1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   6  * under the terms of the GNU General Public License version 2 only, as
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  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).
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  24 
  25 #ifndef SHARE_CODE_CODECACHE_HPP
  26 #define SHARE_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 class ShenandoahParallelCodeHeapIterator;
  79 
  80 class CodeCache : AllStatic {
  81   friend class VMStructs;
  82   friend class JVMCIVMStructs;
  83   template <class T, class Filter> friend class CodeBlobIterator;
  84   friend class WhiteBox;
  85   friend class CodeCacheLoader;
  86   friend class ShenandoahParallelCodeHeapIterator;
  87  private:
  88   // CodeHeaps of the cache
  89   static GrowableArray<CodeHeap*>* _heaps;
  90   static GrowableArray<CodeHeap*>* _compiled_heaps;
  91   static GrowableArray<CodeHeap*>* _nmethod_heaps;
  92   static GrowableArray<CodeHeap*>* _allocable_heaps;
  93 
  94   static address _low_bound;                            // Lower bound of CodeHeap addresses
  95   static address _high_bound;                           // Upper bound of CodeHeap addresses
  96   static int _number_of_nmethods_with_dependencies;     // Total number of nmethods with dependencies
  97   static uint8_t _unloading_cycle;                      // Global state for recognizing old nmethods that need to be unloaded
  98 
  99   static ExceptionCache* volatile _exception_cache_purge_list;
 100 
 101   // CodeHeap management
 102   static void initialize_heaps();                             // Initializes the CodeHeaps
 103   // Check the code heap sizes set by the user via command line
 104   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);
 105   // Creates a new heap with the given name and size, containing CodeBlobs of the given type
 106   static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);
 107   static CodeHeap* get_code_heap_containing(void* p);         // Returns the CodeHeap containing the given pointer, or NULL
 108   static CodeHeap* get_code_heap(const CodeBlob* cb);         // Returns the CodeHeap for the given CodeBlob
 109   static CodeHeap* get_code_heap(int code_blob_type);         // Returns the CodeHeap for the given CodeBlobType
 110   // Returns the name of the VM option to set the size of the corresponding CodeHeap
 111   static const char* get_code_heap_flag_name(int code_blob_type);
 112   static ReservedCodeSpace reserve_heap_memory(size_t size);  // Reserves one continuous chunk of memory for the CodeHeaps
 113 
 114   // Iteration
 115   static CodeBlob* first_blob(CodeHeap* heap);                // Returns the first CodeBlob on the given CodeHeap
 116   static CodeBlob* first_blob(int code_blob_type);            // Returns the first CodeBlob of the given type
 117   static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb);   // Returns the next CodeBlob on the given CodeHeap
 118 
 119   static size_t bytes_allocated_in_freelists();
 120   static int    allocated_segments();
 121   static size_t freelists_length();
 122 
 123   // Make private to prevent unsafe calls.  Not all CodeBlob*'s are embedded in a CodeHeap.
 124   static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }
 125 
 126  public:
 127   // Initialization
 128   static void initialize();
 129   static size_t page_size(bool aligned = true, size_t min_pages = 1); // Returns the page size used by the CodeCache
 130 
 131   static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
 132 
 133   static void add_heap(CodeHeap* heap);
 134   static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
 135   static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
 136   static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
 137 
 138   // Allocation/administration
 139   static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
 140   static void commit(CodeBlob* cb);                        // called when the allocated CodeBlob has been filled
 141   static int  alignment_unit();                            // guaranteed alignment of all CodeBlobs
 142   static int  alignment_offset();                          // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
 143   static void free(CodeBlob* cb);                          // frees a CodeBlob
 144   static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize())
 145   static bool contains(void *p);                           // returns whether p is included
 146   static bool contains(nmethod* nm);                       // returns whether nm is included
 147   static void blobs_do(void f(CodeBlob* cb));              // iterates over all CodeBlobs
 148   static void blobs_do(CodeBlobClosure* f);                // iterates over all CodeBlobs
 149   static void nmethods_do(void f(nmethod* nm));            // iterates over all nmethods
 150   static void metadata_do(MetadataClosure* f);             // iterates over metadata in alive nmethods
 151 
 152   // Lookup
 153   static CodeBlob* find_blob(void* start);              // Returns the CodeBlob containing the given address
 154   static CodeBlob* find_blob_unsafe(void* start);       // Same as find_blob but does not fail if looking up a zombie method
 155   static nmethod*  find_nmethod(void* start);           // Returns the nmethod containing the given address
 156   static CompiledMethod* find_compiled(void* start);
 157 
 158   static int       blob_count();                        // Returns the total number of CodeBlobs in the cache
 159   static int       blob_count(int code_blob_type);
 160   static int       adapter_count();                     // Returns the total number of Adapters in the cache
 161   static int       adapter_count(int code_blob_type);
 162   static int       nmethod_count();                     // Returns the total number of nmethods in the cache
 163   static int       nmethod_count(int code_blob_type);
 164 
 165   // GC support
 166   static void verify_oops();
 167   // If any oops are not marked this method unloads (i.e., breaks root links
 168   // to) any unmarked codeBlobs in the cache.  Sets "marked_for_unloading"
 169   // to "true" iff some code got unloaded.
 170   // "unloading_occurred" controls whether metadata should be cleaned because of class unloading.
 171   class UnloadingScope: StackObj {
 172     ClosureIsUnloadingBehaviour _is_unloading_behaviour;
 173     IsUnloadingBehaviour*       _saved_behaviour;
 174 
 175   public:
 176     UnloadingScope(BoolObjectClosure* is_alive);
 177     ~UnloadingScope();
 178   };
 179 
 180   static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
 181   static uint8_t unloading_cycle() { return _unloading_cycle; }
 182   static void increment_unloading_cycle();
 183   static void release_exception_cache(ExceptionCache* entry);
 184   static void purge_exception_caches();
 185 
 186   // Printing/debugging
 187   static void print();                           // prints summary
 188   static void print_internals();
 189   static void print_memory_overhead();
 190   static void verify();                          // verifies the code cache
 191   static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
 192   static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
 193   static void log_state(outputStream* st);
 194   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"); }
 195   static void report_codemem_full(int code_blob_type, bool print);
 196 
 197   // Dcmd (Diagnostic commands)
 198   static void print_codelist(outputStream* st);
 199   static void print_layout(outputStream* st);
 200 
 201   // The full limits of the codeCache
 202   static address low_bound()                          { return _low_bound; }
 203   static address low_bound(int code_blob_type);
 204   static address high_bound()                         { return _high_bound; }
 205   static address high_bound(int code_blob_type);
 206 
 207   // Have to use far call instructions to call this pc.
 208   static bool is_far_target(address pc);
 209 
 210   // Profiling
 211   static size_t capacity();
 212   static size_t unallocated_capacity(int code_blob_type);
 213   static size_t unallocated_capacity();
 214   static size_t max_capacity();
 215 
 216   static double reverse_free_ratio(int code_blob_type);
 217 
 218   static void clear_inline_caches();                  // clear all inline caches
 219   static void cleanup_inline_caches();                // clean unloaded/zombie nmethods from inline caches
 220 
 221   // Returns true if an own CodeHeap for the given CodeBlobType is available
 222   static bool heap_available(int code_blob_type);
 223 
 224   // Returns the CodeBlobType for the given CompiledMethod
 225   static int get_code_blob_type(CompiledMethod* cm) {
 226     return get_code_heap(cm)->code_blob_type();
 227   }
 228 
 229   static bool code_blob_type_accepts_compiled(int type) {
 230     bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
 231     AOT_ONLY( result = result || type == CodeBlobType::AOT; )
 232     return result;
 233   }
 234 
 235   static bool code_blob_type_accepts_nmethod(int type) {
 236     return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
 237   }
 238 
 239   static bool code_blob_type_accepts_allocable(int type) {
 240     return type <= CodeBlobType::All;
 241   }
 242 
 243 
 244   // Returns the CodeBlobType for the given compilation level
 245   static int get_code_blob_type(int comp_level) {
 246     if (comp_level == CompLevel_none ||
 247         comp_level == CompLevel_simple ||
 248         comp_level == CompLevel_full_optimization) {
 249       // Non profiled methods
 250       return CodeBlobType::MethodNonProfiled;
 251     } else if (comp_level == CompLevel_limited_profile ||
 252                comp_level == CompLevel_full_profile) {
 253       // Profiled methods
 254       return CodeBlobType::MethodProfiled;
 255     }
 256     ShouldNotReachHere();
 257     return 0;
 258   }
 259 
 260   static void verify_clean_inline_caches();
 261   static void verify_icholder_relocations();
 262 
 263   // Deoptimization
 264  private:
 265   static int  mark_for_deoptimization(KlassDepChange& changes);
 266 
 267  public:
 268   static void mark_all_nmethods_for_deoptimization();
 269   static int  mark_for_deoptimization(Method* dependee);
 270   static void make_marked_nmethods_not_entrant();
 271 
 272   // Flushing and deoptimization
 273   static void flush_dependents_on(InstanceKlass* dependee);
 274 
 275   // RedefineClasses support
 276   // Flushing and deoptimization in case of evolution
 277   static void mark_for_evol_deoptimization(InstanceKlass* dependee);
 278   static int  mark_dependents_for_evol_deoptimization();
 279   static void mark_all_nmethods_for_evol_deoptimization();
 280   static void flush_evol_dependents();
 281   static void old_nmethods_do(MetadataClosure* f);
 282   static void unregister_old_nmethod(CompiledMethod* c);
 283 
 284   // Support for fullspeed debugging
 285   static void flush_dependents_on_method(const methodHandle& dependee);
 286 
 287   // tells how many nmethods have dependencies
 288   static int number_of_nmethods_with_dependencies();
 289 
 290   static int get_codemem_full_count(int code_blob_type) {
 291     CodeHeap* heap = get_code_heap(code_blob_type);
 292     return (heap != NULL) ? heap->full_count() : 0;
 293   }
 294 
 295   // CodeHeap State Analytics.
 296   // interface methods for CodeHeap printing, called by CompileBroker
 297   static void aggregate(outputStream *out, size_t granularity);
 298   static void discard(outputStream *out);
 299   static void print_usedSpace(outputStream *out);
 300   static void print_freeSpace(outputStream *out);
 301   static void print_count(outputStream *out);
 302   static void print_space(outputStream *out);
 303   static void print_age(outputStream *out);
 304   static void print_names(outputStream *out);
 305 };
 306 
 307 
 308 // Iterator to iterate over nmethods in the CodeCache.
 309 template <class T, class Filter> class CodeBlobIterator : public StackObj {
 310  public:
 311   enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading };
 312 
 313  private:
 314   CodeBlob* _code_blob;   // Current CodeBlob
 315   GrowableArrayIterator<CodeHeap*> _heap;
 316   GrowableArrayIterator<CodeHeap*> _end;
 317   bool _only_alive;
 318   bool _only_not_unloading;
 319 
 320  public:
 321   CodeBlobIterator(LivenessFilter filter, T* nm = NULL)
 322     : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading),
 323       _only_not_unloading(filter == only_alive_and_not_unloading)
 324   {
 325     if (Filter::heaps() == NULL) {
 326       return;
 327     }
 328     _heap = Filter::heaps()->begin();
 329     _end = Filter::heaps()->end();
 330     // If set to NULL, initialized by first call to next()
 331     _code_blob = (CodeBlob*)nm;
 332     if (nm != NULL) {
 333       while(!(*_heap)->contains_blob(_code_blob)) {
 334         ++_heap;
 335       }
 336       assert((*_heap)->contains_blob(_code_blob), "match not found");
 337     }
 338   }
 339 
 340   // Advance iterator to next blob
 341   bool next() {
 342     assert_locked_or_safepoint(CodeCache_lock);
 343 
 344     for (;;) {
 345       // Walk through heaps as required
 346       if (!next_blob()) {
 347         if (_heap == _end) {
 348           return false;
 349         }
 350         ++_heap;
 351         continue;
 352       }
 353 
 354       // Filter is_alive as required
 355       if (_only_alive && !_code_blob->is_alive()) {
 356         continue;
 357       }
 358 
 359       // Filter is_unloading as required
 360       if (_only_not_unloading) {
 361         CompiledMethod* cm = _code_blob->as_compiled_method_or_null();
 362         if (cm != NULL && cm->is_unloading()) {
 363           continue;
 364         }
 365       }
 366 
 367       return true;
 368     }
 369   }
 370 
 371   bool end()  const { return _code_blob == NULL; }
 372   T* method() const { return (T*)_code_blob; }
 373 
 374 private:
 375 
 376   // Advance iterator to the next blob in the current code heap
 377   bool next_blob() {
 378     if (_heap == _end) {
 379       return false;
 380     }
 381     CodeHeap *heap = *_heap;
 382     // Get first method CodeBlob
 383     if (_code_blob == NULL) {
 384       _code_blob = CodeCache::first_blob(heap);
 385       if (_code_blob == NULL) {
 386         return false;
 387       } else if (Filter::apply(_code_blob)) {
 388         return true;
 389       }
 390     }
 391     // Search for next method CodeBlob
 392     _code_blob = CodeCache::next_blob(heap, _code_blob);
 393     while (_code_blob != NULL && !Filter::apply(_code_blob)) {
 394       _code_blob = CodeCache::next_blob(heap, _code_blob);
 395     }
 396     return _code_blob != NULL;
 397   }
 398 };
 399 
 400 
 401 struct CompiledMethodFilter {
 402   static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
 403   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
 404 };
 405 
 406 
 407 struct NMethodFilter {
 408   static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
 409   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
 410 };
 411 
 412 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
 413 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
 414 
 415 #endif // SHARE_CODE_CODECACHE_HPP