/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dlmalloc_space-inl.h"
#include "gc/accounting/card_table.h"
#include "gc/accounting/space_bitmap-inl.h"
#include "gc/heap.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "runtime.h"
#include "thread.h"
#include "thread_list.h"
#include "utils.h"
#include "valgrind_malloc_space-inl.h"
namespace art {
namespace gc {
namespace space {
static constexpr bool kPrefetchDuringDlMallocFreeList = true;
template class ValgrindMallocSpace<DlMallocSpace, void*>;
DlMallocSpace::DlMallocSpace(const std::string& name, MemMap* mem_map, void* mspace, byte* begin,
byte* end, byte* limit, size_t growth_limit,
bool can_move_objects, size_t starting_size,
size_t initial_size)
: MallocSpace(name, mem_map, begin, end, limit, growth_limit, true, can_move_objects,
starting_size, initial_size),
mspace_(mspace) {
CHECK(mspace != NULL);
}
DlMallocSpace* DlMallocSpace::CreateFromMemMap(MemMap* mem_map, const std::string& name,
size_t starting_size, size_t initial_size,
size_t growth_limit, size_t capacity,
bool can_move_objects) {
DCHECK(mem_map != nullptr);
void* mspace = CreateMspace(mem_map->Begin(), starting_size, initial_size);
if (mspace == nullptr) {
LOG(ERROR) << "Failed to initialize mspace for alloc space (" << name << ")";
return nullptr;
}
// Protect memory beyond the starting size. morecore will add r/w permissions when necessory
byte* end = mem_map->Begin() + starting_size;
if (capacity - starting_size > 0) {
CHECK_MEMORY_CALL(mprotect, (end, capacity - starting_size, PROT_NONE), name);
}
// Everything is set so record in immutable structure and leave
byte* begin = mem_map->Begin();
if (Runtime::Current()->RunningOnValgrind()) {
return new ValgrindMallocSpace<DlMallocSpace, void*>(
name, mem_map, mspace, begin, end, begin + capacity, growth_limit, initial_size,
can_move_objects, starting_size);
} else {
return new DlMallocSpace(name, mem_map, mspace, begin, end, begin + capacity, growth_limit,
can_move_objects, starting_size, initial_size);
}
}
DlMallocSpace* DlMallocSpace::Create(const std::string& name, size_t initial_size,
size_t growth_limit, size_t capacity, byte* requested_begin,
bool can_move_objects) {
uint64_t start_time = 0;
if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
start_time = NanoTime();
LOG(INFO) << "DlMallocSpace::Create entering " << name
<< " initial_size=" << PrettySize(initial_size)
<< " growth_limit=" << PrettySize(growth_limit)
<< " capacity=" << PrettySize(capacity)
<< " requested_begin=" << reinterpret_cast<void*>(requested_begin);
}
// Memory we promise to dlmalloc before it asks for morecore.
// Note: making this value large means that large allocations are unlikely to succeed as dlmalloc
// will ask for this memory from sys_alloc which will fail as the footprint (this value plus the
// size of the large allocation) will be greater than the footprint limit.
size_t starting_size = kPageSize;
MemMap* mem_map = CreateMemMap(name, starting_size, &initial_size, &growth_limit, &capacity,
requested_begin);
if (mem_map == nullptr) {
LOG(ERROR) << "Failed to create mem map for alloc space (" << name << ") of size "
<< PrettySize(capacity);
return nullptr;
}
DlMallocSpace* space = CreateFromMemMap(mem_map, name, starting_size, initial_size,
growth_limit, capacity, can_move_objects);
// We start out with only the initial size possibly containing objects.
if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
LOG(INFO) << "DlMallocSpace::Create exiting (" << PrettyDuration(NanoTime() - start_time)
<< " ) " << *space;
}
return space;
}
void* DlMallocSpace::CreateMspace(void* begin, size_t morecore_start, size_t initial_size) {
// clear errno to allow PLOG on error
errno = 0;
// create mspace using our backing storage starting at begin and with a footprint of
// morecore_start. Don't use an internal dlmalloc lock (as we already hold heap lock). When
// morecore_start bytes of memory is exhaused morecore will be called.
void* msp = create_mspace_with_base(begin, morecore_start, false /*locked*/);
if (msp != nullptr) {
// Do not allow morecore requests to succeed beyond the initial size of the heap
mspace_set_footprint_limit(msp, initial_size);
} else {
PLOG(ERROR) << "create_mspace_with_base failed";
}
return msp;
}
mirror::Object* DlMallocSpace::AllocWithGrowth(Thread* self, size_t num_bytes,
size_t* bytes_allocated, size_t* usable_size) {
mirror::Object* result;
{
MutexLock mu(self, lock_);
// Grow as much as possible within the space.
size_t max_allowed = Capacity();
mspace_set_footprint_limit(mspace_, max_allowed);
// Try the allocation.
result = AllocWithoutGrowthLocked(self, num_bytes, bytes_allocated, usable_size);
// Shrink back down as small as possible.
size_t footprint = mspace_footprint(mspace_);
mspace_set_footprint_limit(mspace_, footprint);
}
if (result != nullptr) {
// Zero freshly allocated memory, done while not holding the space's lock.
memset(result, 0, num_bytes);
// Check that the result is contained in the space.
CHECK(!kDebugSpaces || Contains(result));
}
return result;
}
MallocSpace* DlMallocSpace::CreateInstance(const std::string& name, MemMap* mem_map,
void* allocator, byte* begin, byte* end,
byte* limit, size_t growth_limit,
bool can_move_objects) {
return new DlMallocSpace(name, mem_map, allocator, begin, end, limit, growth_limit,
can_move_objects, starting_size_, initial_size_);
}
size_t DlMallocSpace::Free(Thread* self, mirror::Object* ptr) {
MutexLock mu(self, lock_);
if (kDebugSpaces) {
CHECK(ptr != nullptr);
CHECK(Contains(ptr)) << "Free (" << ptr << ") not in bounds of heap " << *this;
}
const size_t bytes_freed = AllocationSizeNonvirtual(ptr, nullptr);
if (kRecentFreeCount > 0) {
RegisterRecentFree(ptr);
}
mspace_free(mspace_, ptr);
return bytes_freed;
}
size_t DlMallocSpace::FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs) {
DCHECK(ptrs != NULL);
// Don't need the lock to calculate the size of the freed pointers.
size_t bytes_freed = 0;
for (size_t i = 0; i < num_ptrs; i++) {
mirror::Object* ptr = ptrs[i];
const size_t look_ahead = 8;
if (kPrefetchDuringDlMallocFreeList && i + look_ahead < num_ptrs) {
// The head of chunk for the allocation is sizeof(size_t) behind the allocation.
__builtin_prefetch(reinterpret_cast<char*>(ptrs[i + look_ahead]) - sizeof(size_t));
}
bytes_freed += AllocationSizeNonvirtual(ptr, nullptr);
}
if (kRecentFreeCount > 0) {
MutexLock mu(self, lock_);
for (size_t i = 0; i < num_ptrs; i++) {
RegisterRecentFree(ptrs[i]);
}
}
if (kDebugSpaces) {
size_t num_broken_ptrs = 0;
for (size_t i = 0; i < num_ptrs; i++) {
if (!Contains(ptrs[i])) {
num_broken_ptrs++;
LOG(ERROR) << "FreeList[" << i << "] (" << ptrs[i] << ") not in bounds of heap " << *this;
} else {
size_t size = mspace_usable_size(ptrs[i]);
memset(ptrs[i], 0xEF, size);
}
}
CHECK_EQ(num_broken_ptrs, 0u);
}
{
MutexLock mu(self, lock_);
mspace_bulk_free(mspace_, reinterpret_cast<void**>(ptrs), num_ptrs);
return bytes_freed;
}
}
// Callback from dlmalloc when it needs to increase the footprint
extern "C" void* art_heap_morecore(void* mspace, intptr_t increment) {
Heap* heap = Runtime::Current()->GetHeap();
DlMallocSpace* dlmalloc_space = heap->GetDlMallocSpace();
// Support for multiple DlMalloc provided by a slow path.
if (UNLIKELY(dlmalloc_space == nullptr || dlmalloc_space->GetMspace() != mspace)) {
dlmalloc_space = nullptr;
for (space::ContinuousSpace* space : heap->GetContinuousSpaces()) {
if (space->IsDlMallocSpace()) {
DlMallocSpace* cur_dlmalloc_space = space->AsDlMallocSpace();
if (cur_dlmalloc_space->GetMspace() == mspace) {
dlmalloc_space = cur_dlmalloc_space;
break;
}
}
}
CHECK(dlmalloc_space != nullptr) << "Couldn't find DlmMallocSpace with mspace=" << mspace;
}
return dlmalloc_space->MoreCore(increment);
}
size_t DlMallocSpace::Trim() {
MutexLock mu(Thread::Current(), lock_);
// Trim to release memory at the end of the space.
mspace_trim(mspace_, 0);
// Visit space looking for page-sized holes to advise the kernel we don't need.
size_t reclaimed = 0;
mspace_inspect_all(mspace_, DlmallocMadviseCallback, &reclaimed);
return reclaimed;
}
void DlMallocSpace::Walk(void(*callback)(void *start, void *end, size_t num_bytes, void* callback_arg),
void* arg) {
MutexLock mu(Thread::Current(), lock_);
mspace_inspect_all(mspace_, callback, arg);
callback(NULL, NULL, 0, arg); // Indicate end of a space.
}
size_t DlMallocSpace::GetFootprint() {
MutexLock mu(Thread::Current(), lock_);
return mspace_footprint(mspace_);
}
size_t DlMallocSpace::GetFootprintLimit() {
MutexLock mu(Thread::Current(), lock_);
return mspace_footprint_limit(mspace_);
}
void DlMallocSpace::SetFootprintLimit(size_t new_size) {
MutexLock mu(Thread::Current(), lock_);
VLOG(heap) << "DlMallocSpace::SetFootprintLimit " << PrettySize(new_size);
// Compare against the actual footprint, rather than the Size(), because the heap may not have
// grown all the way to the allowed size yet.
size_t current_space_size = mspace_footprint(mspace_);
if (new_size < current_space_size) {
// Don't let the space grow any more.
new_size = current_space_size;
}
mspace_set_footprint_limit(mspace_, new_size);
}
uint64_t DlMallocSpace::GetBytesAllocated() {
MutexLock mu(Thread::Current(), lock_);
size_t bytes_allocated = 0;
mspace_inspect_all(mspace_, DlmallocBytesAllocatedCallback, &bytes_allocated);
return bytes_allocated;
}
uint64_t DlMallocSpace::GetObjectsAllocated() {
MutexLock mu(Thread::Current(), lock_);
size_t objects_allocated = 0;
mspace_inspect_all(mspace_, DlmallocObjectsAllocatedCallback, &objects_allocated);
return objects_allocated;
}
void DlMallocSpace::Clear() {
size_t footprint_limit = GetFootprintLimit();
madvise(GetMemMap()->Begin(), GetMemMap()->Size(), MADV_DONTNEED);
live_bitmap_->Clear();
mark_bitmap_->Clear();
SetEnd(Begin() + starting_size_);
mspace_ = CreateMspace(mem_map_->Begin(), starting_size_, initial_size_);
SetFootprintLimit(footprint_limit);
}
#ifndef NDEBUG
void DlMallocSpace::CheckMoreCoreForPrecondition() {
lock_.AssertHeld(Thread::Current());
}
#endif
static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) {
size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start);
if (used_bytes < chunk_size) {
size_t chunk_free_bytes = chunk_size - used_bytes;
size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg);
max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes);
}
}
void DlMallocSpace::LogFragmentationAllocFailure(std::ostream& os, size_t failed_alloc_bytes) {
Thread* self = Thread::Current();
size_t max_contiguous_allocation = 0;
// To allow the Walk/InspectAll() to exclusively-lock the mutator
// lock, temporarily release the shared access to the mutator
// lock here by transitioning to the suspended state.
Locks::mutator_lock_->AssertSharedHeld(self);
self->TransitionFromRunnableToSuspended(kSuspended);
Walk(MSpaceChunkCallback, &max_contiguous_allocation);
self->TransitionFromSuspendedToRunnable();
Locks::mutator_lock_->AssertSharedHeld(self);
os << "; failed due to fragmentation (largest possible contiguous allocation "
<< max_contiguous_allocation << " bytes)";
}
} // namespace space
} // namespace gc
} // namespace art