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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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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16 * 2 along with this work; if not, write to the Free Software Foundation,
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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 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(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 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
174 public:
175 UnloadingScope(BoolObjectClosure* is_alive);
176 ~UnloadingScope();
177 };
178
179 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
180 static uint8_t unloading_cycle() { return _unloading_cycle; }
181 static void increment_unloading_cycle();
182 static void release_exception_cache(ExceptionCache* entry);
183 static void purge_exception_caches();
184
185 // Printing/debugging
186 static void print(); // prints summary
187 static void print_internals();
188 static void print_memory_overhead();
189 static void verify(); // verifies the code cache
190 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
191 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
192 static void log_state(outputStream* st);
193 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"); }
194 static void report_codemem_full(int code_blob_type, bool print);
195
196 // Dcmd (Diagnostic commands)
197 static void print_codelist(outputStream* st);
198 static void print_layout(outputStream* st);
199
200 // The full limits of the codeCache
201 static address low_bound() { return _low_bound; }
202 static address low_bound(int code_blob_type);
203 static address high_bound() { return _high_bound; }
204 static address high_bound(int code_blob_type);
205
206 // Have to use far call instructions to call this pc.
207 static bool is_far_target(address pc);
208
209 // Profiling
210 static size_t capacity();
211 static size_t unallocated_capacity(int code_blob_type);
212 static size_t unallocated_capacity();
213 static size_t max_capacity();
214
215 static double reverse_free_ratio(int code_blob_type);
216
217 static void clear_inline_caches(); // clear all inline caches
218 static void cleanup_inline_caches(); // clean unloaded/zombie nmethods from inline caches
219
220 // Returns true if an own CodeHeap for the given CodeBlobType is available
221 static bool heap_available(int code_blob_type);
222
223 // Returns the CodeBlobType for the given CompiledMethod
224 static int get_code_blob_type(CompiledMethod* cm) {
225 return get_code_heap(cm)->code_blob_type();
226 }
227
228 static bool code_blob_type_accepts_compiled(int type) {
229 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
230 AOT_ONLY( result = result || type == CodeBlobType::AOT; )
231 return result;
232 }
233
234 static bool code_blob_type_accepts_nmethod(int type) {
235 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
236 }
237
238 static bool code_blob_type_accepts_allocable(int type) {
239 return type <= CodeBlobType::All;
240 }
241
242
243 // Returns the CodeBlobType for the given compilation level
244 static int get_code_blob_type(int comp_level) {
245 if (comp_level == CompLevel_none ||
246 comp_level == CompLevel_simple ||
247 comp_level == CompLevel_full_optimization) {
248 // Non profiled methods
249 return CodeBlobType::MethodNonProfiled;
250 } else if (comp_level == CompLevel_limited_profile ||
251 comp_level == CompLevel_full_profile) {
252 // Profiled methods
253 return CodeBlobType::MethodProfiled;
254 }
255 ShouldNotReachHere();
256 return 0;
257 }
258
259 static void verify_clean_inline_caches();
260 static void verify_icholder_relocations();
261
262 // Deoptimization
263 private:
264 static int mark_for_deoptimization(KlassDepChange& changes);
265
266 public:
267 static void mark_all_nmethods_for_deoptimization();
268 static int mark_for_deoptimization(Method* dependee);
269 static void make_marked_nmethods_not_entrant();
270
271 // Flushing and deoptimization
272 static void flush_dependents_on(InstanceKlass* dependee);
273 // Flushing and deoptimization in case of evolution
274 static void mark_for_evol_deoptimization(InstanceKlass* dependee);
275 static int mark_dependents_for_evol_deoptimization();
276 static void flush_evol_dependents();
277 // Support for fullspeed debugging
278 static void flush_dependents_on_method(const methodHandle& dependee);
279
280 // tells how many nmethods have dependencies
281 static int number_of_nmethods_with_dependencies();
282
283 static int get_codemem_full_count(int code_blob_type) {
284 CodeHeap* heap = get_code_heap(code_blob_type);
285 return (heap != NULL) ? heap->full_count() : 0;
286 }
287
288 // CodeHeap State Analytics.
289 // interface methods for CodeHeap printing, called by CompileBroker
290 static void aggregate(outputStream *out, const char* granularity);
291 static void discard(outputStream *out);
292 static void print_usedSpace(outputStream *out);
293 static void print_freeSpace(outputStream *out);
294 static void print_count(outputStream *out);
295 static void print_space(outputStream *out);
296 static void print_age(outputStream *out);
297 static void print_names(outputStream *out);
298 };
299
300
301 // Iterator to iterate over nmethods in the CodeCache.
302 template <class T, class Filter> class CodeBlobIterator : public StackObj {
303 public:
304 enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading };
305
306 private:
307 CodeBlob* _code_blob; // Current CodeBlob
308 GrowableArrayIterator<CodeHeap*> _heap;
309 GrowableArrayIterator<CodeHeap*> _end;
310 bool _only_alive;
311 bool _only_not_unloading;
312
313 public:
314 CodeBlobIterator(LivenessFilter filter, T* nm = NULL)
315 : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading),
316 _only_not_unloading(filter == only_alive_and_not_unloading)
317 {
318 if (Filter::heaps() == NULL) {
319 return;
320 }
321 _heap = Filter::heaps()->begin();
322 _end = Filter::heaps()->end();
323 // If set to NULL, initialized by first call to next()
324 _code_blob = (CodeBlob*)nm;
325 if (nm != NULL) {
326 while(!(*_heap)->contains_blob(_code_blob)) {
327 ++_heap;
328 }
329 assert((*_heap)->contains_blob(_code_blob), "match not found");
330 }
331 }
332
333 // Advance iterator to next blob
334 bool next() {
335 assert_locked_or_safepoint(CodeCache_lock);
336
337 for (;;) {
338 // Walk through heaps as required
339 if (!next_blob()) {
340 if (_heap == _end) {
341 return false;
342 }
343 ++_heap;
344 continue;
345 }
346
347 // Filter is_alive as required
348 if (_only_alive && !_code_blob->is_alive()) {
349 continue;
350 }
351
352 // Filter is_unloading as required
353 if (_only_not_unloading) {
354 CompiledMethod* cm = _code_blob->as_compiled_method_or_null();
355 if (cm != NULL && cm->is_unloading()) {
356 continue;
357 }
358 }
359
360 return true;
361 }
362 }
363
364 bool end() const { return _code_blob == NULL; }
365 T* method() const { return (T*)_code_blob; }
366
367 private:
368
369 // Advance iterator to the next blob in the current code heap
370 bool next_blob() {
371 if (_heap == _end) {
372 return false;
373 }
374 CodeHeap *heap = *_heap;
375 // Get first method CodeBlob
376 if (_code_blob == NULL) {
377 _code_blob = CodeCache::first_blob(heap);
378 if (_code_blob == NULL) {
379 return false;
380 } else if (Filter::apply(_code_blob)) {
381 return true;
382 }
383 }
384 // Search for next method CodeBlob
385 _code_blob = CodeCache::next_blob(heap, _code_blob);
386 while (_code_blob != NULL && !Filter::apply(_code_blob)) {
387 _code_blob = CodeCache::next_blob(heap, _code_blob);
388 }
389 return _code_blob != NULL;
390 }
391 };
392
393
394 struct CompiledMethodFilter {
395 static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
396 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
397 };
398
399
400 struct NMethodFilter {
401 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
402 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
403 };
404
405 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
406 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
407
408 #endif // SHARE_CODE_CODECACHE_HPP