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.
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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_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