/*
* 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.
*/
#ifndef ART_RUNTIME_GC_HEAP_INL_H_
#define ART_RUNTIME_GC_HEAP_INL_H_
#include "heap.h"
#include "allocation_listener.h"
#include "base/quasi_atomic.h"
#include "base/time_utils.h"
#include "base/utils.h"
#include "gc/accounting/atomic_stack.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/allocation_record.h"
#include "gc/collector/semi_space.h"
#include "gc/space/bump_pointer_space-inl.h"
#include "gc/space/dlmalloc_space-inl.h"
#include "gc/space/large_object_space.h"
#include "gc/space/region_space-inl.h"
#include "gc/space/rosalloc_space-inl.h"
#include "handle_scope-inl.h"
#include "obj_ptr-inl.h"
#include "runtime.h"
#include "thread-inl.h"
#include "verify_object.h"
namespace art {
namespace gc {
template <bool kInstrumented, bool kCheckLargeObject, typename PreFenceVisitor>
inline mirror::Object* Heap::AllocObjectWithAllocator(Thread* self,
ObjPtr<mirror::Class> klass,
size_t byte_count,
AllocatorType allocator,
const PreFenceVisitor& pre_fence_visitor) {
if (kIsDebugBuild) {
CheckPreconditionsForAllocObject(klass, byte_count);
// Since allocation can cause a GC which will need to SuspendAll, make sure all allocations are
// done in the runnable state where suspension is expected.
CHECK_EQ(self->GetState(), kRunnable);
self->AssertThreadSuspensionIsAllowable();
self->AssertNoPendingException();
// Make sure to preserve klass.
StackHandleScope<1> hs(self);
HandleWrapperObjPtr<mirror::Class> h = hs.NewHandleWrapper(&klass);
self->PoisonObjectPointers();
}
// Need to check that we aren't the large object allocator since the large object allocation code
// path includes this function. If we didn't check we would have an infinite loop.
ObjPtr<mirror::Object> obj;
if (kCheckLargeObject && UNLIKELY(ShouldAllocLargeObject(klass, byte_count))) {
obj = AllocLargeObject<kInstrumented, PreFenceVisitor>(self, &klass, byte_count,
pre_fence_visitor);
if (obj != nullptr) {
return obj.Ptr();
} else {
// There should be an OOM exception, since we are retrying, clear it.
self->ClearException();
}
// If the large object allocation failed, try to use the normal spaces (main space,
// non moving space). This can happen if there is significant virtual address space
// fragmentation.
}
// bytes allocated for the (individual) object.
size_t bytes_allocated;
size_t usable_size;
size_t new_num_bytes_allocated = 0;
if (IsTLABAllocator(allocator)) {
byte_count = RoundUp(byte_count, space::BumpPointerSpace::kAlignment);
}
// If we have a thread local allocation we don't need to update bytes allocated.
if (IsTLABAllocator(allocator) && byte_count <= self->TlabSize()) {
obj = self->AllocTlab(byte_count);
DCHECK(obj != nullptr) << "AllocTlab can't fail";
obj->SetClass(klass);
if (kUseBakerReadBarrier) {
obj->AssertReadBarrierState();
}
bytes_allocated = byte_count;
usable_size = bytes_allocated;
pre_fence_visitor(obj, usable_size);
QuasiAtomic::ThreadFenceForConstructor();
} else if (
!kInstrumented && allocator == kAllocatorTypeRosAlloc &&
(obj = rosalloc_space_->AllocThreadLocal(self, byte_count, &bytes_allocated)) != nullptr &&
LIKELY(obj != nullptr)) {
DCHECK(!is_running_on_memory_tool_);
obj->SetClass(klass);
if (kUseBakerReadBarrier) {
obj->AssertReadBarrierState();
}
usable_size = bytes_allocated;
pre_fence_visitor(obj, usable_size);
QuasiAtomic::ThreadFenceForConstructor();
} else {
// Bytes allocated that takes bulk thread-local buffer allocations into account.
size_t bytes_tl_bulk_allocated = 0u;
obj = TryToAllocate<kInstrumented, false>(self, allocator, byte_count, &bytes_allocated,
&usable_size, &bytes_tl_bulk_allocated);
if (UNLIKELY(obj == nullptr)) {
// AllocateInternalWithGc can cause thread suspension, if someone instruments the entrypoints
// or changes the allocator in a suspend point here, we need to retry the allocation.
obj = AllocateInternalWithGc(self,
allocator,
kInstrumented,
byte_count,
&bytes_allocated,
&usable_size,
&bytes_tl_bulk_allocated, &klass);
if (obj == nullptr) {
// The only way that we can get a null return if there is no pending exception is if the
// allocator or instrumentation changed.
if (!self->IsExceptionPending()) {
// AllocObject will pick up the new allocator type, and instrumented as true is the safe
// default.
return AllocObject</*kInstrumented*/true>(self,
klass,
byte_count,
pre_fence_visitor);
}
return nullptr;
}
}
DCHECK_GT(bytes_allocated, 0u);
DCHECK_GT(usable_size, 0u);
obj->SetClass(klass);
if (kUseBakerReadBarrier) {
obj->AssertReadBarrierState();
}
if (collector::SemiSpace::kUseRememberedSet && UNLIKELY(allocator == kAllocatorTypeNonMoving)) {
// (Note this if statement will be constant folded away for the
// fast-path quick entry points.) Because SetClass() has no write
// barrier, if a non-moving space allocation, we need a write
// barrier as the class pointer may point to the bump pointer
// space (where the class pointer is an "old-to-young" reference,
// though rare) under the GSS collector with the remembered set
// enabled. We don't need this for kAllocatorTypeRosAlloc/DlMalloc
// cases because we don't directly allocate into the main alloc
// space (besides promotions) under the SS/GSS collector.
WriteBarrierField(obj, mirror::Object::ClassOffset(), klass);
}
pre_fence_visitor(obj, usable_size);
QuasiAtomic::ThreadFenceForConstructor();
size_t num_bytes_allocated_before =
num_bytes_allocated_.FetchAndAddRelaxed(bytes_tl_bulk_allocated);
new_num_bytes_allocated = num_bytes_allocated_before + bytes_tl_bulk_allocated;
if (bytes_tl_bulk_allocated > 0) {
// Only trace when we get an increase in the number of bytes allocated. This happens when
// obtaining a new TLAB and isn't often enough to hurt performance according to golem.
TraceHeapSize(new_num_bytes_allocated);
}
}
if (kIsDebugBuild && Runtime::Current()->IsStarted()) {
CHECK_LE(obj->SizeOf(), usable_size);
}
// TODO: Deprecate.
if (kInstrumented) {
if (Runtime::Current()->HasStatsEnabled()) {
RuntimeStats* thread_stats = self->GetStats();
++thread_stats->allocated_objects;
thread_stats->allocated_bytes += bytes_allocated;
RuntimeStats* global_stats = Runtime::Current()->GetStats();
++global_stats->allocated_objects;
global_stats->allocated_bytes += bytes_allocated;
}
} else {
DCHECK(!Runtime::Current()->HasStatsEnabled());
}
if (kInstrumented) {
if (IsAllocTrackingEnabled()) {
// allocation_records_ is not null since it never becomes null after allocation tracking is
// enabled.
DCHECK(allocation_records_ != nullptr);
allocation_records_->RecordAllocation(self, &obj, bytes_allocated);
}
AllocationListener* l = alloc_listener_.LoadSequentiallyConsistent();
if (l != nullptr) {
// Same as above. We assume that a listener that was once stored will never be deleted.
// Otherwise we'd have to perform this under a lock.
l->ObjectAllocated(self, &obj, bytes_allocated);
}
} else {
DCHECK(!IsAllocTrackingEnabled());
}
if (AllocatorHasAllocationStack(allocator)) {
PushOnAllocationStack(self, &obj);
}
if (kInstrumented) {
if (gc_stress_mode_) {
CheckGcStressMode(self, &obj);
}
} else {
DCHECK(!gc_stress_mode_);
}
// IsGcConcurrent() isn't known at compile time so we can optimize by not checking it for
// the BumpPointer or TLAB allocators. This is nice since it allows the entire if statement to be
// optimized out. And for the other allocators, AllocatorMayHaveConcurrentGC is a constant since
// the allocator_type should be constant propagated.
if (AllocatorMayHaveConcurrentGC(allocator) && IsGcConcurrent()) {
CheckConcurrentGC(self, new_num_bytes_allocated, &obj);
}
VerifyObject(obj);
self->VerifyStack();
return obj.Ptr();
}
// The size of a thread-local allocation stack in the number of references.
static constexpr size_t kThreadLocalAllocationStackSize = 128;
inline void Heap::PushOnAllocationStack(Thread* self, ObjPtr<mirror::Object>* obj) {
if (kUseThreadLocalAllocationStack) {
if (UNLIKELY(!self->PushOnThreadLocalAllocationStack(obj->Ptr()))) {
PushOnThreadLocalAllocationStackWithInternalGC(self, obj);
}
} else if (UNLIKELY(!allocation_stack_->AtomicPushBack(obj->Ptr()))) {
PushOnAllocationStackWithInternalGC(self, obj);
}
}
template <bool kInstrumented, typename PreFenceVisitor>
inline mirror::Object* Heap::AllocLargeObject(Thread* self,
ObjPtr<mirror::Class>* klass,
size_t byte_count,
const PreFenceVisitor& pre_fence_visitor) {
// Save and restore the class in case it moves.
StackHandleScope<1> hs(self);
auto klass_wrapper = hs.NewHandleWrapper(klass);
return AllocObjectWithAllocator<kInstrumented, false, PreFenceVisitor>(self, *klass, byte_count,
kAllocatorTypeLOS,
pre_fence_visitor);
}
template <const bool kInstrumented, const bool kGrow>
inline mirror::Object* Heap::TryToAllocate(Thread* self,
AllocatorType allocator_type,
size_t alloc_size,
size_t* bytes_allocated,
size_t* usable_size,
size_t* bytes_tl_bulk_allocated) {
if (allocator_type != kAllocatorTypeTLAB &&
allocator_type != kAllocatorTypeRegionTLAB &&
allocator_type != kAllocatorTypeRosAlloc &&
UNLIKELY(IsOutOfMemoryOnAllocation(allocator_type, alloc_size, kGrow))) {
return nullptr;
}
mirror::Object* ret;
switch (allocator_type) {
case kAllocatorTypeBumpPointer: {
DCHECK(bump_pointer_space_ != nullptr);
alloc_size = RoundUp(alloc_size, space::BumpPointerSpace::kAlignment);
ret = bump_pointer_space_->AllocNonvirtual(alloc_size);
if (LIKELY(ret != nullptr)) {
*bytes_allocated = alloc_size;
*usable_size = alloc_size;
*bytes_tl_bulk_allocated = alloc_size;
}
break;
}
case kAllocatorTypeRosAlloc: {
if (kInstrumented && UNLIKELY(is_running_on_memory_tool_)) {
// If running on valgrind or asan, we should be using the instrumented path.
size_t max_bytes_tl_bulk_allocated = rosalloc_space_->MaxBytesBulkAllocatedFor(alloc_size);
if (UNLIKELY(IsOutOfMemoryOnAllocation(allocator_type,
max_bytes_tl_bulk_allocated,
kGrow))) {
return nullptr;
}
ret = rosalloc_space_->Alloc(self, alloc_size, bytes_allocated, usable_size,
bytes_tl_bulk_allocated);
} else {
DCHECK(!is_running_on_memory_tool_);
size_t max_bytes_tl_bulk_allocated =
rosalloc_space_->MaxBytesBulkAllocatedForNonvirtual(alloc_size);
if (UNLIKELY(IsOutOfMemoryOnAllocation(allocator_type,
max_bytes_tl_bulk_allocated,
kGrow))) {
return nullptr;
}
if (!kInstrumented) {
DCHECK(!rosalloc_space_->CanAllocThreadLocal(self, alloc_size));
}
ret = rosalloc_space_->AllocNonvirtual(self,
alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
}
break;
}
case kAllocatorTypeDlMalloc: {
if (kInstrumented && UNLIKELY(is_running_on_memory_tool_)) {
// If running on valgrind, we should be using the instrumented path.
ret = dlmalloc_space_->Alloc(self,
alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
} else {
DCHECK(!is_running_on_memory_tool_);
ret = dlmalloc_space_->AllocNonvirtual(self,
alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
}
break;
}
case kAllocatorTypeNonMoving: {
ret = non_moving_space_->Alloc(self,
alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
break;
}
case kAllocatorTypeLOS: {
ret = large_object_space_->Alloc(self,
alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
// Note that the bump pointer spaces aren't necessarily next to
// the other continuous spaces like the non-moving alloc space or
// the zygote space.
DCHECK(ret == nullptr || large_object_space_->Contains(ret));
break;
}
case kAllocatorTypeRegion: {
DCHECK(region_space_ != nullptr);
alloc_size = RoundUp(alloc_size, space::RegionSpace::kAlignment);
ret = region_space_->AllocNonvirtual<false>(alloc_size,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
break;
}
case kAllocatorTypeTLAB:
FALLTHROUGH_INTENDED;
case kAllocatorTypeRegionTLAB: {
DCHECK_ALIGNED(alloc_size, kObjectAlignment);
static_assert(space::RegionSpace::kAlignment == space::BumpPointerSpace::kAlignment,
"mismatched alignments");
static_assert(kObjectAlignment == space::BumpPointerSpace::kAlignment,
"mismatched alignments");
if (UNLIKELY(self->TlabSize() < alloc_size)) {
// kAllocatorTypeTLAB may be the allocator for region space TLAB if the GC is not marking,
// that is why the allocator is not passed down.
return AllocWithNewTLAB(self,
alloc_size,
kGrow,
bytes_allocated,
usable_size,
bytes_tl_bulk_allocated);
}
// The allocation can't fail.
ret = self->AllocTlab(alloc_size);
DCHECK(ret != nullptr);
*bytes_allocated = alloc_size;
*bytes_tl_bulk_allocated = 0; // Allocated in an existing buffer.
*usable_size = alloc_size;
break;
}
default: {
LOG(FATAL) << "Invalid allocator type";
ret = nullptr;
}
}
return ret;
}
inline bool Heap::ShouldAllocLargeObject(ObjPtr<mirror::Class> c, size_t byte_count) const {
// We need to have a zygote space or else our newly allocated large object can end up in the
// Zygote resulting in it being prematurely freed.
// We can only do this for primitive objects since large objects will not be within the card table
// range. This also means that we rely on SetClass not dirtying the object's card.
return byte_count >= large_object_threshold_ && (c->IsPrimitiveArray() || c->IsStringClass());
}
inline bool Heap::IsOutOfMemoryOnAllocation(AllocatorType allocator_type,
size_t alloc_size,
bool grow) {
size_t new_footprint = num_bytes_allocated_.LoadSequentiallyConsistent() + alloc_size;
if (UNLIKELY(new_footprint > max_allowed_footprint_)) {
if (UNLIKELY(new_footprint > growth_limit_)) {
return true;
}
if (!AllocatorMayHaveConcurrentGC(allocator_type) || !IsGcConcurrent()) {
if (!grow) {
return true;
}
// TODO: Grow for allocation is racy, fix it.
VlogHeapGrowth(max_allowed_footprint_, new_footprint, alloc_size);
max_allowed_footprint_ = new_footprint;
}
}
return false;
}
inline void Heap::CheckConcurrentGC(Thread* self,
size_t new_num_bytes_allocated,
ObjPtr<mirror::Object>* obj) {
if (UNLIKELY(new_num_bytes_allocated >= concurrent_start_bytes_)) {
RequestConcurrentGCAndSaveObject(self, false, obj);
}
}
inline void Heap::WriteBarrierField(ObjPtr<mirror::Object> dst,
MemberOffset offset ATTRIBUTE_UNUSED,
ObjPtr<mirror::Object> new_value ATTRIBUTE_UNUSED) {
card_table_->MarkCard(dst.Ptr());
}
inline void Heap::WriteBarrierArray(ObjPtr<mirror::Object> dst,
int start_offset ATTRIBUTE_UNUSED,
size_t length ATTRIBUTE_UNUSED) {
card_table_->MarkCard(dst.Ptr());
}
inline void Heap::WriteBarrierEveryFieldOf(ObjPtr<mirror::Object> obj) {
card_table_->MarkCard(obj.Ptr());
}
} // namespace gc
} // namespace art
#endif // ART_RUNTIME_GC_HEAP_INL_H_