1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/share/vm/classfile/altHashing.cpp Wed Apr 27 01:25:04 2016 +0800 1.3 @@ -0,0 +1,304 @@ 1.4 +/* 1.5 + * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved. 1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 1.7 + * 1.8 + * This code is free software; you can redistribute it and/or modify it 1.9 + * under the terms of the GNU General Public License version 2 only, as 1.10 + * published by the Free Software Foundation. 1.11 + * 1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT 1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1.15 + * version 2 for more details (a copy is included in the LICENSE file that 1.16 + * accompanied this code). 1.17 + * 1.18 + * You should have received a copy of the GNU General Public License version 1.19 + * 2 along with this work; if not, write to the Free Software Foundation, 1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1.21 + * 1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 1.23 + * or visit www.oracle.com if you need additional information or have any 1.24 + * questions. 1.25 + * 1.26 + */ 1.27 + 1.28 +#include "precompiled.hpp" 1.29 +#include "classfile/altHashing.hpp" 1.30 +#include "classfile/symbolTable.hpp" 1.31 +#include "classfile/systemDictionary.hpp" 1.32 +#include "oops/markOop.hpp" 1.33 +#include "runtime/thread.hpp" 1.34 + 1.35 +// Get the hash code of the classes mirror if it exists, otherwise just 1.36 +// return a random number, which is one of the possible hash code used for 1.37 +// objects. We don't want to call the synchronizer hash code to install 1.38 +// this value because it may safepoint. 1.39 +intptr_t object_hash(Klass* k) { 1.40 + intptr_t hc = k->java_mirror()->mark()->hash(); 1.41 + return hc != markOopDesc::no_hash ? hc : os::random(); 1.42 +} 1.43 + 1.44 +// Seed value used for each alternative hash calculated. 1.45 +juint AltHashing::compute_seed() { 1.46 + jlong nanos = os::javaTimeNanos(); 1.47 + jlong now = os::javaTimeMillis(); 1.48 + int SEED_MATERIAL[8] = { 1.49 + (int) object_hash(SystemDictionary::String_klass()), 1.50 + (int) object_hash(SystemDictionary::System_klass()), 1.51 + (int) os::random(), // current thread isn't a java thread 1.52 + (int) (((julong)nanos) >> 32), 1.53 + (int) nanos, 1.54 + (int) (((julong)now) >> 32), 1.55 + (int) now, 1.56 + (int) (os::javaTimeNanos() >> 2) 1.57 + }; 1.58 + 1.59 + return murmur3_32(SEED_MATERIAL, 8); 1.60 +} 1.61 + 1.62 + 1.63 +// Murmur3 hashing for Symbol 1.64 +juint AltHashing::murmur3_32(juint seed, const jbyte* data, int len) { 1.65 + juint h1 = seed; 1.66 + int count = len; 1.67 + int offset = 0; 1.68 + 1.69 + // body 1.70 + while (count >= 4) { 1.71 + juint k1 = (data[offset] & 0x0FF) 1.72 + | (data[offset + 1] & 0x0FF) << 8 1.73 + | (data[offset + 2] & 0x0FF) << 16 1.74 + | data[offset + 3] << 24; 1.75 + 1.76 + count -= 4; 1.77 + offset += 4; 1.78 + 1.79 + k1 *= 0xcc9e2d51; 1.80 + k1 = Integer_rotateLeft(k1, 15); 1.81 + k1 *= 0x1b873593; 1.82 + 1.83 + h1 ^= k1; 1.84 + h1 = Integer_rotateLeft(h1, 13); 1.85 + h1 = h1 * 5 + 0xe6546b64; 1.86 + } 1.87 + 1.88 + // tail 1.89 + 1.90 + if (count > 0) { 1.91 + juint k1 = 0; 1.92 + 1.93 + switch (count) { 1.94 + case 3: 1.95 + k1 ^= (data[offset + 2] & 0xff) << 16; 1.96 + // fall through 1.97 + case 2: 1.98 + k1 ^= (data[offset + 1] & 0xff) << 8; 1.99 + // fall through 1.100 + case 1: 1.101 + k1 ^= (data[offset] & 0xff); 1.102 + // fall through 1.103 + default: 1.104 + k1 *= 0xcc9e2d51; 1.105 + k1 = Integer_rotateLeft(k1, 15); 1.106 + k1 *= 0x1b873593; 1.107 + h1 ^= k1; 1.108 + } 1.109 + } 1.110 + 1.111 + // finalization 1.112 + h1 ^= len; 1.113 + 1.114 + // finalization mix force all bits of a hash block to avalanche 1.115 + h1 ^= h1 >> 16; 1.116 + h1 *= 0x85ebca6b; 1.117 + h1 ^= h1 >> 13; 1.118 + h1 *= 0xc2b2ae35; 1.119 + h1 ^= h1 >> 16; 1.120 + 1.121 + return h1; 1.122 +} 1.123 + 1.124 +// Murmur3 hashing for Strings 1.125 +juint AltHashing::murmur3_32(juint seed, const jchar* data, int len) { 1.126 + juint h1 = seed; 1.127 + 1.128 + int off = 0; 1.129 + int count = len; 1.130 + 1.131 + // body 1.132 + while (count >= 2) { 1.133 + jchar d1 = data[off++] & 0xFFFF; 1.134 + jchar d2 = data[off++]; 1.135 + juint k1 = (d1 | d2 << 16); 1.136 + 1.137 + count -= 2; 1.138 + 1.139 + k1 *= 0xcc9e2d51; 1.140 + k1 = Integer_rotateLeft(k1, 15); 1.141 + k1 *= 0x1b873593; 1.142 + 1.143 + h1 ^= k1; 1.144 + h1 = Integer_rotateLeft(h1, 13); 1.145 + h1 = h1 * 5 + 0xe6546b64; 1.146 + } 1.147 + 1.148 + // tail 1.149 + 1.150 + if (count > 0) { 1.151 + juint k1 = (juint)data[off]; 1.152 + 1.153 + k1 *= 0xcc9e2d51; 1.154 + k1 = Integer_rotateLeft(k1, 15); 1.155 + k1 *= 0x1b873593; 1.156 + h1 ^= k1; 1.157 + } 1.158 + 1.159 + // finalization 1.160 + h1 ^= len * 2; // (Character.SIZE / Byte.SIZE); 1.161 + 1.162 + // finalization mix force all bits of a hash block to avalanche 1.163 + h1 ^= h1 >> 16; 1.164 + h1 *= 0x85ebca6b; 1.165 + h1 ^= h1 >> 13; 1.166 + h1 *= 0xc2b2ae35; 1.167 + h1 ^= h1 >> 16; 1.168 + 1.169 + return h1; 1.170 +} 1.171 + 1.172 +// Hash used for the seed. 1.173 +juint AltHashing::murmur3_32(juint seed, const int* data, int len) { 1.174 + juint h1 = seed; 1.175 + 1.176 + int off = 0; 1.177 + int end = len; 1.178 + 1.179 + // body 1.180 + while (off < end) { 1.181 + juint k1 = (juint)data[off++]; 1.182 + 1.183 + k1 *= 0xcc9e2d51; 1.184 + k1 = Integer_rotateLeft(k1, 15); 1.185 + k1 *= 0x1b873593; 1.186 + 1.187 + h1 ^= k1; 1.188 + h1 = Integer_rotateLeft(h1, 13); 1.189 + h1 = h1 * 5 + 0xe6546b64; 1.190 + } 1.191 + 1.192 + // tail (always empty, as body is always 32-bit chunks) 1.193 + 1.194 + // finalization 1.195 + 1.196 + h1 ^= len * 4; // (Integer.SIZE / Byte.SIZE); 1.197 + 1.198 + // finalization mix force all bits of a hash block to avalanche 1.199 + h1 ^= h1 >> 16; 1.200 + h1 *= 0x85ebca6b; 1.201 + h1 ^= h1 >> 13; 1.202 + h1 *= 0xc2b2ae35; 1.203 + h1 ^= h1 >> 16; 1.204 + 1.205 + return h1; 1.206 +} 1.207 + 1.208 +juint AltHashing::murmur3_32(const int* data, int len) { 1.209 + return murmur3_32(0, data, len); 1.210 +} 1.211 + 1.212 +#ifndef PRODUCT 1.213 +// Overloaded versions for internal test. 1.214 +juint AltHashing::murmur3_32(const jbyte* data, int len) { 1.215 + return murmur3_32(0, data, len); 1.216 +} 1.217 + 1.218 +juint AltHashing::murmur3_32(const jchar* data, int len) { 1.219 + return murmur3_32(0, data, len); 1.220 +} 1.221 + 1.222 +// Internal test for alternate hashing. Translated from JDK version 1.223 +// test/sun/misc/Hashing.java 1.224 +static const jbyte ONE_BYTE[] = { (jbyte) 0x80}; 1.225 +static const jbyte TWO_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81}; 1.226 +static const jchar ONE_CHAR[] = { (jchar) 0x8180}; 1.227 +static const jbyte THREE_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82}; 1.228 +static const jbyte FOUR_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83}; 1.229 +static const jchar TWO_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382}; 1.230 +static const jint ONE_INT[] = { 0x83828180}; 1.231 +static const jbyte SIX_BYTE[] = { (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85}; 1.232 +static const jchar THREE_CHAR[] = { (jchar) 0x8180, (jchar) 0x8382, (jchar) 0x8584}; 1.233 +static const jbyte EIGHT_BYTE[] = { 1.234 + (jbyte) 0x80, (jbyte) 0x81, (jbyte) 0x82, 1.235 + (jbyte) 0x83, (jbyte) 0x84, (jbyte) 0x85, 1.236 + (jbyte) 0x86, (jbyte) 0x87}; 1.237 +static const jchar FOUR_CHAR[] = { 1.238 + (jchar) 0x8180, (jchar) 0x8382, 1.239 + (jchar) 0x8584, (jchar) 0x8786}; 1.240 + 1.241 +static const jint TWO_INT[] = { 0x83828180, 0x87868584}; 1.242 + 1.243 +static const juint MURMUR3_32_X86_CHECK_VALUE = 0xB0F57EE3; 1.244 + 1.245 +void AltHashing::testMurmur3_32_ByteArray() { 1.246 + // printf("testMurmur3_32_ByteArray\n"); 1.247 + 1.248 + jbyte vector[256]; 1.249 + jbyte hashes[4 * 256]; 1.250 + 1.251 + for (int i = 0; i < 256; i++) { 1.252 + vector[i] = (jbyte) i; 1.253 + } 1.254 + 1.255 + // Hash subranges {}, {0}, {0,1}, {0,1,2}, ..., {0,...,255} 1.256 + for (int i = 0; i < 256; i++) { 1.257 + juint hash = murmur3_32(256 - i, vector, i); 1.258 + hashes[i * 4] = (jbyte) hash; 1.259 + hashes[i * 4 + 1] = (jbyte)(hash >> 8); 1.260 + hashes[i * 4 + 2] = (jbyte)(hash >> 16); 1.261 + hashes[i * 4 + 3] = (jbyte)(hash >> 24); 1.262 + } 1.263 + 1.264 + // hash to get const result. 1.265 + juint final_hash = murmur3_32(hashes, 4*256); 1.266 + 1.267 + assert (MURMUR3_32_X86_CHECK_VALUE == final_hash, 1.268 + err_msg( 1.269 + "Calculated hash result not as expected. Expected %08X got %08X\n", 1.270 + MURMUR3_32_X86_CHECK_VALUE, 1.271 + final_hash)); 1.272 +} 1.273 + 1.274 +void AltHashing::testEquivalentHashes() { 1.275 + juint jbytes, jchars, ints; 1.276 + 1.277 + // printf("testEquivalentHashes\n"); 1.278 + 1.279 + jbytes = murmur3_32(TWO_BYTE, 2); 1.280 + jchars = murmur3_32(ONE_CHAR, 1); 1.281 + assert (jbytes == jchars, 1.282 + err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars)); 1.283 + 1.284 + jbytes = murmur3_32(FOUR_BYTE, 4); 1.285 + jchars = murmur3_32(TWO_CHAR, 2); 1.286 + ints = murmur3_32(ONE_INT, 1); 1.287 + assert ((jbytes == jchars) && (jbytes == ints), 1.288 + err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints)); 1.289 + 1.290 + jbytes = murmur3_32(SIX_BYTE, 6); 1.291 + jchars = murmur3_32(THREE_CHAR, 3); 1.292 + assert (jbytes == jchars, 1.293 + err_msg("Hashes did not match. b:%08x != c:%08x\n", jbytes, jchars)); 1.294 + 1.295 + jbytes = murmur3_32(EIGHT_BYTE, 8); 1.296 + jchars = murmur3_32(FOUR_CHAR, 4); 1.297 + ints = murmur3_32(TWO_INT, 2); 1.298 + assert ((jbytes == jchars) && (jbytes == ints), 1.299 + err_msg("Hashes did not match. b:%08x != c:%08x != i:%08x\n", jbytes, jchars, ints)); 1.300 +} 1.301 + 1.302 +// Returns true if the alternate hashcode is correct 1.303 +void AltHashing::test_alt_hash() { 1.304 + testMurmur3_32_ByteArray(); 1.305 + testEquivalentHashes(); 1.306 +} 1.307 +#endif // PRODUCT