GC clean up.
Greater use of directories and namespaces.
Fix bugs that cause verify options to fail.
Address numerous other issues:
GC barrier wait occurring holding locks:
GC barrier waits occur when we wait for threads to run the check point function
on themselves. This is happening with the heap bitmap and mutator lock held
meaning that a thread that tries to take either lock exclusively will block
waiting on a thread that is waiting. If this thread is the thread we're waiting
to run the check point then the VM will deadlock.
This deadlock occurred unnoticed as the call to check for wait safety was
removed in: https://googleplex-android-review.googlesource.com/#/c/249423/1.
NewTimingLogger:
Existing timing log states when a split ends but not when it begins. This isn't
good for systrace, in the context of GC it means that races between mutators
and the GC are hard to discover what phase the GC is in, we know what phase it
just finished and derive but that's not ideal.
Support for only 1 discontinuous space:
Code special cases continuous and large object space, rather than assuming we
can have a collection of both.
Sorted atomic stacks:
Used to improve verification performance. Simplify their use and add extra
checks.
Simplify mod-union table abstractions.
Reduce use of std::strings and their associated overhead in hot code.
Make time units of fields explicit.
Reduce confusion that IsAllocSpace is really IsDlMallocSpace.
Make GetTotalMemory (exposed via System) equal to the footprint (as in Dalvik)
rather than the max memory footprint.
Change-Id: Ie87067140fa4499b15edab691fe6565d79599812
diff --git a/src/gc/accounting/heap_bitmap.h b/src/gc/accounting/heap_bitmap.h
new file mode 100644
index 0000000..5ff40c6
--- /dev/null
+++ b/src/gc/accounting/heap_bitmap.h
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2012 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_SRC_GC_ACCOUNTING_HEAP_BITMAP_H_
+#define ART_SRC_GC_ACCOUNTING_HEAP_BITMAP_H_
+
+#include "base/logging.h"
+#include "locks.h"
+#include "space_bitmap.h"
+
+namespace art {
+namespace gc {
+
+class Heap;
+
+namespace accounting {
+
+class HeapBitmap {
+ public:
+ bool Test(const mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
+ SpaceBitmap* bitmap = GetContinuousSpaceBitmap(obj);
+ if (LIKELY(bitmap != NULL)) {
+ return bitmap->Test(obj);
+ } else {
+ return GetDiscontinuousSpaceObjectSet(obj) != NULL;
+ }
+ }
+
+ void Clear(const mirror::Object* obj) EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
+ SpaceBitmap* bitmap = GetContinuousSpaceBitmap(obj);
+ if (LIKELY(bitmap != NULL)) {
+ bitmap->Clear(obj);
+ } else {
+ SpaceSetMap* set = GetDiscontinuousSpaceObjectSet(obj);
+ DCHECK(set != NULL);
+ set->Clear(obj);
+ }
+ }
+
+ void Set(const mirror::Object* obj) EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
+ SpaceBitmap* bitmap = GetContinuousSpaceBitmap(obj);
+ if (LIKELY(bitmap != NULL)) {
+ bitmap->Set(obj);
+ } else {
+ SpaceSetMap* set = GetDiscontinuousSpaceObjectSet(obj);
+ DCHECK(set != NULL);
+ set->Set(obj);
+ }
+ }
+
+ SpaceBitmap* GetContinuousSpaceBitmap(const mirror::Object* obj) {
+ // TODO: C++0x auto
+ typedef std::vector<SpaceBitmap*>::iterator It;
+ for (It it = continuous_space_bitmaps_.begin(), end = continuous_space_bitmaps_.end();
+ it != end; ++it) {
+ SpaceBitmap* bitmap = *it;
+ if (bitmap->HasAddress(obj)) {
+ return bitmap;
+ }
+ }
+ return NULL;
+ }
+
+ SpaceSetMap* GetDiscontinuousSpaceObjectSet(const mirror::Object* obj) {
+ // TODO: C++0x auto
+ typedef std::vector<SpaceSetMap*>::iterator It;
+ for (It it = discontinuous_space_sets_.begin(), end = discontinuous_space_sets_.end();
+ it != end; ++it) {
+ SpaceSetMap* set = *it;
+ if (set->Test(obj)) {
+ return set;
+ }
+ }
+ return NULL;
+ }
+
+ void Walk(SpaceBitmap::Callback* callback, void* arg)
+ SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);
+
+ template <typename Visitor>
+ void Visit(const Visitor& visitor)
+ EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ // Find and replace a bitmap pointer, this is used by for the bitmap swapping in the GC.
+ void ReplaceBitmap(SpaceBitmap* old_bitmap, SpaceBitmap* new_bitmap)
+ EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);
+
+ // Find and replace a object set pointer, this is used by for the bitmap swapping in the GC.
+ void ReplaceObjectSet(SpaceSetMap* old_set, SpaceSetMap* new_set)
+ EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);
+
+ HeapBitmap(Heap* heap) : heap_(heap) {
+ }
+
+ private:
+
+ const Heap* const heap_;
+
+ void AddContinuousSpaceBitmap(SpaceBitmap* bitmap);
+ void AddDiscontinuousObjectSet(SpaceSetMap* set);
+
+ // Bitmaps covering continuous spaces.
+ std::vector<SpaceBitmap*> continuous_space_bitmaps_;
+
+ // Sets covering discontinuous spaces.
+ std::vector<SpaceSetMap*> discontinuous_space_sets_;
+
+ friend class art::gc::Heap;
+};
+
+} // namespace accounting
+} // namespace gc
+} // namespace art
+
+#endif // ART_SRC_GC_ACCOUNTING_HEAP_BITMAP_H_