1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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.
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  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  *
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 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
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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 compilation mode 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 tiered mode 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 class NativePostCallNop;
 80 
 81 class CodeCache : AllStatic {
 82   friend class VMStructs;
 83   friend class JVMCIVMStructs;
 84   template <class T, class Filter> friend class CodeBlobIterator;
 85   friend class WhiteBox;
 86   friend class CodeCacheLoader;
 87   friend class ShenandoahParallelCodeHeapIterator;
 88  private:
 89   // CodeHeaps of the cache
 90   static GrowableArray<CodeHeap*>* _heaps;
 91   static GrowableArray<CodeHeap*>* _compiled_heaps;
 92   static GrowableArray<CodeHeap*>* _nmethod_heaps;
 93   static GrowableArray<CodeHeap*>* _allocable_heaps;
 94 
 95   static address _low_bound;                            // Lower bound of CodeHeap addresses
 96   static address _high_bound;                           // Upper bound of CodeHeap addresses
 97   static int _number_of_nmethods_with_dependencies;     // Total number of nmethods with dependencies
 98   static uint8_t _unloading_cycle;                      // Global state for recognizing old nmethods that need to be unloaded
 99   static uint64_t _marking_cycle;
100 
101   static ExceptionCache* volatile _exception_cache_purge_list;
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 ReservedCodeSpace reserve_heap_memory(size_t size);  // Reserves one continuous chunk of memory for the CodeHeaps
115 
116   // Iteration
117   static CodeBlob* first_blob(CodeHeap* heap);                // Returns the first CodeBlob on the given CodeHeap
118   static CodeBlob* first_blob(int code_blob_type);            // Returns the first CodeBlob of the given type
119   static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb);   // Returns the next CodeBlob on the given CodeHeap
120 
121   static size_t bytes_allocated_in_freelists();
122   static int    allocated_segments();
123   static size_t freelists_length();
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   static CodeBlob* patch_nop(NativePostCallNop* nop, void* pc, int& slot);
128 
129  public:
130   // Initialization
131   static void initialize();
132   static size_t page_size(bool aligned = true, size_t min_pages = 1); // Returns the page size used by the CodeCache
133 
134   static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
135 
136   static void add_heap(CodeHeap* heap);
137   static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
138   static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
139   static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
140 
141   // Allocation/administration
142   static CodeBlob* allocate(int size, int code_blob_type, bool handle_alloc_failure = true, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
143   static void commit(CodeBlob* cb);                        // called when the allocated CodeBlob has been filled
144   static int  alignment_unit();                            // guaranteed alignment of all CodeBlobs
145   static int  alignment_offset();                          // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
146   static void free(CodeBlob* cb);                          // frees a CodeBlob
147   static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize())
148   static bool contains(void *p);                           // returns whether p is included
149   static bool contains(nmethod* nm);                       // returns whether nm is included
150   static void blobs_do(void f(CodeBlob* cb));              // iterates over all CodeBlobs
151   static void blobs_do(CodeBlobClosure* f);                // iterates over all CodeBlobs
152   static void nmethods_do(void f(nmethod* nm));            // iterates over all nmethods
153   static void metadata_do(MetadataClosure* f);             // iterates over metadata in alive nmethods
154 
155   // Lookup
156   static CodeBlob* find_blob(void* start);              // Returns the CodeBlob containing the given address
157   static CodeBlob* find_blob_unsafe(void* start);       // Same as find_blob but does not fail if looking up a zombie method
158   static CodeBlob* find_blob_fast(void* start);         // Returns the CodeBlob containing the given address
159   static CodeBlob* find_blob_and_oopmap(void* start, int& slot);         // Returns the CodeBlob containing the given address
160   static int find_oopmap_slot_fast(void* start);        // Returns a fast oopmap slot if there is any; -1 otherwise
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 verify_oops();
173   // If any oops are not marked this method unloads (i.e., breaks root links
174   // to) any unmarked codeBlobs in the cache.  Sets "marked_for_unloading"
175   // to "true" iff some code got unloaded.
176   // "unloading_occurred" controls whether metadata should be cleaned because of class unloading.
177   class UnloadingScope: StackObj {
178     ClosureIsUnloadingBehaviour _is_unloading_behaviour;
179     IsUnloadingBehaviour*       _saved_behaviour;
180 
181   public:
182     UnloadingScope(BoolObjectClosure* is_alive);
183     ~UnloadingScope();
184   };
185 
186   static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
187   static uint8_t unloading_cycle() { return _unloading_cycle; }
188   static void increment_unloading_cycle();
189   static void increment_marking_cycle();
190   static uint64_t marking_cycle() { return _marking_cycle; }
191   static void release_exception_cache(ExceptionCache* entry);
192   static void purge_exception_caches();
193 
194   // Printing/debugging
195   static void print();                           // prints summary
196   static void print_internals();
197   static void print_memory_overhead();
198   static void verify();                          // verifies the code cache
199   static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
200   static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
201   static void log_state(outputStream* st);
202   LINUX_ONLY(static void write_perf_map();)
203   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"); }
204   static void report_codemem_full(int code_blob_type, bool print);
205 
206   // Dcmd (Diagnostic commands)
207   static void print_codelist(outputStream* st);
208   static void print_layout(outputStream* st);
209 
210   // The full limits of the codeCache
211   static address low_bound()                          { return _low_bound; }
212   static address low_bound(int code_blob_type);
213   static address high_bound()                         { return _high_bound; }
214   static address high_bound(int code_blob_type);
215 
216   // Profiling
217   static size_t capacity();
218   static size_t unallocated_capacity(int code_blob_type);
219   static size_t unallocated_capacity();
220   static size_t max_capacity();
221 
222   static double reverse_free_ratio(int code_blob_type);
223 
224   static void clear_inline_caches();                  // clear all inline caches
225   static void cleanup_inline_caches();                // clean unloaded/zombie nmethods from inline caches
226 
227   // Returns true if an own CodeHeap for the given CodeBlobType is available
228   static bool heap_available(int code_blob_type);
229 
230   // Returns the CodeBlobType for the given CompiledMethod
231   static int get_code_blob_type(CompiledMethod* cm) {
232     return get_code_heap(cm)->code_blob_type();
233   }
234 
235   static bool code_blob_type_accepts_compiled(int type) {
236     bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
237     return result;
238   }
239 
240   static bool code_blob_type_accepts_nmethod(int type) {
241     return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
242   }
243 
244   static bool code_blob_type_accepts_allocable(int type) {
245     return type <= CodeBlobType::All;
246   }
247 
248 
249   // Returns the CodeBlobType for the given compilation level
250   static int get_code_blob_type(int comp_level) {
251     if (comp_level == CompLevel_none ||
252         comp_level == CompLevel_simple ||
253         comp_level == CompLevel_full_optimization) {
254       // Non profiled methods
255       return CodeBlobType::MethodNonProfiled;
256     } else if (comp_level == CompLevel_limited_profile ||
257                comp_level == CompLevel_full_profile) {
258       // Profiled methods
259       return CodeBlobType::MethodProfiled;
260     }
261     ShouldNotReachHere();
262     return 0;
263   }
264 
265   static void verify_clean_inline_caches();
266   static void verify_icholder_relocations();
267 
268   // Deoptimization
269  private:
270   static int  mark_for_deoptimization(KlassDepChange& changes);
271 
272  public:
273   static void mark_all_nmethods_for_deoptimization();
274   static int  mark_for_deoptimization(Method* dependee);
275   static void make_marked_nmethods_not_entrant(GrowableArray<CompiledMethod*>* marked);
276   static void make_marked_nmethods_deoptimized(GrowableArray<CompiledMethod*>* marked);
277 
278   // Flushing and deoptimization
279   static void flush_dependents_on(InstanceKlass* dependee);
280 
281   // RedefineClasses support
282   // Flushing and deoptimization in case of evolution
283   static int  mark_dependents_for_evol_deoptimization();
284   static void mark_all_nmethods_for_evol_deoptimization();
285   static void flush_evol_dependents();
286   static void old_nmethods_do(MetadataClosure* f) NOT_JVMTI_RETURN;
287   static void unregister_old_nmethod(CompiledMethod* c) NOT_JVMTI_RETURN;
288 
289   // Support for fullspeed debugging
290   static void flush_dependents_on_method(const methodHandle& dependee);
291 
292   // tells how many nmethods have dependencies
293   static int number_of_nmethods_with_dependencies();
294 
295   static int get_codemem_full_count(int code_blob_type) {
296     CodeHeap* heap = get_code_heap(code_blob_type);
297     return (heap != NULL) ? heap->full_count() : 0;
298   }
299 
300   // CodeHeap State Analytics.
301   // interface methods for CodeHeap printing, called by CompileBroker
302   static void aggregate(outputStream *out, size_t granularity);
303   static void discard(outputStream *out);
304   static void print_usedSpace(outputStream *out);
305   static void print_freeSpace(outputStream *out);
306   static void print_count(outputStream *out);
307   static void print_space(outputStream *out);
308   static void print_age(outputStream *out);
309   static void print_names(outputStream *out);
310 };
311 
312 
313 // Iterator to iterate over nmethods in the CodeCache.
314 template <class T, class Filter> class CodeBlobIterator : public StackObj {
315  public:
316   enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading };
317 
318  private:
319   CodeBlob* _code_blob;   // Current CodeBlob
320   GrowableArrayIterator<CodeHeap*> _heap;
321   GrowableArrayIterator<CodeHeap*> _end;
322   bool _only_alive;
323   bool _only_not_unloading;
324 
325  public:
326   CodeBlobIterator(LivenessFilter filter, T* nm = NULL)
327     : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading),
328       _only_not_unloading(filter == only_alive_and_not_unloading)
329   {
330     if (Filter::heaps() == NULL) {
331       return;
332     }
333     _heap = Filter::heaps()->begin();
334     _end = Filter::heaps()->end();
335     // If set to NULL, initialized by first call to next()
336     _code_blob = (CodeBlob*)nm;
337     if (nm != NULL) {
338       while(!(*_heap)->contains_blob(_code_blob)) {
339         ++_heap;
340       }
341       assert((*_heap)->contains_blob(_code_blob), "match not found");
342     }
343   }
344 
345   // Advance iterator to next blob
346   bool next() {
347     assert_locked_or_safepoint(CodeCache_lock);
348 
349     for (;;) {
350       // Walk through heaps as required
351       if (!next_blob()) {
352         if (_heap == _end) {
353           return false;
354         }
355         ++_heap;
356         continue;
357       }
358 
359       // Filter is_alive as required
360       if (_only_alive && !_code_blob->is_alive()) {
361         continue;
362       }
363 
364       // Filter is_unloading as required
365       if (_only_not_unloading) {
366         CompiledMethod* cm = _code_blob->as_compiled_method_or_null();
367         if (cm != NULL && cm->is_unloading()) {
368           continue;
369         }
370       }
371 
372       return true;
373     }
374   }
375 
376   bool end()  const { return _code_blob == NULL; }
377   T* method() const { return (T*)_code_blob; }
378 
379 private:
380 
381   // Advance iterator to the next blob in the current code heap
382   bool next_blob() {
383     if (_heap == _end) {
384       return false;
385     }
386     CodeHeap *heap = *_heap;
387     // Get first method CodeBlob
388     if (_code_blob == NULL) {
389       _code_blob = CodeCache::first_blob(heap);
390       if (_code_blob == NULL) {
391         return false;
392       } else if (Filter::apply(_code_blob)) {
393         return true;
394       }
395     }
396     // Search for next method CodeBlob
397     _code_blob = CodeCache::next_blob(heap, _code_blob);
398     while (_code_blob != NULL && !Filter::apply(_code_blob)) {
399       _code_blob = CodeCache::next_blob(heap, _code_blob);
400     }
401     return _code_blob != NULL;
402   }
403 };
404 
405 
406 struct CompiledMethodFilter {
407   static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
408   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
409 };
410 
411 
412 struct NMethodFilter {
413   static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
414   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
415 };
416 
417 struct AllCodeBlobsFilter {
418   static bool apply(CodeBlob* cb) { return true; }
419   static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::heaps(); }
420 };
421 
422 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
423 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
424 typedef CodeBlobIterator<CodeBlob, AllCodeBlobsFilter> AllCodeBlobsIterator;
425 
426 #endif // SHARE_CODE_CODECACHE_HPP