runtime/gc/space/bump_pointer_space.cc - platform/art - Git at Google

 /*
  * 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),
       block_lock_("Block lock"),
       main_block_size_(0),
       num_blocks_(0) {
 }

 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),
       block_lock_("Block lock", kBumpPointerSpaceBlockLock),
       main_block_size_(0),
       num_blocks_(0) {
 }

 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);
   growth_end_ = Limit();
   {
     MutexLock mu(Thread::Current(), block_lock_);
     num_blocks_ = 0;
     main_block_size_ = 0;
   }
 }

 void BumpPointerSpace::Dump(std::ostream& os) const {
   os << GetName() << " "
       << reinterpret_cast<void*>(Begin()) << "-" << reinterpret_cast<void*>(End()) << " - "
       << reinterpret_cast<void*>(Limit());
 }

 mirror::Object* BumpPointerSpace::GetNextObject(mirror::Object* obj) {
   const uintptr_t position = reinterpret_cast<uintptr_t>(obj) + obj->SizeOf();
   return reinterpret_cast<mirror::Object*>(RoundUp(position, kAlignment));
 }

 size_t BumpPointerSpace::RevokeThreadLocalBuffers(Thread* thread) {
   MutexLock mu(Thread::Current(), block_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(), block_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_EQ(num_blocks_, 0U);
   main_block_size_ = Size();
 }

 // Returns the start of the storage.
 uint8_t* BumpPointerSpace::AllocBlock(size_t bytes) {
   bytes = RoundUp(bytes, kAlignment);
   if (!num_blocks_) {
     UpdateMainBlock();
   }
   uint8_t* storage = reinterpret_cast<uint8_t*>(
       AllocNonvirtualWithoutAccounting(bytes + sizeof(BlockHeader)));
   if (LIKELY(storage != nullptr)) {
     BlockHeader* header = reinterpret_cast<BlockHeader*>(storage);
     header->size_ = bytes;  // Write out the block header.
     storage += sizeof(BlockHeader);
     ++num_blocks_;
   }
   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(), block_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 (num_blocks_ > 0) {
     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(), block_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 (num_blocks_ > 0) {
     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) {
   MutexLock mu(Thread::Current(), block_lock_);
   RevokeThreadLocalBuffersLocked(self);
   uint8_t* start = AllocBlock(bytes);
   if (start == nullptr) {
     return false;
   }
   self->SetTlab(start, start + bytes, start + 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;
 }

 }  // namespace space
 }  // namespace gc
 }  // namespace art
	/*
	* 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),
	block_lock_("Block lock"),
	main_block_size_(0),
	num_blocks_(0) {
	}

	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),
	block_lock_("Block lock", kBumpPointerSpaceBlockLock),
	main_block_size_(0),
	num_blocks_(0) {
	}

	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);
	growth_end_ = Limit();
	{
	MutexLock mu(Thread::Current(), block_lock_);
	num_blocks_ = 0;
	main_block_size_ = 0;
	}
	}

	void BumpPointerSpace::Dump(std::ostream& os) const {
	os << GetName() << " "
	<< reinterpret_cast<void>(Begin()) << "-" << reinterpret_cast<void>(End()) << " - "
	<< reinterpret_cast<void*>(Limit());
	}

	mirror::Object* BumpPointerSpace::GetNextObject(mirror::Object* obj) {
	const uintptr_t position = reinterpret_cast<uintptr_t>(obj) + obj->SizeOf();
	return reinterpret_cast<mirror::Object*>(RoundUp(position, kAlignment));
	}

	size_t BumpPointerSpace::RevokeThreadLocalBuffers(Thread* thread) {
	MutexLock mu(Thread::Current(), block_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(), block_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_EQ(num_blocks_, 0U);
	main_block_size_ = Size();
	}

	// Returns the start of the storage.
	uint8_t* BumpPointerSpace::AllocBlock(size_t bytes) {
	bytes = RoundUp(bytes, kAlignment);
	if (!num_blocks_) {
	UpdateMainBlock();
	}
	uint8_t* storage = reinterpret_cast<uint8_t*>(
	AllocNonvirtualWithoutAccounting(bytes + sizeof(BlockHeader)));
	if (LIKELY(storage != nullptr)) {
	BlockHeader* header = reinterpret_cast<BlockHeader*>(storage);
	header->size_ = bytes; // Write out the block header.
	storage += sizeof(BlockHeader);
	++num_blocks_;
	}
	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(), block_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 (num_blocks_ > 0) {
	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(), block_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 (num_blocks_ > 0) {
	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) {
	MutexLock mu(Thread::Current(), block_lock_);
	RevokeThreadLocalBuffersLocked(self);
	uint8_t* start = AllocBlock(bytes);
	if (start == nullptr) {
	return false;
	}
	self->SetTlab(start, start + bytes, start + 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;
	}

	} // namespace space
	} // namespace gc
	} // namespace art