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 // Keep valgrind happy if there is any large objects such as dex cache arrays which aren't
49 // freed since they are held live by the class linker.
50 MutexLock mu(Thread::Current(), lock_);
51 for (auto& m : large_objects_) {
52 delete m.second.mem_map;
53 }
54 }
55
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)56 mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
57 size_t* usable_size, size_t* bytes_tl_bulk_allocated)
58 OVERRIDE {
59 mirror::Object* obj =
60 LargeObjectMapSpace::Alloc(self, num_bytes + kMemoryToolRedZoneBytes * 2, bytes_allocated,
61 usable_size, bytes_tl_bulk_allocated);
62 mirror::Object* object_without_rdz = reinterpret_cast<mirror::Object*>(
63 reinterpret_cast<uintptr_t>(obj) + kMemoryToolRedZoneBytes);
64 MEMORY_TOOL_MAKE_NOACCESS(reinterpret_cast<void*>(obj), kMemoryToolRedZoneBytes);
65 MEMORY_TOOL_MAKE_NOACCESS(
66 reinterpret_cast<uint8_t*>(object_without_rdz) + num_bytes,
67 kMemoryToolRedZoneBytes);
68 if (usable_size != nullptr) {
69 *usable_size = num_bytes; // Since we have redzones, shrink the usable size.
70 }
71 return object_without_rdz;
72 }
73
AllocationSize(mirror::Object * obj,size_t * usable_size)74 size_t AllocationSize(mirror::Object* obj, size_t* usable_size) OVERRIDE {
75 return LargeObjectMapSpace::AllocationSize(ObjectWithRedzone(obj), usable_size);
76 }
77
IsZygoteLargeObject(Thread * self,mirror::Object * obj) const78 bool IsZygoteLargeObject(Thread* self, mirror::Object* obj) const OVERRIDE {
79 return LargeObjectMapSpace::IsZygoteLargeObject(self, ObjectWithRedzone(obj));
80 }
81
Free(Thread * self,mirror::Object * obj)82 size_t Free(Thread* self, mirror::Object* obj) OVERRIDE {
83 mirror::Object* object_with_rdz = ObjectWithRedzone(obj);
84 MEMORY_TOOL_MAKE_UNDEFINED(object_with_rdz, AllocationSize(obj, nullptr));
85 return LargeObjectMapSpace::Free(self, object_with_rdz);
86 }
87
Contains(const mirror::Object * obj) const88 bool Contains(const mirror::Object* obj) const OVERRIDE {
89 return LargeObjectMapSpace::Contains(ObjectWithRedzone(obj));
90 }
91
92 private:
ObjectWithRedzone(const mirror::Object * obj)93 static const mirror::Object* ObjectWithRedzone(const mirror::Object* obj) {
94 return reinterpret_cast<const mirror::Object*>(
95 reinterpret_cast<uintptr_t>(obj) - kMemoryToolRedZoneBytes);
96 }
97
ObjectWithRedzone(mirror::Object * obj)98 static mirror::Object* ObjectWithRedzone(mirror::Object* obj) {
99 return reinterpret_cast<mirror::Object*>(
100 reinterpret_cast<uintptr_t>(obj) - kMemoryToolRedZoneBytes);
101 }
102
103 static constexpr size_t kMemoryToolRedZoneBytes = kPageSize;
104 };
105
SwapBitmaps()106 void LargeObjectSpace::SwapBitmaps() {
107 live_bitmap_.swap(mark_bitmap_);
108 // Swap names to get more descriptive diagnostics.
109 std::string temp_name = live_bitmap_->GetName();
110 live_bitmap_->SetName(mark_bitmap_->GetName());
111 mark_bitmap_->SetName(temp_name);
112 }
113
LargeObjectSpace(const std::string & name,uint8_t * begin,uint8_t * end)114 LargeObjectSpace::LargeObjectSpace(const std::string& name, uint8_t* begin, uint8_t* end)
115 : DiscontinuousSpace(name, kGcRetentionPolicyAlwaysCollect),
116 num_bytes_allocated_(0), num_objects_allocated_(0), total_bytes_allocated_(0),
117 total_objects_allocated_(0), begin_(begin), end_(end) {
118 }
119
120
CopyLiveToMarked()121 void LargeObjectSpace::CopyLiveToMarked() {
122 mark_bitmap_->CopyFrom(live_bitmap_.get());
123 }
124
LargeObjectMapSpace(const std::string & name)125 LargeObjectMapSpace::LargeObjectMapSpace(const std::string& name)
126 : LargeObjectSpace(name, nullptr, nullptr),
127 lock_("large object map space lock", kAllocSpaceLock) {}
128
Create(const std::string & name)129 LargeObjectMapSpace* LargeObjectMapSpace::Create(const std::string& name) {
130 if (Runtime::Current()->IsRunningOnMemoryTool()) {
131 return new MemoryToolLargeObjectMapSpace(name);
132 } else {
133 return new LargeObjectMapSpace(name);
134 }
135 }
136
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)137 mirror::Object* LargeObjectMapSpace::Alloc(Thread* self, size_t num_bytes,
138 size_t* bytes_allocated, size_t* usable_size,
139 size_t* bytes_tl_bulk_allocated) {
140 std::string error_msg;
141 MemMap* mem_map = MemMap::MapAnonymous("large object space allocation", nullptr, num_bytes,
142 PROT_READ | PROT_WRITE, true, false, &error_msg);
143 if (UNLIKELY(mem_map == nullptr)) {
144 LOG(WARNING) << "Large object allocation failed: " << error_msg;
145 return nullptr;
146 }
147 mirror::Object* const obj = reinterpret_cast<mirror::Object*>(mem_map->Begin());
148 MutexLock mu(self, lock_);
149 large_objects_.Put(obj, LargeObject {mem_map, false /* not zygote */});
150 const size_t allocation_size = mem_map->BaseSize();
151 DCHECK(bytes_allocated != nullptr);
152
153 if (begin_ == nullptr || begin_ > reinterpret_cast<uint8_t*>(obj)) {
154 begin_ = reinterpret_cast<uint8_t*>(obj);
155 }
156 end_ = std::max(end_, reinterpret_cast<uint8_t*>(obj) + allocation_size);
157
158 *bytes_allocated = allocation_size;
159 if (usable_size != nullptr) {
160 *usable_size = allocation_size;
161 }
162 DCHECK(bytes_tl_bulk_allocated != nullptr);
163 *bytes_tl_bulk_allocated = allocation_size;
164 num_bytes_allocated_ += allocation_size;
165 total_bytes_allocated_ += allocation_size;
166 ++num_objects_allocated_;
167 ++total_objects_allocated_;
168 return obj;
169 }
170
IsZygoteLargeObject(Thread * self,mirror::Object * obj) const171 bool LargeObjectMapSpace::IsZygoteLargeObject(Thread* self, mirror::Object* obj) const {
172 MutexLock mu(self, lock_);
173 auto it = large_objects_.find(obj);
174 CHECK(it != large_objects_.end());
175 return it->second.is_zygote;
176 }
177
SetAllLargeObjectsAsZygoteObjects(Thread * self)178 void LargeObjectMapSpace::SetAllLargeObjectsAsZygoteObjects(Thread* self) {
179 MutexLock mu(self, lock_);
180 for (auto& pair : large_objects_) {
181 pair.second.is_zygote = true;
182 }
183 }
184
Free(Thread * self,mirror::Object * ptr)185 size_t LargeObjectMapSpace::Free(Thread* self, mirror::Object* ptr) {
186 MutexLock mu(self, lock_);
187 auto it = large_objects_.find(ptr);
188 if (UNLIKELY(it == large_objects_.end())) {
189 ScopedObjectAccess soa(self);
190 Runtime::Current()->GetHeap()->DumpSpaces(LOG_STREAM(FATAL_WITHOUT_ABORT));
191 LOG(FATAL) << "Attempted to free large object " << ptr << " which was not live";
192 }
193 MemMap* mem_map = it->second.mem_map;
194 const size_t map_size = 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 delete mem_map;
200 large_objects_.erase(it);
201 return allocation_size;
202 }
203
AllocationSize(mirror::Object * obj,size_t * usable_size)204 size_t LargeObjectMapSpace::AllocationSize(mirror::Object* obj, size_t* usable_size) {
205 MutexLock mu(Thread::Current(), lock_);
206 auto it = large_objects_.find(obj);
207 CHECK(it != large_objects_.end()) << "Attempted to get size of a large object which is not live";
208 size_t alloc_size = it->second.mem_map->BaseSize();
209 if (usable_size != nullptr) {
210 *usable_size = alloc_size;
211 }
212 return alloc_size;
213 }
214
FreeList(Thread * self,size_t num_ptrs,mirror::Object ** ptrs)215 size_t LargeObjectSpace::FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs) {
216 size_t total = 0;
217 for (size_t i = 0; i < num_ptrs; ++i) {
218 if (kDebugSpaces) {
219 CHECK(Contains(ptrs[i]));
220 }
221 total += Free(self, ptrs[i]);
222 }
223 return total;
224 }
225
Walk(DlMallocSpace::WalkCallback callback,void * arg)226 void LargeObjectMapSpace::Walk(DlMallocSpace::WalkCallback callback, void* arg) {
227 MutexLock mu(Thread::Current(), lock_);
228 for (auto& pair : large_objects_) {
229 MemMap* mem_map = pair.second.mem_map;
230 callback(mem_map->Begin(), mem_map->End(), mem_map->Size(), arg);
231 callback(nullptr, nullptr, 0, arg);
232 }
233 }
234
Contains(const mirror::Object * obj) const235 bool LargeObjectMapSpace::Contains(const mirror::Object* obj) const {
236 Thread* self = Thread::Current();
237 if (lock_.IsExclusiveHeld(self)) {
238 // We hold lock_ so do the check.
239 return large_objects_.find(const_cast<mirror::Object*>(obj)) != large_objects_.end();
240 } else {
241 MutexLock mu(self, lock_);
242 return large_objects_.find(const_cast<mirror::Object*>(obj)) != large_objects_.end();
243 }
244 }
245
246 // Keeps track of allocation sizes + whether or not the previous allocation is free.
247 // Used to coalesce free blocks and find the best fit block for an allocation for best fit object
248 // allocation. Each allocation has an AllocationInfo which contains the size of the previous free
249 // block preceding it. Implemented in such a way that we can also find the iterator for any
250 // allocation info pointer.
251 class AllocationInfo {
252 public:
AllocationInfo()253 AllocationInfo() : prev_free_(0), alloc_size_(0) {
254 }
255 // Return the number of pages that the allocation info covers.
AlignSize() const256 size_t AlignSize() const {
257 return alloc_size_ & kFlagsMask;
258 }
259 // Returns the allocation size in bytes.
ByteSize() const260 size_t ByteSize() const {
261 return AlignSize() * FreeListSpace::kAlignment;
262 }
263 // Updates the allocation size and whether or not it is free.
SetByteSize(size_t size,bool free)264 void SetByteSize(size_t size, bool free) {
265 DCHECK_EQ(size & ~kFlagsMask, 0u);
266 DCHECK_ALIGNED(size, FreeListSpace::kAlignment);
267 alloc_size_ = (size / FreeListSpace::kAlignment) | (free ? kFlagFree : 0u);
268 }
269 // Returns true if the block is free.
IsFree() const270 bool IsFree() const {
271 return (alloc_size_ & kFlagFree) != 0;
272 }
273 // Return true if the large object is a zygote object.
IsZygoteObject() const274 bool IsZygoteObject() const {
275 return (alloc_size_ & kFlagZygote) != 0;
276 }
277 // Change the object to be a zygote object.
SetZygoteObject()278 void SetZygoteObject() {
279 alloc_size_ |= kFlagZygote;
280 }
281 // Return true if this is a zygote large object.
282 // Finds and returns the next non free allocation info after ourself.
GetNextInfo()283 AllocationInfo* GetNextInfo() {
284 return this + AlignSize();
285 }
GetNextInfo() const286 const AllocationInfo* GetNextInfo() const {
287 return this + AlignSize();
288 }
289 // Returns the previous free allocation info by using the prev_free_ member to figure out
290 // where it is. This is only used for coalescing so we only need to be able to do it if the
291 // previous allocation info is free.
GetPrevFreeInfo()292 AllocationInfo* GetPrevFreeInfo() {
293 DCHECK_NE(prev_free_, 0U);
294 return this - prev_free_;
295 }
296 // Returns the address of the object associated with this allocation info.
GetObjectAddress()297 mirror::Object* GetObjectAddress() {
298 return reinterpret_cast<mirror::Object*>(reinterpret_cast<uintptr_t>(this) + sizeof(*this));
299 }
300 // Return how many kAlignment units there are before the free block.
GetPrevFree() const301 size_t GetPrevFree() const {
302 return prev_free_;
303 }
304 // Returns how many free bytes there is before the block.
GetPrevFreeBytes() const305 size_t GetPrevFreeBytes() const {
306 return GetPrevFree() * FreeListSpace::kAlignment;
307 }
308 // Update the size of the free block prior to the allocation.
SetPrevFreeBytes(size_t bytes)309 void SetPrevFreeBytes(size_t bytes) {
310 DCHECK_ALIGNED(bytes, FreeListSpace::kAlignment);
311 prev_free_ = bytes / FreeListSpace::kAlignment;
312 }
313
314 private:
315 static constexpr uint32_t kFlagFree = 0x80000000; // If block is free.
316 static constexpr uint32_t kFlagZygote = 0x40000000; // If the large object is a zygote object.
317 static constexpr uint32_t kFlagsMask = ~(kFlagFree | kFlagZygote); // Combined flags for masking.
318 // Contains the size of the previous free block with kAlignment as the unit. If 0 then the
319 // allocation before us is not free.
320 // These variables are undefined in the middle of allocations / free blocks.
321 uint32_t prev_free_;
322 // Allocation size of this object in kAlignment as the unit.
323 uint32_t alloc_size_;
324 };
325
GetSlotIndexForAllocationInfo(const AllocationInfo * info) const326 size_t FreeListSpace::GetSlotIndexForAllocationInfo(const AllocationInfo* info) const {
327 DCHECK_GE(info, allocation_info_);
328 DCHECK_LT(info, reinterpret_cast<AllocationInfo*>(allocation_info_map_->End()));
329 return info - allocation_info_;
330 }
331
GetAllocationInfoForAddress(uintptr_t address)332 AllocationInfo* FreeListSpace::GetAllocationInfoForAddress(uintptr_t address) {
333 return &allocation_info_[GetSlotIndexForAddress(address)];
334 }
335
GetAllocationInfoForAddress(uintptr_t address) const336 const AllocationInfo* FreeListSpace::GetAllocationInfoForAddress(uintptr_t address) const {
337 return &allocation_info_[GetSlotIndexForAddress(address)];
338 }
339
operator ()(const AllocationInfo * a,const AllocationInfo * b) const340 inline bool FreeListSpace::SortByPrevFree::operator()(const AllocationInfo* a,
341 const AllocationInfo* b) const {
342 if (a->GetPrevFree() < b->GetPrevFree()) return true;
343 if (a->GetPrevFree() > b->GetPrevFree()) return false;
344 if (a->AlignSize() < b->AlignSize()) return true;
345 if (a->AlignSize() > b->AlignSize()) return false;
346 return reinterpret_cast<uintptr_t>(a) < reinterpret_cast<uintptr_t>(b);
347 }
348
Create(const std::string & name,uint8_t * requested_begin,size_t size)349 FreeListSpace* FreeListSpace::Create(const std::string& name, uint8_t* requested_begin, size_t size) {
350 CHECK_EQ(size % kAlignment, 0U);
351 std::string error_msg;
352 MemMap* mem_map = MemMap::MapAnonymous(name.c_str(), requested_begin, size,
353 PROT_READ | PROT_WRITE, true, false, &error_msg);
354 CHECK(mem_map != nullptr) << "Failed to allocate large object space mem map: " << error_msg;
355 return new FreeListSpace(name, mem_map, mem_map->Begin(), mem_map->End());
356 }
357
FreeListSpace(const std::string & name,MemMap * mem_map,uint8_t * begin,uint8_t * end)358 FreeListSpace::FreeListSpace(const std::string& name, MemMap* mem_map, uint8_t* begin, uint8_t* end)
359 : LargeObjectSpace(name, begin, end),
360 mem_map_(mem_map),
361 lock_("free list space lock", kAllocSpaceLock) {
362 const size_t space_capacity = end - begin;
363 free_end_ = space_capacity;
364 CHECK_ALIGNED(space_capacity, kAlignment);
365 const size_t alloc_info_size = sizeof(AllocationInfo) * (space_capacity / kAlignment);
366 std::string error_msg;
367 allocation_info_map_.reset(
368 MemMap::MapAnonymous("large object free list space allocation info map",
369 nullptr, alloc_info_size, PROT_READ | PROT_WRITE,
370 false, false, &error_msg));
371 CHECK(allocation_info_map_.get() != nullptr) << "Failed to allocate allocation info map"
372 << error_msg;
373 allocation_info_ = reinterpret_cast<AllocationInfo*>(allocation_info_map_->Begin());
374 }
375
~FreeListSpace()376 FreeListSpace::~FreeListSpace() {}
377
Walk(DlMallocSpace::WalkCallback callback,void * arg)378 void FreeListSpace::Walk(DlMallocSpace::WalkCallback callback, void* arg) {
379 MutexLock mu(Thread::Current(), lock_);
380 const uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
381 AllocationInfo* cur_info = &allocation_info_[0];
382 const AllocationInfo* end_info = GetAllocationInfoForAddress(free_end_start);
383 while (cur_info < end_info) {
384 if (!cur_info->IsFree()) {
385 size_t alloc_size = cur_info->ByteSize();
386 uint8_t* byte_start = reinterpret_cast<uint8_t*>(GetAddressForAllocationInfo(cur_info));
387 uint8_t* byte_end = byte_start + alloc_size;
388 callback(byte_start, byte_end, alloc_size, arg);
389 callback(nullptr, nullptr, 0, arg);
390 }
391 cur_info = cur_info->GetNextInfo();
392 }
393 CHECK_EQ(cur_info, end_info);
394 }
395
RemoveFreePrev(AllocationInfo * info)396 void FreeListSpace::RemoveFreePrev(AllocationInfo* info) {
397 CHECK_GT(info->GetPrevFree(), 0U);
398 auto it = free_blocks_.lower_bound(info);
399 CHECK(it != free_blocks_.end());
400 CHECK_EQ(*it, info);
401 free_blocks_.erase(it);
402 }
403
Free(Thread * self,mirror::Object * obj)404 size_t FreeListSpace::Free(Thread* self, mirror::Object* obj) {
405 MutexLock mu(self, lock_);
406 DCHECK(Contains(obj)) << reinterpret_cast<void*>(Begin()) << " " << obj << " "
407 << reinterpret_cast<void*>(End());
408 DCHECK_ALIGNED(obj, kAlignment);
409 AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
410 DCHECK(!info->IsFree());
411 const size_t allocation_size = info->ByteSize();
412 DCHECK_GT(allocation_size, 0U);
413 DCHECK_ALIGNED(allocation_size, kAlignment);
414 info->SetByteSize(allocation_size, true); // Mark as free.
415 // Look at the next chunk.
416 AllocationInfo* next_info = info->GetNextInfo();
417 // Calculate the start of the end free block.
418 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
419 size_t prev_free_bytes = info->GetPrevFreeBytes();
420 size_t new_free_size = allocation_size;
421 if (prev_free_bytes != 0) {
422 // Coalesce with previous free chunk.
423 new_free_size += prev_free_bytes;
424 RemoveFreePrev(info);
425 info = info->GetPrevFreeInfo();
426 // The previous allocation info must not be free since we are supposed to always coalesce.
427 DCHECK_EQ(info->GetPrevFreeBytes(), 0U) << "Previous allocation was free";
428 }
429 uintptr_t next_addr = GetAddressForAllocationInfo(next_info);
430 if (next_addr >= free_end_start) {
431 // Easy case, the next chunk is the end free region.
432 CHECK_EQ(next_addr, free_end_start);
433 free_end_ += new_free_size;
434 } else {
435 AllocationInfo* new_free_info;
436 if (next_info->IsFree()) {
437 AllocationInfo* next_next_info = next_info->GetNextInfo();
438 // Next next info can't be free since we always coalesce.
439 DCHECK(!next_next_info->IsFree());
440 DCHECK_ALIGNED(next_next_info->ByteSize(), kAlignment);
441 new_free_info = next_next_info;
442 new_free_size += next_next_info->GetPrevFreeBytes();
443 RemoveFreePrev(next_next_info);
444 } else {
445 new_free_info = next_info;
446 }
447 new_free_info->SetPrevFreeBytes(new_free_size);
448 free_blocks_.insert(new_free_info);
449 info->SetByteSize(new_free_size, true);
450 DCHECK_EQ(info->GetNextInfo(), new_free_info);
451 }
452 --num_objects_allocated_;
453 DCHECK_LE(allocation_size, num_bytes_allocated_);
454 num_bytes_allocated_ -= allocation_size;
455 madvise(obj, allocation_size, MADV_DONTNEED);
456 if (kIsDebugBuild) {
457 // Can't disallow reads since we use them to find next chunks during coalescing.
458 CheckedCall(mprotect, __FUNCTION__, obj, allocation_size, PROT_READ);
459 }
460 return allocation_size;
461 }
462
AllocationSize(mirror::Object * obj,size_t * usable_size)463 size_t FreeListSpace::AllocationSize(mirror::Object* obj, size_t* usable_size) {
464 DCHECK(Contains(obj));
465 AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
466 DCHECK(!info->IsFree());
467 size_t alloc_size = info->ByteSize();
468 if (usable_size != nullptr) {
469 *usable_size = alloc_size;
470 }
471 return alloc_size;
472 }
473
Alloc(Thread * self,size_t num_bytes,size_t * bytes_allocated,size_t * usable_size,size_t * bytes_tl_bulk_allocated)474 mirror::Object* FreeListSpace::Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
475 size_t* usable_size, size_t* bytes_tl_bulk_allocated) {
476 MutexLock mu(self, lock_);
477 const size_t allocation_size = RoundUp(num_bytes, kAlignment);
478 AllocationInfo temp_info;
479 temp_info.SetPrevFreeBytes(allocation_size);
480 temp_info.SetByteSize(0, false);
481 AllocationInfo* new_info;
482 // Find the smallest chunk at least num_bytes in size.
483 auto it = free_blocks_.lower_bound(&temp_info);
484 if (it != free_blocks_.end()) {
485 AllocationInfo* info = *it;
486 free_blocks_.erase(it);
487 // Fit our object in the previous allocation info free space.
488 new_info = info->GetPrevFreeInfo();
489 // Remove the newly allocated block from the info and update the prev_free_.
490 info->SetPrevFreeBytes(info->GetPrevFreeBytes() - allocation_size);
491 if (info->GetPrevFreeBytes() > 0) {
492 AllocationInfo* new_free = info - info->GetPrevFree();
493 new_free->SetPrevFreeBytes(0);
494 new_free->SetByteSize(info->GetPrevFreeBytes(), true);
495 // If there is remaining space, insert back into the free set.
496 free_blocks_.insert(info);
497 }
498 } else {
499 // Try to steal some memory from the free space at the end of the space.
500 if (LIKELY(free_end_ >= allocation_size)) {
501 // Fit our object at the start of the end free block.
502 new_info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(End()) - free_end_);
503 free_end_ -= allocation_size;
504 } else {
505 return nullptr;
506 }
507 }
508 DCHECK(bytes_allocated != nullptr);
509 *bytes_allocated = allocation_size;
510 if (usable_size != nullptr) {
511 *usable_size = allocation_size;
512 }
513 DCHECK(bytes_tl_bulk_allocated != nullptr);
514 *bytes_tl_bulk_allocated = allocation_size;
515 // Need to do these inside of the lock.
516 ++num_objects_allocated_;
517 ++total_objects_allocated_;
518 num_bytes_allocated_ += allocation_size;
519 total_bytes_allocated_ += allocation_size;
520 mirror::Object* obj = reinterpret_cast<mirror::Object*>(GetAddressForAllocationInfo(new_info));
521 // We always put our object at the start of the free block, there cannot be another free block
522 // before it.
523 if (kIsDebugBuild) {
524 CheckedCall(mprotect, __FUNCTION__, obj, allocation_size, PROT_READ | PROT_WRITE);
525 }
526 new_info->SetPrevFreeBytes(0);
527 new_info->SetByteSize(allocation_size, false);
528 return obj;
529 }
530
Dump(std::ostream & os) const531 void FreeListSpace::Dump(std::ostream& os) const {
532 MutexLock mu(Thread::Current(), lock_);
533 os << GetName() << " -"
534 << " begin: " << reinterpret_cast<void*>(Begin())
535 << " end: " << reinterpret_cast<void*>(End()) << "\n";
536 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
537 const AllocationInfo* cur_info =
538 GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(Begin()));
539 const AllocationInfo* end_info = GetAllocationInfoForAddress(free_end_start);
540 while (cur_info < end_info) {
541 size_t size = cur_info->ByteSize();
542 uintptr_t address = GetAddressForAllocationInfo(cur_info);
543 if (cur_info->IsFree()) {
544 os << "Free block at address: " << reinterpret_cast<const void*>(address)
545 << " of length " << size << " bytes\n";
546 } else {
547 os << "Large object at address: " << reinterpret_cast<const void*>(address)
548 << " of length " << size << " bytes\n";
549 }
550 cur_info = cur_info->GetNextInfo();
551 }
552 if (free_end_) {
553 os << "Free block at address: " << reinterpret_cast<const void*>(free_end_start)
554 << " of length " << free_end_ << " bytes\n";
555 }
556 }
557
IsZygoteLargeObject(Thread * self ATTRIBUTE_UNUSED,mirror::Object * obj) const558 bool FreeListSpace::IsZygoteLargeObject(Thread* self ATTRIBUTE_UNUSED, mirror::Object* obj) const {
559 const AllocationInfo* info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(obj));
560 DCHECK(info != nullptr);
561 return info->IsZygoteObject();
562 }
563
SetAllLargeObjectsAsZygoteObjects(Thread * self)564 void FreeListSpace::SetAllLargeObjectsAsZygoteObjects(Thread* self) {
565 MutexLock mu(self, lock_);
566 uintptr_t free_end_start = reinterpret_cast<uintptr_t>(end_) - free_end_;
567 for (AllocationInfo* cur_info = GetAllocationInfoForAddress(reinterpret_cast<uintptr_t>(Begin())),
568 *end_info = GetAllocationInfoForAddress(free_end_start); cur_info < end_info;
569 cur_info = cur_info->GetNextInfo()) {
570 if (!cur_info->IsFree()) {
571 cur_info->SetZygoteObject();
572 }
573 }
574 }
575
SweepCallback(size_t num_ptrs,mirror::Object ** ptrs,void * arg)576 void LargeObjectSpace::SweepCallback(size_t num_ptrs, mirror::Object** ptrs, void* arg) {
577 SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg);
578 space::LargeObjectSpace* space = context->space->AsLargeObjectSpace();
579 Thread* self = context->self;
580 Locks::heap_bitmap_lock_->AssertExclusiveHeld(self);
581 // If the bitmaps aren't swapped we need to clear the bits since the GC isn't going to re-swap
582 // the bitmaps as an optimization.
583 if (!context->swap_bitmaps) {
584 accounting::LargeObjectBitmap* bitmap = space->GetLiveBitmap();
585 for (size_t i = 0; i < num_ptrs; ++i) {
586 bitmap->Clear(ptrs[i]);
587 }
588 }
589 context->freed.objects += num_ptrs;
590 context->freed.bytes += space->FreeList(self, num_ptrs, ptrs);
591 }
592
Sweep(bool swap_bitmaps)593 collector::ObjectBytePair LargeObjectSpace::Sweep(bool swap_bitmaps) {
594 if (Begin() >= End()) {
595 return collector::ObjectBytePair(0, 0);
596 }
597 accounting::LargeObjectBitmap* live_bitmap = GetLiveBitmap();
598 accounting::LargeObjectBitmap* mark_bitmap = GetMarkBitmap();
599 if (swap_bitmaps) {
600 std::swap(live_bitmap, mark_bitmap);
601 }
602 AllocSpace::SweepCallbackContext scc(swap_bitmaps, this);
603 std::pair<uint8_t*, uint8_t*> range = GetBeginEndAtomic();
604 accounting::LargeObjectBitmap::SweepWalk(*live_bitmap, *mark_bitmap,
605 reinterpret_cast<uintptr_t>(range.first),
606 reinterpret_cast<uintptr_t>(range.second),
607 SweepCallback,
608 &scc);
609 return scc.freed;
610 }
611
LogFragmentationAllocFailure(std::ostream &,size_t)612 void LargeObjectSpace::LogFragmentationAllocFailure(std::ostream& /*os*/,
613 size_t /*failed_alloc_bytes*/) {
614 UNIMPLEMENTED(FATAL);
615 }
616
GetBeginEndAtomic() const617 std::pair<uint8_t*, uint8_t*> LargeObjectMapSpace::GetBeginEndAtomic() const {
618 MutexLock mu(Thread::Current(), lock_);
619 return std::make_pair(Begin(), End());
620 }
621
GetBeginEndAtomic() const622 std::pair<uint8_t*, uint8_t*> FreeListSpace::GetBeginEndAtomic() const {
623 MutexLock mu(Thread::Current(), lock_);
624 return std::make_pair(Begin(), End());
625 }
626
627 } // namespace space
628 } // namespace gc
629 } // namespace art
630