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 "ci/ciUtilities.hpp"
30 #include "code/oopRecorder.inline.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/jniHandles.inline.hpp"
35 #include "runtime/mutexLocker.hpp"
36 #include "runtime/os.hpp"
37 #include "utilities/copy.hpp"
38
39 #ifdef ASSERT
40 template <class T> int ValueRecorder<T>::_find_index_calls = 0;
41 template <class T> int ValueRecorder<T>::_hit_indexes = 0;
42 template <class T> int ValueRecorder<T>::_missed_indexes = 0;
43 #endif //ASSERT
44
45
46 template <class T> ValueRecorder<T>::ValueRecorder(Arena* arena) {
47 _handles = nullptr;
48 _indexes = nullptr;
49 _arena = arena;
50 _complete = false;
51 }
52
53 template <class T> template <class X> ValueRecorder<T>::IndexCache<X>::IndexCache() {
54 assert(first_index > 0, "initial zero state of cache must be invalid index");
55 Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
56 }
57
58 template <class T> int ValueRecorder<T>::size() {
59 _complete = true;
60 if (_handles == nullptr) return 0;
61 return _handles->length() * sizeof(T);
62 }
63
64 template <class T> void ValueRecorder<T>::copy_values_to(nmethod* nm) {
65 assert(_complete, "must be frozen");
66 maybe_initialize(); // get non-null handles, even if we have no oops
67 nm->copy_values(_handles);
68 }
69
70 template <class T> void ValueRecorder<T>::maybe_initialize() {
71 if (_handles == nullptr) {
72 if (_arena != nullptr) {
73 _handles = new(_arena) GrowableArray<T>(_arena, 10, 0, T{});
74 _no_finds = new(_arena) GrowableArray<int>(_arena, 10, 0, 0);
75 } else {
76 _handles = new GrowableArray<T>(10, 0, T{});
77 _no_finds = new GrowableArray<int>(10, 0, 0);
78 }
79 }
80 }
81
82
83 template <class T> T ValueRecorder<T>::at(int index) {
84 // there is always a nullptr virtually present as first object
85 if (index == null_index) return nullptr;
86 return _handles->at(index - first_index);
87 }
88
89
90 template <class T> int ValueRecorder<T>::add_handle(T h, bool make_findable) {
91 assert(!_complete, "cannot allocate more elements after size query");
92 maybe_initialize();
93 // indexing uses 1 as an origin--0 means null
94 int index = _handles->length() + first_index;
95 _handles->append(h);
96
97 // Support correct operation of find_index().
98 assert(!(make_findable && !is_real(h)), "nulls are not findable");
99 if (make_findable) {
100 // This index may be returned from find_index().
101 if (_indexes != nullptr) {
102 int* cloc = _indexes->cache_location(h);
103 _indexes->set_cache_location_index(cloc, index);
104 } else if (index == index_cache_threshold && _arena != nullptr) {
105 _indexes = new(_arena) IndexCache<T>();
106 for (int i = 0; i < _handles->length(); i++) {
107 // Load the cache with pre-existing elements.
108 int index0 = i + first_index;
109 if (_no_finds->contains(index0)) continue;
110 int* cloc = _indexes->cache_location(_handles->at(i));
111 _indexes->set_cache_location_index(cloc, index0);
112 }
113 }
114 } else if (is_real(h)) {
115 // Remember that this index is not to be returned from find_index().
116 // This case is rare, because most or all uses of allocate_index pass
117 // an argument of nullptr or Universe::non_oop_word.
118 // Thus, the expected length of _no_finds is zero.
119 _no_finds->append(index);
120 }
121
122 return index;
123 }
124
125
126 template <class T> int ValueRecorder<T>::maybe_find_index(T h) {
127 debug_only(_find_index_calls++);
128 assert(!_complete, "cannot allocate more elements after size query");
129 maybe_initialize();
130 if (h == nullptr) return null_index;
131 assert(is_real(h), "must be valid");
132 int* cloc = (_indexes == nullptr)? nullptr: _indexes->cache_location(h);
133 if (cloc != nullptr) {
134 int cindex = _indexes->cache_location_index(cloc);
135 if (cindex == 0) {
136 return -1; // We know this handle is completely new.
137 }
138 if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
139 debug_only(_hit_indexes++);
140 return cindex;
141 }
142 if (!_indexes->cache_location_collision(cloc)) {
143 return -1; // We know the current cache occupant is unique to that cloc.
144 }
145 }
146
147 // Not found in cache, due to a cache collision. (Or, no cache at all.)
148 // Do a linear search, most recent to oldest.
149 for (int i = _handles->length() - 1; i >= 0; i--) {
150 if (_handles->at(i) == h) {
151 int findex = i + first_index;
152 if (_no_finds->contains(findex)) continue; // oops; skip this one
153 if (cloc != nullptr) {
154 _indexes->set_cache_location_index(cloc, findex);
155 }
156 debug_only(_missed_indexes++);
157 return findex;
158 }
159 }
160 return -1;
161 }
162
163 // Explicitly instantiate these types
164 template class ValueRecorder<Metadata*>;
165 template class ValueRecorder<jobject>;
166
167 oop ObjectLookup::ObjectEntry::oop_value() const { return JNIHandles::resolve(_value); }
168
169 ObjectLookup::ObjectLookup(): _values(4), _gc_count(Universe::heap()->total_collections()) {}
170
171 void ObjectLookup::maybe_resort() {
172 // The values are kept sorted by address which may be invalidated
173 // after a GC, so resort if a GC has occurred since last time.
174 if (_gc_count != Universe::heap()->total_collections()) {
175 _gc_count = Universe::heap()->total_collections();
176 _values.sort(sort_by_address);
177 }
178 }
179
180 int ObjectLookup::sort_by_address(oop a, oop b) {
181 // oopDesc::compare returns the opposite of what this function returned
182 return -(oopDesc::compare(a, b));
183 }
184
185 int ObjectLookup::sort_by_address(ObjectEntry* a, ObjectEntry* b) {
186 return sort_by_address(a->oop_value(), b->oop_value());
187 }
188
189 int ObjectLookup::sort_oop_by_address(oop const& a, ObjectEntry const& b) {
190 return sort_by_address(a, b.oop_value());
191 }
192
193 int ObjectLookup::find_index(jobject handle, OopRecorder* oop_recorder) {
194 if (handle == nullptr) {
195 return 0;
196 }
197 oop object = JNIHandles::resolve(handle);
198 maybe_resort();
199 bool found;
200 int location = _values.find_sorted<oop, sort_oop_by_address>(object, found);
201 if (!found) {
202 jobject handle = JNIHandles::make_local(object);
203 ObjectEntry r(handle, oop_recorder->allocate_oop_index(handle));
204 _values.insert_before(location, r);
205 return r.index();
206 }
207 return _values.at(location).index();
208 }
209
210 OopRecorder::OopRecorder(Arena* arena, bool deduplicate): _oops(arena), _metadata(arena) {
211 if (deduplicate) {
212 _object_lookup = new ObjectLookup();
213 } else {
214 _object_lookup = nullptr;
215 }
216 }
217
218 // Explicitly instantiate
219 template class ValueRecorder<address>;
220
221 ExternalsRecorder* ExternalsRecorder::_recorder = nullptr;
222
223 ExternalsRecorder::ExternalsRecorder(): _arena(mtCode), _externals(&_arena) {}
224
225 #ifndef PRODUCT
226 static int total_access_count = 0;
227 static GrowableArray<int>* extern_hist = nullptr;
228 #endif
229
230 void ExternalsRecorder_init() {
231 ExternalsRecorder::initialize();
232 }
233
234 void ExternalsRecorder::initialize() {
235 // After Mutex and before CodeCache are initialized
236 assert(_recorder == nullptr, "should initialize only once");
237 _recorder = new ExternalsRecorder();
238 #ifndef PRODUCT
239 if (PrintNMethodStatistics) {
240 Arena* arena = &_recorder->_arena;
241 extern_hist = new(arena) GrowableArray<int>(arena, 512, 512, 0);
242 }
243 #endif
244 }
245
246 int ExternalsRecorder::find_index(address adr) {
247 assert(_recorder != nullptr, "sanity");
248 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
249 int index = _recorder->_externals.find_index(adr);
250 #ifndef PRODUCT
251 if (PrintNMethodStatistics) {
252 total_access_count++;
253 int n = extern_hist->at_grow(index, 0);
254 extern_hist->at_put(index, (n + 1));
255 }
256 #endif
257 return index;
258 }
259
260 address ExternalsRecorder::at(int index) {
261 assert(_recorder != nullptr, "sanity");
262 // find_index() may resize array by reallocating it and freeing old,
263 // we need loock here to make sure we not accessing to old freed array.
264 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
265 return _recorder->_externals.at(index);
266 }
267
268 int ExternalsRecorder::count() {
269 assert(_recorder != nullptr, "sanity");
270 MutexLocker ml(ExternalsRecorder_lock, Mutex::_no_safepoint_check_flag);
271 return _recorder->_externals.count();
272 }
273
274 #ifndef PRODUCT
275 extern "C" {
276 // Order from large to small values
277 static int count_cmp(const void *i, const void *j) {
278 int a = *(int*)i;
279 int b = *(int*)j;
280 return a < b ? 1 : a > b ? -1 : 0;
281 }
282 }
283
284 void ExternalsRecorder::print_statistics() {
285 int cnt = count();
286 tty->print_cr("External addresses table: %d entries, %d accesses", cnt, total_access_count);
287 { // Print most accessed entries in the table.
288 int* array = NEW_C_HEAP_ARRAY(int, (2 * cnt), mtCode);
289 for (int i = 0; i < cnt; i++) {
290 array[(2 * i) + 0] = extern_hist->at(i);
291 array[(2 * i) + 1] = i;
292 }
293 // Reverse sort to have "hottest" addresses first.
294 qsort(array, cnt, 2*sizeof(int), count_cmp);
295 // Print all entries with Verbose flag otherwise only top 5.
296 int limit = (Verbose || cnt <= 5) ? cnt : 5;
297 int j = 0;
298 for (int i = 0; i < limit; i++) {
299 int index = array[(2 * i) + 1];
300 int n = extern_hist->at(index);
301 if (n > 0) {
302 address addr = at(index);
303 tty->print("%d: %8d " INTPTR_FORMAT " :", j++, n, p2i(addr));
304 if (addr != nullptr) {
305 if (is_card_table_address(addr)) {
306 tty->print(" card_table_base");
307 } else if (StubRoutines::contains(addr)) {
308 StubCodeDesc* desc = StubCodeDesc::desc_for(addr);
309 if (desc == nullptr) {
310 desc = StubCodeDesc::desc_for(addr + frame::pc_return_offset);
311 }
312 const char* stub_name = (desc != nullptr) ? desc->name() : "<unknown>";
313 tty->print(" stub: %s", stub_name);
314 } else {
315 ResourceMark rm;
316 const int buflen = 1024;
317 char* buf = NEW_RESOURCE_ARRAY(char, buflen);
318 int offset = 0;
319 if (os::dll_address_to_function_name(addr, buf, buflen, &offset)) {
320 tty->print(" extn: %s", buf);
321 if (offset != 0) {
322 tty->print("+%d", offset);
323 }
324 } else {
325 if (CodeCache::contains((void*)addr)) {
326 // Something in CodeCache
327 tty->print(" in CodeCache");
328 } else {
329 // It could be string
330 memcpy(buf, (char*)addr, 80);
331 buf[80] = '\0';
332 tty->print(" '%s'", buf);
333 }
334 }
335 }
336 }
337 tty->cr();
338 }
339 }
340 }
341 }
342 #endif