 static constexpr uint32_t kFlagsMask = ~(kFlagFree | kFlagZygote); // Combined flags for masking.
324 // Contains the size of the previous free block with kAlignment as the unit. If 0 then the
325 // allocation before us is not free.
326 // These variables are undefined in the middle of allocations / free blocks.
327 uint32_t prev_free_;
328 // Allocation size of this object in kAlignment as the unit.
329 uint32_t alloc_size_;
330 };
331
GetSlotIndexForAllocationInfo(const AllocationInfo * info) const332 size_t FreeListSpace::GetSlotIndexForAllocationInfo(const AllocationInfo* info) const {
333 DCHECK_GE(info, allocation_info_);
334 DCHECK_LT(info, reinterpret_cast<AllocationInfo*>(allocation_info_map_.End()));
335 return info - allocation_info_;
336 }
337
GetAllocationInfoForAddress(uintptr_t address)338 AllocationInfo* FreeListSpace::GetAllocationInfoForAddress(uintptr_t address) {
339 return &allocation_info_[GetSlotIndexForAddress(address)];
340 }
341
GetAllocationInfoForAddress(uintptr_t address) const342 const AllocationInfo* FreeListSpace::GetAllocationInfoForAddress(uintptr_t address) const {
343 return &allocation_info_[GetSlotIndexForAddress(address)];
344 }
345
operator ()(const AllocationInfo * a,const AllocationInfo * b) const346 inline bool FreeListSpace::SortByPrevFree::operator()(const AllocationInfo* a,
347 const AllocationInfo* b) const {
348 if (a->GetPrevFree() < b->GetPrevFree()) return true;
349 if (a->GetPrevFree() > b->GetPrevFree()) return false;
350 if (a->AlignSize() < b->AlignSize()) return true;
351 if (a->AlignSize() > b->AlignSize()) return false;
352 return reinterpret_cast<uintptr_t>(a) < reinterpret_cast<uintptr_t>(b);
353 }
354
Create(const std::string & name,size_t size)355 FreeListSpace* FreeListSpace::Create(const std::string& name, size_t size) {
356 CHECK_EQ(size % kAlignment, 0U);
357 std::string error_msg;
358 MemMap mem_map = MemMap::MapAnonymous(name.c_str(),
359 size,
360 PROT_READ | PROT_WRITE,
361 /*low_4gb=*/ true,
362 &error_msg);
363 CHECK(mem_map.IsValid()) << "Failed to allocate large object space mem map: " << error_msg;
364 return new FreeListSpace(name, std::move(mem_map), mem_map.Begin(), mem_map.End());
365 }
366
FreeListSpace(const std::string & name,MemMap && mem_map,uint8_t * begin,uint8_t * end)367 FreeListSpace::FreeListSpace(const std::string& name,
368 MemMap&& mem_map,
369 uint8_t* begin,
370 uint8_t* end)
371 : LargeObjectSpace(name, begin, end, "free list space lock"),
372 mem_map_(std::move(mem_map)) {
373 const size_t space_capacity = end - begin;
374 free_end_ = space_capacity;
375 CHECK_ALIGNED(space_capacity, kAlignment);
376 const size_t alloc_info_size = sizeof(AllocationInfo) * (space_capacity / kAlignment);
377 std::string error_msg;
378 allocation_info_map_ =
379 MemMap::MapAnonymous("large object free list space allocation info map",
380 alloc_info_size,
381 PROT_READ | PROT_WRITE,
382 /*low_4gb=*/ false,
383 &error_msg);
384 CHECK(allocation_info_map_.IsValid()) << "Failed to allocate allocation info map" << error_msg;
385 allocation_info_ = reinterpret_cast<AllocationInfo*>(allocation_info_map_.Begin());
386 }
387
~FreeListSpace()388 FreeListSpace::~FreeListSpace() {}
389
Walk(DlMallocSpace::WalkCallback callback,void * arg)390 void FreeListSpace::Walk(DlMallocSpace::WalkCallback callback, void* arg) {
391 MutexLock mu(Thread::Current(), lock_);
392 const uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
393 AllocationInfo* cur_info = &allocation_info_[0];
394 const AllocationInfo* end_info = GetAllocationInfoForAddress(free_end_start);
395 while (cur_info < end_info) {
396 if (!cur_info->IsFree()) {
397 size_t alloc_size = cur_info->ByteSize();
398 uint8_t* byte_start = reinterpret_cast<uint8_t*>(GetAddressForAllocationInfo(cur_info));
399 uint8_t* byte_end = byte_start + alloc_size;
400 callback(byte_start, byte_end, alloc_size, arg);
401 callback(nullptr, nullptr, 0, arg);
402 }
403 cur_info = cur_info->GetNextInfo();
404 }
405 CHECK_EQ(cur_info, end_info);
406 }
407
ForEachMemMap(std::function<void (const MemMap &)> func) const408 void FreeListSpace::ForEachMemMap(std::function<void(const MemMap&)> func) const {
409 MutexLock mu(Thread::Current(), lock_);
410 func(allocation_info_map_);
411 func(mem_map_);
412 }
413
RemoveFreePrev(AllocationInfo * info)414 void FreeListSpace::RemoveFreePrev(AllocationInfo* info) {
415 CHECK_GT(info->GetPrevFree(), 0U);
416 auto it = free_blocks_.lower_bound(info);
417 CHECK(it != free_blocks_.end());
418 CHECK_EQ(*it, info);
419 free_blocks_.erase(it);
420 }
421
Free(Thread * self,mirror::Object * obj)422 size_t FreeListSpace::Free(Thread* self, mirror::Object* obj) {
423 MutexLock mu(self, lock_);
424 DCHECK(Contains(obj)) << reinterpret_cast<void*>(Begin()) << " " << obj << " "
425 << reinterpret_cast<void*>(End());
426 DCHECK_ALIGNED(obj, kAlignment);
427 AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
428 DCHECK(!info->IsFree());
429 const size_t allocation_size = info->ByteSize();
430 DCHECK_GT(allocation_size, 0U);
431 DCHECK_ALIGNED(allocation_size, kAlignment);
432 info->SetByteSize(allocation_size, true); // Mark as free.
433 // Look at the next chunk.
434 AllocationInfo* next_info = info->GetNextInfo();
435 // Calculate the start of the end free block.
436 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
437 size_t prev_free_bytes = info->GetPrevFreeBytes();
438 size_t new_free_size = allocation_size;
439 if (prev_free_bytes != 0) {
440 // Coalesce with previous free chunk.
441 new_free_size += prev_free_bytes;
442 RemoveFreePrev(info);
443 info = info->GetPrevFreeInfo();
444 // The previous allocation info must not be free since we are supposed to always coalesce.
445 DCHECK_EQ(info->GetPrevFreeBytes(), 0U) << "Previous allocation was free";
446 }
447 uintptr_t next_addr = GetAddressForAllocationInfo(next_info);
448 if (next_addr >= free_end_start) {
449 // Easy case, the next chunk is the end free region.
450 CHECK_EQ(next_addr, free_end_start);
451 free_end_ += new_free_size;
452 } else {
453 AllocationInfo* new_free_info;
454 if (next_info->IsFree()) {
455 AllocationInfo* next_next_info = next_info->GetNextInfo();
456 // Next next info can't be free since we always coalesce.
457 DCHECK(!next_next_info->IsFree());
458 DCHECK_ALIGNED(next_next_info->ByteSize(), kAlignment);
459 new_free_info = next_next_info;
460 new_free_size += next_next_info->GetPrevFreeBytes();
461 RemoveFreePrev(next_next_info);
462 } else {
463 new_free_info = next_info;
464 }
465 new_free_info->SetPrevFreeBytes(new_free_size);
466 free_blocks_.insert(new_free_info);
467 info->SetByteSize(new_free_size, true);
468 DCHECK_EQ(info->GetNextInfo(), new_free_info);
469 }
470 --num_objects_allocated_;
471 DCHECK_LE(allocation_size, num_bytes_allocated_);
472 num_bytes_allocated_ -= allocation_size;
473 madvise(obj, allocation_size, MADV_DONTNEED);
474 if (kIsDebugBuild) {
475 // Can't disallow reads since we use them to find next chunks during coalescing.
476 CheckedCall(mprotect, __FUNCTION__, obj, allocation_size, PROT_READ);
477 }
478 return allocation_size;
479 }
480
AllocationSize(mirror::Object * obj,size_t * usable_size)481 size_t FreeListSpace::AllocationSize(mirror::Object* obj, size_t* usable_size) {
482 DCHECK(Contains(obj));
483 AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
484 DCHECK(!info->IsFree());
485 size_t alloc_size = info->ByteSize();
486 if (usable_size != nullptr) {
487 *usable_size = alloc_size;
488 }
489 return alloc_size;
490 }
491
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)492 mirror::Object* FreeListSpace::Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
493 size_t* usable_size, size_t* bytes_tl_bulk_allocated) {
494 MutexLock mu(self, lock_);
495 const size_t allocation_size = RoundUp(num_bytes, kAlignment);
496 AllocationInfo temp_info;
497 temp_info.SetPrevFreeBytes(allocation_size);
498 temp_info.SetByteSize(0, false);
499 AllocationInfo* new_info;
500 // Find the smallest chunk at least num_bytes in size.
501 auto it = free_blocks_.lower_bound(&temp_info);
502 if (it != free_blocks_.end()) {
503 AllocationInfo* info = *it;
504 free_blocks_.erase(it);
505 // Fit our object in the previous allocation info free space.
506 new_info = info->GetPrevFreeInfo();
507 // Remove the newly allocated block from the info and update the prev_free_.
508 info->SetPrevFreeBytes(info->GetPrevFreeBytes() - allocation_size);
509 if (info->GetPrevFreeBytes() > 0) {
510 AllocationInfo* new_free = info - info->GetPrevFree();
511 new_free->SetPrevFreeBytes(0);
512 new_free->SetByteSize(info->GetPrevFreeBytes(), true);
513 // If there is remaining space, insert back into the free set.
514 free_blocks_.insert(info);
515 }
516 } else {
517 // Try to steal some memory from the free space at the end of the space.
518 if (LIKELY(free_end_ >= allocation_size)) {
519 // Fit our object at the start of the end free block.
520 new_info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(End()) - free_end_);
521 free_end_ -= allocation_size;
522 } else {
523 return nullptr;
524 }
525 }
526 DCHECK(bytes_allocated != nullptr);
527 *bytes_allocated = allocation_size;
528 if (usable_size != nullptr) {
529 *usable_size = allocation_size;
530 }
531 DCHECK(bytes_tl_bulk_allocated != nullptr);
532 *bytes_tl_bulk_allocated = allocation_size;
533 // Need to do these inside of the lock.
534 ++num_objects_allocated_;
535 ++total_objects_allocated_;
536 num_bytes_allocated_ += allocation_size;
537 total_bytes_allocated_ += allocation_size;
538 mirror::Object* obj = reinterpret_cast<mirror::Object*>(GetAddressForAllocationInfo(new_info));
539 // We always put our object at the start of the free block, there cannot be another free block
540 // before it.
541 if (kIsDebugBuild) {
542 CheckedCall(mprotect, __FUNCTION__, obj, allocation_size, PROT_READ | PROT_WRITE);
543 }
544 new_info->SetPrevFreeBytes(0);
545 new_info->SetByteSize(allocation_size, false);
546 return obj;
547 }
548
Dump(std::ostream & os) const549 void FreeListSpace::Dump(std::ostream& os) const {
550 MutexLock mu(Thread::Current(), lock_);
551 os << GetName() << " -"
552 << " begin: " << reinterpret_cast<void*>(Begin())
553 << " end: " << reinterpret_cast<void*>(End()) << "\n";
554 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
555 const AllocationInfo* cur_info =
556 GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(Begin()));
557 const AllocationInfo* end_info = GetAllocationInfoForAddress(free_end_start);
558 while (cur_info < end_info) {
559 size_t size = cur_info->ByteSize();
560 uintptr_t address = GetAddressForAllocationInfo(cur_info);
561 if (cur_info->IsFree()) {
562 os << "Free block at address: " << reinterpret_cast<const void*>(address)
563 << " of length " << size << " bytes\n";
564 } else {
565 os << "Large object at address: " << reinterpret_cast<const void*>(address)
566 << " of length " << size << " bytes\n";
567 }
568 cur_info = cur_info->GetNextInfo();
569 }
570 if (free_end_) {
571 os << "Free block at address: " << reinterpret_cast<const void*>(free_end_start)
572 << " of length " << free_end_ << " bytes\n";
573 }
574 }
575
IsZygoteLargeObject(Thread * self ATTRIBUTE_UNUSED,mirror::Object * obj) const576 bool FreeListSpace::IsZygoteLargeObject(Thread* self ATTRIBUTE_UNUSED, mirror::Object* obj) const {
577 const AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
578 DCHECK(info != nullptr);
579 return info->IsZygoteObject();
580 }
581
SetAllLargeObjectsAsZygoteObjects(Thread * self)582 void FreeListSpace::SetAllLargeObjectsAsZygoteObjects(Thread* self) {
583 MutexLock mu(self, lock_);
584 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
585 for (AllocationInfo* cur_info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(Begin())),
586 *end_info = GetAllocationInfoForAddress(free_end_start); cur_info < end_info;
587 cur_info = cur_info->GetNextInfo()) {
588 if (!cur_info->IsFree()) {
589 cur_info->SetZygoteObject();
590 }
591 }
592 }
593
SweepCallback(size_t num_ptrs,mirror::Object ** ptrs,void * arg)594 void LargeObjectSpace::SweepCallback(size_t num_ptrs, mirror::Object** ptrs, void* arg) {
595 SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg);
596 space::LargeObjectSpace* space = context->space->AsLargeObjectSpace();
597 Thread* self = context->self;
598 Locks::heap_bitmap_lock_->AssertExclusiveHeld(self);
599 // If the bitmaps aren't swapped we need to clear the bits since the GC isn't going to re-swap
600 // the bitmaps as an optimization.
601 if (!context->swap_bitmaps) {
602 accounting::LargeObjectBitmap* bitmap = space->GetLiveBitmap();
603 for (size_t i = 0; i < num_ptrs; ++i) {
604 bitmap->Clear(ptrs[i]);
605 }
606 }
607 context->freed.objects += num_ptrs;
608 context->freed.bytes += space->FreeList(self, num_ptrs, ptrs);
609 }
610
Sweep(bool swap_bitmaps)611 collector::ObjectBytePair LargeObjectSpace::Sweep(bool swap_bitmaps) {
612 if (Begin() >= End()) {
613 return collector::ObjectBytePair(0, 0);
614 }
615 accounting::LargeObjectBitmap* live_bitmap = GetLiveBitmap();
616 accounting::LargeObjectBitmap* mark_bitmap = GetMarkBitmap();
617 if (swap_bitmaps) {
618 std::swap(live_bitmap, mark_bitmap);
619 }
620 AllocSpace::SweepCallbackContext scc(swap_bitmaps, this);
621 std::pair<uint8_t*, uint8_t*> range = GetBeginEndAtomic();
622 accounting::LargeObjectBitmap::SweepWalk(*live_bitmap, *mark_bitmap,
623 reinterpret_cast<uintptr_t>(range.first),
624 reinterpret_cast<uintptr_t>(range.second),
625 SweepCallback,
626 &scc);
627 return scc.freed;
628 }
629
LogFragmentationAllocFailure(std::ostream &,size_t)630 void LargeObjectSpace::LogFragmentationAllocFailure(std::ostream& /*os*/,
631 size_t /*failed_alloc_bytes*/) {
632 UNIMPLEMENTED(FATAL);
633 }
634
GetBeginEndAtomic() const635 std::pair<uint8_t*, uint8_t*> LargeObjectMapSpace::GetBeginEndAtomic() const {
636 MutexLock mu(Thread::Current(), lock_);
637 return std::make_pair(Begin(), End());
638 }
639
GetBeginEndAtomic() const640 std::pair<uint8_t*, uint8_t*> FreeListSpace::GetBeginEndAtomic() const {
641 MutexLock mu(Thread::Current(), lock_);
642 return std::make_pair(Begin(), End());
643 }
644
645 } // namespace space
646 } // namespace gc
647 } // namespace art
648