Thu, 13 Jun 2013 22:02:40 -0700
8014431: cleanup warnings indicated by the -Wunused-value compiler option on linux
Reviewed-by: dholmes, coleenp
Contributed-by: jeremymanson@google.com, calvin.cheung@oracle.com
duke@435 | 1 | /* |
sla@5237 | 2 | * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_MEMORY_DEFNEWGENERATION_HPP |
stefank@2314 | 26 | #define SHARE_VM_MEMORY_DEFNEWGENERATION_HPP |
stefank@2314 | 27 | |
stefank@2314 | 28 | #include "gc_implementation/shared/ageTable.hpp" |
stefank@2314 | 29 | #include "gc_implementation/shared/cSpaceCounters.hpp" |
stefank@2314 | 30 | #include "gc_implementation/shared/generationCounters.hpp" |
sla@5237 | 31 | #include "gc_implementation/shared/copyFailedInfo.hpp" |
stefank@2314 | 32 | #include "memory/generation.inline.hpp" |
stefank@2314 | 33 | #include "utilities/stack.hpp" |
stefank@2314 | 34 | |
duke@435 | 35 | class EdenSpace; |
duke@435 | 36 | class ContiguousSpace; |
coleenp@548 | 37 | class ScanClosure; |
sla@5237 | 38 | class STWGCTimer; |
duke@435 | 39 | |
duke@435 | 40 | // DefNewGeneration is a young generation containing eden, from- and |
duke@435 | 41 | // to-space. |
duke@435 | 42 | |
duke@435 | 43 | class DefNewGeneration: public Generation { |
duke@435 | 44 | friend class VMStructs; |
duke@435 | 45 | |
duke@435 | 46 | protected: |
duke@435 | 47 | Generation* _next_gen; |
jwilhelm@4129 | 48 | uint _tenuring_threshold; // Tenuring threshold for next collection. |
duke@435 | 49 | ageTable _age_table; |
duke@435 | 50 | // Size of object to pretenure in words; command line provides bytes |
sla@5237 | 51 | size_t _pretenure_size_threshold_words; |
duke@435 | 52 | |
duke@435 | 53 | ageTable* age_table() { return &_age_table; } |
sla@5237 | 54 | |
duke@435 | 55 | // Initialize state to optimistically assume no promotion failure will |
duke@435 | 56 | // happen. |
duke@435 | 57 | void init_assuming_no_promotion_failure(); |
duke@435 | 58 | // True iff a promotion has failed in the current collection. |
duke@435 | 59 | bool _promotion_failed; |
duke@435 | 60 | bool promotion_failed() { return _promotion_failed; } |
sla@5237 | 61 | PromotionFailedInfo _promotion_failed_info; |
duke@435 | 62 | |
duke@435 | 63 | // Handling promotion failure. A young generation collection |
duke@435 | 64 | // can fail if a live object cannot be copied out of its |
duke@435 | 65 | // location in eden or from-space during the collection. If |
duke@435 | 66 | // a collection fails, the young generation is left in a |
duke@435 | 67 | // consistent state such that it can be collected by a |
duke@435 | 68 | // full collection. |
duke@435 | 69 | // Before the collection |
duke@435 | 70 | // Objects are in eden or from-space |
duke@435 | 71 | // All roots into the young generation point into eden or from-space. |
duke@435 | 72 | // |
duke@435 | 73 | // After a failed collection |
duke@435 | 74 | // Objects may be in eden, from-space, or to-space |
duke@435 | 75 | // An object A in eden or from-space may have a copy B |
duke@435 | 76 | // in to-space. If B exists, all roots that once pointed |
duke@435 | 77 | // to A must now point to B. |
duke@435 | 78 | // All objects in the young generation are unmarked. |
duke@435 | 79 | // Eden, from-space, and to-space will all be collected by |
duke@435 | 80 | // the full collection. |
duke@435 | 81 | void handle_promotion_failure(oop); |
duke@435 | 82 | |
duke@435 | 83 | // In the absence of promotion failure, we wouldn't look at "from-space" |
duke@435 | 84 | // objects after a young-gen collection. When promotion fails, however, |
duke@435 | 85 | // the subsequent full collection will look at from-space objects: |
duke@435 | 86 | // therefore we must remove their forwarding pointers. |
duke@435 | 87 | void remove_forwarding_pointers(); |
duke@435 | 88 | |
duke@435 | 89 | // Preserve the mark of "obj", if necessary, in preparation for its mark |
duke@435 | 90 | // word being overwritten with a self-forwarding-pointer. |
duke@435 | 91 | void preserve_mark_if_necessary(oop obj, markOop m); |
ysr@2380 | 92 | void preserve_mark(oop obj, markOop m); // work routine used by the above |
duke@435 | 93 | |
jcoomes@2191 | 94 | // Together, these keep <object with a preserved mark, mark value> pairs. |
jcoomes@2191 | 95 | // They should always contain the same number of elements. |
zgu@3900 | 96 | Stack<oop, mtGC> _objs_with_preserved_marks; |
zgu@3900 | 97 | Stack<markOop, mtGC> _preserved_marks_of_objs; |
duke@435 | 98 | |
duke@435 | 99 | // Promotion failure handling |
coleenp@4037 | 100 | ExtendedOopClosure *_promo_failure_scan_stack_closure; |
coleenp@4037 | 101 | void set_promo_failure_scan_stack_closure(ExtendedOopClosure *scan_stack_closure) { |
duke@435 | 102 | _promo_failure_scan_stack_closure = scan_stack_closure; |
duke@435 | 103 | } |
duke@435 | 104 | |
zgu@3900 | 105 | Stack<oop, mtGC> _promo_failure_scan_stack; |
duke@435 | 106 | void drain_promo_failure_scan_stack(void); |
duke@435 | 107 | bool _promo_failure_drain_in_progress; |
duke@435 | 108 | |
duke@435 | 109 | // Performance Counters |
duke@435 | 110 | GenerationCounters* _gen_counters; |
duke@435 | 111 | CSpaceCounters* _eden_counters; |
duke@435 | 112 | CSpaceCounters* _from_counters; |
duke@435 | 113 | CSpaceCounters* _to_counters; |
duke@435 | 114 | |
duke@435 | 115 | // sizing information |
duke@435 | 116 | size_t _max_eden_size; |
duke@435 | 117 | size_t _max_survivor_size; |
duke@435 | 118 | |
duke@435 | 119 | // Allocation support |
duke@435 | 120 | bool _should_allocate_from_space; |
duke@435 | 121 | bool should_allocate_from_space() const { |
duke@435 | 122 | return _should_allocate_from_space; |
duke@435 | 123 | } |
duke@435 | 124 | void clear_should_allocate_from_space() { |
duke@435 | 125 | _should_allocate_from_space = false; |
duke@435 | 126 | } |
duke@435 | 127 | void set_should_allocate_from_space() { |
duke@435 | 128 | _should_allocate_from_space = true; |
duke@435 | 129 | } |
duke@435 | 130 | |
brutisso@4452 | 131 | // Tenuring |
brutisso@4452 | 132 | void adjust_desired_tenuring_threshold(); |
brutisso@4452 | 133 | |
duke@435 | 134 | // Spaces |
duke@435 | 135 | EdenSpace* _eden_space; |
duke@435 | 136 | ContiguousSpace* _from_space; |
duke@435 | 137 | ContiguousSpace* _to_space; |
duke@435 | 138 | |
sla@5237 | 139 | STWGCTimer* _gc_timer; |
sla@5237 | 140 | |
duke@435 | 141 | enum SomeProtectedConstants { |
duke@435 | 142 | // Generations are GenGrain-aligned and have size that are multiples of |
duke@435 | 143 | // GenGrain. |
duke@435 | 144 | MinFreeScratchWords = 100 |
duke@435 | 145 | }; |
duke@435 | 146 | |
duke@435 | 147 | // Return the size of a survivor space if this generation were of size |
duke@435 | 148 | // gen_size. |
duke@435 | 149 | size_t compute_survivor_size(size_t gen_size, size_t alignment) const { |
duke@435 | 150 | size_t n = gen_size / (SurvivorRatio + 2); |
duke@435 | 151 | return n > alignment ? align_size_down(n, alignment) : alignment; |
duke@435 | 152 | } |
duke@435 | 153 | |
duke@435 | 154 | public: // was "protected" but caused compile error on win32 |
duke@435 | 155 | class IsAliveClosure: public BoolObjectClosure { |
duke@435 | 156 | Generation* _g; |
duke@435 | 157 | public: |
duke@435 | 158 | IsAliveClosure(Generation* g); |
duke@435 | 159 | bool do_object_b(oop p); |
duke@435 | 160 | }; |
duke@435 | 161 | |
duke@435 | 162 | class KeepAliveClosure: public OopClosure { |
duke@435 | 163 | protected: |
duke@435 | 164 | ScanWeakRefClosure* _cl; |
duke@435 | 165 | CardTableRS* _rs; |
coleenp@548 | 166 | template <class T> void do_oop_work(T* p); |
duke@435 | 167 | public: |
duke@435 | 168 | KeepAliveClosure(ScanWeakRefClosure* cl); |
coleenp@548 | 169 | virtual void do_oop(oop* p); |
coleenp@548 | 170 | virtual void do_oop(narrowOop* p); |
duke@435 | 171 | }; |
duke@435 | 172 | |
duke@435 | 173 | class FastKeepAliveClosure: public KeepAliveClosure { |
duke@435 | 174 | protected: |
duke@435 | 175 | HeapWord* _boundary; |
coleenp@548 | 176 | template <class T> void do_oop_work(T* p); |
duke@435 | 177 | public: |
duke@435 | 178 | FastKeepAliveClosure(DefNewGeneration* g, ScanWeakRefClosure* cl); |
coleenp@548 | 179 | virtual void do_oop(oop* p); |
coleenp@548 | 180 | virtual void do_oop(narrowOop* p); |
duke@435 | 181 | }; |
duke@435 | 182 | |
duke@435 | 183 | class EvacuateFollowersClosure: public VoidClosure { |
duke@435 | 184 | GenCollectedHeap* _gch; |
duke@435 | 185 | int _level; |
duke@435 | 186 | ScanClosure* _scan_cur_or_nonheap; |
duke@435 | 187 | ScanClosure* _scan_older; |
duke@435 | 188 | public: |
duke@435 | 189 | EvacuateFollowersClosure(GenCollectedHeap* gch, int level, |
duke@435 | 190 | ScanClosure* cur, ScanClosure* older); |
duke@435 | 191 | void do_void(); |
duke@435 | 192 | }; |
duke@435 | 193 | |
duke@435 | 194 | class FastEvacuateFollowersClosure: public VoidClosure { |
duke@435 | 195 | GenCollectedHeap* _gch; |
duke@435 | 196 | int _level; |
duke@435 | 197 | DefNewGeneration* _gen; |
duke@435 | 198 | FastScanClosure* _scan_cur_or_nonheap; |
duke@435 | 199 | FastScanClosure* _scan_older; |
duke@435 | 200 | public: |
duke@435 | 201 | FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level, |
duke@435 | 202 | DefNewGeneration* gen, |
duke@435 | 203 | FastScanClosure* cur, |
duke@435 | 204 | FastScanClosure* older); |
duke@435 | 205 | void do_void(); |
duke@435 | 206 | }; |
duke@435 | 207 | |
duke@435 | 208 | public: |
duke@435 | 209 | DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level, |
duke@435 | 210 | const char* policy="Copy"); |
duke@435 | 211 | |
sla@5237 | 212 | virtual void ref_processor_init(); |
sla@5237 | 213 | |
duke@435 | 214 | virtual Generation::Name kind() { return Generation::DefNew; } |
duke@435 | 215 | |
duke@435 | 216 | // Accessing spaces |
duke@435 | 217 | EdenSpace* eden() const { return _eden_space; } |
duke@435 | 218 | ContiguousSpace* from() const { return _from_space; } |
duke@435 | 219 | ContiguousSpace* to() const { return _to_space; } |
duke@435 | 220 | |
coleenp@548 | 221 | virtual CompactibleSpace* first_compaction_space() const; |
duke@435 | 222 | |
duke@435 | 223 | // Space enquiries |
duke@435 | 224 | size_t capacity() const; |
duke@435 | 225 | size_t used() const; |
duke@435 | 226 | size_t free() const; |
duke@435 | 227 | size_t max_capacity() const; |
duke@435 | 228 | size_t capacity_before_gc() const; |
duke@435 | 229 | size_t unsafe_max_alloc_nogc() const; |
duke@435 | 230 | size_t contiguous_available() const; |
duke@435 | 231 | |
duke@435 | 232 | size_t max_eden_size() const { return _max_eden_size; } |
duke@435 | 233 | size_t max_survivor_size() const { return _max_survivor_size; } |
duke@435 | 234 | |
duke@435 | 235 | bool supports_inline_contig_alloc() const { return true; } |
duke@435 | 236 | HeapWord** top_addr() const; |
duke@435 | 237 | HeapWord** end_addr() const; |
duke@435 | 238 | |
duke@435 | 239 | // Thread-local allocation buffers |
duke@435 | 240 | bool supports_tlab_allocation() const { return true; } |
coleenp@548 | 241 | size_t tlab_capacity() const; |
coleenp@548 | 242 | size_t unsafe_max_tlab_alloc() const; |
duke@435 | 243 | |
duke@435 | 244 | // Grow the generation by the specified number of bytes. |
duke@435 | 245 | // The size of bytes is assumed to be properly aligned. |
duke@435 | 246 | // Return true if the expansion was successful. |
duke@435 | 247 | bool expand(size_t bytes); |
duke@435 | 248 | |
duke@435 | 249 | // DefNewGeneration cannot currently expand except at |
duke@435 | 250 | // a GC. |
duke@435 | 251 | virtual bool is_maximal_no_gc() const { return true; } |
duke@435 | 252 | |
duke@435 | 253 | // Iteration |
duke@435 | 254 | void object_iterate(ObjectClosure* blk); |
duke@435 | 255 | void object_iterate_since_last_GC(ObjectClosure* cl); |
duke@435 | 256 | |
duke@435 | 257 | void younger_refs_iterate(OopsInGenClosure* cl); |
duke@435 | 258 | |
duke@435 | 259 | void space_iterate(SpaceClosure* blk, bool usedOnly = false); |
duke@435 | 260 | |
duke@435 | 261 | // Allocation support |
duke@435 | 262 | virtual bool should_allocate(size_t word_size, bool is_tlab) { |
duke@435 | 263 | assert(UseTLAB || !is_tlab, "Should not allocate tlab"); |
duke@435 | 264 | |
duke@435 | 265 | size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize); |
duke@435 | 266 | |
duke@435 | 267 | const bool non_zero = word_size > 0; |
duke@435 | 268 | const bool overflows = word_size >= overflow_limit; |
duke@435 | 269 | const bool check_too_big = _pretenure_size_threshold_words > 0; |
duke@435 | 270 | const bool not_too_big = word_size < _pretenure_size_threshold_words; |
duke@435 | 271 | const bool size_ok = is_tlab || !check_too_big || not_too_big; |
duke@435 | 272 | |
duke@435 | 273 | bool result = !overflows && |
duke@435 | 274 | non_zero && |
duke@435 | 275 | size_ok; |
duke@435 | 276 | |
duke@435 | 277 | return result; |
duke@435 | 278 | } |
duke@435 | 279 | |
coleenp@548 | 280 | HeapWord* allocate(size_t word_size, bool is_tlab); |
duke@435 | 281 | HeapWord* allocate_from_space(size_t word_size); |
duke@435 | 282 | |
coleenp@548 | 283 | HeapWord* par_allocate(size_t word_size, bool is_tlab); |
duke@435 | 284 | |
duke@435 | 285 | // Prologue & Epilogue |
coleenp@548 | 286 | virtual void gc_prologue(bool full); |
duke@435 | 287 | virtual void gc_epilogue(bool full); |
duke@435 | 288 | |
jmasa@698 | 289 | // Save the tops for eden, from, and to |
jmasa@698 | 290 | virtual void record_spaces_top(); |
jmasa@698 | 291 | |
duke@435 | 292 | // Doesn't require additional work during GC prologue and epilogue |
duke@435 | 293 | virtual bool performs_in_place_marking() const { return false; } |
duke@435 | 294 | |
duke@435 | 295 | // Accessing marks |
duke@435 | 296 | void save_marks(); |
duke@435 | 297 | void reset_saved_marks(); |
duke@435 | 298 | bool no_allocs_since_save_marks(); |
duke@435 | 299 | |
duke@435 | 300 | // Need to declare the full complement of closures, whether we'll |
duke@435 | 301 | // override them or not, or get message from the compiler: |
duke@435 | 302 | // oop_since_save_marks_iterate_nv hides virtual function... |
duke@435 | 303 | #define DefNew_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ |
duke@435 | 304 | void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); |
duke@435 | 305 | |
duke@435 | 306 | ALL_SINCE_SAVE_MARKS_CLOSURES(DefNew_SINCE_SAVE_MARKS_DECL) |
duke@435 | 307 | |
duke@435 | 308 | #undef DefNew_SINCE_SAVE_MARKS_DECL |
duke@435 | 309 | |
duke@435 | 310 | // For non-youngest collection, the DefNewGeneration can contribute |
duke@435 | 311 | // "to-space". |
jmasa@698 | 312 | virtual void contribute_scratch(ScratchBlock*& list, Generation* requestor, |
duke@435 | 313 | size_t max_alloc_words); |
duke@435 | 314 | |
jmasa@698 | 315 | // Reset for contribution of "to-space". |
jmasa@698 | 316 | virtual void reset_scratch(); |
jmasa@698 | 317 | |
duke@435 | 318 | // GC support |
duke@435 | 319 | virtual void compute_new_size(); |
ysr@2243 | 320 | |
ysr@2243 | 321 | // Returns true if the collection is likely to be safely |
ysr@2243 | 322 | // completed. Even if this method returns true, a collection |
ysr@2243 | 323 | // may not be guaranteed to succeed, and the system should be |
ysr@2243 | 324 | // able to safely unwind and recover from that failure, albeit |
ysr@2243 | 325 | // at some additional cost. Override superclass's implementation. |
ysr@2243 | 326 | virtual bool collection_attempt_is_safe(); |
ysr@2243 | 327 | |
duke@435 | 328 | virtual void collect(bool full, |
duke@435 | 329 | bool clear_all_soft_refs, |
duke@435 | 330 | size_t size, |
duke@435 | 331 | bool is_tlab); |
duke@435 | 332 | HeapWord* expand_and_allocate(size_t size, |
duke@435 | 333 | bool is_tlab, |
duke@435 | 334 | bool parallel = false); |
duke@435 | 335 | |
coleenp@548 | 336 | oop copy_to_survivor_space(oop old); |
jwilhelm@4129 | 337 | uint tenuring_threshold() { return _tenuring_threshold; } |
duke@435 | 338 | |
duke@435 | 339 | // Performance Counter support |
duke@435 | 340 | void update_counters(); |
duke@435 | 341 | |
duke@435 | 342 | // Printing |
duke@435 | 343 | virtual const char* name() const; |
duke@435 | 344 | virtual const char* short_name() const { return "DefNew"; } |
duke@435 | 345 | |
duke@435 | 346 | bool must_be_youngest() const { return true; } |
duke@435 | 347 | bool must_be_oldest() const { return false; } |
duke@435 | 348 | |
duke@435 | 349 | // PrintHeapAtGC support. |
duke@435 | 350 | void print_on(outputStream* st) const; |
duke@435 | 351 | |
brutisso@3711 | 352 | void verify(); |
duke@435 | 353 | |
jcoomes@2191 | 354 | bool promo_failure_scan_is_complete() const { |
jcoomes@2191 | 355 | return _promo_failure_scan_stack.is_empty(); |
jcoomes@2191 | 356 | } |
jcoomes@2191 | 357 | |
duke@435 | 358 | protected: |
jmasa@698 | 359 | // If clear_space is true, clear the survivor spaces. Eden is |
jmasa@698 | 360 | // cleared if the minimum size of eden is 0. If mangle_space |
jmasa@698 | 361 | // is true, also mangle the space in debug mode. |
jmasa@698 | 362 | void compute_space_boundaries(uintx minimum_eden_size, |
jmasa@698 | 363 | bool clear_space, |
jmasa@698 | 364 | bool mangle_space); |
duke@435 | 365 | // Scavenge support |
duke@435 | 366 | void swap_spaces(); |
duke@435 | 367 | }; |
stefank@2314 | 368 | |
stefank@2314 | 369 | #endif // SHARE_VM_MEMORY_DEFNEWGENERATION_HPP |