1 /* 2 * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // Inline functions of BarrierSet, which de-virtualize certain 26 // performance-critical calls when the barrier is the most common 27 // card-table kind. 28 29 template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) { 30 if (kind() == CardTableModRef) { 31 ((CardTableModRefBS*)this)->inline_write_ref_field_pre(field, new_val); 32 } else { 33 write_ref_field_pre_work(field, new_val); 34 } 35 } 36 37 void BarrierSet::write_ref_field(void* field, oop new_val) { 38 if (kind() == CardTableModRef) { 39 ((CardTableModRefBS*)this)->inline_write_ref_field(field, new_val); 40 } else { 41 write_ref_field_work(field, new_val); 42 } 43 } 44 45 // count is number of array elements being written 46 void BarrierSet::write_ref_array(HeapWord* start, size_t count) { 47 assert(count <= (size_t)max_intx, "count too large"); 48 HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize)); 49 // In the case of compressed oops, start and end may potentially be misaligned; 50 // so we need to conservatively align the first downward (this is not 51 // strictly necessary for current uses, but a case of good hygiene and, 52 // if you will, aesthetics) and the second upward (this is essential for 53 // current uses) to a HeapWord boundary, so we mark all cards overlapping 54 // this write. If this evolves in the future to calling a 55 // logging barrier of narrow oop granularity, like the pre-barrier for G1 56 // (mentioned here merely by way of example), we will need to change this 57 // interface, so it is "exactly precise" (if i may be allowed the adverbial 58 // redundancy for emphasis) and does not include narrow oop slots not 59 // included in the original write interval. 60 HeapWord* aligned_start = (HeapWord*)align_size_down((uintptr_t)start, HeapWordSize); 61 HeapWord* aligned_end = (HeapWord*)align_size_up ((uintptr_t)end, HeapWordSize); 62 // If compressed oops were not being used, these should already be aligned 63 assert(UseCompressedOops || (aligned_start == start && aligned_end == end), 64 "Expected heap word alignment of start and end"); 65 #if 0 66 warning("Post:\t" INTPTR_FORMAT "[" SIZE_FORMAT "] : [" INTPTR_FORMAT","INTPTR_FORMAT")\t", 67 start, count, aligned_start, aligned_end); 68 #endif 69 write_ref_array_work(MemRegion(aligned_start, aligned_end)); 70 } 71 72 73 void BarrierSet::write_region(MemRegion mr) { 74 if (kind() == CardTableModRef) { 75 ((CardTableModRefBS*)this)->inline_write_region(mr); 76 } else { 77 write_region_work(mr); 78 } 79 }