Wed, 27 Apr 2016 01:25:04 +0800
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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. |
aoqi@0 | 8 | * |
aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 13 | * accompanied this code). |
aoqi@0 | 14 | * |
aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 18 | * |
aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 21 | * questions. |
aoqi@0 | 22 | * |
aoqi@0 | 23 | */ |
aoqi@0 | 24 | |
aoqi@0 | 25 | #ifndef SHARE_VM_OOPS_MARKOOP_HPP |
aoqi@0 | 26 | #define SHARE_VM_OOPS_MARKOOP_HPP |
aoqi@0 | 27 | |
aoqi@0 | 28 | #include "oops/oop.hpp" |
aoqi@0 | 29 | |
aoqi@0 | 30 | // The markOop describes the header of an object. |
aoqi@0 | 31 | // |
aoqi@0 | 32 | // Note that the mark is not a real oop but just a word. |
aoqi@0 | 33 | // It is placed in the oop hierarchy for historical reasons. |
aoqi@0 | 34 | // |
aoqi@0 | 35 | // Bit-format of an object header (most significant first, big endian layout below): |
aoqi@0 | 36 | // |
aoqi@0 | 37 | // 32 bits: |
aoqi@0 | 38 | // -------- |
aoqi@0 | 39 | // hash:25 ------------>| age:4 biased_lock:1 lock:2 (normal object) |
aoqi@0 | 40 | // JavaThread*:23 epoch:2 age:4 biased_lock:1 lock:2 (biased object) |
aoqi@0 | 41 | // size:32 ------------------------------------------>| (CMS free block) |
aoqi@0 | 42 | // PromotedObject*:29 ---------->| promo_bits:3 ----->| (CMS promoted object) |
aoqi@0 | 43 | // |
aoqi@0 | 44 | // 64 bits: |
aoqi@0 | 45 | // -------- |
aoqi@0 | 46 | // unused:25 hash:31 -->| unused:1 age:4 biased_lock:1 lock:2 (normal object) |
aoqi@0 | 47 | // JavaThread*:54 epoch:2 unused:1 age:4 biased_lock:1 lock:2 (biased object) |
aoqi@0 | 48 | // PromotedObject*:61 --------------------->| promo_bits:3 ----->| (CMS promoted object) |
aoqi@0 | 49 | // size:64 ----------------------------------------------------->| (CMS free block) |
aoqi@0 | 50 | // |
aoqi@0 | 51 | // unused:25 hash:31 -->| cms_free:1 age:4 biased_lock:1 lock:2 (COOPs && normal object) |
aoqi@0 | 52 | // JavaThread*:54 epoch:2 cms_free:1 age:4 biased_lock:1 lock:2 (COOPs && biased object) |
aoqi@0 | 53 | // narrowOop:32 unused:24 cms_free:1 unused:4 promo_bits:3 ----->| (COOPs && CMS promoted object) |
aoqi@0 | 54 | // unused:21 size:35 -->| cms_free:1 unused:7 ------------------>| (COOPs && CMS free block) |
aoqi@0 | 55 | // |
aoqi@0 | 56 | // - hash contains the identity hash value: largest value is |
aoqi@0 | 57 | // 31 bits, see os::random(). Also, 64-bit vm's require |
aoqi@0 | 58 | // a hash value no bigger than 32 bits because they will not |
aoqi@0 | 59 | // properly generate a mask larger than that: see library_call.cpp |
aoqi@0 | 60 | // and c1_CodePatterns_sparc.cpp. |
aoqi@0 | 61 | // |
aoqi@0 | 62 | // - the biased lock pattern is used to bias a lock toward a given |
aoqi@0 | 63 | // thread. When this pattern is set in the low three bits, the lock |
aoqi@0 | 64 | // is either biased toward a given thread or "anonymously" biased, |
aoqi@0 | 65 | // indicating that it is possible for it to be biased. When the |
aoqi@0 | 66 | // lock is biased toward a given thread, locking and unlocking can |
aoqi@0 | 67 | // be performed by that thread without using atomic operations. |
aoqi@0 | 68 | // When a lock's bias is revoked, it reverts back to the normal |
aoqi@0 | 69 | // locking scheme described below. |
aoqi@0 | 70 | // |
aoqi@0 | 71 | // Note that we are overloading the meaning of the "unlocked" state |
aoqi@0 | 72 | // of the header. Because we steal a bit from the age we can |
aoqi@0 | 73 | // guarantee that the bias pattern will never be seen for a truly |
aoqi@0 | 74 | // unlocked object. |
aoqi@0 | 75 | // |
aoqi@0 | 76 | // Note also that the biased state contains the age bits normally |
aoqi@0 | 77 | // contained in the object header. Large increases in scavenge |
aoqi@0 | 78 | // times were seen when these bits were absent and an arbitrary age |
aoqi@0 | 79 | // assigned to all biased objects, because they tended to consume a |
aoqi@0 | 80 | // significant fraction of the eden semispaces and were not |
aoqi@0 | 81 | // promoted promptly, causing an increase in the amount of copying |
aoqi@0 | 82 | // performed. The runtime system aligns all JavaThread* pointers to |
aoqi@0 | 83 | // a very large value (currently 128 bytes (32bVM) or 256 bytes (64bVM)) |
aoqi@0 | 84 | // to make room for the age bits & the epoch bits (used in support of |
aoqi@0 | 85 | // biased locking), and for the CMS "freeness" bit in the 64bVM (+COOPs). |
aoqi@0 | 86 | // |
aoqi@0 | 87 | // [JavaThread* | epoch | age | 1 | 01] lock is biased toward given thread |
aoqi@0 | 88 | // [0 | epoch | age | 1 | 01] lock is anonymously biased |
aoqi@0 | 89 | // |
aoqi@0 | 90 | // - the two lock bits are used to describe three states: locked/unlocked and monitor. |
aoqi@0 | 91 | // |
aoqi@0 | 92 | // [ptr | 00] locked ptr points to real header on stack |
aoqi@0 | 93 | // [header | 0 | 01] unlocked regular object header |
aoqi@0 | 94 | // [ptr | 10] monitor inflated lock (header is wapped out) |
aoqi@0 | 95 | // [ptr | 11] marked used by markSweep to mark an object |
aoqi@0 | 96 | // not valid at any other time |
aoqi@0 | 97 | // |
aoqi@0 | 98 | // We assume that stack/thread pointers have the lowest two bits cleared. |
aoqi@0 | 99 | |
aoqi@0 | 100 | class BasicLock; |
aoqi@0 | 101 | class ObjectMonitor; |
aoqi@0 | 102 | class JavaThread; |
aoqi@0 | 103 | |
aoqi@0 | 104 | class markOopDesc: public oopDesc { |
aoqi@0 | 105 | private: |
aoqi@0 | 106 | // Conversion |
aoqi@0 | 107 | uintptr_t value() const { return (uintptr_t) this; } |
aoqi@0 | 108 | |
aoqi@0 | 109 | public: |
aoqi@0 | 110 | // Constants |
aoqi@0 | 111 | enum { age_bits = 4, |
aoqi@0 | 112 | lock_bits = 2, |
aoqi@0 | 113 | biased_lock_bits = 1, |
aoqi@0 | 114 | max_hash_bits = BitsPerWord - age_bits - lock_bits - biased_lock_bits, |
aoqi@0 | 115 | hash_bits = max_hash_bits > 31 ? 31 : max_hash_bits, |
aoqi@0 | 116 | cms_bits = LP64_ONLY(1) NOT_LP64(0), |
aoqi@0 | 117 | epoch_bits = 2 |
aoqi@0 | 118 | }; |
aoqi@0 | 119 | |
aoqi@0 | 120 | // The biased locking code currently requires that the age bits be |
aoqi@0 | 121 | // contiguous to the lock bits. |
aoqi@0 | 122 | enum { lock_shift = 0, |
aoqi@0 | 123 | biased_lock_shift = lock_bits, |
aoqi@0 | 124 | age_shift = lock_bits + biased_lock_bits, |
aoqi@0 | 125 | cms_shift = age_shift + age_bits, |
aoqi@0 | 126 | hash_shift = cms_shift + cms_bits, |
aoqi@0 | 127 | epoch_shift = hash_shift |
aoqi@0 | 128 | }; |
aoqi@0 | 129 | |
aoqi@0 | 130 | enum { lock_mask = right_n_bits(lock_bits), |
aoqi@0 | 131 | lock_mask_in_place = lock_mask << lock_shift, |
aoqi@0 | 132 | biased_lock_mask = right_n_bits(lock_bits + biased_lock_bits), |
aoqi@0 | 133 | biased_lock_mask_in_place= biased_lock_mask << lock_shift, |
aoqi@0 | 134 | biased_lock_bit_in_place = 1 << biased_lock_shift, |
aoqi@0 | 135 | age_mask = right_n_bits(age_bits), |
aoqi@0 | 136 | age_mask_in_place = age_mask << age_shift, |
aoqi@0 | 137 | epoch_mask = right_n_bits(epoch_bits), |
aoqi@0 | 138 | epoch_mask_in_place = epoch_mask << epoch_shift, |
aoqi@0 | 139 | cms_mask = right_n_bits(cms_bits), |
aoqi@0 | 140 | cms_mask_in_place = cms_mask << cms_shift |
aoqi@0 | 141 | #ifndef _WIN64 |
aoqi@0 | 142 | ,hash_mask = right_n_bits(hash_bits), |
aoqi@0 | 143 | hash_mask_in_place = (address_word)hash_mask << hash_shift |
aoqi@0 | 144 | #endif |
aoqi@0 | 145 | }; |
aoqi@0 | 146 | |
aoqi@0 | 147 | // Alignment of JavaThread pointers encoded in object header required by biased locking |
aoqi@0 | 148 | enum { biased_lock_alignment = 2 << (epoch_shift + epoch_bits) |
aoqi@0 | 149 | }; |
aoqi@0 | 150 | |
aoqi@0 | 151 | #ifdef _WIN64 |
aoqi@0 | 152 | // These values are too big for Win64 |
aoqi@0 | 153 | const static uintptr_t hash_mask = right_n_bits(hash_bits); |
aoqi@0 | 154 | const static uintptr_t hash_mask_in_place = |
aoqi@0 | 155 | (address_word)hash_mask << hash_shift; |
aoqi@0 | 156 | #endif |
aoqi@0 | 157 | |
aoqi@0 | 158 | enum { locked_value = 0, |
aoqi@0 | 159 | unlocked_value = 1, |
aoqi@0 | 160 | monitor_value = 2, |
aoqi@0 | 161 | marked_value = 3, |
aoqi@0 | 162 | biased_lock_pattern = 5 |
aoqi@0 | 163 | }; |
aoqi@0 | 164 | |
aoqi@0 | 165 | enum { no_hash = 0 }; // no hash value assigned |
aoqi@0 | 166 | |
aoqi@0 | 167 | enum { no_hash_in_place = (address_word)no_hash << hash_shift, |
aoqi@0 | 168 | no_lock_in_place = unlocked_value |
aoqi@0 | 169 | }; |
aoqi@0 | 170 | |
aoqi@0 | 171 | enum { max_age = age_mask }; |
aoqi@0 | 172 | |
aoqi@0 | 173 | enum { max_bias_epoch = epoch_mask }; |
aoqi@0 | 174 | |
aoqi@0 | 175 | // Biased Locking accessors. |
aoqi@0 | 176 | // These must be checked by all code which calls into the |
aoqi@0 | 177 | // ObjectSynchronizer and other code. The biasing is not understood |
aoqi@0 | 178 | // by the lower-level CAS-based locking code, although the runtime |
aoqi@0 | 179 | // fixes up biased locks to be compatible with it when a bias is |
aoqi@0 | 180 | // revoked. |
aoqi@0 | 181 | bool has_bias_pattern() const { |
aoqi@0 | 182 | return (mask_bits(value(), biased_lock_mask_in_place) == biased_lock_pattern); |
aoqi@0 | 183 | } |
aoqi@0 | 184 | JavaThread* biased_locker() const { |
aoqi@0 | 185 | assert(has_bias_pattern(), "should not call this otherwise"); |
aoqi@0 | 186 | return (JavaThread*) ((intptr_t) (mask_bits(value(), ~(biased_lock_mask_in_place | age_mask_in_place | epoch_mask_in_place)))); |
aoqi@0 | 187 | } |
aoqi@0 | 188 | // Indicates that the mark has the bias bit set but that it has not |
aoqi@0 | 189 | // yet been biased toward a particular thread |
aoqi@0 | 190 | bool is_biased_anonymously() const { |
aoqi@0 | 191 | return (has_bias_pattern() && (biased_locker() == NULL)); |
aoqi@0 | 192 | } |
aoqi@0 | 193 | // Indicates epoch in which this bias was acquired. If the epoch |
aoqi@0 | 194 | // changes due to too many bias revocations occurring, the biases |
aoqi@0 | 195 | // from the previous epochs are all considered invalid. |
aoqi@0 | 196 | int bias_epoch() const { |
aoqi@0 | 197 | assert(has_bias_pattern(), "should not call this otherwise"); |
aoqi@0 | 198 | return (mask_bits(value(), epoch_mask_in_place) >> epoch_shift); |
aoqi@0 | 199 | } |
aoqi@0 | 200 | markOop set_bias_epoch(int epoch) { |
aoqi@0 | 201 | assert(has_bias_pattern(), "should not call this otherwise"); |
aoqi@0 | 202 | assert((epoch & (~epoch_mask)) == 0, "epoch overflow"); |
aoqi@0 | 203 | return markOop(mask_bits(value(), ~epoch_mask_in_place) | (epoch << epoch_shift)); |
aoqi@0 | 204 | } |
aoqi@0 | 205 | markOop incr_bias_epoch() { |
aoqi@0 | 206 | return set_bias_epoch((1 + bias_epoch()) & epoch_mask); |
aoqi@0 | 207 | } |
aoqi@0 | 208 | // Prototype mark for initialization |
aoqi@0 | 209 | static markOop biased_locking_prototype() { |
aoqi@0 | 210 | return markOop( biased_lock_pattern ); |
aoqi@0 | 211 | } |
aoqi@0 | 212 | |
aoqi@0 | 213 | // lock accessors (note that these assume lock_shift == 0) |
aoqi@0 | 214 | bool is_locked() const { |
aoqi@0 | 215 | return (mask_bits(value(), lock_mask_in_place) != unlocked_value); |
aoqi@0 | 216 | } |
aoqi@0 | 217 | bool is_unlocked() const { |
aoqi@0 | 218 | return (mask_bits(value(), biased_lock_mask_in_place) == unlocked_value); |
aoqi@0 | 219 | } |
aoqi@0 | 220 | bool is_marked() const { |
aoqi@0 | 221 | return (mask_bits(value(), lock_mask_in_place) == marked_value); |
aoqi@0 | 222 | } |
aoqi@0 | 223 | bool is_neutral() const { return (mask_bits(value(), biased_lock_mask_in_place) == unlocked_value); } |
aoqi@0 | 224 | |
aoqi@0 | 225 | // Special temporary state of the markOop while being inflated. |
aoqi@0 | 226 | // Code that looks at mark outside a lock need to take this into account. |
aoqi@0 | 227 | bool is_being_inflated() const { return (value() == 0); } |
aoqi@0 | 228 | |
aoqi@0 | 229 | // Distinguished markword value - used when inflating over |
aoqi@0 | 230 | // an existing stacklock. 0 indicates the markword is "BUSY". |
aoqi@0 | 231 | // Lockword mutators that use a LD...CAS idiom should always |
aoqi@0 | 232 | // check for and avoid overwriting a 0 value installed by some |
aoqi@0 | 233 | // other thread. (They should spin or block instead. The 0 value |
aoqi@0 | 234 | // is transient and *should* be short-lived). |
aoqi@0 | 235 | static markOop INFLATING() { return (markOop) 0; } // inflate-in-progress |
aoqi@0 | 236 | |
aoqi@0 | 237 | // Should this header be preserved during GC? |
aoqi@0 | 238 | inline bool must_be_preserved(oop obj_containing_mark) const; |
aoqi@0 | 239 | inline bool must_be_preserved_with_bias(oop obj_containing_mark) const; |
aoqi@0 | 240 | |
aoqi@0 | 241 | // Should this header (including its age bits) be preserved in the |
aoqi@0 | 242 | // case of a promotion failure during scavenge? |
aoqi@0 | 243 | // Note that we special case this situation. We want to avoid |
aoqi@0 | 244 | // calling BiasedLocking::preserve_marks()/restore_marks() (which |
aoqi@0 | 245 | // decrease the number of mark words that need to be preserved |
aoqi@0 | 246 | // during GC) during each scavenge. During scavenges in which there |
aoqi@0 | 247 | // is no promotion failure, we actually don't need to call the above |
aoqi@0 | 248 | // routines at all, since we don't mutate and re-initialize the |
aoqi@0 | 249 | // marks of promoted objects using init_mark(). However, during |
aoqi@0 | 250 | // scavenges which result in promotion failure, we do re-initialize |
aoqi@0 | 251 | // the mark words of objects, meaning that we should have called |
aoqi@0 | 252 | // these mark word preservation routines. Currently there's no good |
aoqi@0 | 253 | // place in which to call them in any of the scavengers (although |
aoqi@0 | 254 | // guarded by appropriate locks we could make one), but the |
aoqi@0 | 255 | // observation is that promotion failures are quite rare and |
aoqi@0 | 256 | // reducing the number of mark words preserved during them isn't a |
aoqi@0 | 257 | // high priority. |
aoqi@0 | 258 | inline bool must_be_preserved_for_promotion_failure(oop obj_containing_mark) const; |
aoqi@0 | 259 | inline bool must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const; |
aoqi@0 | 260 | |
aoqi@0 | 261 | // Should this header be preserved during a scavenge where CMS is |
aoqi@0 | 262 | // the old generation? |
aoqi@0 | 263 | // (This is basically the same body as must_be_preserved_for_promotion_failure(), |
aoqi@0 | 264 | // but takes the Klass* as argument instead) |
aoqi@0 | 265 | inline bool must_be_preserved_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const; |
aoqi@0 | 266 | inline bool must_be_preserved_with_bias_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const; |
aoqi@0 | 267 | |
aoqi@0 | 268 | // WARNING: The following routines are used EXCLUSIVELY by |
aoqi@0 | 269 | // synchronization functions. They are not really gc safe. |
aoqi@0 | 270 | // They must get updated if markOop layout get changed. |
aoqi@0 | 271 | markOop set_unlocked() const { |
aoqi@0 | 272 | return markOop(value() | unlocked_value); |
aoqi@0 | 273 | } |
aoqi@0 | 274 | bool has_locker() const { |
aoqi@0 | 275 | return ((value() & lock_mask_in_place) == locked_value); |
aoqi@0 | 276 | } |
aoqi@0 | 277 | BasicLock* locker() const { |
aoqi@0 | 278 | assert(has_locker(), "check"); |
aoqi@0 | 279 | return (BasicLock*) value(); |
aoqi@0 | 280 | } |
aoqi@0 | 281 | bool has_monitor() const { |
aoqi@0 | 282 | return ((value() & monitor_value) != 0); |
aoqi@0 | 283 | } |
aoqi@0 | 284 | ObjectMonitor* monitor() const { |
aoqi@0 | 285 | assert(has_monitor(), "check"); |
aoqi@0 | 286 | // Use xor instead of &~ to provide one extra tag-bit check. |
aoqi@0 | 287 | return (ObjectMonitor*) (value() ^ monitor_value); |
aoqi@0 | 288 | } |
aoqi@0 | 289 | bool has_displaced_mark_helper() const { |
aoqi@0 | 290 | return ((value() & unlocked_value) == 0); |
aoqi@0 | 291 | } |
aoqi@0 | 292 | markOop displaced_mark_helper() const { |
aoqi@0 | 293 | assert(has_displaced_mark_helper(), "check"); |
aoqi@0 | 294 | intptr_t ptr = (value() & ~monitor_value); |
aoqi@0 | 295 | return *(markOop*)ptr; |
aoqi@0 | 296 | } |
aoqi@0 | 297 | void set_displaced_mark_helper(markOop m) const { |
aoqi@0 | 298 | assert(has_displaced_mark_helper(), "check"); |
aoqi@0 | 299 | intptr_t ptr = (value() & ~monitor_value); |
aoqi@0 | 300 | *(markOop*)ptr = m; |
aoqi@0 | 301 | } |
aoqi@0 | 302 | markOop copy_set_hash(intptr_t hash) const { |
aoqi@0 | 303 | intptr_t tmp = value() & (~hash_mask_in_place); |
aoqi@0 | 304 | tmp |= ((hash & hash_mask) << hash_shift); |
aoqi@0 | 305 | return (markOop)tmp; |
aoqi@0 | 306 | } |
aoqi@0 | 307 | // it is only used to be stored into BasicLock as the |
aoqi@0 | 308 | // indicator that the lock is using heavyweight monitor |
aoqi@0 | 309 | static markOop unused_mark() { |
aoqi@0 | 310 | return (markOop) marked_value; |
aoqi@0 | 311 | } |
aoqi@0 | 312 | // the following two functions create the markOop to be |
aoqi@0 | 313 | // stored into object header, it encodes monitor info |
aoqi@0 | 314 | static markOop encode(BasicLock* lock) { |
aoqi@0 | 315 | return (markOop) lock; |
aoqi@0 | 316 | } |
aoqi@0 | 317 | static markOop encode(ObjectMonitor* monitor) { |
aoqi@0 | 318 | intptr_t tmp = (intptr_t) monitor; |
aoqi@0 | 319 | return (markOop) (tmp | monitor_value); |
aoqi@0 | 320 | } |
aoqi@0 | 321 | static markOop encode(JavaThread* thread, uint age, int bias_epoch) { |
aoqi@0 | 322 | intptr_t tmp = (intptr_t) thread; |
aoqi@0 | 323 | assert(UseBiasedLocking && ((tmp & (epoch_mask_in_place | age_mask_in_place | biased_lock_mask_in_place)) == 0), "misaligned JavaThread pointer"); |
aoqi@0 | 324 | assert(age <= max_age, "age too large"); |
aoqi@0 | 325 | assert(bias_epoch <= max_bias_epoch, "bias epoch too large"); |
aoqi@0 | 326 | return (markOop) (tmp | (bias_epoch << epoch_shift) | (age << age_shift) | biased_lock_pattern); |
aoqi@0 | 327 | } |
aoqi@0 | 328 | |
aoqi@0 | 329 | // used to encode pointers during GC |
aoqi@0 | 330 | markOop clear_lock_bits() { return markOop(value() & ~lock_mask_in_place); } |
aoqi@0 | 331 | |
aoqi@0 | 332 | // age operations |
aoqi@0 | 333 | markOop set_marked() { return markOop((value() & ~lock_mask_in_place) | marked_value); } |
aoqi@0 | 334 | markOop set_unmarked() { return markOop((value() & ~lock_mask_in_place) | unlocked_value); } |
aoqi@0 | 335 | |
aoqi@0 | 336 | uint age() const { return mask_bits(value() >> age_shift, age_mask); } |
aoqi@0 | 337 | markOop set_age(uint v) const { |
aoqi@0 | 338 | assert((v & ~age_mask) == 0, "shouldn't overflow age field"); |
aoqi@0 | 339 | return markOop((value() & ~age_mask_in_place) | (((uintptr_t)v & age_mask) << age_shift)); |
aoqi@0 | 340 | } |
aoqi@0 | 341 | markOop incr_age() const { return age() == max_age ? markOop(this) : set_age(age() + 1); } |
aoqi@0 | 342 | |
aoqi@0 | 343 | // hash operations |
aoqi@0 | 344 | intptr_t hash() const { |
aoqi@0 | 345 | return mask_bits(value() >> hash_shift, hash_mask); |
aoqi@0 | 346 | } |
aoqi@0 | 347 | |
aoqi@0 | 348 | bool has_no_hash() const { |
aoqi@0 | 349 | return hash() == no_hash; |
aoqi@0 | 350 | } |
aoqi@0 | 351 | |
aoqi@0 | 352 | // Prototype mark for initialization |
aoqi@0 | 353 | static markOop prototype() { |
aoqi@0 | 354 | return markOop( no_hash_in_place | no_lock_in_place ); |
aoqi@0 | 355 | } |
aoqi@0 | 356 | |
aoqi@0 | 357 | // Helper function for restoration of unmarked mark oops during GC |
aoqi@0 | 358 | static inline markOop prototype_for_object(oop obj); |
aoqi@0 | 359 | |
aoqi@0 | 360 | // Debugging |
aoqi@0 | 361 | void print_on(outputStream* st) const; |
aoqi@0 | 362 | |
aoqi@0 | 363 | // Prepare address of oop for placement into mark |
aoqi@0 | 364 | inline static markOop encode_pointer_as_mark(void* p) { return markOop(p)->set_marked(); } |
aoqi@0 | 365 | |
aoqi@0 | 366 | // Recover address of oop from encoded form used in mark |
aoqi@0 | 367 | inline void* decode_pointer() { if (UseBiasedLocking && has_bias_pattern()) return NULL; return clear_lock_bits(); } |
aoqi@0 | 368 | |
aoqi@0 | 369 | // These markOops indicate cms free chunk blocks and not objects. |
aoqi@0 | 370 | // In 64 bit, the markOop is set to distinguish them from oops. |
aoqi@0 | 371 | // These are defined in 32 bit mode for vmStructs. |
aoqi@0 | 372 | const static uintptr_t cms_free_chunk_pattern = 0x1; |
aoqi@0 | 373 | |
aoqi@0 | 374 | // Constants for the size field. |
aoqi@0 | 375 | enum { size_shift = cms_shift + cms_bits, |
aoqi@0 | 376 | size_bits = 35 // need for compressed oops 32G |
aoqi@0 | 377 | }; |
aoqi@0 | 378 | // These values are too big for Win64 |
aoqi@0 | 379 | const static uintptr_t size_mask = LP64_ONLY(right_n_bits(size_bits)) |
aoqi@0 | 380 | NOT_LP64(0); |
aoqi@0 | 381 | const static uintptr_t size_mask_in_place = |
aoqi@0 | 382 | (address_word)size_mask << size_shift; |
aoqi@0 | 383 | |
aoqi@0 | 384 | #ifdef _LP64 |
aoqi@0 | 385 | static markOop cms_free_prototype() { |
aoqi@0 | 386 | return markOop(((intptr_t)prototype() & ~cms_mask_in_place) | |
aoqi@0 | 387 | ((cms_free_chunk_pattern & cms_mask) << cms_shift)); |
aoqi@0 | 388 | } |
aoqi@0 | 389 | uintptr_t cms_encoding() const { |
aoqi@0 | 390 | return mask_bits(value() >> cms_shift, cms_mask); |
aoqi@0 | 391 | } |
aoqi@0 | 392 | bool is_cms_free_chunk() const { |
aoqi@0 | 393 | return is_neutral() && |
aoqi@0 | 394 | (cms_encoding() & cms_free_chunk_pattern) == cms_free_chunk_pattern; |
aoqi@0 | 395 | } |
aoqi@0 | 396 | |
aoqi@0 | 397 | size_t get_size() const { return (size_t)(value() >> size_shift); } |
aoqi@0 | 398 | static markOop set_size_and_free(size_t size) { |
aoqi@0 | 399 | assert((size & ~size_mask) == 0, "shouldn't overflow size field"); |
aoqi@0 | 400 | return markOop(((intptr_t)cms_free_prototype() & ~size_mask_in_place) | |
aoqi@0 | 401 | (((intptr_t)size & size_mask) << size_shift)); |
aoqi@0 | 402 | } |
aoqi@0 | 403 | #endif // _LP64 |
aoqi@0 | 404 | }; |
aoqi@0 | 405 | |
aoqi@0 | 406 | #endif // SHARE_VM_OOPS_MARKOOP_HPP |