1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
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
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7 * published by the Free Software Foundation.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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23 */
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 nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()
98 static uint8_t _unloading_cycle; // Global state for recognizing old nmethods that need to be unloaded
99
100 static ExceptionCache* volatile _exception_cache_purge_list;
101
102 static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
103 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
104
105 // CodeHeap management
106 static void initialize_heaps(); // Initializes the CodeHeaps
107 // Check the code heap sizes set by the user via command line
108 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);
109 // Creates a new heap with the given name and size, containing CodeBlobs of the given type
110 static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);
111 static CodeHeap* get_code_heap_containing(void* p); // Returns the CodeHeap containing the given pointer, or NULL
112 static CodeHeap* get_code_heap(const CodeBlob* cb); // Returns the CodeHeap for the given CodeBlob
113 static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType
114 // Returns the name of the VM option to set the size of the corresponding CodeHeap
115 static const char* get_code_heap_flag_name(int code_blob_type);
116 static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps
117
118 // Iteration
119 static CodeBlob* first_blob(CodeHeap* heap); // Returns the first CodeBlob on the given CodeHeap
120 static CodeBlob* first_blob(int code_blob_type); // Returns the first CodeBlob of the given type
121 static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb); // Returns the next CodeBlob on the given CodeHeap
122
123 static size_t bytes_allocated_in_freelists();
124 static int allocated_segments();
125 static size_t freelists_length();
126
127 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
128 static void prune_scavenge_root_nmethods();
129 static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev);
130
131 // Make private to prevent unsafe calls. Not all CodeBlob*'s are embedded in a CodeHeap.
132 static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }
133
134 public:
135 // Initialization
136 static void initialize();
137 static size_t page_size(bool aligned = true, size_t min_pages = 1); // Returns the page size used by the CodeCache
138
139 static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
140
141 static void add_heap(CodeHeap* heap);
142 static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
143 static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
144 static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
145
146 // Allocation/administration
147 static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
148 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
149 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
150 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
151 static void free(CodeBlob* cb); // frees a CodeBlob
152 static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize())
153 static bool contains(void *p); // returns whether p is included
154 static bool contains(nmethod* nm); // returns whether nm is included
155 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
156 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
157 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
158 static void metadata_do(void f(Metadata* m)); // iterates over metadata in alive nmethods
159
160 // Lookup
161 static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address
162 static CodeBlob* find_blob_unsafe(void* start); // Same as find_blob but does not fail if looking up a zombie method
163 static nmethod* find_nmethod(void* start); // Returns the nmethod containing the given address
164 static CompiledMethod* find_compiled(void* start);
165
166 static int blob_count(); // Returns the total number of CodeBlobs in the cache
167 static int blob_count(int code_blob_type);
168 static int adapter_count(); // Returns the total number of Adapters in the cache
169 static int adapter_count(int code_blob_type);
170 static int nmethod_count(); // Returns the total number of nmethods in the cache
171 static int nmethod_count(int code_blob_type);
172
173 // GC support
174 static void gc_epilogue();
175 static void gc_prologue();
176 static void verify_oops();
177 // If any oops are not marked this method unloads (i.e., breaks root links
178 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
179 // to "true" iff some code got unloaded.
180 // "unloading_occurred" controls whether metadata should be cleaned because of class unloading.
181 class UnloadingScope: StackObj {
182 ClosureIsUnloadingBehaviour _is_unloading_behaviour;
183
184 public:
185 UnloadingScope(BoolObjectClosure* is_alive);
186 ~UnloadingScope();
187 };
188
189 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
190 static uint8_t unloading_cycle() { return _unloading_cycle; }
191 static void increment_unloading_cycle();
192 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
193 static void release_exception_cache(ExceptionCache* entry);
194 static void purge_exception_caches();
195
196 // Apply f to every live code blob in scavengable nmethods. Prune nmethods
197 // from the list of scavengable nmethods if f->fix_relocations() and a nmethod
198 // no longer has scavengable oops. If f->fix_relocations(), then f must copy
199 // objects to their new location immediately to avoid fixing nmethods on the
200 // basis of the old object locations.
201 static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f);
202
203 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
204 // register_scavenge_root_nmethod() conditionally adds the nmethod to the list
205 // if it is not already on the list and has a scavengeable root
206 static void register_scavenge_root_nmethod(nmethod* nm);
207 static void verify_scavenge_root_nmethod(nmethod* nm);
208 static void add_scavenge_root_nmethod(nmethod* nm);
209 static void drop_scavenge_root_nmethod(nmethod* nm);
210
211 // Printing/debugging
212 static void print(); // prints summary
213 static void print_internals();
214 static void print_memory_overhead();
215 static void verify(); // verifies the code cache
216 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
217 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
218 static void log_state(outputStream* st);
219 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"); }
220 static void report_codemem_full(int code_blob_type, bool print);
221
222 // Dcmd (Diagnostic commands)
223 static void print_codelist(outputStream* st);
224 static void print_layout(outputStream* st);
225
226 // The full limits of the codeCache
227 static address low_bound() { return _low_bound; }
228 static address low_bound(int code_blob_type);
229 static address high_bound() { return _high_bound; }
230 static address high_bound(int code_blob_type);
231
232 // Have to use far call instructions to call this pc.
233 static bool is_far_target(address pc);
234
235 // Profiling
236 static size_t capacity();
237 static size_t unallocated_capacity(int code_blob_type);
238 static size_t unallocated_capacity();
239 static size_t max_capacity();
240
241 static double reverse_free_ratio(int code_blob_type);
242
243 static void clear_inline_caches(); // clear all inline caches
244 static void cleanup_inline_caches(); // clean unloaded/zombie nmethods from inline caches
245
246 // Returns true if an own CodeHeap for the given CodeBlobType is available
247 static bool heap_available(int code_blob_type);
248
249 // Returns the CodeBlobType for the given CompiledMethod
250 static int get_code_blob_type(CompiledMethod* cm) {
251 return get_code_heap(cm)->code_blob_type();
252 }
253
254 static bool code_blob_type_accepts_compiled(int type) {
255 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
256 AOT_ONLY( result = result || type == CodeBlobType::AOT; )
257 return result;
258 }
259
260 static bool code_blob_type_accepts_nmethod(int type) {
261 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
262 }
263
264 static bool code_blob_type_accepts_allocable(int type) {
265 return type <= CodeBlobType::All;
266 }
267
268
269 // Returns the CodeBlobType for the given compilation level
270 static int get_code_blob_type(int comp_level) {
271 if (comp_level == CompLevel_none ||
272 comp_level == CompLevel_simple ||
273 comp_level == CompLevel_full_optimization) {
274 // Non profiled methods
275 return CodeBlobType::MethodNonProfiled;
276 } else if (comp_level == CompLevel_limited_profile ||
277 comp_level == CompLevel_full_profile) {
278 // Profiled methods
279 return CodeBlobType::MethodProfiled;
280 }
281 ShouldNotReachHere();
282 return 0;
283 }
284
285 static void verify_clean_inline_caches();
286 static void verify_icholder_relocations();
287
288 // Deoptimization
289 private:
290 static int mark_for_deoptimization(KlassDepChange& changes);
291
292 public:
293 static void mark_all_nmethods_for_deoptimization();
294 static int mark_for_deoptimization(Method* dependee);
295 static void make_marked_nmethods_not_entrant();
296
297 // Flushing and deoptimization
298 static void flush_dependents_on(InstanceKlass* dependee);
299 // Flushing and deoptimization in case of evolution
300 static void mark_for_evol_deoptimization(InstanceKlass* dependee);
301 static int mark_dependents_for_evol_deoptimization();
302 static void flush_evol_dependents();
303 // Support for fullspeed debugging
304 static void flush_dependents_on_method(const methodHandle& dependee);
305
306 // tells how many nmethods have dependencies
307 static int number_of_nmethods_with_dependencies();
308
309 static int get_codemem_full_count(int code_blob_type) {
310 CodeHeap* heap = get_code_heap(code_blob_type);
311 return (heap != NULL) ? heap->full_count() : 0;
312 }
313
314 // CodeHeap State Analytics.
315 // interface methods for CodeHeap printing, called by CompileBroker
316 static void aggregate(outputStream *out, const char* granularity);
317 static void discard(outputStream *out);
318 static void print_usedSpace(outputStream *out);
319 static void print_freeSpace(outputStream *out);
320 static void print_count(outputStream *out);
321 static void print_space(outputStream *out);
322 static void print_age(outputStream *out);
323 static void print_names(outputStream *out);
324 };
325
326
327 // Iterator to iterate over nmethods in the CodeCache.
328 template <class T, class Filter> class CodeBlobIterator : public StackObj {
329 public:
330 enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading };
331
332 private:
333 CodeBlob* _code_blob; // Current CodeBlob
334 GrowableArrayIterator<CodeHeap*> _heap;
335 GrowableArrayIterator<CodeHeap*> _end;
336 bool _only_alive;
337 bool _only_not_unloading;
338
339 public:
340 CodeBlobIterator(LivenessFilter filter, T* nm = NULL)
341 : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading),
342 _only_not_unloading(filter == only_alive_and_not_unloading)
343 {
344 if (Filter::heaps() == NULL) {
345 return;
346 }
347 _heap = Filter::heaps()->begin();
348 _end = Filter::heaps()->end();
349 // If set to NULL, initialized by first call to next()
350 _code_blob = (CodeBlob*)nm;
351 if (nm != NULL) {
352 while(!(*_heap)->contains_blob(_code_blob)) {
353 ++_heap;
354 }
355 assert((*_heap)->contains_blob(_code_blob), "match not found");
356 }
357 }
358
359 // Advance iterator to next blob
360 bool next() {
361 assert_locked_or_safepoint(CodeCache_lock);
362
363 for (;;) {
364 // Walk through heaps as required
365 if (!next_blob()) {
366 if (_heap == _end) {
367 return false;
368 }
369 ++_heap;
370 continue;
371 }
372
373 // Filter is_alive as required
374 if (_only_alive && !_code_blob->is_alive()) {
375 continue;
376 }
377
378 // Filter is_unloading as required
379 if (_only_not_unloading) {
380 CompiledMethod* cm = _code_blob->as_compiled_method_or_null();
381 if (cm != NULL && cm->is_unloading()) {
382 continue;
383 }
384 }
385
386 return true;
387 }
388 }
389
390 bool end() const { return _code_blob == NULL; }
391 T* method() const { return (T*)_code_blob; }
392
393 private:
394
395 // Advance iterator to the next blob in the current code heap
396 bool next_blob() {
397 if (_heap == _end) {
398 return false;
399 }
400 CodeHeap *heap = *_heap;
401 // Get first method CodeBlob
402 if (_code_blob == NULL) {
403 _code_blob = CodeCache::first_blob(heap);
404 if (_code_blob == NULL) {
405 return false;
406 } else if (Filter::apply(_code_blob)) {
407 return true;
408 }
409 }
410 // Search for next method CodeBlob
411 _code_blob = CodeCache::next_blob(heap, _code_blob);
412 while (_code_blob != NULL && !Filter::apply(_code_blob)) {
413 _code_blob = CodeCache::next_blob(heap, _code_blob);
414 }
415 return _code_blob != NULL;
416 }
417 };
418
419
420 struct CompiledMethodFilter {
421 static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
422 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
423 };
424
425
426 struct NMethodFilter {
427 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
428 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
429 };
430
431 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
432 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
433
434 #endif // SHARE_CODE_CODECACHE_HPP