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/*
* 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 "space.h"
#include "base/logging.h"
#include "gc/accounting/heap_bitmap.h"
#include "gc/accounting/space_bitmap-inl.h"
#include "gc/heap.h"
#include "runtime.h"
#include "thread-current-inl.h"
namespace art {
namespace gc {
namespace space {
Space::Space(const std::string& name, GcRetentionPolicy gc_retention_policy)
: name_(name), gc_retention_policy_(gc_retention_policy) { }
void Space::Dump(std::ostream& os) const {
os << GetName() << ":" << GetGcRetentionPolicy();
}
std::ostream& operator<<(std::ostream& os, const Space& space) {
space.Dump(os);
return os;
}
DlMallocSpace* Space::AsDlMallocSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
RosAllocSpace* Space::AsRosAllocSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
ZygoteSpace* Space::AsZygoteSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
BumpPointerSpace* Space::AsBumpPointerSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
RegionSpace* Space::AsRegionSpace() {
LOG(FATAL) << "Unreachable";
return nullptr;
}
AllocSpace* Space::AsAllocSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
ContinuousMemMapAllocSpace* Space::AsContinuousMemMapAllocSpace() {
UNIMPLEMENTED(FATAL) << "Unreachable";
UNREACHABLE();
}
DiscontinuousSpace::DiscontinuousSpace(const std::string& name,
GcRetentionPolicy gc_retention_policy) :
Space(name, gc_retention_policy) {
// TODO: Fix this if we ever support objects not in the low 32 bit.
const size_t capacity = static_cast<size_t>(std::numeric_limits<uint32_t>::max());
live_bitmap_.reset(accounting::LargeObjectBitmap::Create("large live objects", nullptr,
capacity));
CHECK(live_bitmap_.get() != nullptr);
mark_bitmap_.reset(accounting::LargeObjectBitmap::Create("large marked objects", nullptr,
capacity));
CHECK(mark_bitmap_.get() != nullptr);
}
collector::ObjectBytePair ContinuousMemMapAllocSpace::Sweep(bool swap_bitmaps) {
accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
accounting::ContinuousSpaceBitmap* mark_bitmap = GetMarkBitmap();
// If the bitmaps are bound then sweeping this space clearly won't do anything.
if (live_bitmap == mark_bitmap) {
return collector::ObjectBytePair(0, 0);
}
SweepCallbackContext scc(swap_bitmaps, this);
if (swap_bitmaps) {
std::swap(live_bitmap, mark_bitmap);
}
// Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked.
accounting::ContinuousSpaceBitmap::SweepWalk(
*live_bitmap, *mark_bitmap, reinterpret_cast<uintptr_t>(Begin()),
reinterpret_cast<uintptr_t>(End()), GetSweepCallback(), reinterpret_cast<void*>(&scc));
return scc.freed;
}
// Returns the old mark bitmap.
void ContinuousMemMapAllocSpace::BindLiveToMarkBitmap() {
CHECK(!HasBoundBitmaps());
accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
if (live_bitmap != mark_bitmap_.get()) {
accounting::ContinuousSpaceBitmap* mark_bitmap = mark_bitmap_.release();
Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap);
temp_bitmap_.reset(mark_bitmap);
mark_bitmap_.reset(live_bitmap);
}
}
bool ContinuousMemMapAllocSpace::HasBoundBitmaps() const {
return temp_bitmap_.get() != nullptr;
}
void ContinuousMemMapAllocSpace::UnBindBitmaps() {
CHECK(HasBoundBitmaps());
// At this point, the temp_bitmap holds our old mark bitmap.
accounting::ContinuousSpaceBitmap* new_bitmap = temp_bitmap_.release();
Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap_.get(), new_bitmap);
CHECK_EQ(mark_bitmap_.release(), live_bitmap_.get());
mark_bitmap_.reset(new_bitmap);
DCHECK(temp_bitmap_.get() == nullptr);
}
void ContinuousMemMapAllocSpace::SwapBitmaps() {
live_bitmap_.swap(mark_bitmap_);
// Swap names to get more descriptive diagnostics.
std::string temp_name(live_bitmap_->GetName());
live_bitmap_->SetName(mark_bitmap_->GetName());
mark_bitmap_->SetName(temp_name);
}
AllocSpace::SweepCallbackContext::SweepCallbackContext(bool swap_bitmaps_in, space::Space* space_in)
: swap_bitmaps(swap_bitmaps_in), space(space_in), self(Thread::Current()) {
}
} // namespace space
} // namespace gc
} // namespace art
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