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 "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 ExceptionCache;
75 class KlassDepChange;
76 class OopClosure;
77
78 class CodeCache : AllStatic {
79 friend class VMStructs;
80 friend class JVMCIVMStructs;
81 template <class T, class Filter> friend class CodeBlobIterator;
82 friend class WhiteBox;
83 friend class CodeCacheLoader;
84 private:
85 // CodeHeaps of the cache
86 static GrowableArray<CodeHeap*>* _heaps;
87 static GrowableArray<CodeHeap*>* _compiled_heaps;
88 static GrowableArray<CodeHeap*>* _nmethod_heaps;
89 static GrowableArray<CodeHeap*>* _allocable_heaps;
90
91 static address _low_bound; // Lower bound of CodeHeap addresses
92 static address _high_bound; // Upper bound of CodeHeap addresses
93 static int _number_of_nmethods_with_dependencies; // Total number of nmethods with dependencies
94 static bool _needs_cache_clean; // True if inline caches of the nmethods needs to be flushed
95 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()
96
97 static ExceptionCache* volatile _exception_cache_purge_list;
98
99 static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
100 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
101
102 // CodeHeap management
103 static void initialize_heaps(); // Initializes the CodeHeaps
104 // Check the code heap sizes set by the user via command line
105 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);
106 // Creates a new heap with the given name and size, containing CodeBlobs of the given type
107 static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);
108 static CodeHeap* get_code_heap_containing(void* p); // Returns the CodeHeap containing the given pointer, or NULL
109 static CodeHeap* get_code_heap(const CodeBlob* cb); // Returns the CodeHeap for the given CodeBlob
110 static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType
111 // Returns the name of the VM option to set the size of the corresponding CodeHeap
112 static const char* get_code_heap_flag_name(int code_blob_type);
113 static size_t page_size(bool aligned = true); // Returns the page size used by the CodeCache
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 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
126 static void prune_scavenge_root_nmethods();
127 static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev);
128
129 // Make private to prevent unsafe calls. Not all CodeBlob*'s are embedded in a CodeHeap.
130 static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }
131
132 public:
133 // Initialization
134 static void initialize();
135
136 static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);
137
138 static void add_heap(CodeHeap* heap);
139 static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }
140 static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }
141 static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }
142
143 // Allocation/administration
144 static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob
145 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
146 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
147 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
148 static void free(CodeBlob* cb); // frees a CodeBlob
149 static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize())
150 static bool contains(void *p); // returns whether p is included
151 static bool contains(nmethod* nm); // returns whether nm is included
152 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
153 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
154 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
155 static void metadata_do(void f(Metadata* m)); // iterates over metadata in alive nmethods
156
157 // Lookup
158 static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address
159 static CodeBlob* find_blob_unsafe(void* start); // Same as find_blob but does not fail if looking up a zombie method
160 static nmethod* find_nmethod(void* start); // Returns the nmethod containing the given address
161 static CompiledMethod* find_compiled(void* start);
162
163 static int blob_count(); // Returns the total number of CodeBlobs in the cache
164 static int blob_count(int code_blob_type);
165 static int adapter_count(); // Returns the total number of Adapters in the cache
166 static int adapter_count(int code_blob_type);
167 static int nmethod_count(); // Returns the total number of nmethods in the cache
168 static int nmethod_count(int code_blob_type);
169
170 // GC support
171 static void gc_epilogue();
172 static void gc_prologue();
173 static void verify_oops();
174 // If any oops are not marked this method unloads (i.e., breaks root links
175 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
176 // to "true" iff some code got unloaded.
177 // "unloading_occurred" controls whether metadata should be cleaned because of class unloading.
178 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
179 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
180 static void release_exception_cache(ExceptionCache* entry);
181 static void purge_exception_caches();
182
183 // Apply f to every live code blob in scavengable nmethods. Prune nmethods
184 // from the list of scavengable nmethods if f->fix_relocations() and a nmethod
185 // no longer has scavengable oops. If f->fix_relocations(), then f must copy
186 // objects to their new location immediately to avoid fixing nmethods on the
187 // basis of the old object locations.
188 static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f);
189
190 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
191 // register_scavenge_root_nmethod() conditionally adds the nmethod to the list
192 // if it is not already on the list and has a scavengeable root
193 static void register_scavenge_root_nmethod(nmethod* nm);
194 static void verify_scavenge_root_nmethod(nmethod* nm);
195 static void add_scavenge_root_nmethod(nmethod* nm);
196 static void drop_scavenge_root_nmethod(nmethod* nm);
197
198 // Printing/debugging
199 static void print(); // prints summary
200 static void print_internals();
201 static void print_memory_overhead();
202 static void verify(); // verifies the code cache
203 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
204 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
205 static void log_state(outputStream* st);
206 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"); }
207 static void report_codemem_full(int code_blob_type, bool print);
208
209 // Dcmd (Diagnostic commands)
210 static void print_codelist(outputStream* st);
211 static void print_layout(outputStream* st);
212
213 // The full limits of the codeCache
214 static address low_bound() { return _low_bound; }
215 static address low_bound(int code_blob_type);
216 static address high_bound() { return _high_bound; }
217 static address high_bound(int code_blob_type);
218
219 // Have to use far call instructions to call this pc.
220 static bool is_far_target(address pc);
221
222 // Profiling
223 static size_t capacity();
224 static size_t unallocated_capacity(int code_blob_type);
225 static size_t unallocated_capacity();
226 static size_t max_capacity();
227
228 static double reverse_free_ratio(int code_blob_type);
229
230 static bool needs_cache_clean() { return _needs_cache_clean; }
231 static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
232
233 static void clear_inline_caches(); // clear all inline caches
234 static void cleanup_inline_caches(); // clean unloaded/zombie nmethods from inline caches
235 static void do_unloading_nmethod_caches(bool class_unloading_occurred); // clean all nmethod caches for unloading, including inline caches
236
237 // Returns true if an own CodeHeap for the given CodeBlobType is available
238 static bool heap_available(int code_blob_type);
239
240 // Returns the CodeBlobType for the given CompiledMethod
241 static int get_code_blob_type(CompiledMethod* cm) {
242 return get_code_heap(cm)->code_blob_type();
243 }
244
245 static bool code_blob_type_accepts_compiled(int type) {
246 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
247 AOT_ONLY( result = result || type == CodeBlobType::AOT; )
248 return result;
249 }
250
251 static bool code_blob_type_accepts_nmethod(int type) {
252 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
253 }
254
255 static bool code_blob_type_accepts_allocable(int type) {
256 return type <= CodeBlobType::All;
257 }
258
259
260 // Returns the CodeBlobType for the given compilation level
261 static int get_code_blob_type(int comp_level) {
262 if (comp_level == CompLevel_none ||
263 comp_level == CompLevel_simple ||
264 comp_level == CompLevel_full_optimization) {
265 // Non profiled methods
266 return CodeBlobType::MethodNonProfiled;
267 } else if (comp_level == CompLevel_limited_profile ||
268 comp_level == CompLevel_full_profile) {
269 // Profiled methods
270 return CodeBlobType::MethodProfiled;
271 }
272 ShouldNotReachHere();
273 return 0;
274 }
275
276 static void verify_clean_inline_caches();
277 static void verify_icholder_relocations();
278
279 // Deoptimization
280 private:
281 static int mark_for_deoptimization(KlassDepChange& changes);
282 #ifdef HOTSWAP
283 static int mark_for_evol_deoptimization(InstanceKlass* dependee);
284 #endif // HOTSWAP
285
286 public:
287 static void mark_all_nmethods_for_deoptimization();
288 static int mark_for_deoptimization(Method* dependee);
289 static void make_marked_nmethods_not_entrant();
290
291 // Flushing and deoptimization
292 static void flush_dependents_on(InstanceKlass* dependee);
293 #ifdef HOTSWAP
294 // Flushing and deoptimization in case of evolution
295 static void flush_evol_dependents_on(InstanceKlass* dependee);
296 #endif // HOTSWAP
297 // Support for fullspeed debugging
298 static void flush_dependents_on_method(const methodHandle& dependee);
299
300 // tells how many nmethods have dependencies
301 static int number_of_nmethods_with_dependencies();
302
303 static int get_codemem_full_count(int code_blob_type) {
304 CodeHeap* heap = get_code_heap(code_blob_type);
305 return (heap != NULL) ? heap->full_count() : 0;
306 }
307
308 // CodeHeap State Analytics.
309 // interface methods for CodeHeap printing, called by CompileBroker
310 static void aggregate(outputStream *out, const char* granularity);
311 static void discard(outputStream *out);
312 static void print_usedSpace(outputStream *out);
313 static void print_freeSpace(outputStream *out);
314 static void print_count(outputStream *out);
315 static void print_space(outputStream *out);
316 static void print_age(outputStream *out);
317 static void print_names(outputStream *out);
318 };
319
320
321 // Iterator to iterate over nmethods in the CodeCache.
322 template <class T, class Filter> class CodeBlobIterator : public StackObj {
323 private:
324 CodeBlob* _code_blob; // Current CodeBlob
325 GrowableArrayIterator<CodeHeap*> _heap;
326 GrowableArrayIterator<CodeHeap*> _end;
327
328 public:
329 CodeBlobIterator(T* nm = NULL) {
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 bool result = next_blob();
350 while (!result && _heap != _end) {
351 // Advance to next code heap of segmented code cache
352 if (++_heap == _end) {
353 break;
354 }
355 result = next_blob();
356 }
357
358 return result;
359 }
360
361 // Advance iterator to next alive blob
362 bool next_alive() {
363 bool result = next();
364 while(result && !_code_blob->is_alive()) {
365 result = next();
366 }
367 return result;
368 }
369
370 bool end() const { return _code_blob == NULL; }
371 T* method() const { return (T*)_code_blob; }
372
373 private:
374
375 // Advance iterator to the next blob in the current code heap
376 bool next_blob() {
377 if (_heap == _end) {
378 return false;
379 }
380 CodeHeap *heap = *_heap;
381 // Get first method CodeBlob
382 if (_code_blob == NULL) {
383 _code_blob = CodeCache::first_blob(heap);
384 if (_code_blob == NULL) {
385 return false;
386 } else if (Filter::apply(_code_blob)) {
387 return true;
388 }
389 }
390 // Search for next method CodeBlob
391 _code_blob = CodeCache::next_blob(heap, _code_blob);
392 while (_code_blob != NULL && !Filter::apply(_code_blob)) {
393 _code_blob = CodeCache::next_blob(heap, _code_blob);
394 }
395 return _code_blob != NULL;
396 }
397 };
398
399
400 struct CompiledMethodFilter {
401 static bool apply(CodeBlob* cb) { return cb->is_compiled(); }
402 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }
403 };
404
405
406 struct NMethodFilter {
407 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }
408 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }
409 };
410
411
412 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;
413 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;
414
415 #endif // SHARE_VM_CODE_CODECACHE_HPP