1 /*
2 * Copyright (c) 1997, 2017, 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
12 * version 2 for more details (a copy is included in the LICENSE file that
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 "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 static GrowableArray<CodeHeap*>* _allocable_heaps;
89
90 static address _low_bound; // Lower bound of CodeHeap addresses
91 static address _high_bound; // Upper bound of CodeHeap addresses
92 static int _number_of_nmethods_with_dependencies; // Total number of nmethods with dependencies
93 static bool _needs_cache_clean; // True if inline caches of the nmethods needs to be flushed
94 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()
95
96 static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
97 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
98
99 // CodeHeap management
100 static void initialize_heaps(); // Initializes the CodeHeaps
101 // Check the code heap sizes set by the user via command line
102 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);
103 // Creates a new heap with the given name and size, containing CodeBlobs of the given type
104 static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);
105 static CodeHeap* get_code_heap_containing(void* p); // Returns the CodeHeap containing the given pointer, or NULL
106 static CodeHeap* get_code_heap(const CodeBlob* cb); // Returns the CodeHeap for the given CodeBlob
107 static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType
108 // Returns the name of the VM option to set the size of the corresponding CodeHeap
109 static const char* get_code_heap_flag_name(int code_blob_type);
110 static size_t heap_alignment(); // Returns the alignment of the CodeHeaps in bytes
111 static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps
112
113 // Iteration
114 static CodeBlob* first_blob(CodeHeap* heap); // Returns the first CodeBlob on the given CodeHeap
115 static CodeBlob* first_blob(int code_blob_type); // Returns the first CodeBlob of the given type
116 static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb); // Returns the next CodeBlob on the given CodeHeap
117
118 static size_t bytes_allocated_in_freelists();
119 static int allocated_segments();
120 static size_t freelists_length();
121
122 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
123 static void prune_scavenge_root_nmethods();
124 static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev);
125
126 // Make private to prevent unsafe calls. Not all CodeBlob*'s are embedded in a CodeHeap.
127 static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }
128
129 public:
130 // Initialization
131 static void initialize();
132
133 static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
134
135 static void add_heap(CodeHeap* heap);
136 static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
137 static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
138 static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
139
140 // Allocation/administration
141 static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
142 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
143 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
144 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
145 static void free(CodeBlob* cb); // frees a CodeBlob
146 static bool contains(void *p); // returns whether p is included
147 static bool contains(nmethod* nm); // returns whether nm is included
148 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
149 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
150 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
151 static void metadata_do(void f(Metadata* m)); // iterates over metadata in alive nmethods
152
153 // Lookup
154 static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address
155 static CodeBlob* find_blob_unsafe(void* start); // Same as find_blob but does not fail if looking up a zombie method
156 static nmethod* find_nmethod(void* start); // Returns the nmethod containing the given address
157 static CompiledMethod* find_compiled(void* start);
158
159 static int blob_count(); // Returns the total number of CodeBlobs in the cache
160 static int blob_count(int code_blob_type);
161 static int adapter_count(); // Returns the total number of Adapters in the cache
162 static int adapter_count(int code_blob_type);
163 static int nmethod_count(); // Returns the total number of nmethods in the cache
164 static int nmethod_count(int code_blob_type);
165
166 // GC support
167 static void gc_epilogue();
168 static void gc_prologue();
169 static void verify_oops();
170 // If "unloading_occurred" is true, then unloads (i.e., breaks root links
171 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
172 // to "true" iff some code got unloaded.
173 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
174 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
175
176 // Apply f to every live code blob in scavengable nmethods. Prune nmethods
177 // from the list of scavengable nmethods if f->fix_relocations() and a nmethod
178 // no longer has scavengable oops. If f->fix_relocations(), then f must copy
179 // objects to their new location immediately to avoid fixing nmethods on the
180 // basis of the old object locations.
181 static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f);
182
183 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
184 static void add_scavenge_root_nmethod(nmethod* nm);
185 static void drop_scavenge_root_nmethod(nmethod* nm);
186
187 // Printing/debugging
188 static void print(); // prints summary
189 static void print_internals();
190 static void print_memory_overhead();
191 static void verify(); // verifies the code cache
192 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
193 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
194 static void log_state(outputStream* st);
195 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"); }
196 static void report_codemem_full(int code_blob_type, bool print);
197
198 // Dcmd (Diagnostic commands)
199 static void print_codelist(outputStream* st);
200 static void print_layout(outputStream* st);
201
202 // The full limits of the codeCache
203 static address low_bound() { return _low_bound; }
204 static address low_bound(int code_blob_type);
205 static address high_bound() { return _high_bound; }
206 static address high_bound(int code_blob_type);
207
208 // Have to use far call instructions to call this pc.
209 static bool is_far_target(address pc);
210
211 // Profiling
212 static size_t capacity();
213 static size_t unallocated_capacity(int code_blob_type);
214 static size_t unallocated_capacity();
215 static size_t max_capacity();
216
217 static double reverse_free_ratio(int code_blob_type);
218
219 static bool needs_cache_clean() { return _needs_cache_clean; }
220 static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
221 static void clear_inline_caches(); // clear all inline caches
222 static void cleanup_inline_caches();
223
224 // Returns true if an own CodeHeap for the given CodeBlobType is available
225 static bool heap_available(int code_blob_type);
226
227 // Returns the CodeBlobType for the given CompiledMethod
228 static int get_code_blob_type(CompiledMethod* cm) {
229 return get_code_heap(cm)->code_blob_type();
230 }
231
232 static bool code_blob_type_accepts_compiled(int type) {
233 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
234 AOT_ONLY( result = result || type == CodeBlobType::AOT; )
235 return result;
236 }
237
238 static bool code_blob_type_accepts_nmethod(int type) {
239 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
240 }
241
242 static bool code_blob_type_accepts_allocable(int type) {
243 return type <= CodeBlobType::All;
244 }
245
246
247 // Returns the CodeBlobType for the given compilation level
248 static int get_code_blob_type(int comp_level) {
249 if (comp_level == CompLevel_none ||
250 comp_level == CompLevel_simple ||
251 comp_level == CompLevel_full_optimization) {
252 // Non profiled methods
253 return CodeBlobType::MethodNonProfiled;
254 } else if (comp_level == CompLevel_limited_profile ||
255 comp_level == CompLevel_full_profile) {
256 // Profiled methods
257 return CodeBlobType::MethodProfiled;
258 }
259 ShouldNotReachHere();
260 return 0;
261 }
262
263 static void verify_clean_inline_caches();
264 static void verify_icholder_relocations();
265
266 // Deoptimization
267 private:
268 static int mark_for_deoptimization(KlassDepChange& changes);
269 #ifdef HOTSWAP
270 static int mark_for_evol_deoptimization(InstanceKlass* dependee);
271 #endif // HOTSWAP
272
273 public:
274 static void mark_all_nmethods_for_deoptimization();
275 static int mark_for_deoptimization(Method* dependee);
276 static void make_marked_nmethods_not_entrant();
277
278 // Flushing and deoptimization
279 static void flush_dependents_on(InstanceKlass* dependee);
280 #ifdef HOTSWAP
281 // Flushing and deoptimization in case of evolution
282 static void flush_evol_dependents_on(InstanceKlass* dependee);
283 #endif // HOTSWAP
284 // Support for fullspeed debugging
285 static void flush_dependents_on_method(methodHandle dependee);
286
287 // tells how many nmethods have dependencies
288 static int number_of_nmethods_with_dependencies();
289
290 static int get_codemem_full_count(int code_blob_type) {
291 CodeHeap* heap = get_code_heap(code_blob_type);
292 return (heap != NULL) ? heap->full_count() : 0;
293 }
294 };
295
296
297 // Iterator to iterate over nmethods in the CodeCache.
298 template <class T, class Filter> class CodeBlobIterator : public StackObj {
299 private:
300 CodeBlob* _code_blob; // Current CodeBlob
301 GrowableArrayIterator<CodeHeap*> _heap;
302 GrowableArrayIterator<CodeHeap*> _end;
303
304 public:
305 CodeBlobIterator(T* nm = NULL) {
306 if (Filter::heaps() == NULL) {
307 return;
308 }
309 _heap = Filter::heaps()->begin();
310 _end = Filter::heaps()->end();
311 // If set to NULL, initialized by first call to next()
312 _code_blob = (CodeBlob*)nm;
313 if (nm != NULL) {
314 while(!(*_heap)->contains_blob(_code_blob)) {
315 ++_heap;
316 }
317 assert((*_heap)->contains_blob(_code_blob), "match not found");
318 }
319 }
320
321 // Advance iterator to next blob
322 bool next() {
323 assert_locked_or_safepoint(CodeCache_lock);
324
325 bool result = next_blob();
326 while (!result && _heap != _end) {
327 // Advance to next code heap of segmented code cache
328 if (++_heap == _end) {
329 break;
330 }
331 result = next_blob();
332 }
333
334 return result;
335 }
336
337 // Advance iterator to next alive blob
338 bool next_alive() {
339 bool result = next();
340 while(result && !_code_blob->is_alive()) {
341 result = next();
342 }
343 return result;
344 }
345
346 bool end() const { return _code_blob == NULL; }
347 T* method() const { return (T*)_code_blob; }
348
349 private:
350
351 // Advance iterator to the next blob in the current code heap
352 bool next_blob() {
353 if (_heap == _end) {
354 return false;
355 }
356 CodeHeap *heap = *_heap;
357 // Get first method CodeBlob
358 if (_code_blob == NULL) {
359 _code_blob = CodeCache::first_blob(heap);
360 if (_code_blob == NULL) {
361 return false;
362 } else if (Filter::apply(_code_blob)) {
363 return true;
364 }
365 }
366 // Search for next method CodeBlob
367 _code_blob = CodeCache::next_blob(heap, _code_blob);
368 while (_code_blob != NULL && !Filter::apply(_code_blob)) {
369 _code_blob = CodeCache::next_blob(heap, _code_blob);
370 }
371 return _code_blob != NULL;
372 }
373 };
374
375
376 struct CompiledMethodFilter {
377 static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
378 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
379 };
380
381
382 struct NMethodFilter {
383 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
384 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
385 };
386
387
388 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
389 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
390
391 #endif // SHARE_VM_CODE_CODECACHE_HPP