1 /* 2 * Copyright (c) 2006, 2010, 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 #include "precompiled.hpp" 26 #include "runtime/sharedRuntime.hpp" 27 #include "utilities/copy.hpp" 28 29 30 // Copy bytes; larger units are filled atomically if everything is aligned. 31 void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) { 32 address src = (address) from; 33 address dst = (address) to; 34 uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size; 35 36 // (Note: We could improve performance by ignoring the low bits of size, 37 // and putting a short cleanup loop after each bulk copy loop. 38 // There are plenty of other ways to make this faster also, 39 // and it's a slippery slope. For now, let's keep this code simple 40 // since the simplicity helps clarify the atomicity semantics of 41 // this operation. There are also CPU-specific assembly versions 42 // which may or may not want to include such optimizations.) 43 44 if (bits % sizeof(jlong) == 0) { 45 Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong)); 46 } else if (bits % sizeof(jint) == 0) { 47 Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint)); 48 } else if (bits % sizeof(jshort) == 0) { 49 Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort)); 50 } else { 51 // Not aligned, so no need to be atomic. 52 Copy::conjoint_jbytes((void*) src, (void*) dst, size); 53 } 54 } 55 56 57 // Fill bytes; larger units are filled atomically if everything is aligned. 58 void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) { 59 address dst = (address) to; 60 uintptr_t bits = (uintptr_t) to | (uintptr_t) size; 61 if (bits % sizeof(jlong) == 0) { 62 jlong fill = (julong)( (jubyte)value ); // zero-extend 63 if (fill != 0) { 64 fill += fill << 8; 65 fill += fill << 16; 66 fill += fill << 32; 67 } 68 //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong)); 69 for (uintptr_t off = 0; off < size; off += sizeof(jlong)) { 70 *(jlong*)(dst + off) = fill; 71 } 72 } else if (bits % sizeof(jint) == 0) { 73 jint fill = (juint)( (jubyte)value ); // zero-extend 74 if (fill != 0) { 75 fill += fill << 8; 76 fill += fill << 16; 77 } 78 //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint)); 79 for (uintptr_t off = 0; off < size; off += sizeof(jint)) { 80 *(jint*)(dst + off) = fill; 81 } 82 } else if (bits % sizeof(jshort) == 0) { 83 jshort fill = (jushort)( (jubyte)value ); // zero-extend 84 fill += fill << 8; 85 //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort)); 86 for (uintptr_t off = 0; off < size; off += sizeof(jshort)) { 87 *(jshort*)(dst + off) = fill; 88 } 89 } else { 90 // Not aligned, so no need to be atomic. 91 Copy::fill_to_bytes(dst, size, value); 92 } 93 }