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/*
* Copyright (C) 2013 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 "bump_pointer_space.h"
#include "bump_pointer_space-inl.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "thread_list.h"
namespace art {
namespace gc {
namespace space {
BumpPointerSpace* BumpPointerSpace::Create(const std::string& name, size_t capacity) {
capacity = RoundUp(capacity, kPageSize);
std::string error_msg;
MemMap mem_map = MemMap::MapAnonymous(name.c_str(),
capacity,
PROT_READ | PROT_WRITE,
/*low_4gb=*/ true,
&error_msg);
if (!mem_map.IsValid()) {
LOG(ERROR) << "Failed to allocate pages for alloc space (" << name << ") of size "
<< PrettySize(capacity) << " with message " << error_msg;
return nullptr;
}
return new BumpPointerSpace(name, std::move(mem_map));
}
BumpPointerSpace* BumpPointerSpace::CreateFromMemMap(const std::string& name, MemMap&& mem_map) {
return new BumpPointerSpace(name, std::move(mem_map));
}
BumpPointerSpace::BumpPointerSpace(const std::string& name, uint8_t* begin, uint8_t* limit)
: ContinuousMemMapAllocSpace(
name, MemMap::Invalid(), begin, begin, limit, kGcRetentionPolicyAlwaysCollect),
growth_end_(limit),
objects_allocated_(0),
bytes_allocated_(0),
lock_("Bump-pointer space lock"),
main_block_size_(0) {
// This constructor gets called only from Heap::PreZygoteFork(), which
// doesn't require a mark_bitmap.
}
BumpPointerSpace::BumpPointerSpace(const std::string& name, MemMap&& mem_map)
: ContinuousMemMapAllocSpace(name,
std::move(mem_map),
mem_map.Begin(),
mem_map.Begin(),
mem_map.End(),
kGcRetentionPolicyAlwaysCollect),
growth_end_(mem_map_.End()),
objects_allocated_(0),
bytes_allocated_(0),
lock_("Bump-pointer space lock", kBumpPointerSpaceBlockLock),
main_block_size_(0) {
mark_bitmap_ =
accounting::ContinuousSpaceBitmap::Create("bump-pointer space live bitmap",
Begin(),
Capacity());
}
void BumpPointerSpace::Clear() {
// Release the pages back to the operating system.
if (!kMadviseZeroes) {
memset(Begin(), 0, Limit() - Begin());
}
CHECK_NE(madvise(Begin(), Limit() - Begin(), MADV_DONTNEED), -1) << "madvise failed";
// Reset the end of the space back to the beginning, we move the end forward as we allocate
// objects.
SetEnd(Begin());
objects_allocated_.store(0, std::memory_order_relaxed);
bytes_allocated_.store(0, std::memory_order_relaxed);
{
MutexLock mu(Thread::Current(), lock_);
growth_end_ = Limit();
block_sizes_.clear();
main_block_size_ = 0;
}
}
size_t BumpPointerSpace::ClampGrowthLimit(size_t new_capacity) {
CHECK(gUseUserfaultfd);
MutexLock mu(Thread::Current(), lock_);
CHECK_EQ(growth_end_, Limit());
uint8_t* end = End();
CHECK_LE(end, growth_end_);
size_t free_capacity = growth_end_ - end;
size_t clamp_size = Capacity() - new_capacity;
if (clamp_size > free_capacity) {
new_capacity += clamp_size - free_capacity;
}
SetLimit(Begin() + new_capacity);
growth_end_ = Limit();
GetMemMap()->SetSize(new_capacity);
if (GetMarkBitmap()->HeapBegin() != 0) {
GetMarkBitmap()->SetHeapSize(new_capacity);
}
return new_capacity;
}
void BumpPointerSpace::Dump(std::ostream& os) const {
os << GetName() << " "
<< reinterpret_cast<void*>(Begin()) << "-" << reinterpret_cast<void*>(End()) << " - "
<< reinterpret_cast<void*>(Limit());
}
size_t BumpPointerSpace::RevokeThreadLocalBuffers(Thread* thread) {
MutexLock mu(Thread::Current(), lock_);
RevokeThreadLocalBuffersLocked(thread);
return 0U;
}
size_t BumpPointerSpace::RevokeAllThreadLocalBuffers() {
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
MutexLock mu2(self, *Locks::thread_list_lock_);
// TODO: Not do a copy of the thread list?
std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList();
for (Thread* thread : thread_list) {
RevokeThreadLocalBuffers(thread);
}
return 0U;
}
void BumpPointerSpace::AssertThreadLocalBuffersAreRevoked(Thread* thread) {
if (kIsDebugBuild) {
MutexLock mu(Thread::Current(), lock_);
DCHECK(!thread->HasTlab());
}
}
void BumpPointerSpace::AssertAllThreadLocalBuffersAreRevoked() {
if (kIsDebugBuild) {
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
MutexLock mu2(self, *Locks::thread_list_lock_);
// TODO: Not do a copy of the thread list?
std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList();
for (Thread* thread : thread_list) {
AssertThreadLocalBuffersAreRevoked(thread);
}
}
}
void BumpPointerSpace::UpdateMainBlock() {
DCHECK(block_sizes_.empty());
main_block_size_ = Size();
}
// Returns the start of the storage.
uint8_t* BumpPointerSpace::AllocBlock(size_t bytes) {
if (block_sizes_.empty()) {
UpdateMainBlock();
}
uint8_t* storage = reinterpret_cast<uint8_t*>(AllocNonvirtualWithoutAccounting(bytes));
if (LIKELY(storage != nullptr)) {
block_sizes_.push_back(bytes);
}
return storage;
}
accounting::ContinuousSpaceBitmap::SweepCallback* BumpPointerSpace::GetSweepCallback() {
UNIMPLEMENTED(FATAL);
UNREACHABLE();
}
uint64_t BumpPointerSpace::GetBytesAllocated() {
// Start out pre-determined amount (blocks which are not being allocated into).
uint64_t total = static_cast<uint64_t>(bytes_allocated_.load(std::memory_order_relaxed));
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
MutexLock mu2(self, *Locks::thread_list_lock_);
std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList();
MutexLock mu3(Thread::Current(), lock_);
// If we don't have any blocks, we don't have any thread local buffers. This check is required
// since there can exist multiple bump pointer spaces which exist at the same time.
if (!block_sizes_.empty()) {
for (Thread* thread : thread_list) {
total += thread->GetThreadLocalBytesAllocated();
}
}
return total;
}
uint64_t BumpPointerSpace::GetObjectsAllocated() {
// Start out pre-determined amount (blocks which are not being allocated into).
uint64_t total = static_cast<uint64_t>(objects_allocated_.load(std::memory_order_relaxed));
Thread* self = Thread::Current();
MutexLock mu(self, *Locks::runtime_shutdown_lock_);
MutexLock mu2(self, *Locks::thread_list_lock_);
std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList();
MutexLock mu3(Thread::Current(), lock_);
// If we don't have any blocks, we don't have any thread local buffers. This check is required
// since there can exist multiple bump pointer spaces which exist at the same time.
if (!block_sizes_.empty()) {
for (Thread* thread : thread_list) {
total += thread->GetThreadLocalObjectsAllocated();
}
}
return total;
}
void BumpPointerSpace::RevokeThreadLocalBuffersLocked(Thread* thread) {
objects_allocated_.fetch_add(thread->GetThreadLocalObjectsAllocated(), std::memory_order_relaxed);
bytes_allocated_.fetch_add(thread->GetThreadLocalBytesAllocated(), std::memory_order_relaxed);
thread->ResetTlab();
}
bool BumpPointerSpace::AllocNewTlab(Thread* self, size_t bytes, size_t* bytes_tl_bulk_allocated) {
bytes = RoundUp(bytes, kAlignment);
MutexLock mu(Thread::Current(), lock_);
RevokeThreadLocalBuffersLocked(self);
uint8_t* start = AllocBlock(bytes);
if (start == nullptr) {
return false;
}
self->SetTlab(start, start + bytes, start + bytes);
if (bytes_tl_bulk_allocated != nullptr) {
*bytes_tl_bulk_allocated = bytes;
}
return true;
}
bool BumpPointerSpace::LogFragmentationAllocFailure(std::ostream& os,
size_t failed_alloc_bytes) {
size_t max_contiguous_allocation = Limit() - End();
if (failed_alloc_bytes > max_contiguous_allocation) {
os << "; failed due to fragmentation (largest possible contiguous allocation "
<< max_contiguous_allocation << " bytes)";
return true;
}
// Caller's job to print failed_alloc_bytes.
return false;
}
size_t BumpPointerSpace::AllocationSizeNonvirtual(mirror::Object* obj, size_t* usable_size) {
size_t num_bytes = obj->SizeOf();
if (usable_size != nullptr) {
*usable_size = RoundUp(num_bytes, kAlignment);
}
return num_bytes;
}
uint8_t* BumpPointerSpace::AlignEnd(Thread* self, size_t alignment, Heap* heap) {
Locks::mutator_lock_->AssertExclusiveHeld(self);
DCHECK(IsAligned<kAlignment>(alignment));
uint8_t* end = end_.load(std::memory_order_relaxed);
uint8_t* aligned_end = AlignUp(end, alignment);
ptrdiff_t diff = aligned_end - end;
if (diff > 0) {
end_.store(aligned_end, std::memory_order_relaxed);
heap->AddBytesAllocated(diff);
// If we have blocks after the main one. Then just add the diff to the last
// block.
MutexLock mu(self, lock_);
if (!block_sizes_.empty()) {
block_sizes_.back() += diff;
}
}
return aligned_end;
}
std::vector<size_t>* BumpPointerSpace::GetBlockSizes(Thread* self, size_t* main_block_size) {
std::vector<size_t>* block_sizes = nullptr;
MutexLock mu(self, lock_);
if (!block_sizes_.empty()) {
block_sizes = new std::vector<size_t>(block_sizes_.begin(), block_sizes_.end());
} else {
UpdateMainBlock();
}
*main_block_size = main_block_size_;
return block_sizes;
}
void BumpPointerSpace::SetBlockSizes(Thread* self,
const size_t main_block_size,
const size_t first_valid_idx) {
MutexLock mu(self, lock_);
main_block_size_ = main_block_size;
if (!block_sizes_.empty()) {
block_sizes_.erase(block_sizes_.begin(), block_sizes_.begin() + first_valid_idx);
}
size_t size = main_block_size;
for (size_t block_size : block_sizes_) {
size += block_size;
}
DCHECK(IsAligned<kAlignment>(size));
end_.store(Begin() + size, std::memory_order_relaxed);
}
} // namespace space
} // namespace gc
} // namespace art