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
   7  * published by the Free Software Foundation.
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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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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  20  * or visit www.oracle.com if you need additional information or have any
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  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 "memory/allocation.hpp"
  31 #include "memory/heap.hpp"
  32 #include "oops/instanceKlass.hpp"
  33 #include "oops/oopsHierarchy.hpp"
  34 #include "runtime/mutexLocker.hpp"
  35 
  36 // The CodeCache implements the code cache for various pieces of generated
  37 // code, e.g., compiled java methods, runtime stubs, transition frames, etc.
  38 // The entries in the CodeCache are all CodeBlob's.
  39 
  40 // -- Implementation --
  41 // The CodeCache consists of one or more CodeHeaps, each of which contains
  42 // CodeBlobs of a specific CodeBlobType. Currently heaps for the following
  43 // types are available:
  44 //  - Non-nmethods: Non-nmethods like Buffers, Adapters and Runtime Stubs
  45 //  - Profiled nmethods: nmethods that are profiled, i.e., those
  46 //    executed at level 2 or 3
  47 //  - Non-Profiled nmethods: nmethods that are not profiled, i.e., those
  48 //    executed at level 1 or 4 and native methods
  49 //  - All: Used for code of all types if code cache segmentation is disabled.
  50 //
  51 // In the rare case of the non-nmethod code heap getting full, non-nmethod code
  52 // will be stored in the non-profiled code heap as a fallback solution.
  53 //
  54 // Depending on the availability of compilers and TieredCompilation there
  55 // may be fewer heaps. The size of the code heaps depends on the values of
  56 // ReservedCodeCacheSize, NonProfiledCodeHeapSize and ProfiledCodeHeapSize
  57 // (see CodeCache::heap_available(..) and CodeCache::initialize_heaps(..)
  58 // for details).
  59 //
  60 // Code cache segmentation is controlled by the flag SegmentedCodeCache.
  61 // If turned off, all code types are stored in a single code heap. By default
  62 // code cache segmentation is turned on if TieredCompilation is enabled and
  63 // ReservedCodeCacheSize >= 240 MB.
  64 //
  65 // All methods of the CodeCache accepting a CodeBlobType only apply to
  66 // CodeBlobs of the given type. For example, iteration over the
  67 // CodeBlobs of a specific type can be done by using CodeCache::first_blob(..)
  68 // and CodeCache::next_blob(..) and providing the corresponding CodeBlobType.
  69 //
  70 // IMPORTANT: If you add new CodeHeaps to the code cache or change the
  71 // existing ones, make sure to adapt the dtrace scripts (jhelper.d) for
  72 // Solaris and BSD.
  73 
  74 class OopClosure;
  75 class KlassDepChange;
  76 
  77 class CodeCache : AllStatic {
  78   friend class VMStructs;
  79   friend class JVMCIVMStructs;
  80   template <class T, class Filter> friend class CodeBlobIterator;
  81   friend class WhiteBox;
  82   friend class CodeCacheLoader;
  83  private:
  84   // CodeHeaps of the cache
  85   static GrowableArray<CodeHeap*>* _heaps;
  86   static GrowableArray<CodeHeap*>* _compiled_heaps;
  87   static GrowableArray<CodeHeap*>* _nmethod_heaps;
  88 
  89   static address _low_bound;                            // Lower bound of CodeHeap addresses
  90   static address _high_bound;                           // Upper bound of CodeHeap addresses
  91   static int _number_of_nmethods_with_dependencies;     // Total number of nmethods with dependencies
  92   static bool _needs_cache_clean;                       // True if inline caches of the nmethods needs to be flushed
  93   static nmethod* _scavenge_root_nmethods;              // linked via nm->scavenge_root_link()
  94 
  95   static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
  96   static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
  97 
  98   // CodeHeap management
  99   static void initialize_heaps();                             // Initializes the CodeHeaps
 100   // Check the code heap sizes set by the user via command line
 101   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);
 102   // Creates a new heap with the given name and size, containing CodeBlobs of the given type
 103   static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);
 104   static CodeHeap* get_code_heap_containing(void* p);         // Returns the CodeHeap containing the given pointer, or NULL
 105   static CodeHeap* get_code_heap(const CodeBlob* cb);         // Returns the CodeHeap for the given CodeBlob
 106   static CodeHeap* get_code_heap(int code_blob_type);         // Returns the CodeHeap for the given CodeBlobType
 107   // Returns the name of the VM option to set the size of the corresponding CodeHeap
 108   static const char* get_code_heap_flag_name(int code_blob_type);
 109   static size_t heap_alignment();                             // Returns the alignment of the CodeHeaps in bytes
 110   static ReservedCodeSpace reserve_heap_memory(size_t size);  // Reserves one continuous chunk of memory for the CodeHeaps
 111 
 112   // Iteration
 113   static CodeBlob* first_blob(CodeHeap* heap);                // Returns the first CodeBlob on the given CodeHeap
 114   static CodeBlob* first_blob(int code_blob_type);            // Returns the first CodeBlob of the given type
 115   static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb);   // Returns the next CodeBlob on the given CodeHeap
 116 
 117   static size_t bytes_allocated_in_freelists();
 118   static int    allocated_segments();
 119   static size_t freelists_length();
 120 
 121   static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
 122   static void prune_scavenge_root_nmethods();
 123   static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev);
 124 
 125   // Make private to prevent unsafe calls.  Not all CodeBlob*'s are embedded in a CodeHeap.
 126   static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }
 127 
 128  public:
 129   // Initialization
 130   static void initialize();
 131 
 132   static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
 133 
 134   static void add_heap(CodeHeap* heap);
 135   static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
 136   static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
 137   static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
 138 
 139   // Allocation/administration
 140   static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
 141   static void commit(CodeBlob* cb);                        // called when the allocated CodeBlob has been filled
 142   static int  alignment_unit();                            // guaranteed alignment of all CodeBlobs
 143   static int  alignment_offset();                          // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
 144   static void free(CodeBlob* cb);                          // frees a CodeBlob
 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(void f(Metadata* m));            // 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 gc_epilogue();
 167   static void gc_prologue();
 168   static void verify_oops();
 169   // If "unloading_occurred" is true, then unloads (i.e., breaks root links
 170   // to) any unmarked codeBlobs in the cache.  Sets "marked_for_unloading"
 171   // to "true" iff some code got unloaded.
 172   static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
 173   static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
 174 
 175   // Apply f to every live code blob in scavengable nmethods. Prune nmethods
 176   // from the list of scavengable nmethods if f->fix_relocations() and a nmethod
 177   // no longer has scavengable oops.  If f->fix_relocations(), then f must copy
 178   // objects to their new location immediately to avoid fixing nmethods on the
 179   // basis of the old object locations.
 180   static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f);
 181 
 182   static nmethod* scavenge_root_nmethods()            { return _scavenge_root_nmethods; }
 183   static void add_scavenge_root_nmethod(nmethod* nm);
 184   static void drop_scavenge_root_nmethod(nmethod* nm);
 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 bool needs_cache_clean()                     { return _needs_cache_clean; }
 219   static void set_needs_cache_clean(bool v)           { _needs_cache_clean = v;    }
 220   static void clear_inline_caches();                  // clear all inline caches
 221   static void cleanup_inline_caches();
 222 
 223   // Returns true if an own CodeHeap for the given CodeBlobType is available
 224   static bool heap_available(int code_blob_type);
 225 
 226   // Returns the CodeBlobType for the given CompiledMethod
 227   static int get_code_blob_type(CompiledMethod* cm) {
 228     return get_code_heap(cm)->code_blob_type();
 229   }
 230 
 231   static bool code_blob_type_accepts_compiled(int type) {
 232     bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
 233     AOT_ONLY( result = result || type == CodeBlobType::AOT; )
 234     return result;
 235   }
 236 
 237   static bool code_blob_type_accepts_nmethod(int type) {
 238     return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
 239   }
 240 
 241   // Returns the CodeBlobType for the given compilation level
 242   static int get_code_blob_type(int comp_level) {
 243     if (comp_level == CompLevel_none ||
 244         comp_level == CompLevel_simple ||
 245         comp_level == CompLevel_full_optimization) {
 246       // Non profiled methods
 247       return CodeBlobType::MethodNonProfiled;
 248     } else if (comp_level == CompLevel_limited_profile ||
 249                comp_level == CompLevel_full_profile) {
 250       // Profiled methods
 251       return CodeBlobType::MethodProfiled;
 252     }
 253     ShouldNotReachHere();
 254     return 0;
 255   }
 256 
 257   static void verify_clean_inline_caches();
 258   static void verify_icholder_relocations();
 259 
 260   // Deoptimization
 261  private:
 262   static int  mark_for_deoptimization(KlassDepChange& changes);
 263 #ifdef HOTSWAP
 264   static int  mark_for_evol_deoptimization(InstanceKlass* dependee);
 265 #endif // HOTSWAP
 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 #ifdef HOTSWAP
 275   // Flushing and deoptimization in case of evolution
 276   static void flush_evol_dependents_on(InstanceKlass* dependee);
 277 #endif // HOTSWAP
 278   // Support for fullspeed debugging
 279   static void flush_dependents_on_method(methodHandle dependee);
 280 
 281   // tells how many nmethods have dependencies
 282   static int number_of_nmethods_with_dependencies();
 283 
 284   static int get_codemem_full_count(int code_blob_type) {
 285     CodeHeap* heap = get_code_heap(code_blob_type);
 286     return (heap != NULL) ? heap->full_count() : 0;
 287   }
 288 };
 289 
 290 
 291 // Iterator to iterate over nmethods in the CodeCache.
 292 template <class T, class Filter> class CodeBlobIterator : public StackObj {
 293  private:
 294   CodeBlob* _code_blob;   // Current CodeBlob
 295   GrowableArrayIterator<CodeHeap*> _heap;
 296   GrowableArrayIterator<CodeHeap*> _end;
 297 
 298  public:
 299   CodeBlobIterator(T* nm = NULL) {
 300     if (Filter::heaps() == NULL) {
 301       return;
 302     }
 303     _heap = Filter::heaps()->begin();
 304     _end = Filter::heaps()->end();
 305     // If set to NULL, initialized by first call to next()
 306     _code_blob = (CodeBlob*)nm;
 307     if (nm != NULL) {
 308       while(!(*_heap)->contains_blob(_code_blob)) {
 309         ++_heap;
 310       }
 311       assert((*_heap)->contains_blob(_code_blob), "match not found");
 312     }
 313   }
 314 
 315   // Advance iterator to next blob
 316   bool next() {
 317     assert_locked_or_safepoint(CodeCache_lock);
 318 
 319     bool result = next_blob();
 320     while (!result && _heap != _end) {
 321       // Advance to next code heap of segmented code cache
 322       if (++_heap == _end) {
 323         break;
 324       }
 325       result = next_blob();
 326     }
 327 
 328     return result;
 329   }
 330 
 331   // Advance iterator to next alive blob
 332   bool next_alive() {
 333     bool result = next();
 334     while(result && !_code_blob->is_alive()) {
 335       result = next();
 336     }
 337     return result;
 338   }
 339 
 340   bool end()        const   { return _code_blob == NULL; }
 341   T* method() const   { return (T*)_code_blob; }
 342 
 343 private:
 344 
 345   // Advance iterator to the next blob in the current code heap
 346   bool next_blob() {
 347     if (_heap == _end) {
 348       return false;
 349     }
 350     CodeHeap *heap = *_heap;
 351     // Get first method CodeBlob
 352     if (_code_blob == NULL) {
 353       _code_blob = CodeCache::first_blob(heap);
 354       if (_code_blob == NULL) {
 355         return false;
 356       } else if (Filter::apply(_code_blob)) {
 357         return true;
 358       }
 359     }
 360     // Search for next method CodeBlob
 361     _code_blob = CodeCache::next_blob(heap, _code_blob);
 362     while (_code_blob != NULL && !Filter::apply(_code_blob)) {
 363       _code_blob = CodeCache::next_blob(heap, _code_blob);
 364     }
 365     return _code_blob != NULL;
 366   }
 367 };
 368 
 369 
 370 struct CompiledMethodFilter {
 371   static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
 372   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
 373 };
 374 
 375 
 376 struct NMethodFilter {
 377   static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
 378   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
 379 };
 380 
 381 
 382 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
 383 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
 384 
 385 #endif // SHARE_VM_CODE_CODECACHE_HPP