/* * Copyright (c) 2001, 2018, 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_VM_GC_SHARED_BARRIERSET_INLINE_HPP #define SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP #include "gc/shared/barrierSet.hpp" #include "utilities/align.hpp" // count is number of array elements being written void BarrierSet::write_ref_array(HeapWord* start, size_t count) { assert(count <= (size_t)max_intx, "count too large"); HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize)); // In the case of compressed oops, start and end may potentially be misaligned; // so we need to conservatively align the first downward (this is not // strictly necessary for current uses, but a case of good hygiene and, // if you will, aesthetics) and the second upward (this is essential for // current uses) to a HeapWord boundary, so we mark all cards overlapping // this write. If this evolves in the future to calling a // logging barrier of narrow oop granularity, like the pre-barrier for G1 // (mentioned here merely by way of example), we will need to change this // interface, so it is "exactly precise" (if i may be allowed the adverbial // redundancy for emphasis) and does not include narrow oop slots not // included in the original write interval. HeapWord* aligned_start = align_down(start, HeapWordSize); HeapWord* aligned_end = align_up (end, HeapWordSize); // If compressed oops were not being used, these should already be aligned assert(UseCompressedOops || (aligned_start == start && aligned_end == end), "Expected heap word alignment of start and end"); write_ref_array_work(MemRegion(aligned_start, aligned_end)); } #endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP