1 /* 2 * Copyright (c) 1997, 2018, 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 #ifndef SHARE_VM_CODE_CODECACHE_HPP 26 #define SHARE_VM_CODE_CODECACHE_HPP 27 28 #include "code/codeBlob.hpp" 29 #include "code/nmethod.hpp" 30 #include "gc/shared/gcBehaviours.hpp" 31 #include "memory/allocation.hpp" 32 #include "memory/heap.hpp" 33 #include "oops/instanceKlass.hpp" 34 #include "oops/oopsHierarchy.hpp" 35 #include "runtime/mutexLocker.hpp" 36 37 // The CodeCache implements the code cache for various pieces of generated 38 // code, e.g., compiled java methods, runtime stubs, transition frames, etc. 39 // The entries in the CodeCache are all CodeBlob's. 40 41 // -- Implementation -- 42 // The CodeCache consists of one or more CodeHeaps, each of which contains 43 // CodeBlobs of a specific CodeBlobType. Currently heaps for the following 44 // types are available: 45 // - Non-nmethods: Non-nmethods like Buffers, Adapters and Runtime Stubs 46 // - Profiled nmethods: nmethods that are profiled, i.e., those 47 // executed at level 2 or 3 48 // - Non-Profiled nmethods: nmethods that are not profiled, i.e., those 49 // executed at level 1 or 4 and native methods 50 // - All: Used for code of all types if code cache segmentation is disabled. 51 // 52 // In the rare case of the non-nmethod code heap getting full, non-nmethod code 53 // will be stored in the non-profiled code heap as a fallback solution. 54 // 55 // Depending on the availability of compilers and TieredCompilation there 56 // may be fewer heaps. The size of the code heaps depends on the values of 57 // ReservedCodeCacheSize, NonProfiledCodeHeapSize and ProfiledCodeHeapSize 58 // (see CodeCache::heap_available(..) and CodeCache::initialize_heaps(..) 59 // for details). 60 // 61 // Code cache segmentation is controlled by the flag SegmentedCodeCache. 62 // If turned off, all code types are stored in a single code heap. By default 63 // code cache segmentation is turned on if TieredCompilation is enabled and 64 // ReservedCodeCacheSize >= 240 MB. 65 // 66 // All methods of the CodeCache accepting a CodeBlobType only apply to 67 // CodeBlobs of the given type. For example, iteration over the 68 // CodeBlobs of a specific type can be done by using CodeCache::first_blob(..) 69 // and CodeCache::next_blob(..) and providing the corresponding CodeBlobType. 70 // 71 // IMPORTANT: If you add new CodeHeaps to the code cache or change the 72 // existing ones, make sure to adapt the dtrace scripts (jhelper.d) for 73 // Solaris and BSD. 74 75 class ExceptionCache; 76 class KlassDepChange; 77 class OopClosure; 78 79 class CodeCache : AllStatic { 80 friend class VMStructs; 81 friend class JVMCIVMStructs; 82 template <class T, class Filter> friend class CodeBlobIterator; 83 friend class WhiteBox; 84 friend class CodeCacheLoader; 85 private: 86 // CodeHeaps of the cache 87 static GrowableArray<CodeHeap*>* _heaps; 88 static GrowableArray<CodeHeap*>* _compiled_heaps; 89 static GrowableArray<CodeHeap*>* _nmethod_heaps; 90 static GrowableArray<CodeHeap*>* _allocable_heaps; 91 92 static address _low_bound; // Lower bound of CodeHeap addresses 93 static address _high_bound; // Upper bound of CodeHeap addresses 94 static int _number_of_nmethods_with_dependencies; // Total number of nmethods with dependencies 95 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link() 96 static uint8_t _unloading_cycle; // Global state for recognizing old nmethods that need to be unloaded 97 98 static ExceptionCache* volatile _exception_cache_purge_list; 99 100 static void mark_scavenge_root_nmethods() PRODUCT_RETURN; 101 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN; 102 103 // CodeHeap management 104 static void initialize_heaps(); // Initializes the CodeHeaps 105 // Check the code heap sizes set by the user via command line 106 static void check_heap_sizes(size_t non_nmethod_size, size_t profiled_size, size_t non_profiled_size, size_t cache_size, bool all_set); 107 // Creates a new heap with the given name and size, containing CodeBlobs of the given type 108 static void add_heap(ReservedSpace rs, const char* name, int code_blob_type); 109 static CodeHeap* get_code_heap_containing(void* p); // Returns the CodeHeap containing the given pointer, or NULL 110 static CodeHeap* get_code_heap(const CodeBlob* cb); // Returns the CodeHeap for the given CodeBlob 111 static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType 112 // Returns the name of the VM option to set the size of the corresponding CodeHeap 113 static const char* get_code_heap_flag_name(int code_blob_type); 114 static size_t page_size(bool aligned = true); // Returns the page size used by the CodeCache 115 static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps 116 117 // Iteration 118 static CodeBlob* first_blob(CodeHeap* heap); // Returns the first CodeBlob on the given CodeHeap 119 static CodeBlob* first_blob(int code_blob_type); // Returns the first CodeBlob of the given type 120 static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb); // Returns the next CodeBlob on the given CodeHeap 121 122 static size_t bytes_allocated_in_freelists(); 123 static int allocated_segments(); 124 static size_t freelists_length(); 125 126 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; } 127 static void prune_scavenge_root_nmethods(); 128 static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev); 129 130 // Make private to prevent unsafe calls. Not all CodeBlob*'s are embedded in a CodeHeap. 131 static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; } 132 133 public: 134 // Initialization 135 static void initialize(); 136 137 static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs); 138 139 static void add_heap(CodeHeap* heap); 140 static const GrowableArray<CodeHeap*>* heaps() { return _heaps; } 141 static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; } 142 static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; } 143 144 // Allocation/administration 145 static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob 146 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled 147 static int alignment_unit(); // guaranteed alignment of all CodeBlobs 148 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header) 149 static void free(CodeBlob* cb); // frees a CodeBlob 150 static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize()) 151 static bool contains(void *p); // returns whether p is included 152 static bool contains(nmethod* nm); // returns whether nm is included 153 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs 154 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs 155 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods 156 static void metadata_do(void f(Metadata* m)); // iterates over metadata in alive nmethods 157 158 // Lookup 159 static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address 160 static CodeBlob* find_blob_unsafe(void* start); // Same as find_blob but does not fail if looking up a zombie method 161 static nmethod* find_nmethod(void* start); // Returns the nmethod containing the given address 162 static CompiledMethod* find_compiled(void* start); 163 164 static int blob_count(); // Returns the total number of CodeBlobs in the cache 165 static int blob_count(int code_blob_type); 166 static int adapter_count(); // Returns the total number of Adapters in the cache 167 static int adapter_count(int code_blob_type); 168 static int nmethod_count(); // Returns the total number of nmethods in the cache 169 static int nmethod_count(int code_blob_type); 170 171 // GC support 172 static void gc_epilogue(); 173 static void gc_prologue(); 174 static void verify_oops(); 175 // If any oops are not marked this method unloads (i.e., breaks root links 176 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading" 177 // to "true" iff some code got unloaded. 178 // "unloading_occurred" controls whether metadata should be cleaned because of class unloading. 179 class UnloadingScope: StackObj { 180 ClosureIsUnloadingBehaviour _is_unloading_behaviour; 181 182 public: 183 UnloadingScope(BoolObjectClosure* is_alive); 184 ~UnloadingScope(); 185 }; 186 187 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred); 188 static uint8_t unloading_cycle() { return _unloading_cycle; } 189 static void increment_unloading_cycle(); 190 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN; 191 static void release_exception_cache(ExceptionCache* entry); 192 static void purge_exception_caches(); 193 194 // Apply f to every live code blob in scavengable nmethods. Prune nmethods 195 // from the list of scavengable nmethods if f->fix_relocations() and a nmethod 196 // no longer has scavengable oops. If f->fix_relocations(), then f must copy 197 // objects to their new location immediately to avoid fixing nmethods on the 198 // basis of the old object locations. 199 static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f); 200 201 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; } 202 // register_scavenge_root_nmethod() conditionally adds the nmethod to the list 203 // if it is not already on the list and has a scavengeable root 204 static void register_scavenge_root_nmethod(nmethod* nm); 205 static void verify_scavenge_root_nmethod(nmethod* nm); 206 static void add_scavenge_root_nmethod(nmethod* nm); 207 static void drop_scavenge_root_nmethod(nmethod* nm); 208 209 // Printing/debugging 210 static void print(); // prints summary 211 static void print_internals(); 212 static void print_memory_overhead(); 213 static void verify(); // verifies the code cache 214 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN; 215 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage 216 static void log_state(outputStream* st); 217 static const char* get_code_heap_name(int code_blob_type) { return (heap_available(code_blob_type) ? get_code_heap(code_blob_type)->name() : "Unused"); } 218 static void report_codemem_full(int code_blob_type, bool print); 219 220 // Dcmd (Diagnostic commands) 221 static void print_codelist(outputStream* st); 222 static void print_layout(outputStream* st); 223 224 // The full limits of the codeCache 225 static address low_bound() { return _low_bound; } 226 static address low_bound(int code_blob_type); 227 static address high_bound() { return _high_bound; } 228 static address high_bound(int code_blob_type); 229 230 // Have to use far call instructions to call this pc. 231 static bool is_far_target(address pc); 232 233 // Profiling 234 static size_t capacity(); 235 static size_t unallocated_capacity(int code_blob_type); 236 static size_t unallocated_capacity(); 237 static size_t max_capacity(); 238 239 static double reverse_free_ratio(int code_blob_type); 240 241 static void clear_inline_caches(); // clear all inline caches 242 static void cleanup_inline_caches(); // clean unloaded/zombie nmethods from inline caches 243 244 // Returns true if an own CodeHeap for the given CodeBlobType is available 245 static bool heap_available(int code_blob_type); 246 247 // Returns the CodeBlobType for the given CompiledMethod 248 static int get_code_blob_type(CompiledMethod* cm) { 249 return get_code_heap(cm)->code_blob_type(); 250 } 251 252 static bool code_blob_type_accepts_compiled(int type) { 253 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled; 254 AOT_ONLY( result = result || type == CodeBlobType::AOT; ) 255 return result; 256 } 257 258 static bool code_blob_type_accepts_nmethod(int type) { 259 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled; 260 } 261 262 static bool code_blob_type_accepts_allocable(int type) { 263 return type <= CodeBlobType::All; 264 } 265 266 267 // Returns the CodeBlobType for the given compilation level 268 static int get_code_blob_type(int comp_level) { 269 if (comp_level == CompLevel_none || 270 comp_level == CompLevel_simple || 271 comp_level == CompLevel_full_optimization) { 272 // Non profiled methods 273 return CodeBlobType::MethodNonProfiled; 274 } else if (comp_level == CompLevel_limited_profile || 275 comp_level == CompLevel_full_profile) { 276 // Profiled methods 277 return CodeBlobType::MethodProfiled; 278 } 279 ShouldNotReachHere(); 280 return 0; 281 } 282 283 static void verify_clean_inline_caches(); 284 static void verify_icholder_relocations(); 285 286 // Deoptimization 287 private: 288 static int mark_for_deoptimization(KlassDepChange& changes); 289 #ifdef HOTSWAP 290 static int mark_for_evol_deoptimization(InstanceKlass* dependee); 291 #endif // HOTSWAP 292 293 public: 294 static void mark_all_nmethods_for_deoptimization(); 295 static int mark_for_deoptimization(Method* dependee); 296 static void make_marked_nmethods_not_entrant(); 297 298 // Flushing and deoptimization 299 static void flush_dependents_on(InstanceKlass* dependee); 300 #ifdef HOTSWAP 301 // Flushing and deoptimization in case of evolution 302 static void flush_evol_dependents_on(InstanceKlass* dependee); 303 #endif // HOTSWAP 304 // Support for fullspeed debugging 305 static void flush_dependents_on_method(const methodHandle& dependee); 306 307 // tells how many nmethods have dependencies 308 static int number_of_nmethods_with_dependencies(); 309 310 static int get_codemem_full_count(int code_blob_type) { 311 CodeHeap* heap = get_code_heap(code_blob_type); 312 return (heap != NULL) ? heap->full_count() : 0; 313 } 314 315 // CodeHeap State Analytics. 316 // interface methods for CodeHeap printing, called by CompileBroker 317 static void aggregate(outputStream *out, const char* granularity); 318 static void discard(outputStream *out); 319 static void print_usedSpace(outputStream *out); 320 static void print_freeSpace(outputStream *out); 321 static void print_count(outputStream *out); 322 static void print_space(outputStream *out); 323 static void print_age(outputStream *out); 324 static void print_names(outputStream *out); 325 }; 326 327 328 // Iterator to iterate over nmethods in the CodeCache. 329 template <class T, class Filter> class CodeBlobIterator : public StackObj { 330 public: 331 enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading }; 332 333 private: 334 CodeBlob* _code_blob; // Current CodeBlob 335 GrowableArrayIterator<CodeHeap*> _heap; 336 GrowableArrayIterator<CodeHeap*> _end; 337 bool _only_alive; 338 bool _only_not_unloading; 339 340 public: 341 CodeBlobIterator(LivenessFilter filter, T* nm = NULL) 342 : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading), 343 _only_not_unloading(filter == only_alive_and_not_unloading) 344 { 345 if (Filter::heaps() == NULL) { 346 return; 347 } 348 _heap = Filter::heaps()->begin(); 349 _end = Filter::heaps()->end(); 350 // If set to NULL, initialized by first call to next() 351 _code_blob = (CodeBlob*)nm; 352 if (nm != NULL) { 353 while(!(*_heap)->contains_blob(_code_blob)) { 354 ++_heap; 355 } 356 assert((*_heap)->contains_blob(_code_blob), "match not found"); 357 } 358 } 359 360 // Advance iterator to next blob 361 bool next() { 362 assert_locked_or_safepoint(CodeCache_lock); 363 364 for (;;) { 365 // Walk through heaps as required 366 if (!next_blob()) { 367 if (_heap == _end) { 368 return false; 369 } 370 ++_heap; 371 continue; 372 } 373 374 // Filter is_alive as required 375 if (_only_alive && !_code_blob->is_alive()) { 376 continue; 377 } 378 379 // Filter is_unloading as required 380 if (_only_not_unloading) { 381 CompiledMethod* cm = _code_blob->as_compiled_method_or_null(); 382 if (cm != NULL && cm->is_unloading()) { 383 continue; 384 } 385 } 386 387 return true; 388 } 389 } 390 391 bool end() const { return _code_blob == NULL; } 392 T* method() const { return (T*)_code_blob; } 393 394 private: 395 396 // Advance iterator to the next blob in the current code heap 397 bool next_blob() { 398 if (_heap == _end) { 399 return false; 400 } 401 CodeHeap *heap = *_heap; 402 // Get first method CodeBlob 403 if (_code_blob == NULL) { 404 _code_blob = CodeCache::first_blob(heap); 405 if (_code_blob == NULL) { 406 return false; 407 } else if (Filter::apply(_code_blob)) { 408 return true; 409 } 410 } 411 // Search for next method CodeBlob 412 _code_blob = CodeCache::next_blob(heap, _code_blob); 413 while (_code_blob != NULL && !Filter::apply(_code_blob)) { 414 _code_blob = CodeCache::next_blob(heap, _code_blob); 415 } 416 return _code_blob != NULL; 417 } 418 }; 419 420 421 struct CompiledMethodFilter { 422 static bool apply(CodeBlob* cb) { return cb->is_compiled(); } 423 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); } 424 }; 425 426 427 struct NMethodFilter { 428 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); } 429 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); } 430 }; 431 432 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator; 433 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator; 434 435 #endif // SHARE_VM_CODE_CODECACHE_HPP