You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
87 lines
2.3 KiB
87 lines
2.3 KiB
/*
|
|
* Copyright (C) 2014 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_COLLECTOR_IMMUNE_REGION_H_
|
|
#define ART_RUNTIME_GC_COLLECTOR_IMMUNE_REGION_H_
|
|
|
|
#include "base/macros.h"
|
|
|
|
namespace art {
|
|
namespace mirror {
|
|
class Object;
|
|
} // namespace mirror
|
|
namespace gc {
|
|
namespace space {
|
|
class ContinuousSpace;
|
|
} // namespace space
|
|
|
|
namespace collector {
|
|
|
|
// An immune region is a continuous region of memory for which all objects contained are assumed to
|
|
// be marked. This is used as an optimization in the GC to avoid needing to test the mark bitmap of
|
|
// the zygote, image spaces, and sometimes non moving spaces. Doing the ContainsObject check is
|
|
// faster than doing a bitmap read. There is no support for discontinuous spaces and you need to be
|
|
// careful that your immune region doesn't contain any large objects.
|
|
class ImmuneRegion {
|
|
public:
|
|
ImmuneRegion();
|
|
|
|
void Reset();
|
|
|
|
// Returns true if an object is inside of the immune region (assumed to be marked).
|
|
ALWAYS_INLINE bool ContainsObject(const mirror::Object* obj) const {
|
|
// Note: Relies on integer underflow behavior.
|
|
return reinterpret_cast<uintptr_t>(obj) - reinterpret_cast<uintptr_t>(begin_) < size_;
|
|
}
|
|
|
|
void SetBegin(mirror::Object* begin) {
|
|
begin_ = begin;
|
|
UpdateSize();
|
|
}
|
|
|
|
void SetEnd(mirror::Object* end) {
|
|
end_ = end;
|
|
UpdateSize();
|
|
}
|
|
|
|
mirror::Object* Begin() const {
|
|
return begin_;
|
|
}
|
|
|
|
mirror::Object* End() const {
|
|
return end_;
|
|
}
|
|
|
|
size_t Size() const {
|
|
return size_;
|
|
}
|
|
|
|
private:
|
|
void UpdateSize() {
|
|
size_ = reinterpret_cast<uintptr_t>(end_) - reinterpret_cast<uintptr_t>(begin_);
|
|
}
|
|
|
|
mirror::Object* begin_;
|
|
mirror::Object* end_;
|
|
uintptr_t size_;
|
|
};
|
|
|
|
} // namespace collector
|
|
} // namespace gc
|
|
} // namespace art
|
|
|
|
#endif // ART_RUNTIME_GC_COLLECTOR_IMMUNE_REGION_H_
|