Mercurial > hg > truffle
annotate src/share/vm/gc_interface/collectedHeap.hpp @ 3774:c9ca3f51cf41
6994322: Remove the is_tlab and is_noref / is_large_noref parameters from the CollectedHeap
Summary: Remove two unused parameters from the mem_allocate() method and update its uses accordingly.
Reviewed-by: stefank, johnc
| author | tonyp |
|---|---|
| date | Thu, 16 Jun 2011 15:51:57 -0400 |
| parents | 6747fd0512e0 |
| children | a92cdbac8b9e |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP |
| 26 #define SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP | |
| 27 | |
| 28 #include "gc_interface/gcCause.hpp" | |
| 29 #include "memory/allocation.hpp" | |
| 30 #include "memory/barrierSet.hpp" | |
| 31 #include "runtime/handles.hpp" | |
| 32 #include "runtime/perfData.hpp" | |
| 33 #include "runtime/safepoint.hpp" | |
| 34 | |
| 0 | 35 // A "CollectedHeap" is an implementation of a java heap for HotSpot. This |
| 36 // is an abstract class: there may be many different kinds of heaps. This | |
| 37 // class defines the functions that a heap must implement, and contains | |
| 38 // infrastructure common to all heaps. | |
| 39 | |
| 40 class BarrierSet; | |
| 41 class ThreadClosure; | |
| 42 class AdaptiveSizePolicy; | |
| 43 class Thread; | |
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44 class CollectorPolicy; |
| 0 | 45 |
| 46 // | |
| 47 // CollectedHeap | |
| 48 // SharedHeap | |
| 49 // GenCollectedHeap | |
| 50 // G1CollectedHeap | |
| 51 // ParallelScavengeHeap | |
| 52 // | |
| 53 class CollectedHeap : public CHeapObj { | |
| 54 friend class VMStructs; | |
| 55 friend class IsGCActiveMark; // Block structured external access to _is_gc_active | |
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56 friend class constantPoolCacheKlass; // allocate() method inserts is_conc_safe |
| 0 | 57 |
| 58 #ifdef ASSERT | |
| 59 static int _fire_out_of_memory_count; | |
| 60 #endif | |
| 61 | |
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62 // Used for filler objects (static, but initialized in ctor). |
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63 static size_t _filler_array_max_size; |
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64 |
| 1166 | 65 // Used in support of ReduceInitialCardMarks; only consulted if COMPILER2 is being used |
| 66 bool _defer_initial_card_mark; | |
| 67 | |
| 0 | 68 protected: |
| 69 MemRegion _reserved; | |
| 70 BarrierSet* _barrier_set; | |
| 71 bool _is_gc_active; | |
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72 int _n_par_threads; |
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73 |
| 0 | 74 unsigned int _total_collections; // ... started |
| 75 unsigned int _total_full_collections; // ... started | |
| 76 NOT_PRODUCT(volatile size_t _promotion_failure_alot_count;) | |
| 77 NOT_PRODUCT(volatile size_t _promotion_failure_alot_gc_number;) | |
| 78 | |
| 79 // Reason for current garbage collection. Should be set to | |
| 80 // a value reflecting no collection between collections. | |
| 81 GCCause::Cause _gc_cause; | |
| 82 GCCause::Cause _gc_lastcause; | |
| 83 PerfStringVariable* _perf_gc_cause; | |
| 84 PerfStringVariable* _perf_gc_lastcause; | |
| 85 | |
| 86 // Constructor | |
| 87 CollectedHeap(); | |
| 88 | |
| 1166 | 89 // Do common initializations that must follow instance construction, |
| 90 // for example, those needing virtual calls. | |
| 91 // This code could perhaps be moved into initialize() but would | |
| 92 // be slightly more awkward because we want the latter to be a | |
| 93 // pure virtual. | |
| 94 void pre_initialize(); | |
| 95 | |
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96 // Create a new tlab. All TLAB allocations must go through this. |
| 0 | 97 virtual HeapWord* allocate_new_tlab(size_t size); |
| 98 | |
| 99 // Accumulate statistics on all tlabs. | |
| 100 virtual void accumulate_statistics_all_tlabs(); | |
| 101 | |
| 102 // Reinitialize tlabs before resuming mutators. | |
| 103 virtual void resize_all_tlabs(); | |
| 104 | |
| 105 protected: | |
| 106 // Allocate from the current thread's TLAB, with broken-out slow path. | |
| 107 inline static HeapWord* allocate_from_tlab(Thread* thread, size_t size); | |
| 108 static HeapWord* allocate_from_tlab_slow(Thread* thread, size_t size); | |
| 109 | |
| 110 // Allocate an uninitialized block of the given size, or returns NULL if | |
| 111 // this is impossible. | |
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112 inline static HeapWord* common_mem_allocate_noinit(size_t size, TRAPS); |
| 0 | 113 |
| 114 // Like allocate_init, but the block returned by a successful allocation | |
| 115 // is guaranteed initialized to zeros. | |
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116 inline static HeapWord* common_mem_allocate_init(size_t size, TRAPS); |
| 0 | 117 |
| 118 // Same as common_mem version, except memory is allocated in the permanent area | |
| 119 // If there is no permanent area, revert to common_mem_allocate_noinit | |
| 120 inline static HeapWord* common_permanent_mem_allocate_noinit(size_t size, TRAPS); | |
| 121 | |
| 122 // Same as common_mem version, except memory is allocated in the permanent area | |
| 123 // If there is no permanent area, revert to common_mem_allocate_init | |
| 124 inline static HeapWord* common_permanent_mem_allocate_init(size_t size, TRAPS); | |
| 125 | |
| 126 // Helper functions for (VM) allocation. | |
| 127 inline static void post_allocation_setup_common(KlassHandle klass, | |
| 128 HeapWord* obj, size_t size); | |
| 129 inline static void post_allocation_setup_no_klass_install(KlassHandle klass, | |
| 130 HeapWord* objPtr, | |
| 131 size_t size); | |
| 132 | |
| 133 inline static void post_allocation_setup_obj(KlassHandle klass, | |
| 134 HeapWord* obj, size_t size); | |
| 135 | |
| 136 inline static void post_allocation_setup_array(KlassHandle klass, | |
| 137 HeapWord* obj, size_t size, | |
| 138 int length); | |
| 139 | |
| 140 // Clears an allocated object. | |
| 141 inline static void init_obj(HeapWord* obj, size_t size); | |
| 142 | |
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143 // Filler object utilities. |
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144 static inline size_t filler_array_hdr_size(); |
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145 static inline size_t filler_array_min_size(); |
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146 static inline size_t filler_array_max_size(); |
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147 |
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148 DEBUG_ONLY(static void fill_args_check(HeapWord* start, size_t words);) |
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149 DEBUG_ONLY(static void zap_filler_array(HeapWord* start, size_t words, bool zap = true);) |
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150 |
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151 // Fill with a single array; caller must ensure filler_array_min_size() <= |
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152 // words <= filler_array_max_size(). |
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153 static inline void fill_with_array(HeapWord* start, size_t words, bool zap = true); |
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154 |
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155 // Fill with a single object (either an int array or a java.lang.Object). |
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156 static inline void fill_with_object_impl(HeapWord* start, size_t words, bool zap = true); |
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157 |
| 0 | 158 // Verification functions |
| 159 virtual void check_for_bad_heap_word_value(HeapWord* addr, size_t size) | |
| 160 PRODUCT_RETURN; | |
| 161 virtual void check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) | |
| 162 PRODUCT_RETURN; | |
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163 debug_only(static void check_for_valid_allocation_state();) |
| 0 | 164 |
| 165 public: | |
| 166 enum Name { | |
| 167 Abstract, | |
| 168 SharedHeap, | |
| 169 GenCollectedHeap, | |
| 170 ParallelScavengeHeap, | |
| 171 G1CollectedHeap | |
| 172 }; | |
| 173 | |
| 174 virtual CollectedHeap::Name kind() const { return CollectedHeap::Abstract; } | |
| 175 | |
| 176 /** | |
| 177 * Returns JNI error code JNI_ENOMEM if memory could not be allocated, | |
| 178 * and JNI_OK on success. | |
| 179 */ | |
| 180 virtual jint initialize() = 0; | |
| 181 | |
| 182 // In many heaps, there will be a need to perform some initialization activities | |
| 183 // after the Universe is fully formed, but before general heap allocation is allowed. | |
| 184 // This is the correct place to place such initialization methods. | |
| 185 virtual void post_initialize() = 0; | |
| 186 | |
| 187 MemRegion reserved_region() const { return _reserved; } | |
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188 address base() const { return (address)reserved_region().start(); } |
| 0 | 189 |
| 190 // Future cleanup here. The following functions should specify bytes or | |
| 191 // heapwords as part of their signature. | |
| 192 virtual size_t capacity() const = 0; | |
| 193 virtual size_t used() const = 0; | |
| 194 | |
| 195 // Return "true" if the part of the heap that allocates Java | |
| 196 // objects has reached the maximal committed limit that it can | |
| 197 // reach, without a garbage collection. | |
| 198 virtual bool is_maximal_no_gc() const = 0; | |
| 199 | |
| 200 virtual size_t permanent_capacity() const = 0; | |
| 201 virtual size_t permanent_used() const = 0; | |
| 202 | |
| 203 // Support for java.lang.Runtime.maxMemory(): return the maximum amount of | |
| 204 // memory that the vm could make available for storing 'normal' java objects. | |
| 205 // This is based on the reserved address space, but should not include space | |
| 206 // that the vm uses internally for bookkeeping or temporary storage (e.g., | |
| 207 // perm gen space or, in the case of the young gen, one of the survivor | |
| 208 // spaces). | |
| 209 virtual size_t max_capacity() const = 0; | |
| 210 | |
| 211 // Returns "TRUE" if "p" points into the reserved area of the heap. | |
| 212 bool is_in_reserved(const void* p) const { | |
| 213 return _reserved.contains(p); | |
| 214 } | |
| 215 | |
| 216 bool is_in_reserved_or_null(const void* p) const { | |
| 217 return p == NULL || is_in_reserved(p); | |
| 218 } | |
| 219 | |
| 220 // Returns "TRUE" if "p" points to the head of an allocated object in the | |
| 221 // heap. Since this method can be expensive in general, we restrict its | |
| 222 // use to assertion checking only. | |
| 223 virtual bool is_in(const void* p) const = 0; | |
| 224 | |
| 225 bool is_in_or_null(const void* p) const { | |
| 226 return p == NULL || is_in(p); | |
| 227 } | |
| 228 | |
| 229 // Let's define some terms: a "closed" subset of a heap is one that | |
| 230 // | |
| 231 // 1) contains all currently-allocated objects, and | |
| 232 // | |
| 233 // 2) is closed under reference: no object in the closed subset | |
| 234 // references one outside the closed subset. | |
| 235 // | |
| 236 // Membership in a heap's closed subset is useful for assertions. | |
| 237 // Clearly, the entire heap is a closed subset, so the default | |
| 238 // implementation is to use "is_in_reserved". But this may not be too | |
| 239 // liberal to perform useful checking. Also, the "is_in" predicate | |
| 240 // defines a closed subset, but may be too expensive, since "is_in" | |
| 241 // verifies that its argument points to an object head. The | |
| 242 // "closed_subset" method allows a heap to define an intermediate | |
| 243 // predicate, allowing more precise checking than "is_in_reserved" at | |
| 244 // lower cost than "is_in." | |
| 245 | |
| 246 // One important case is a heap composed of disjoint contiguous spaces, | |
| 247 // such as the Garbage-First collector. Such heaps have a convenient | |
| 248 // closed subset consisting of the allocated portions of those | |
| 249 // contiguous spaces. | |
| 250 | |
| 251 // Return "TRUE" iff the given pointer points into the heap's defined | |
| 252 // closed subset (which defaults to the entire heap). | |
| 253 virtual bool is_in_closed_subset(const void* p) const { | |
| 254 return is_in_reserved(p); | |
| 255 } | |
| 256 | |
| 257 bool is_in_closed_subset_or_null(const void* p) const { | |
| 258 return p == NULL || is_in_closed_subset(p); | |
| 259 } | |
| 260 | |
| 941 | 261 // XXX is_permanent() and is_in_permanent() should be better named |
| 262 // to distinguish one from the other. | |
| 263 | |
| 0 | 264 // Returns "TRUE" if "p" is allocated as "permanent" data. |
| 265 // If the heap does not use "permanent" data, returns the same | |
| 266 // value is_in_reserved() would return. | |
| 267 // NOTE: this actually returns true if "p" is in reserved space | |
| 268 // for the space not that it is actually allocated (i.e. in committed | |
| 269 // space). If you need the more conservative answer use is_permanent(). | |
| 270 virtual bool is_in_permanent(const void *p) const = 0; | |
| 271 | |
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272 |
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273 #ifdef ASSERT |
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274 // Returns true if "p" is in the part of the |
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275 // heap being collected. |
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276 virtual bool is_in_partial_collection(const void *p) = 0; |
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277 #endif |
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278 |
| 941 | 279 bool is_in_permanent_or_null(const void *p) const { |
| 280 return p == NULL || is_in_permanent(p); | |
| 281 } | |
| 282 | |
| 0 | 283 // Returns "TRUE" if "p" is in the committed area of "permanent" data. |
| 284 // If the heap does not use "permanent" data, returns the same | |
| 285 // value is_in() would return. | |
| 286 virtual bool is_permanent(const void *p) const = 0; | |
| 287 | |
| 941 | 288 bool is_permanent_or_null(const void *p) const { |
| 289 return p == NULL || is_permanent(p); | |
| 0 | 290 } |
| 291 | |
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292 // An object is scavengable if its location may move during a scavenge. |
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293 // (A scavenge is a GC which is not a full GC.) |
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294 virtual bool is_scavengable(const void *p) = 0; |
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295 |
| 0 | 296 // Returns "TRUE" if "p" is a method oop in the |
| 297 // current heap, with high probability. This predicate | |
| 298 // is not stable, in general. | |
| 299 bool is_valid_method(oop p) const; | |
| 300 | |
| 301 void set_gc_cause(GCCause::Cause v) { | |
| 302 if (UsePerfData) { | |
| 303 _gc_lastcause = _gc_cause; | |
| 304 _perf_gc_lastcause->set_value(GCCause::to_string(_gc_lastcause)); | |
| 305 _perf_gc_cause->set_value(GCCause::to_string(v)); | |
| 306 } | |
| 307 _gc_cause = v; | |
| 308 } | |
| 309 GCCause::Cause gc_cause() { return _gc_cause; } | |
| 310 | |
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311 // Number of threads currently working on GC tasks. |
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312 int n_par_threads() { return _n_par_threads; } |
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313 |
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314 // May be overridden to set additional parallelism. |
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315 virtual void set_par_threads(int t) { _n_par_threads = t; }; |
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316 |
| 0 | 317 // Preload classes into the shared portion of the heap, and then dump |
| 318 // that data to a file so that it can be loaded directly by another | |
| 319 // VM (then terminate). | |
| 320 virtual void preload_and_dump(TRAPS) { ShouldNotReachHere(); } | |
| 321 | |
| 322 // General obj/array allocation facilities. | |
| 323 inline static oop obj_allocate(KlassHandle klass, int size, TRAPS); | |
| 324 inline static oop array_allocate(KlassHandle klass, int size, int length, TRAPS); | |
| 325 | |
| 326 // Special obj/array allocation facilities. | |
| 327 // Some heaps may want to manage "permanent" data uniquely. These default | |
| 328 // to the general routines if the heap does not support such handling. | |
| 329 inline static oop permanent_obj_allocate(KlassHandle klass, int size, TRAPS); | |
| 330 // permanent_obj_allocate_no_klass_install() does not do the installation of | |
| 331 // the klass pointer in the newly created object (as permanent_obj_allocate() | |
| 332 // above does). This allows for a delay in the installation of the klass | |
| 333 // pointer that is needed during the create of klassKlass's. The | |
| 334 // method post_allocation_install_obj_klass() is used to install the | |
| 335 // klass pointer. | |
| 336 inline static oop permanent_obj_allocate_no_klass_install(KlassHandle klass, | |
| 337 int size, | |
| 338 TRAPS); | |
| 339 inline static void post_allocation_install_obj_klass(KlassHandle klass, | |
| 340 oop obj, | |
| 341 int size); | |
| 342 inline static oop permanent_array_allocate(KlassHandle klass, int size, int length, TRAPS); | |
| 343 | |
| 344 // Raw memory allocation facilities | |
| 345 // The obj and array allocate methods are covers for these methods. | |
| 346 // The permanent allocation method should default to mem_allocate if | |
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347 // permanent memory isn't supported. mem_allocate() should never be |
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348 // called to allocate TLABs, only individual objects. |
| 0 | 349 virtual HeapWord* mem_allocate(size_t size, |
| 350 bool* gc_overhead_limit_was_exceeded) = 0; | |
| 351 virtual HeapWord* permanent_mem_allocate(size_t size) = 0; | |
| 352 | |
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353 // Utilities for turning raw memory into filler objects. |
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354 // |
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355 // min_fill_size() is the smallest region that can be filled. |
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356 // fill_with_objects() can fill arbitrary-sized regions of the heap using |
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357 // multiple objects. fill_with_object() is for regions known to be smaller |
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358 // than the largest array of integers; it uses a single object to fill the |
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359 // region and has slightly less overhead. |
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360 static size_t min_fill_size() { |
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361 return size_t(align_object_size(oopDesc::header_size())); |
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362 } |
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363 |
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364 static void fill_with_objects(HeapWord* start, size_t words, bool zap = true); |
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365 |
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366 static void fill_with_object(HeapWord* start, size_t words, bool zap = true); |
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367 static void fill_with_object(MemRegion region, bool zap = true) { |
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368 fill_with_object(region.start(), region.word_size(), zap); |
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369 } |
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370 static void fill_with_object(HeapWord* start, HeapWord* end, bool zap = true) { |
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371 fill_with_object(start, pointer_delta(end, start), zap); |
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372 } |
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373 |
| 0 | 374 // Some heaps may offer a contiguous region for shared non-blocking |
| 375 // allocation, via inlined code (by exporting the address of the top and | |
| 376 // end fields defining the extent of the contiguous allocation region.) | |
| 377 | |
| 378 // This function returns "true" iff the heap supports this kind of | |
| 379 // allocation. (Default is "no".) | |
| 380 virtual bool supports_inline_contig_alloc() const { | |
| 381 return false; | |
| 382 } | |
| 383 // These functions return the addresses of the fields that define the | |
| 384 // boundaries of the contiguous allocation area. (These fields should be | |
| 385 // physically near to one another.) | |
| 386 virtual HeapWord** top_addr() const { | |
| 387 guarantee(false, "inline contiguous allocation not supported"); | |
| 388 return NULL; | |
| 389 } | |
| 390 virtual HeapWord** end_addr() const { | |
| 391 guarantee(false, "inline contiguous allocation not supported"); | |
| 392 return NULL; | |
| 393 } | |
| 394 | |
| 395 // Some heaps may be in an unparseable state at certain times between | |
| 396 // collections. This may be necessary for efficient implementation of | |
| 397 // certain allocation-related activities. Calling this function before | |
| 398 // attempting to parse a heap ensures that the heap is in a parsable | |
| 399 // state (provided other concurrent activity does not introduce | |
| 400 // unparsability). It is normally expected, therefore, that this | |
| 401 // method is invoked with the world stopped. | |
| 402 // NOTE: if you override this method, make sure you call | |
| 403 // super::ensure_parsability so that the non-generational | |
| 404 // part of the work gets done. See implementation of | |
| 405 // CollectedHeap::ensure_parsability and, for instance, | |
| 406 // that of GenCollectedHeap::ensure_parsability(). | |
| 407 // The argument "retire_tlabs" controls whether existing TLABs | |
| 408 // are merely filled or also retired, thus preventing further | |
| 409 // allocation from them and necessitating allocation of new TLABs. | |
| 410 virtual void ensure_parsability(bool retire_tlabs); | |
| 411 | |
| 412 // Return an estimate of the maximum allocation that could be performed | |
| 413 // without triggering any collection or expansion activity. In a | |
| 414 // generational collector, for example, this is probably the largest | |
| 415 // allocation that could be supported (without expansion) in the youngest | |
| 416 // generation. It is "unsafe" because no locks are taken; the result | |
| 417 // should be treated as an approximation, not a guarantee, for use in | |
| 418 // heuristic resizing decisions. | |
| 419 virtual size_t unsafe_max_alloc() = 0; | |
| 420 | |
| 421 // Section on thread-local allocation buffers (TLABs) | |
| 422 // If the heap supports thread-local allocation buffers, it should override | |
| 423 // the following methods: | |
| 424 // Returns "true" iff the heap supports thread-local allocation buffers. | |
| 425 // The default is "no". | |
| 426 virtual bool supports_tlab_allocation() const { | |
| 427 return false; | |
| 428 } | |
| 429 // The amount of space available for thread-local allocation buffers. | |
| 430 virtual size_t tlab_capacity(Thread *thr) const { | |
| 431 guarantee(false, "thread-local allocation buffers not supported"); | |
| 432 return 0; | |
| 433 } | |
| 434 // An estimate of the maximum allocation that could be performed | |
| 435 // for thread-local allocation buffers without triggering any | |
| 436 // collection or expansion activity. | |
| 437 virtual size_t unsafe_max_tlab_alloc(Thread *thr) const { | |
| 438 guarantee(false, "thread-local allocation buffers not supported"); | |
| 439 return 0; | |
| 440 } | |
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441 |
| 0 | 442 // Can a compiler initialize a new object without store barriers? |
| 443 // This permission only extends from the creation of a new object | |
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444 // via a TLAB up to the first subsequent safepoint. If such permission |
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445 // is granted for this heap type, the compiler promises to call |
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446 // defer_store_barrier() below on any slow path allocation of |
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447 // a new object for which such initializing store barriers will |
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448 // have been elided. |
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449 virtual bool can_elide_tlab_store_barriers() const = 0; |
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450 |
| 0 | 451 // If a compiler is eliding store barriers for TLAB-allocated objects, |
| 452 // there is probably a corresponding slow path which can produce | |
| 453 // an object allocated anywhere. The compiler's runtime support | |
| 454 // promises to call this function on such a slow-path-allocated | |
| 455 // object before performing initializations that have elided | |
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456 // store barriers. Returns new_obj, or maybe a safer copy thereof. |
| 1166 | 457 virtual oop new_store_pre_barrier(JavaThread* thread, oop new_obj); |
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458 |
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459 // Answers whether an initializing store to a new object currently |
| 1166 | 460 // allocated at the given address doesn't need a store |
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461 // barrier. Returns "true" if it doesn't need an initializing |
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462 // store barrier; answers "false" if it does. |
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463 virtual bool can_elide_initializing_store_barrier(oop new_obj) = 0; |
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464 |
| 1166 | 465 // If a compiler is eliding store barriers for TLAB-allocated objects, |
| 466 // we will be informed of a slow-path allocation by a call | |
| 467 // to new_store_pre_barrier() above. Such a call precedes the | |
| 468 // initialization of the object itself, and no post-store-barriers will | |
| 469 // be issued. Some heap types require that the barrier strictly follows | |
| 470 // the initializing stores. (This is currently implemented by deferring the | |
| 471 // barrier until the next slow-path allocation or gc-related safepoint.) | |
| 472 // This interface answers whether a particular heap type needs the card | |
| 473 // mark to be thus strictly sequenced after the stores. | |
| 474 virtual bool card_mark_must_follow_store() const = 0; | |
| 475 | |
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476 // If the CollectedHeap was asked to defer a store barrier above, |
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477 // this informs it to flush such a deferred store barrier to the |
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478 // remembered set. |
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479 virtual void flush_deferred_store_barrier(JavaThread* thread); |
| 0 | 480 |
| 481 // Can a compiler elide a store barrier when it writes | |
| 482 // a permanent oop into the heap? Applies when the compiler | |
| 483 // is storing x to the heap, where x->is_perm() is true. | |
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484 virtual bool can_elide_permanent_oop_store_barriers() const = 0; |
| 0 | 485 |
| 486 // Does this heap support heap inspection (+PrintClassHistogram?) | |
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487 virtual bool supports_heap_inspection() const = 0; |
| 0 | 488 |
| 489 // Perform a collection of the heap; intended for use in implementing | |
| 490 // "System.gc". This probably implies as full a collection as the | |
| 491 // "CollectedHeap" supports. | |
| 492 virtual void collect(GCCause::Cause cause) = 0; | |
| 493 | |
| 494 // This interface assumes that it's being called by the | |
| 495 // vm thread. It collects the heap assuming that the | |
| 496 // heap lock is already held and that we are executing in | |
| 497 // the context of the vm thread. | |
| 498 virtual void collect_as_vm_thread(GCCause::Cause cause) = 0; | |
| 499 | |
| 500 // Returns the barrier set for this heap | |
| 501 BarrierSet* barrier_set() { return _barrier_set; } | |
| 502 | |
| 503 // Returns "true" iff there is a stop-world GC in progress. (I assume | |
| 504 // that it should answer "false" for the concurrent part of a concurrent | |
| 505 // collector -- dld). | |
| 506 bool is_gc_active() const { return _is_gc_active; } | |
| 507 | |
| 508 // Total number of GC collections (started) | |
| 509 unsigned int total_collections() const { return _total_collections; } | |
| 510 unsigned int total_full_collections() const { return _total_full_collections;} | |
| 511 | |
| 512 // Increment total number of GC collections (started) | |
| 513 // Should be protected but used by PSMarkSweep - cleanup for 1.4.2 | |
| 514 void increment_total_collections(bool full = false) { | |
| 515 _total_collections++; | |
| 516 if (full) { | |
| 517 increment_total_full_collections(); | |
| 518 } | |
| 519 } | |
| 520 | |
| 521 void increment_total_full_collections() { _total_full_collections++; } | |
| 522 | |
| 523 // Return the AdaptiveSizePolicy for the heap. | |
| 524 virtual AdaptiveSizePolicy* size_policy() = 0; | |
| 525 | |
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526 // Return the CollectorPolicy for the heap |
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527 virtual CollectorPolicy* collector_policy() const = 0; |
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528 |
| 0 | 529 // Iterate over all the ref-containing fields of all objects, calling |
| 530 // "cl.do_oop" on each. This includes objects in permanent memory. | |
| 531 virtual void oop_iterate(OopClosure* cl) = 0; | |
| 532 | |
| 533 // Iterate over all objects, calling "cl.do_object" on each. | |
| 534 // This includes objects in permanent memory. | |
| 535 virtual void object_iterate(ObjectClosure* cl) = 0; | |
| 536 | |
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537 // Similar to object_iterate() except iterates only |
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538 // over live objects. |
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539 virtual void safe_object_iterate(ObjectClosure* cl) = 0; |
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540 |
| 0 | 541 // Behaves the same as oop_iterate, except only traverses |
| 542 // interior pointers contained in permanent memory. If there | |
| 543 // is no permanent memory, does nothing. | |
| 544 virtual void permanent_oop_iterate(OopClosure* cl) = 0; | |
| 545 | |
| 546 // Behaves the same as object_iterate, except only traverses | |
| 547 // object contained in permanent memory. If there is no | |
| 548 // permanent memory, does nothing. | |
| 549 virtual void permanent_object_iterate(ObjectClosure* cl) = 0; | |
| 550 | |
| 551 // NOTE! There is no requirement that a collector implement these | |
| 552 // functions. | |
| 553 // | |
| 554 // A CollectedHeap is divided into a dense sequence of "blocks"; that is, | |
| 555 // each address in the (reserved) heap is a member of exactly | |
| 556 // one block. The defining characteristic of a block is that it is | |
| 557 // possible to find its size, and thus to progress forward to the next | |
| 558 // block. (Blocks may be of different sizes.) Thus, blocks may | |
| 559 // represent Java objects, or they might be free blocks in a | |
| 560 // free-list-based heap (or subheap), as long as the two kinds are | |
| 561 // distinguishable and the size of each is determinable. | |
| 562 | |
| 563 // Returns the address of the start of the "block" that contains the | |
| 564 // address "addr". We say "blocks" instead of "object" since some heaps | |
| 565 // may not pack objects densely; a chunk may either be an object or a | |
| 566 // non-object. | |
| 567 virtual HeapWord* block_start(const void* addr) const = 0; | |
| 568 | |
| 569 // Requires "addr" to be the start of a chunk, and returns its size. | |
| 570 // "addr + size" is required to be the start of a new chunk, or the end | |
| 571 // of the active area of the heap. | |
| 572 virtual size_t block_size(const HeapWord* addr) const = 0; | |
| 573 | |
| 574 // Requires "addr" to be the start of a block, and returns "TRUE" iff | |
| 575 // the block is an object. | |
| 576 virtual bool block_is_obj(const HeapWord* addr) const = 0; | |
| 577 | |
| 578 // Returns the longest time (in ms) that has elapsed since the last | |
| 579 // time that any part of the heap was examined by a garbage collection. | |
| 580 virtual jlong millis_since_last_gc() = 0; | |
| 581 | |
| 582 // Perform any cleanup actions necessary before allowing a verification. | |
| 583 virtual void prepare_for_verify() = 0; | |
| 584 | |
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585 // Generate any dumps preceding or following a full gc |
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586 void pre_full_gc_dump(); |
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587 void post_full_gc_dump(); |
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588 |
| 0 | 589 virtual void print() const = 0; |
| 590 virtual void print_on(outputStream* st) const = 0; | |
| 591 | |
| 592 // Print all GC threads (other than the VM thread) | |
| 593 // used by this heap. | |
| 594 virtual void print_gc_threads_on(outputStream* st) const = 0; | |
| 595 void print_gc_threads() { print_gc_threads_on(tty); } | |
| 596 // Iterator for all GC threads (other than VM thread) | |
| 597 virtual void gc_threads_do(ThreadClosure* tc) const = 0; | |
| 598 | |
| 599 // Print any relevant tracing info that flags imply. | |
| 600 // Default implementation does nothing. | |
| 601 virtual void print_tracing_info() const = 0; | |
| 602 | |
| 603 // Heap verification | |
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604 virtual void verify(bool allow_dirty, bool silent, VerifyOption option) = 0; |
| 0 | 605 |
| 606 // Non product verification and debugging. | |
| 607 #ifndef PRODUCT | |
| 608 // Support for PromotionFailureALot. Return true if it's time to cause a | |
| 609 // promotion failure. The no-argument version uses | |
| 610 // this->_promotion_failure_alot_count as the counter. | |
| 611 inline bool promotion_should_fail(volatile size_t* count); | |
| 612 inline bool promotion_should_fail(); | |
| 613 | |
| 614 // Reset the PromotionFailureALot counters. Should be called at the end of a | |
| 615 // GC in which promotion failure ocurred. | |
| 616 inline void reset_promotion_should_fail(volatile size_t* count); | |
| 617 inline void reset_promotion_should_fail(); | |
| 618 #endif // #ifndef PRODUCT | |
| 619 | |
| 620 #ifdef ASSERT | |
| 621 static int fired_fake_oom() { | |
| 622 return (CIFireOOMAt > 1 && _fire_out_of_memory_count >= CIFireOOMAt); | |
| 623 } | |
| 624 #endif | |
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625 |
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626 public: |
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627 // This is a convenience method that is used in cases where |
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628 // the actual number of GC worker threads is not pertinent but |
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629 // only whether there more than 0. Use of this method helps |
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630 // reduce the occurrence of ParallelGCThreads to uses where the |
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631 // actual number may be germane. |
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632 static bool use_parallel_gc_threads() { return ParallelGCThreads > 0; } |
| 0 | 633 }; |
| 634 | |
| 635 // Class to set and reset the GC cause for a CollectedHeap. | |
| 636 | |
| 637 class GCCauseSetter : StackObj { | |
| 638 CollectedHeap* _heap; | |
| 639 GCCause::Cause _previous_cause; | |
| 640 public: | |
| 641 GCCauseSetter(CollectedHeap* heap, GCCause::Cause cause) { | |
| 642 assert(SafepointSynchronize::is_at_safepoint(), | |
| 643 "This method manipulates heap state without locking"); | |
| 644 _heap = heap; | |
| 645 _previous_cause = _heap->gc_cause(); | |
| 646 _heap->set_gc_cause(cause); | |
| 647 } | |
| 648 | |
| 649 ~GCCauseSetter() { | |
| 650 assert(SafepointSynchronize::is_at_safepoint(), | |
| 651 "This method manipulates heap state without locking"); | |
| 652 _heap->set_gc_cause(_previous_cause); | |
| 653 } | |
| 654 }; | |
| 1972 | 655 |
| 656 #endif // SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP |