Refactor and remove copy mark bits.

Refactor code GC realted code to be in a GC folder.

Remove copy mark bits by using pointer changing instead.

Enable concurrent sweeping of system weaks.

Fix non concurrent GC plan.

Change-Id: I9c71478be27d21a75f8a4e6af6faabe896e5e263
diff --git a/src/gc/space.cc b/src/gc/space.cc
new file mode 100644
index 0000000..9c8819b
--- /dev/null
+++ b/src/gc/space.cc
@@ -0,0 +1,770 @@
+/*
+ * 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 "UniquePtr.h"
+#include "dlmalloc.h"
+#include "file.h"
+#include "image.h"
+#include "logging.h"
+#include "os.h"
+#include "space_bitmap.h"
+#include "stl_util.h"
+#include "utils.h"
+
+namespace art {
+
+#ifndef NDEBUG
+static const bool kDebugSpaces = true;
+#else
+static const bool kDebugSpaces = false;
+#endif
+// Magic padding value that we use to check for buffer overruns.
+static const word kPaddingValue = 0xBAC0BAC0;
+
+// TODO: Remove define macro
+#define CHECK_MEMORY_CALL(call, args, what) \
+  do { \
+    int rc = call args; \
+    if (UNLIKELY(rc != 0)) { \
+      errno = rc; \
+      PLOG(FATAL) << # call << " failed for " << what; \
+    } \
+  } while (false)
+
+Space::Space(const std::string& name, GcRetentionPolicy gc_retention_policy)
+    : name_(name),
+      gc_retention_policy_(gc_retention_policy) {
+
+}
+
+ContinuousSpace::ContinuousSpace(const std::string& name, byte* begin, byte* end,
+                                 GcRetentionPolicy gc_retention_policy)
+    : Space(name, gc_retention_policy),
+      begin_(begin),
+      end_(end) {
+
+}
+
+MemMapSpace::MemMapSpace(const std::string& name, MemMap* mem_map, size_t initial_size,
+                         GcRetentionPolicy gc_retention_policy)
+    : ContinuousSpace(name, mem_map->Begin(), mem_map->Begin() + initial_size, gc_retention_policy),
+      mem_map_(mem_map)
+{
+
+}
+
+size_t AllocSpace::bitmap_index_ = 0;
+
+AllocSpace::AllocSpace(const std::string& name, MemMap* mem_map, void* mspace, byte* begin,
+                       byte* end, size_t growth_limit)
+    : MemMapSpace(name, mem_map, end - begin, kGcRetentionPolicyAlwaysCollect),
+      num_bytes_allocated_(0), num_objects_allocated_(0),
+      lock_("allocation space lock", kAllocSpaceLock), mspace_(mspace),
+      growth_limit_(growth_limit) {
+  CHECK(mspace != NULL);
+
+  size_t bitmap_index = bitmap_index_++;
+
+  static const uintptr_t kGcCardSize = static_cast<uintptr_t>(CardTable::kCardSize);
+  CHECK(reinterpret_cast<uintptr_t>(mem_map->Begin()) % kGcCardSize == 0);
+  CHECK(reinterpret_cast<uintptr_t>(mem_map->End()) % kGcCardSize == 0);
+  live_bitmap_.reset(SpaceBitmap::Create(
+      StringPrintf("allocspace-%s-live-bitmap-%d", name.c_str(), static_cast<int>(bitmap_index)),
+      Begin(), Capacity()));
+  DCHECK(live_bitmap_.get() != NULL) << "could not create allocspace live bitmap #" << bitmap_index;
+
+  mark_bitmap_.reset(SpaceBitmap::Create(
+      StringPrintf("allocspace-%s-mark-bitmap-%d", name.c_str(), static_cast<int>(bitmap_index)),
+      Begin(), Capacity()));
+  DCHECK(live_bitmap_.get() != NULL) << "could not create allocspace mark bitmap #" << bitmap_index;
+}
+
+AllocSpace* AllocSpace::Create(const std::string& name, size_t initial_size, size_t growth_limit,
+                               size_t capacity, byte* 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;
+  uint64_t start_time = 0;
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    start_time = NanoTime();
+    VLOG(startup) << "Space::CreateAllocSpace entering " << name
+                  << " initial_size=" << PrettySize(initial_size)
+                  << " growth_limit=" << PrettySize(growth_limit)
+                  << " capacity=" << PrettySize(capacity)
+                  << " requested_begin=" << reinterpret_cast<void*>(requested_begin);
+  }
+
+  // Sanity check arguments
+  if (starting_size > initial_size) {
+    initial_size = starting_size;
+  }
+  if (initial_size > growth_limit) {
+    LOG(ERROR) << "Failed to create alloc space (" << name << ") where the initial size ("
+        << PrettySize(initial_size) << ") is larger than its capacity ("
+        << PrettySize(growth_limit) << ")";
+    return NULL;
+  }
+  if (growth_limit > capacity) {
+    LOG(ERROR) << "Failed to create alloc space (" << name << ") where the growth limit capacity ("
+        << PrettySize(growth_limit) << ") is larger than the capacity ("
+        << PrettySize(capacity) << ")";
+    return NULL;
+  }
+
+  // Page align growth limit and capacity which will be used to manage mmapped storage
+  growth_limit = RoundUp(growth_limit, kPageSize);
+  capacity = RoundUp(capacity, kPageSize);
+
+  UniquePtr<MemMap> mem_map(MemMap::MapAnonymous(name.c_str(), requested_begin,
+                                                 capacity, PROT_READ | PROT_WRITE));
+  if (mem_map.get() == NULL) {
+    LOG(ERROR) << "Failed to allocate pages for alloc space (" << name << ") of size "
+        << PrettySize(capacity);
+    return NULL;
+  }
+
+  void* mspace = AllocSpace::CreateMallocSpace(mem_map->Begin(), starting_size, initial_size);
+  if (mspace == NULL) {
+    LOG(ERROR) << "Failed to initialize mspace for alloc space (" << name << ")";
+    return NULL;
+  }
+
+  // Protect memory beyond the initial size.
+  byte* end = mem_map->Begin() + starting_size;
+  if (capacity - initial_size > 0) {
+    CHECK_MEMORY_CALL(mprotect, (end, capacity - initial_size, PROT_NONE), name);
+  }
+
+  // Everything is set so record in immutable structure and leave
+  MemMap* mem_map_ptr = mem_map.release();
+  AllocSpace* space = new AllocSpace(name, mem_map_ptr, mspace, mem_map_ptr->Begin(), end,
+                                     growth_limit);
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    LOG(INFO) << "Space::CreateAllocSpace exiting (" << PrettyDuration(NanoTime() - start_time)
+        << " ) " << *space;
+  }
+  return space;
+}
+
+void* AllocSpace::CreateMallocSpace(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 != NULL) {
+    // 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;
+}
+
+void AllocSpace::SwapBitmaps() {
+  SpaceBitmap* temp_live_bitmap = live_bitmap_.release();
+  live_bitmap_.reset(mark_bitmap_.release());
+  mark_bitmap_.reset(temp_live_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);
+}
+
+Object* AllocSpace::AllocWithoutGrowthLocked(size_t num_bytes) {
+  if (kDebugSpaces) {
+    num_bytes += sizeof(word);
+  }
+
+  Object* result = reinterpret_cast<Object*>(mspace_calloc(mspace_, 1, num_bytes));
+  if (kDebugSpaces && result != NULL) {
+    CHECK(Contains(result)) << "Allocation (" << reinterpret_cast<void*>(result)
+        << ") not in bounds of allocation space " << *this;
+    // Put a magic pattern before and after the allocation.
+    *reinterpret_cast<word*>(reinterpret_cast<byte*>(result) + AllocationSize(result)
+        - sizeof(word) - kChunkOverhead) = kPaddingValue;
+  }
+  num_bytes_allocated_ += AllocationSize(result);
+  ++num_objects_allocated_;
+  return result;
+}
+
+Object* AllocSpace::AllocWithoutGrowth(Thread* self, size_t num_bytes) {
+  MutexLock mu(self, lock_);
+  return AllocWithoutGrowthLocked(num_bytes);
+}
+
+Object* AllocSpace::AllocWithGrowth(Thread* self, size_t num_bytes) {
+  MutexLock mu(self, lock_);
+  // Grow as much as possible within the mspace.
+  size_t max_allowed = Capacity();
+  mspace_set_footprint_limit(mspace_, max_allowed);
+  // Try the allocation.
+  void* ptr = AllocWithoutGrowthLocked(num_bytes);
+  // Shrink back down as small as possible.
+  size_t footprint = mspace_footprint(mspace_);
+  mspace_set_footprint_limit(mspace_, footprint);
+  // Return the new allocation or NULL.
+  Object* result = reinterpret_cast<Object*>(ptr);
+  CHECK(!kDebugSpaces || result == NULL || Contains(result));
+  return result;
+}
+
+void AllocSpace::SetGrowthLimit(size_t growth_limit) {
+  growth_limit = RoundUp(growth_limit, kPageSize);
+  growth_limit_ = growth_limit;
+  if (Size() > growth_limit_) {
+    end_ = begin_ + growth_limit;
+  }
+}
+
+AllocSpace* AllocSpace::CreateZygoteSpace() {
+  end_ = reinterpret_cast<byte*>(RoundUp(reinterpret_cast<uintptr_t>(end_), kPageSize));
+  DCHECK(IsAligned<CardTable::kCardSize>(begin_));
+  DCHECK(IsAligned<CardTable::kCardSize>(end_));
+  DCHECK(IsAligned<kPageSize>(begin_));
+  DCHECK(IsAligned<kPageSize>(end_));
+  size_t size = RoundUp(Size(), kPageSize);
+  // Trim the heap so that we minimize the size of the Zygote space.
+  Trim();
+  // Trim our mem-map to free unused pages.
+  GetMemMap()->UnMapAtEnd(end_);
+  // TODO: Not hardcode these in?
+  const size_t starting_size = kPageSize;
+  const size_t initial_size = 2 * MB;
+  // Remaining size is for the new alloc space.
+  const size_t growth_limit = growth_limit_ - size;
+  const size_t capacity = Capacity() - size;
+  VLOG(heap) << "Begin " << reinterpret_cast<const void*>(begin_) << "\n"
+             << "End " << reinterpret_cast<const void*>(end_) << "\n"
+             << "Size " << size << "\n"
+             << "GrowthLimit " << growth_limit_ << "\n"
+             << "Capacity " << Capacity();
+  SetGrowthLimit(RoundUp(size, kPageSize));
+  SetFootprintLimit(RoundUp(size, kPageSize));
+  // FIXME: Do we need reference counted pointers here?
+  // Make the two spaces share the same mark bitmaps since the bitmaps span both of the spaces.
+  VLOG(heap) << "Creating new AllocSpace: ";
+  VLOG(heap) << "Size " << GetMemMap()->Size();
+  VLOG(heap) << "GrowthLimit " << PrettySize(growth_limit);
+  VLOG(heap) << "Capacity " << PrettySize(capacity);
+  UniquePtr<MemMap> mem_map(MemMap::MapAnonymous(GetName().c_str(), End(), capacity, PROT_READ | PROT_WRITE));
+  void* mspace = CreateMallocSpace(end_, starting_size, initial_size);
+  // Protect memory beyond the initial size.
+  byte* end = mem_map->Begin() + starting_size;
+  if (capacity - initial_size > 0) {
+    CHECK_MEMORY_CALL(mprotect, (end, capacity - initial_size, PROT_NONE), name_.c_str());
+  }
+  AllocSpace* alloc_space = new AllocSpace(name_, mem_map.release(), mspace, end_, end, growth_limit);
+  live_bitmap_->SetHeapLimit(reinterpret_cast<uintptr_t>(End()));
+  CHECK_EQ(live_bitmap_->HeapLimit(), reinterpret_cast<uintptr_t>(End()));
+  mark_bitmap_->SetHeapLimit(reinterpret_cast<uintptr_t>(End()));
+  CHECK_EQ(mark_bitmap_->HeapLimit(), reinterpret_cast<uintptr_t>(End()));
+  name_ += "-zygote-transformed";
+  VLOG(heap) << "zygote space creation done";
+  return alloc_space;
+}
+
+void AllocSpace::Free(Thread* self, Object* ptr) {
+  MutexLock mu(self, lock_);
+  if (kDebugSpaces) {
+    CHECK(ptr != NULL);
+    CHECK(Contains(ptr)) << "Free (" << ptr << ") not in bounds of heap " << *this;
+    CHECK_EQ(
+        *reinterpret_cast<word*>(reinterpret_cast<byte*>(ptr) + AllocationSize(ptr) -
+            sizeof(word) - kChunkOverhead), kPaddingValue);
+  }
+  num_bytes_allocated_ -= AllocationSize(ptr);
+  --num_objects_allocated_;
+  mspace_free(mspace_, ptr);
+}
+
+void AllocSpace::FreeList(Thread* self, size_t num_ptrs, Object** ptrs) {
+  MutexLock mu(self, lock_);
+  if (kDebugSpaces) {
+    CHECK(ptrs != NULL);
+    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);
+  }
+  for (size_t i = 0; i < num_ptrs; i++) {
+    num_bytes_allocated_ -= AllocationSize(ptrs[i]);
+  }
+  num_objects_allocated_ -= num_ptrs;
+  mspace_bulk_free(mspace_, reinterpret_cast<void**>(ptrs), num_ptrs);
+}
+
+// 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();
+  DCHECK_EQ(heap->GetAllocSpace()->GetMspace(), mspace);
+  return heap->GetAllocSpace()->MoreCore(increment);
+}
+
+void* AllocSpace::MoreCore(intptr_t increment) {
+  lock_.AssertHeld(Thread::Current());
+  byte* original_end = end_;
+  if (increment != 0) {
+    VLOG(heap) << "AllocSpace::MoreCore " << PrettySize(increment);
+    byte* new_end = original_end + increment;
+    if (increment > 0) {
+#if DEBUG_SPACES
+      // Should never be asked to increase the allocation beyond the capacity of the space. Enforced
+      // by mspace_set_footprint_limit.
+      CHECK_LE(new_end, Begin() + Capacity());
+#endif
+      CHECK_MEMORY_CALL(mprotect, (original_end, increment, PROT_READ | PROT_WRITE), GetName());
+    } else {
+#if DEBUG_SPACES
+      // Should never be asked for negative footprint (ie before begin)
+      CHECK_GT(original_end + increment, Begin());
+#endif
+      // Advise we don't need the pages and protect them
+      // TODO: by removing permissions to the pages we may be causing TLB shoot-down which can be
+      // expensive (note the same isn't true for giving permissions to a page as the protected
+      // page shouldn't be in a TLB). We should investigate performance impact of just
+      // removing ignoring the memory protection change here and in Space::CreateAllocSpace. It's
+      // likely just a useful debug feature.
+      size_t size = -increment;
+      CHECK_MEMORY_CALL(madvise, (new_end, size, MADV_DONTNEED), GetName());
+      CHECK_MEMORY_CALL(mprotect, (new_end, size, PROT_NONE), GetName());
+    }
+    // Update end_
+    end_ = new_end;
+  }
+  return original_end;
+}
+
+size_t AllocSpace::AllocationSize(const Object* obj) {
+  return mspace_usable_size(const_cast<void*>(reinterpret_cast<const void*>(obj))) +
+      kChunkOverhead;
+}
+
+void MspaceMadviseCallback(void* start, void* end, size_t used_bytes, void* /* arg */) {
+  // Is this chunk in use?
+  if (used_bytes != 0) {
+    return;
+  }
+  // Do we have any whole pages to give back?
+  start = reinterpret_cast<void*>(RoundUp(reinterpret_cast<uintptr_t>(start), kPageSize));
+  end = reinterpret_cast<void*>(RoundDown(reinterpret_cast<uintptr_t>(end), kPageSize));
+  if (end > start) {
+    size_t length = reinterpret_cast<byte*>(end) - reinterpret_cast<byte*>(start);
+    CHECK_MEMORY_CALL(madvise, (start, length, MADV_DONTNEED), "trim");
+  }
+}
+
+void AllocSpace::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.
+  mspace_inspect_all(mspace_, MspaceMadviseCallback, NULL);
+}
+
+void AllocSpace::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 AllocSpace::GetFootprintLimit() {
+  MutexLock mu(Thread::Current(), lock_);
+  return mspace_footprint_limit(mspace_);
+}
+
+void AllocSpace::SetFootprintLimit(size_t new_size) {
+  MutexLock mu(Thread::Current(), lock_);
+  VLOG(heap) << "AllocSpace::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);
+}
+
+size_t ImageSpace::bitmap_index_ = 0;
+
+ImageSpace::ImageSpace(const std::string& name, MemMap* mem_map)
+    : MemMapSpace(name, mem_map, mem_map->Size(), kGcRetentionPolicyNeverCollect) {
+  const size_t bitmap_index = bitmap_index_++;
+  live_bitmap_.reset(SpaceBitmap::Create(
+      StringPrintf("imagespace-%s-live-bitmap-%d", name.c_str(), static_cast<int>(bitmap_index)),
+      Begin(), Capacity()));
+  DCHECK(live_bitmap_.get() != NULL) << "could not create imagespace live bitmap #" << bitmap_index;
+}
+
+ImageSpace* ImageSpace::Create(const std::string& image_file_name) {
+  CHECK(!image_file_name.empty());
+
+  uint64_t start_time = 0;
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    start_time = NanoTime();
+    LOG(INFO) << "Space::CreateImageSpace entering" << " image_file_name=" << image_file_name;
+  }
+
+  UniquePtr<File> file(OS::OpenFile(image_file_name.c_str(), false));
+  if (file.get() == NULL) {
+    LOG(ERROR) << "Failed to open " << image_file_name;
+    return NULL;
+  }
+  ImageHeader image_header;
+  bool success = file->ReadFully(&image_header, sizeof(image_header));
+  if (!success || !image_header.IsValid()) {
+    LOG(ERROR) << "Invalid image header " << image_file_name;
+    return NULL;
+  }
+  UniquePtr<MemMap> map(MemMap::MapFileAtAddress(image_header.GetImageBegin(),
+                                                 file->Length(),
+                                                 // TODO: selectively PROT_EXEC stubs
+                                                 PROT_READ | PROT_WRITE | PROT_EXEC,
+                                                 MAP_PRIVATE | MAP_FIXED,
+                                                 file->Fd(),
+                                                 0));
+  if (map.get() == NULL) {
+    LOG(ERROR) << "Failed to map " << image_file_name;
+    return NULL;
+  }
+  CHECK_EQ(image_header.GetImageBegin(), map->Begin());
+  DCHECK_EQ(0, memcmp(&image_header, map->Begin(), sizeof(ImageHeader)));
+
+  Runtime* runtime = Runtime::Current();
+  Object* jni_stub_array = image_header.GetImageRoot(ImageHeader::kJniStubArray);
+  runtime->SetJniDlsymLookupStub(down_cast<ByteArray*>(jni_stub_array));
+
+  Object* ame_stub_array = image_header.GetImageRoot(ImageHeader::kAbstractMethodErrorStubArray);
+  runtime->SetAbstractMethodErrorStubArray(down_cast<ByteArray*>(ame_stub_array));
+
+  Object* resolution_stub_array =
+      image_header.GetImageRoot(ImageHeader::kStaticResolutionStubArray);
+  runtime->SetResolutionStubArray(
+      down_cast<ByteArray*>(resolution_stub_array), Runtime::kStaticMethod);
+  resolution_stub_array = image_header.GetImageRoot(ImageHeader::kUnknownMethodResolutionStubArray);
+  runtime->SetResolutionStubArray(
+      down_cast<ByteArray*>(resolution_stub_array), Runtime::kUnknownMethod);
+
+  Object* resolution_method = image_header.GetImageRoot(ImageHeader::kResolutionMethod);
+  runtime->SetResolutionMethod(down_cast<AbstractMethod*>(resolution_method));
+
+  Object* callee_save_method = image_header.GetImageRoot(ImageHeader::kCalleeSaveMethod);
+  runtime->SetCalleeSaveMethod(down_cast<AbstractMethod*>(callee_save_method), Runtime::kSaveAll);
+  callee_save_method = image_header.GetImageRoot(ImageHeader::kRefsOnlySaveMethod);
+  runtime->SetCalleeSaveMethod(down_cast<AbstractMethod*>(callee_save_method), Runtime::kRefsOnly);
+  callee_save_method = image_header.GetImageRoot(ImageHeader::kRefsAndArgsSaveMethod);
+  runtime->SetCalleeSaveMethod(down_cast<AbstractMethod*>(callee_save_method), Runtime::kRefsAndArgs);
+
+  ImageSpace* space = new ImageSpace(image_file_name, map.release());
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    LOG(INFO) << "Space::CreateImageSpace exiting (" << PrettyDuration(NanoTime() - start_time)
+        << ") " << *space;
+  }
+  return space;
+}
+
+void ImageSpace::RecordImageAllocations(SpaceBitmap* live_bitmap) const {
+  uint64_t start_time = 0;
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    LOG(INFO) << "ImageSpace::RecordImageAllocations entering";
+    start_time = NanoTime();
+  }
+  DCHECK(!Runtime::Current()->IsStarted());
+  CHECK(live_bitmap != NULL);
+  byte* current = Begin() + RoundUp(sizeof(ImageHeader), kObjectAlignment);
+  byte* end = End();
+  while (current < end) {
+    DCHECK_ALIGNED(current, kObjectAlignment);
+    const Object* obj = reinterpret_cast<const Object*>(current);
+    live_bitmap->Set(obj);
+    current += RoundUp(obj->SizeOf(), kObjectAlignment);
+  }
+  if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
+    LOG(INFO) << "ImageSpace::RecordImageAllocations exiting ("
+        << PrettyDuration(NanoTime() - start_time) << ")";
+  }
+}
+
+std::ostream& operator<<(std::ostream& os, const Space& space) {
+  space.Dump(os);
+  return os;
+}
+
+void AllocSpace::Dump(std::ostream& os) const {
+  os << GetType()
+      << "begin=" << reinterpret_cast<void*>(Begin())
+      << ",end=" << reinterpret_cast<void*>(End())
+      << ",size=" << PrettySize(Size()) << ",capacity=" << PrettySize(Capacity())
+      << ",name=\"" << GetName() << "\"]";
+}
+
+void ImageSpace::Dump(std::ostream& os) const {
+  os << GetType()
+      << "begin=" << reinterpret_cast<void*>(Begin())
+      << ",end=" << reinterpret_cast<void*>(End())
+      << ",size=" << PrettySize(Size())
+      << ",name=\"" << GetName() << "\"]";
+}
+
+void LargeObjectSpace::SwapBitmaps() {
+  SpaceSetMap* temp_live_objects = live_objects_.release();
+  live_objects_.reset(mark_objects_.release());
+  mark_objects_.reset(temp_live_objects);
+  // Swap names to get more descriptive diagnostics.
+  std::string temp_name = live_objects_->GetName();
+  live_objects_->SetName(mark_objects_->GetName());
+  mark_objects_->SetName(temp_name);
+}
+
+DiscontinuousSpace::DiscontinuousSpace(const std::string& name,
+                                       GcRetentionPolicy gc_retention_policy)
+    : Space(name, gc_retention_policy) {
+
+}
+
+LargeObjectSpace::LargeObjectSpace(const std::string& name)
+    : DiscontinuousSpace(name, kGcRetentionPolicyAlwaysCollect),
+      num_bytes_allocated_(0),
+      num_objects_allocated_(0) {
+  live_objects_.reset(new SpaceSetMap("large live objects"));
+  mark_objects_.reset(new SpaceSetMap("large marked objects"));
+}
+
+
+void LargeObjectSpace::CopyLiveToMarked() {
+  mark_objects_->CopyFrom(*live_objects_.get());
+}
+
+LargeObjectMapSpace::LargeObjectMapSpace(const std::string& name)
+    : LargeObjectSpace(name),
+      lock_("large object space lock", kAllocSpaceLock)
+{
+
+}
+
+LargeObjectMapSpace* LargeObjectMapSpace::Create(const std::string& name) {
+  return new LargeObjectMapSpace(name);
+}
+
+Object* LargeObjectMapSpace::Alloc(Thread* self, size_t num_bytes) {
+  MemMap* mem_map = MemMap::MapAnonymous("allocation", NULL, num_bytes, PROT_READ | PROT_WRITE);
+  if (mem_map == NULL) {
+    return NULL;
+  }
+  MutexLock mu(self, lock_);
+  Object* obj = reinterpret_cast<Object*>(mem_map->Begin());
+  large_objects_.push_back(obj);
+  mem_maps_.Put(obj, mem_map);
+  num_bytes_allocated_ += mem_map->Size();
+  ++num_objects_allocated_;
+  return obj;
+}
+
+void LargeObjectMapSpace::Free(Thread* self, Object* ptr) {
+  MutexLock mu(self, lock_);
+  MemMaps::iterator found = mem_maps_.find(ptr);
+  CHECK(found != mem_maps_.end()) << "Attempted to free large object which was not live";
+  DCHECK_GE(num_bytes_allocated_, found->second->Size());
+  num_bytes_allocated_ -= found->second->Size();
+  --num_objects_allocated_;
+  delete found->second;
+  mem_maps_.erase(found);
+}
+
+size_t LargeObjectMapSpace::AllocationSize(const Object* obj) {
+  MutexLock mu(Thread::Current(), lock_);
+  MemMaps::iterator found = mem_maps_.find(const_cast<Object*>(obj));
+  CHECK(found != mem_maps_.end()) << "Attempted to get size of a large object which is not live";
+  return found->second->Size();
+}
+
+void LargeObjectMapSpace::Walk(AllocSpace::WalkCallback callback, void* arg) {
+  MutexLock mu(Thread::Current(), lock_);
+  for (MemMaps::iterator it = mem_maps_.begin(); it != mem_maps_.end(); ++it) {
+    MemMap* mem_map = it->second;
+    callback(mem_map->Begin(), mem_map->End(), mem_map->Size(), arg);
+    callback(NULL, NULL, 0, arg);
+  }
+}
+
+bool LargeObjectMapSpace::Contains(const Object* obj) const {
+  MutexLock mu(Thread::Current(), lock_);
+  return mem_maps_.find(const_cast<Object*>(obj)) != mem_maps_.end();
+}
+
+FreeListSpace* FreeListSpace::Create(const std::string& name, byte* requested_begin, size_t size) {
+  CHECK(size % kAlignment == 0);
+  MemMap* mem_map = MemMap::MapAnonymous(name.c_str(), requested_begin, size,
+                                         PROT_READ | PROT_WRITE);
+  CHECK(mem_map != NULL) << "Failed to allocate large object space mem map";
+  return new FreeListSpace(name, mem_map, mem_map->Begin(), mem_map->End());
+}
+
+FreeListSpace::FreeListSpace(const std::string& name, MemMap* mem_map, byte* begin, byte* end)
+    : LargeObjectSpace(name),
+      begin_(begin),
+      end_(end),
+      mem_map_(mem_map),
+      lock_("free list space lock", kAllocSpaceLock) {
+  chunks_.resize(Size() / kAlignment + 1);
+  // Add a dummy chunk so we don't need to handle chunks having no next chunk.
+  chunks_.back().SetSize(kAlignment, false);
+  // Start out with one large free chunk.
+  AddFreeChunk(begin_, end_ - begin_, NULL);
+}
+
+FreeListSpace::~FreeListSpace() {
+
+}
+
+void FreeListSpace::AddFreeChunk(void* address, size_t size, Chunk* previous) {
+  Chunk* chunk = ChunkFromAddr(address);
+  chunk->SetSize(size, true);
+  chunk->SetPrevious(previous);
+  Chunk* next_chunk = GetNextChunk(chunk);
+  next_chunk->SetPrevious(chunk);
+  free_chunks_.insert(chunk);
+}
+
+FreeListSpace::Chunk* FreeListSpace::ChunkFromAddr(void* address) {
+  size_t offset = reinterpret_cast<byte*>(address) - Begin();
+  DCHECK(IsAligned<kAlignment>(offset));
+  DCHECK_LT(offset, Size());
+  return &chunks_[offset / kAlignment];
+}
+
+void* FreeListSpace::AddrFromChunk(Chunk* chunk) {
+  return reinterpret_cast<void*>(Begin() + (chunk - &chunks_.front()) * kAlignment);
+}
+
+void FreeListSpace::RemoveFreeChunk(Chunk* chunk) {
+  // TODO: C++0x
+  // TODO: Improve performance, this might be slow.
+  std::pair<FreeChunks::iterator, FreeChunks::iterator> range = free_chunks_.equal_range(chunk);
+  for (FreeChunks::iterator it = range.first; it != range.second; ++it) {
+    if (*it == chunk) {
+      free_chunks_.erase(it);
+      return;
+    }
+  }
+}
+
+void FreeListSpace::Walk(AllocSpace::WalkCallback callback, void* arg) {
+  MutexLock mu(Thread::Current(), lock_);
+  for (Chunk* chunk = &chunks_.front(); chunk < &chunks_.back(); ) {
+    if (!chunk->IsFree()) {
+      size_t size = chunk->GetSize();
+      void* begin = AddrFromChunk(chunk);
+      void* end = reinterpret_cast<void*>(reinterpret_cast<byte*>(begin) + size);
+      callback(begin, end, size, arg);
+      callback(NULL, NULL, 0, arg);
+    }
+    chunk = GetNextChunk(chunk);
+  }
+}
+
+void FreeListSpace::Free(Thread* self, Object* obj) {
+  MutexLock mu(self, lock_);
+  CHECK(Contains(obj));
+  // Check adjacent chunks to see if we need to combine.
+  Chunk* chunk = ChunkFromAddr(obj);
+  CHECK(!chunk->IsFree());
+
+  size_t allocation_size = chunk->GetSize();
+  madvise(obj, allocation_size, MADV_DONTNEED);
+  num_objects_allocated_--;
+  num_bytes_allocated_ -= allocation_size;
+  Chunk* prev = chunk->GetPrevious();
+  Chunk* next = GetNextChunk(chunk);
+
+  // Combine any adjacent free chunks
+  size_t extra_size = chunk->GetSize();
+  if (next->IsFree()) {
+    extra_size += next->GetSize();
+    RemoveFreeChunk(next);
+  }
+  if (prev != NULL && prev->IsFree()) {
+    RemoveFreeChunk(prev);
+    AddFreeChunk(AddrFromChunk(prev), prev->GetSize() + extra_size, prev->GetPrevious());
+  } else {
+    AddFreeChunk(AddrFromChunk(chunk), extra_size, prev);
+  }
+}
+
+bool FreeListSpace::Contains(const Object* obj) const {
+  return mem_map_->HasAddress(obj);
+}
+
+FreeListSpace::Chunk* FreeListSpace::GetNextChunk(Chunk* chunk) {
+  return chunk + chunk->GetSize() / kAlignment;
+}
+
+size_t FreeListSpace::AllocationSize(const Object* obj) {
+  Chunk* chunk = ChunkFromAddr(const_cast<Object*>(obj));
+  CHECK(!chunk->IsFree());
+  return chunk->GetSize();
+}
+
+Object* FreeListSpace::Alloc(Thread* self, size_t num_bytes) {
+  MutexLock mu(self, lock_);
+  num_bytes = RoundUp(num_bytes, kAlignment);
+  Chunk temp;
+  temp.SetSize(num_bytes);
+  // Find the smallest chunk at least num_bytes in size.
+  FreeChunks::iterator found = free_chunks_.lower_bound(&temp);
+  if (found == free_chunks_.end()) {
+    // Out of memory, or too much fragmentation.
+    return NULL;
+  }
+  Chunk* chunk = *found;
+  free_chunks_.erase(found);
+  CHECK(chunk->IsFree());
+  void* addr = AddrFromChunk(chunk);
+  size_t chunk_size = chunk->GetSize();
+  chunk->SetSize(num_bytes);
+  if (chunk_size > num_bytes) {
+    // Split the chunk into two chunks.
+    Chunk* new_chunk = GetNextChunk(chunk);
+    AddFreeChunk(AddrFromChunk(new_chunk), chunk_size - num_bytes, chunk);
+  }
+
+  num_objects_allocated_++;
+  num_bytes_allocated_ += num_bytes;
+  return reinterpret_cast<Object*>(addr);
+}
+
+void FreeListSpace::FreeList(Thread* self, size_t num_ptrs, Object** ptrs) {
+  for (size_t i = 0; i < num_ptrs; ++i) {
+    Free(self, ptrs[i]);
+  }
+}
+
+}  // namespace art