--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/commitMask.hpp Tue Sep 10 09:24:05 2019 +0200
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2019, SAP SE. All rights reserved.
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_COMMITMASK_HPP
+#define SHARE_MEMORY_METASPACE_COMMITMASK_HPP
+
+#include "utilities/debug.hpp"
+#include "utilities/bitMap.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+
+namespace metaspace {
+
+// A bitmap covering a range of metaspace; each bit in this mask corresponds to
+//
+class CommitMask : public CHeapBitMap {
+
+ const MetaWord* const _base;
+ const size_t _word_size;
+ const size_t _words_per_bit;
+
+ // Given an offset, in words, into the area, return the number of the bit
+ // covering it.
+ static idx_t bitno_for_word_offset(size_t offset, size_t words_per_bit) {
+ return offset / words_per_bit;
+ }
+
+ idx_t bitno_for_address(const MetaWord* p) const {
+ // Note: we allow one-beyond since this is a typical need.
+ assert(p >= _base && p <= _base + _word_size, "Invalid address");
+ const size_t off = p - _base;
+ return bitno_for_word_offset(off, _words_per_bit);
+ }
+
+ static idx_t mask_size(size_t word_size, size_t words_per_bit) {
+ return bitno_for_word_offset(word_size, words_per_bit);
+ }
+
+ struct BitCounterClosure : public BitMapClosure {
+ idx_t cnt;
+ bool do_bit(BitMap::idx_t offset) { cnt ++; return true; }
+ };
+
+ // Missing from BitMap.
+ // Count 1 bits in range [start, end).
+ idx_t count_one_bits_in_range(idx_t start, idx_t end) const {
+ assert(start < end, "Zero range");
+ // TODO: This can be done more efficiently.
+ BitCounterClosure bcc;
+ bcc.cnt = 0;
+ iterate(&bcc, start, end);
+ return bcc.cnt;
+ }
+
+#ifdef ASSERT
+ // Given a pointer, check if it points into the range this bitmap covers.
+ bool is_pointer_valid(const MetaWord* p) const {
+ return p >= _base && p < _base + _word_size;
+ }
+
+ // Given a pointer, check if it points into the range this bitmap covers.
+ void check_pointer(const MetaWord* p) const {
+ assert(is_pointer_valid(p),
+ "Pointer " PTR_FORMAT " not in range of this bitmap [" PTR_FORMAT ", " PTR_FORMAT ").",
+ p2i(p), p2i(_base), p2i(_base + _word_size));
+ }
+ // Given a pointer, check if it points into the range this bitmap covers,
+ // and if it is aligned to commit granule border.
+ void check_pointer_aligned(const MetaWord* p) const {
+ check_pointer(p);
+ assert(is_aligned(p, _words_per_bit * BytesPerWord),
+ "Pointer " PTR_FORMAT " should be aligned to commit granule size " SIZE_FORMAT ".",
+ p2i(p), _words_per_bit * BytesPerWord);
+ }
+ // Given a range, check if it points into the range this bitmap covers,
+ // and if its borders are aligned to commit granule border.
+ void check_range(const MetaWord* start, size_t word_size) const {
+ check_pointer_aligned(start);
+ assert(is_aligned(word_size, _words_per_bit),
+ "Range " SIZE_FORMAT " should be aligned to commit granule size " SIZE_FORMAT ".",
+ word_size, _words_per_bit);
+ check_pointer(start + word_size - 1);
+ }
+#endif
+
+ // Marks a single commit granule as committed (value == true)
+ // or uncomitted (value == false) and returns
+ // its prior state.
+ bool mark_granule(idx_t bitno, bool value) {
+ bool b = at(bitno);
+ at_put(bitno, value);
+ return b;
+ }
+
+public:
+
+ CommitMask(const MetaWord* start, size_t word_size);
+
+ const MetaWord* base() const { return _base; }
+ size_t word_size() const { return _word_size; }
+ const MetaWord* end() const { return _base + word_size(); }
+
+ // Given an address, returns true if the address is committed, false if not.
+ bool is_committed_address(const MetaWord* p) const {
+ DEBUG_ONLY(check_pointer(p));
+ const idx_t bitno = bitno_for_address(p);
+ return at(bitno);
+ }
+
+ // Given an address range [start..end), returns true if area is fully committed through.
+ bool is_fully_committed_range(const MetaWord* start, size_t word_size) const {
+ DEBUG_ONLY(check_range(start, word_size));
+ assert(word_size > 0, "zero range");
+ const idx_t b1 = bitno_for_address(start);
+ const idx_t b2 = bitno_for_address(start + word_size);
+ return get_next_zero_offset(b1, b2) == b2;
+ }
+
+ // Given an address range, return size, in number of words, of committed area within that range.
+ size_t get_committed_size_in_range(const MetaWord* start, size_t word_size) const {
+ DEBUG_ONLY(check_range(start, word_size));
+ assert(word_size > 0, "zero range");
+ const idx_t b1 = bitno_for_address(start);
+ const idx_t b2 = bitno_for_address(start + word_size);
+ const idx_t num_bits = count_one_bits_in_range(b1, b2);
+ return num_bits * _words_per_bit;
+ }
+
+ // Return total committed size, in number of words.
+ size_t get_committed_size() const {
+ return count_one_bits() * _words_per_bit;
+ }
+
+ // Mark a whole address range [start, end) as committed.
+ // Return the number of words which had already been committed before this operation.
+ size_t mark_range_as_committed(const MetaWord* start, size_t word_size) {
+ DEBUG_ONLY(check_range(start, word_size));
+ assert(word_size > 0, "zero range");
+ const idx_t b1 = bitno_for_address(start);
+ const idx_t b2 = bitno_for_address(start + word_size);
+ if (b1 == b2) { // Simple case, 1 granule
+ bool was_committed = mark_granule(b1, true);
+ return was_committed ? _words_per_bit : 0;
+ }
+ const idx_t one_bits_in_range_before = count_one_bits_in_range(b1, b2);
+ set_range(b1, b2);
+ return one_bits_in_range_before * _words_per_bit;
+ }
+
+ // Mark a whole address range [start, end) as uncommitted.
+ // Return the number of words which had already been uncommitted before this operation.
+ size_t mark_range_as_uncommitted(const MetaWord* start, size_t word_size) {
+ DEBUG_ONLY(check_range(start, word_size));
+ assert(word_size > 0, "zero range");
+ const idx_t b1 = bitno_for_address(start);
+ const idx_t b2 = bitno_for_address(start + word_size);
+ if (b1 == b2) { // Simple case, 1 granule
+ bool was_committed = mark_granule(b1, false);
+ return was_committed ? 0 : _words_per_bit;
+ }
+ const idx_t zero_bits_in_range_before =
+ (b2 - b1) - count_one_bits_in_range(b1, b2);
+ clear_range(b1, b2);
+ return zero_bits_in_range_before * _words_per_bit;
+ }
+
+
+ //// Debug stuff ////
+ DEBUG_ONLY(void verify(bool slow, bool do_touch_test = true) const;)
+
+ void print_on(outputStream* st) const;
+
+};
+
+} // namespace metaspace
+
+#endif // SHARE_MEMORY_METASPACE_COMMITMASK_HPP