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/*
* Copyright (C) 2008 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_SPACE_BITMAP_INL_H_
#define ART_SRC_GC_ACCOUNTING_SPACE_BITMAP_INL_H_
#include "base/logging.h"
#include "cutils/atomic-inline.h"
#include "utils.h"
namespace art {
namespace gc {
namespace accounting {
inline bool SpaceBitmap::AtomicTestAndSet(const mirror::Object* obj) {
uintptr_t addr = reinterpret_cast<uintptr_t>(obj);
DCHECK_GE(addr, heap_begin_);
const uintptr_t offset = addr - heap_begin_;
const size_t index = OffsetToIndex(offset);
const word mask = OffsetToMask(offset);
word* const address = &bitmap_begin_[index];
DCHECK_LT(index, bitmap_size_ / kWordSize) << " bitmap_size_ = " << bitmap_size_;
word old_word;
do {
old_word = *address;
// Fast path: The bit is already set.
if ((old_word & mask) != 0) {
return true;
}
} while (UNLIKELY(android_atomic_cas(old_word, old_word | mask, address) != 0));
return false;
}
inline bool SpaceBitmap::Test(const mirror::Object* obj) const {
uintptr_t addr = reinterpret_cast<uintptr_t>(obj);
DCHECK(HasAddress(obj)) << obj;
DCHECK(bitmap_begin_ != NULL);
DCHECK_GE(addr, heap_begin_);
const uintptr_t offset = addr - heap_begin_;
return (bitmap_begin_[OffsetToIndex(offset)] & OffsetToMask(offset)) != 0;
}
template <typename Visitor, typename FingerVisitor>
void SpaceBitmap::VisitMarkedRange(uintptr_t visit_begin, uintptr_t visit_end,
const Visitor& visitor,
const FingerVisitor& finger_visitor) const {
DCHECK_LT(visit_begin, visit_end);
const size_t word_span = kAlignment * kBitsPerWord; // Equals IndexToOffset(1).
const size_t bit_index_start = (visit_begin - heap_begin_) / kAlignment;
const size_t bit_index_end = (visit_end - heap_begin_ - 1) / kAlignment;
size_t word_start = bit_index_start / kBitsPerWord;
size_t word_end = bit_index_end / kBitsPerWord;
DCHECK_LT(word_end * kWordSize, Size());
// Trim off left_bits of left bits.
size_t edge_word = bitmap_begin_[word_start];
// Handle bits on the left first as a special case
size_t left_bits = bit_index_start & (kBitsPerWord - 1);
if (left_bits != 0) {
edge_word &= (1 << (kBitsPerWord - left_bits)) - 1;
}
// If word_start == word_end then handle this case at the same place we handle the right edge.
if (edge_word != 0 && word_start < word_end) {
uintptr_t ptr_base = IndexToOffset(word_start) + heap_begin_;
finger_visitor(reinterpret_cast<void*>(ptr_base + word_span));
do {
const size_t shift = CLZ(edge_word);
mirror::Object* obj = reinterpret_cast<mirror::Object*>(ptr_base + shift * kAlignment);
visitor(obj);
edge_word ^= static_cast<size_t>(kWordHighBitMask) >> shift;
} while (edge_word != 0);
}
word_start++;
for (size_t i = word_start; i < word_end; i++) {
size_t w = bitmap_begin_[i];
if (w != 0) {
uintptr_t ptr_base = IndexToOffset(i) + heap_begin_;
finger_visitor(reinterpret_cast<void*>(ptr_base + word_span));
do {
const size_t shift = CLZ(w);
mirror::Object* obj = reinterpret_cast<mirror::Object*>(ptr_base + shift * kAlignment);
visitor(obj);
w ^= static_cast<size_t>(kWordHighBitMask) >> shift;
} while (w != 0);
}
}
// Handle the right edge, and also the left edge if both edges are on the same word.
size_t right_bits = bit_index_end & (kBitsPerWord - 1);
// If word_start == word_end then we need to use the word which we removed the left bits.
if (word_start <= word_end) {
edge_word = bitmap_begin_[word_end];
}
// Bits that we trim off the right.
edge_word &= ~((static_cast<size_t>(kWordHighBitMask) >> right_bits) - 1);
uintptr_t ptr_base = IndexToOffset(word_end) + heap_begin_;
finger_visitor(reinterpret_cast<void*>(ptr_base + word_span));
while (edge_word != 0) {
const size_t shift = CLZ(edge_word);
mirror::Object* obj = reinterpret_cast<mirror::Object*>(ptr_base + shift * kAlignment);
visitor(obj);
edge_word ^= static_cast<size_t>(kWordHighBitMask) >> shift;
}
}
inline bool SpaceBitmap::Modify(const mirror::Object* obj, bool do_set) {
uintptr_t addr = reinterpret_cast<uintptr_t>(obj);
DCHECK_GE(addr, heap_begin_);
const uintptr_t offset = addr - heap_begin_;
const size_t index = OffsetToIndex(offset);
const word mask = OffsetToMask(offset);
DCHECK_LT(index, bitmap_size_ / kWordSize) << " bitmap_size_ = " << bitmap_size_;
word* address = &bitmap_begin_[index];
word old_word = *address;
if (do_set) {
*address = old_word | mask;
} else {
*address = old_word & ~mask;
}
return (old_word & mask) != 0;
}
} // namespace accounting
} // namespace gc
} // namespace art
#endif // ART_SRC_GC_ACCOUNTING_SPACE_BITMAP_INL_H_
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