1 /*
2 * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
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).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciEnv.hpp"
27 #include "ci/ciInstance.hpp"
28 #include "ci/ciMetadata.hpp"
29 #include "code/oopRecorder.inline.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "runtime/jniHandles.inline.hpp"
34 #include "runtime/mutexLocker.hpp"
35 #include "runtime/os.hpp"
36 #include "utilities/copy.hpp"
37
38 #ifdef ASSERT
39 template <class T> int ValueRecorder<T>::_find_index_calls = 0;
40 template <class T> int ValueRecorder<T>::_hit_indexes = 0;
41 template <class T> int ValueRecorder<T>::_missed_indexes = 0;
42 #endif //ASSERT
43
44
45 template <class T> ValueRecorder<T>::ValueRecorder(Arena* arena) {
46 _handles = nullptr;
47 _indexes = nullptr;
48 _arena = arena;
49 _complete = false;
50 }
51
52 template <class T> template <class X> ValueRecorder<T>::IndexCache<X>::IndexCache() {
53 assert(first_index > 0, "initial zero state of cache must be invalid index");
54 Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
55 }
56
57 template <class T> int ValueRecorder<T>::size() {
58 _complete = true;
59 if (_handles == nullptr) return 0;
60 return _handles->length() * sizeof(T);
61 }
62
63 template <class T> void ValueRecorder<T>::copy_values_to(nmethod* nm) {
64 assert(_complete, "must be frozen");
65 maybe_initialize(); // get non-null handles, even if we have no oops
66 nm->copy_values(_handles);
67 }
68
69 template <class T> void ValueRecorder<T>::maybe_initialize() {
70 if (_handles == nullptr) {
71 if (_arena != nullptr) {
72 _handles = new(_arena) GrowableArray<T>(_arena, 10, 0, T{});
73 _no_finds = new(_arena) GrowableArray<int>(_arena, 10, 0, 0);
74 } else {
75 _handles = new GrowableArray<T>(10, 0, T{});
76 _no_finds = new GrowableArray<int>(10, 0, 0);
77 }
78 }
79 }
80
81
82 template <class T> T ValueRecorder<T>::at(int index) {
83 // there is always a nullptr virtually present as first object
84 if (index == null_index) return nullptr;
85 return _handles->at(index - first_index);
86 }
87
88
89 template <class T> int ValueRecorder<T>::add_handle(T h, bool make_findable) {
90 assert(!_complete, "cannot allocate more elements after size query");
91 maybe_initialize();
92 // indexing uses 1 as an origin--0 means null
93 int index = _handles->length() + first_index;
94 _handles->append(h);
95
96 // Support correct operation of find_index().
97 assert(!(make_findable && !is_real(h)), "nulls are not findable");
98 if (make_findable) {
99 // This index may be returned from find_index().
100 if (_indexes != nullptr) {
101 int* cloc = _indexes->cache_location(h);
102 _indexes->set_cache_location_index(cloc, index);
103 } else if (index == index_cache_threshold && _arena != nullptr) {
104 _indexes = new(_arena) IndexCache<T>();
105 for (int i = 0; i < _handles->length(); i++) {
106 // Load the cache with pre-existing elements.
107 int index0 = i + first_index;
108 if (_no_finds->contains(index0)) continue;
109 int* cloc = _indexes->cache_location(_handles->at(i));
110 _indexes->set_cache_location_index(cloc, index0);
111 }
112 }
113 } else if (is_real(h)) {
114 // Remember that this index is not to be returned from find_index().
115 // This case is rare, because most or all uses of allocate_index pass
116 // an argument of nullptr or Universe::non_oop_word.
117 // Thus, the expected length of _no_finds is zero.
118 _no_finds->append(index);
119 }
120
121 return index;
122 }
123
124
125 template <class T> int ValueRecorder<T>::maybe_find_index(T h) {
126 debug_only(_find_index_calls++);
127 assert(!_complete, "cannot allocate more elements after size query");
128 maybe_initialize();
129 if (h == nullptr) return null_index;
130 assert(is_real(h), "must be valid");
131 int* cloc = (_indexes == nullptr)? nullptr: _indexes->cache_location(h);
132 if (cloc != nullptr) {
133 int cindex = _indexes->cache_location_index(cloc);
134 if (cindex == 0) {
135 return -1; // We know this handle is completely new.
136 }
137 if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
138 debug_only(_hit_indexes++);
139 return cindex;
140 }
141 if (!_indexes->cache_location_collision(cloc)) {
142 return -1; // We know the current cache occupant is unique to that cloc.
143 }
144 }
145
146 // Not found in cache, due to a cache collision. (Or, no cache at all.)
147 // Do a linear search, most recent to oldest.
148 for (int i = _handles->length() - 1; i >= 0; i--) {
149 if (_handles->at(i) == h) {
150 int findex = i + first_index;
151 if (_no_finds->contains(findex)) continue; // oops; skip this one
152 if (cloc != nullptr) {
153 _indexes->set_cache_location_index(cloc, findex);
154 }
155 debug_only(_missed_indexes++);
156 return findex;
157 }
158 }
159 return -1;
160 }
161
162 // Explicitly instantiate these types
163 template class ValueRecorder<Metadata*>;
164 template class ValueRecorder<jobject>;
165
166 oop ObjectLookup::ObjectEntry::oop_value() const { return JNIHandles::resolve(_value); }
167
168 ObjectLookup::ObjectLookup(): _values(4), _gc_count(Universe::heap()->total_collections()) {}
169
170 void ObjectLookup::maybe_resort() {
171 // The values are kept sorted by address which may be invalidated
172 // after a GC, so resort if a GC has occurred since last time.
173 if (_gc_count != Universe::heap()->total_collections()) {
174 _gc_count = Universe::heap()->total_collections();
175 _values.sort(sort_by_address);
176 }
177 }
178
179 int ObjectLookup::sort_by_address(oop a, oop b) {
180 // oopDesc::compare returns the opposite of what this function returned
181 return -(oopDesc::compare(a, b));
182 }
183
184 int ObjectLookup::sort_by_address(ObjectEntry* a, ObjectEntry* b) {
185 return sort_by_address(a->oop_value(), b->oop_value());
186 }
187
188 int ObjectLookup::sort_oop_by_address(oop const& a, ObjectEntry const& b) {
189 return sort_by_address(a, b.oop_value());
190 }
191
192 int ObjectLookup::find_index(jobject handle, OopRecorder* oop_recorder) {
193 if (handle == nullptr) {
194 return 0;
195 }
196 oop object = JNIHandles::resolve(handle);
197 maybe_resort();
198 bool found;
199 int location = _values.find_sorted<oop, sort_oop_by_address>(object, found);
200 if (!found) {
201 jobject handle = JNIHandles::make_local(object);
202 ObjectEntry r(handle, oop_recorder->allocate_oop_index(handle));
203 _values.insert_before(location, r);
204 return r.index();
205 }
206 return _values.at(location).index();
207 }
208
209 OopRecorder::OopRecorder(Arena* arena, bool deduplicate): _oops(arena), _metadata(arena) {
210 if (deduplicate) {
211 _object_lookup = new ObjectLookup();
212 } else {
213 _object_lookup = nullptr;
214 }
215 }
216
217 // Explicitly instantiate
218 template class ValueRecorder<address>;
219
220 ExternalsRecorder* ExternalsRecorder::_recorder = nullptr;
221
222 ExternalsRecorder::ExternalsRecorder(): _arena(mtCode), _externals(&_arena) {}
223
224 #ifndef PRODUCT
225 static int total_access_count = 0;
226 static GrowableArray<int>* extern_hist = nullptr;
227 #endif
228
229 void ExternalsRecorder_init() {
230 ExternalsRecorder::initialize();
231 }
232
233 void ExternalsRecorder::initialize() {
234 // After Mutex and before CodeCache are initialized
235 assert(_recorder == nullptr, "should initialize only once");
236 _recorder = new ExternalsRecorder();
237 #ifndef PRODUCT
238 if (PrintNMethodStatistics) {
239 Arena* arena = &_recorder->_arena;
240 extern_hist = new(arena) GrowableArray<int>(arena, 512, 512, 0);
241 }
242 #endif
243 }
244
245 int ExternalsRecorder::find_index(address adr) {
246 assert(_recorder != nullptr, "sanity");
247 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
248 int index = _recorder->_externals.find_index(adr);
249 #ifndef PRODUCT
250 if (PrintNMethodStatistics) {
251 total_access_count++;
252 int n = extern_hist->at_grow(index, 0);
253 extern_hist->at_put(index, (n + 1));
254 }
255 #endif
256 return index;
257 }
258
259 address ExternalsRecorder::at(int index) {
260 assert(_recorder != nullptr, "sanity");
261 // find_index() may resize array by reallocating it and freeing old,
262 // we need loock here to make sure we not accessing to old freed array.
263 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
264 return _recorder->_externals.at(index);
265 }
266
267 int ExternalsRecorder::count() {
268 assert(_recorder != nullptr, "sanity");
269 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
270 return _recorder->_externals.count();
271 }
272
273 #ifndef PRODUCT
274 extern "C" {
275 // Order from large to small values
276 static int count_cmp(const void *i, const void *j) {
277 int a = *(int*)i;
278 int b = *(int*)j;
279 return a < b ? 1 : a > b ? -1 : 0;
280 }
281 }
282
283 void ExternalsRecorder::print_statistics() {
284 int cnt = count();
285 tty->print_cr("External addresses table: %d entries, %d accesses", cnt, total_access_count);
286 { // Print most accessed entries in the table.
287 int* array = NEW_C_HEAP_ARRAY(int, (2 * cnt), mtCode);
288 for (int i = 0; i < cnt; i++) {
289 array[(2 * i) + 0] = extern_hist->at(i);
290 array[(2 * i) + 1] = i;
291 }
292 // Reverse sort to have "hottest" addresses first.
293 qsort(array, cnt, 2*sizeof(int), count_cmp);
294 // Print all entries with Verbose flag otherwise only top 5.
295 int limit = (Verbose || cnt <= 5) ? cnt : 5;
296 int j = 0;
297 for (int i = 0; i < limit; i++) {
298 int index = array[(2 * i) + 1];
299 int n = extern_hist->at(index);
300 if (n > 0) {
301 address addr = at(index);
302 tty->print("%d: %8d " INTPTR_FORMAT " :", j++, n, p2i(addr));
303 if (addr != nullptr) {
304 if (StubRoutines::contains(addr)) {
305 StubCodeDesc* desc = StubCodeDesc::desc_for(addr);
306 if (desc == nullptr) {
307 desc = StubCodeDesc::desc_for(addr + frame::pc_return_offset);
308 }
309 const char* stub_name = (desc != nullptr) ? desc->name() : "<unknown>";
310 tty->print(" stub: %s", stub_name);
311 } else {
312 ResourceMark rm;
313 const int buflen = 1024;
314 char* buf = NEW_RESOURCE_ARRAY(char, buflen);
315 int offset = 0;
316 if (os::dll_address_to_function_name(addr, buf, buflen, &offset)) {
317 tty->print(" extn: %s", buf);
318 if (offset != 0) {
319 tty->print("+%d", offset);
320 }
321 } else {
322 if (CodeCache::contains((void*)addr)) {
323 // Something in CodeCache
324 tty->print(" in CodeCache");
325 } else {
326 // It could be string
327 memcpy(buf, (char*)addr, 80);
328 buf[80] = '\0';
329 tty->print(" '%s'", buf);
330 }
331 }
332 }
333 }
334 tty->cr();
335 }
336 }
337 }
338 }
339 #endif