| File: | jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp |
| Warning: | line 487, column 20 Value stored to 'data' during its initialization is never read |
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| 1 | /* |
| 2 | * Copyright (c) 2018, 2021, 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 "classfile/classLoaderDataGraph.inline.hpp" |
| 27 | #include "classfile/dictionary.hpp" |
| 28 | #include "classfile/javaClasses.hpp" |
| 29 | #include "classfile/metadataOnStackMark.hpp" |
| 30 | #include "classfile/moduleEntry.hpp" |
| 31 | #include "classfile/packageEntry.hpp" |
| 32 | #include "code/dependencyContext.hpp" |
| 33 | #include "logging/log.hpp" |
| 34 | #include "logging/logStream.hpp" |
| 35 | #include "memory/allocation.inline.hpp" |
| 36 | #include "memory/metaspace.hpp" |
| 37 | #include "memory/resourceArea.hpp" |
| 38 | #include "runtime/atomic.hpp" |
| 39 | #include "runtime/handles.inline.hpp" |
| 40 | #include "runtime/mutex.hpp" |
| 41 | #include "runtime/safepoint.hpp" |
| 42 | #include "runtime/safepointVerifiers.hpp" |
| 43 | #include "runtime/vmOperations.hpp" |
| 44 | #include "runtime/vmThread.hpp" |
| 45 | #include "utilities/growableArray.hpp" |
| 46 | #include "utilities/macros.hpp" |
| 47 | #include "utilities/ostream.hpp" |
| 48 | #include "utilities/vmError.hpp" |
| 49 | |
| 50 | volatile size_t ClassLoaderDataGraph::_num_array_classes = 0; |
| 51 | volatile size_t ClassLoaderDataGraph::_num_instance_classes = 0; |
| 52 | |
| 53 | void ClassLoaderDataGraph::clear_claimed_marks() { |
| 54 | // The claimed marks of the CLDs in the ClassLoaderDataGraph are cleared |
| 55 | // outside a safepoint and without locking the ClassLoaderDataGraph_lock. |
| 56 | // This is required to avoid a deadlock between concurrent GC threads and safepointing. |
| 57 | // |
| 58 | // We need to make sure that the CLD contents are fully visible to the |
| 59 | // reader thread. This is accomplished by acquire/release of the _head, |
| 60 | // and is sufficient. |
| 61 | // |
| 62 | // Any ClassLoaderData added after or during walking the list are prepended to |
| 63 | // _head. Their claim mark need not be handled here. |
| 64 | for (ClassLoaderData* cld = Atomic::load_acquire(&_head); cld != NULL__null; cld = cld->next()) { |
| 65 | cld->clear_claim(); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | void ClassLoaderDataGraph::clear_claimed_marks(int claim) { |
| 70 | for (ClassLoaderData* cld = Atomic::load_acquire(&_head); cld != NULL__null; cld = cld->next()) { |
| 71 | cld->clear_claim(claim); |
| 72 | } |
| 73 | } |
| 74 | // Class iterator used by the compiler. It gets some number of classes at |
| 75 | // a safepoint to decay invocation counters on the methods. |
| 76 | class ClassLoaderDataGraphKlassIteratorStatic { |
| 77 | ClassLoaderData* _current_loader_data; |
| 78 | Klass* _current_class_entry; |
| 79 | public: |
| 80 | |
| 81 | ClassLoaderDataGraphKlassIteratorStatic() : _current_loader_data(NULL__null), _current_class_entry(NULL__null) {} |
| 82 | |
| 83 | InstanceKlass* try_get_next_class() { |
| 84 | assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 84, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "only called at safepoint"); ::breakpoint(); } } while (0); |
| 85 | size_t max_classes = ClassLoaderDataGraph::num_instance_classes(); |
| 86 | assert(max_classes > 0, "should not be called with no instance classes")do { if (!(max_classes > 0)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 86, "assert(" "max_classes > 0" ") failed", "should not be called with no instance classes" ); ::breakpoint(); } } while (0); |
| 87 | for (size_t i = 0; i < max_classes; ) { |
| 88 | |
| 89 | if (_current_class_entry != NULL__null) { |
| 90 | Klass* k = _current_class_entry; |
| 91 | _current_class_entry = _current_class_entry->next_link(); |
| 92 | |
| 93 | if (k->is_instance_klass()) { |
| 94 | InstanceKlass* ik = InstanceKlass::cast(k); |
| 95 | i++; // count all instance classes found |
| 96 | // Not yet loaded classes are counted in max_classes |
| 97 | // but only return loaded classes. |
| 98 | if (ik->is_loaded()) { |
| 99 | return ik; |
| 100 | } |
| 101 | } |
| 102 | } else { |
| 103 | // Go to next CLD |
| 104 | if (_current_loader_data != NULL__null) { |
| 105 | _current_loader_data = _current_loader_data->next(); |
| 106 | } |
| 107 | // Start at the beginning |
| 108 | if (_current_loader_data == NULL__null) { |
| 109 | _current_loader_data = ClassLoaderDataGraph::_head; |
| 110 | } |
| 111 | |
| 112 | _current_class_entry = _current_loader_data->klasses(); |
| 113 | } |
| 114 | } |
| 115 | // Should never be reached unless all instance classes have failed or are not fully loaded. |
| 116 | // Caller handles NULL. |
| 117 | return NULL__null; |
| 118 | } |
| 119 | |
| 120 | // If the current class for the static iterator is a class being unloaded or |
| 121 | // deallocated, adjust the current class. |
| 122 | void adjust_saved_class(ClassLoaderData* cld) { |
| 123 | if (_current_loader_data == cld) { |
| 124 | _current_loader_data = cld->next(); |
| 125 | if (_current_loader_data != NULL__null) { |
| 126 | _current_class_entry = _current_loader_data->klasses(); |
| 127 | } // else try_get_next_class will start at the head |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | void adjust_saved_class(Klass* klass) { |
| 132 | if (_current_class_entry == klass) { |
| 133 | _current_class_entry = klass->next_link(); |
| 134 | } |
| 135 | } |
| 136 | }; |
| 137 | |
| 138 | static ClassLoaderDataGraphKlassIteratorStatic static_klass_iterator; |
| 139 | |
| 140 | InstanceKlass* ClassLoaderDataGraph::try_get_next_class() { |
| 141 | assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 141, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "only called at safepoint"); ::breakpoint(); } } while (0); |
| 142 | return static_klass_iterator.try_get_next_class(); |
| 143 | } |
| 144 | |
| 145 | void ClassLoaderDataGraph::adjust_saved_class(ClassLoaderData* cld) { |
| 146 | return static_klass_iterator.adjust_saved_class(cld); |
| 147 | } |
| 148 | |
| 149 | void ClassLoaderDataGraph::adjust_saved_class(Klass* klass) { |
| 150 | return static_klass_iterator.adjust_saved_class(klass); |
| 151 | } |
| 152 | |
| 153 | void ClassLoaderDataGraph::clean_deallocate_lists(bool walk_previous_versions) { |
| 154 | assert(SafepointSynchronize::is_at_safepoint(), "must only be called at safepoint")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 154, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "must only be called at safepoint"); ::breakpoint(); } } while (0); |
| 155 | uint loaders_processed = 0; |
| 156 | for (ClassLoaderData* cld = _head; cld != NULL__null; cld = cld->next()) { |
| 157 | // is_alive check will be necessary for concurrent class unloading. |
| 158 | if (cld->is_alive()) { |
| 159 | // clean metaspace |
| 160 | if (walk_previous_versions) { |
| 161 | cld->classes_do(InstanceKlass::purge_previous_versions); |
| 162 | } |
| 163 | cld->free_deallocate_list(); |
| 164 | loaders_processed++; |
| 165 | } |
| 166 | } |
| 167 | log_debug(class, loader, data)(!(LogImpl<(LogTag::_class), (LogTag::_loader), (LogTag::_data ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Debug))) ? (void)0 : LogImpl<(LogTag ::_class), (LogTag::_loader), (LogTag::_data), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Debug>("clean_deallocate_lists: loaders processed %u %s", |
| 168 | loaders_processed, walk_previous_versions ? "walk_previous_versions" : ""); |
| 169 | } |
| 170 | |
| 171 | void ClassLoaderDataGraph::safepoint_and_clean_metaspaces() { |
| 172 | // Safepoint and mark all metadata with MetadataOnStackMark and then deallocate unused bits of metaspace. |
| 173 | // This needs to be exclusive to Redefinition, so needs to be a safepoint. |
| 174 | VM_CleanClassLoaderDataMetaspaces op; |
| 175 | VMThread::execute(&op); |
| 176 | } |
| 177 | |
| 178 | void ClassLoaderDataGraph::walk_metadata_and_clean_metaspaces() { |
| 179 | assert(SafepointSynchronize::is_at_safepoint(), "must only be called at safepoint")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 179, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "must only be called at safepoint"); ::breakpoint(); } } while (0); |
| 180 | |
| 181 | _should_clean_deallocate_lists = false; // assume everything gets cleaned |
| 182 | |
| 183 | // Mark metadata seen on the stack so we can delete unreferenced entries. |
| 184 | // Walk all metadata, including the expensive code cache walk, only for class redefinition. |
| 185 | // The MetadataOnStackMark walk during redefinition saves previous versions if it finds old methods |
| 186 | // on the stack or in the code cache, so we only have to repeat the full walk if |
| 187 | // they were found at that time. |
| 188 | // TODO: have redefinition clean old methods out of the code cache. They still exist in some places. |
| 189 | bool walk_all_metadata = InstanceKlass::has_previous_versions_and_reset(); |
| 190 | |
| 191 | MetadataOnStackMark md_on_stack(walk_all_metadata, /*redefinition_walk*/false); |
| 192 | clean_deallocate_lists(walk_all_metadata); |
| 193 | } |
| 194 | |
| 195 | // GC root of class loader data created. |
| 196 | ClassLoaderData* volatile ClassLoaderDataGraph::_head = NULL__null; |
| 197 | ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL__null; |
| 198 | |
| 199 | bool ClassLoaderDataGraph::_should_clean_deallocate_lists = false; |
| 200 | bool ClassLoaderDataGraph::_safepoint_cleanup_needed = false; |
| 201 | bool ClassLoaderDataGraph::_metaspace_oom = false; |
| 202 | |
| 203 | // Add a new class loader data node to the list. Assign the newly created |
| 204 | // ClassLoaderData into the java/lang/ClassLoader object as a hidden field |
| 205 | ClassLoaderData* ClassLoaderDataGraph::add_to_graph(Handle loader, bool has_class_mirror_holder) { |
| 206 | |
| 207 | assert_lock_strong(ClassLoaderDataGraph_lock); |
| 208 | |
| 209 | ClassLoaderData* cld; |
| 210 | |
| 211 | // First check if another thread beat us to creating the CLD and installing |
| 212 | // it into the loader while we were waiting for the lock. |
| 213 | if (!has_class_mirror_holder && loader.not_null()) { |
| 214 | cld = java_lang_ClassLoader::loader_data_acquire(loader()); |
| 215 | if (cld != NULL__null) { |
| 216 | return cld; |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | // We mustn't GC until we've installed the ClassLoaderData in the Graph since the CLD |
| 221 | // contains oops in _handles that must be walked. GC doesn't walk CLD from the |
| 222 | // loader oop in all collections, particularly young collections. |
| 223 | NoSafepointVerifier no_safepoints; |
| 224 | |
| 225 | cld = new ClassLoaderData(loader, has_class_mirror_holder); |
| 226 | |
| 227 | // First install the new CLD to the Graph. |
| 228 | cld->set_next(_head); |
| 229 | Atomic::release_store(&_head, cld); |
| 230 | |
| 231 | // Next associate with the class_loader. |
| 232 | if (!has_class_mirror_holder) { |
| 233 | // Use OrderAccess, since readers need to get the loader_data only after |
| 234 | // it's added to the Graph |
| 235 | java_lang_ClassLoader::release_set_loader_data(loader(), cld); |
| 236 | } |
| 237 | |
| 238 | // Lastly log, if requested |
| 239 | LogTarget(Trace, class, loader, data)LogTargetImpl<LogLevel::Trace, (LogTag::_class), (LogTag:: _loader), (LogTag::_data), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG)> lt; |
| 240 | if (lt.is_enabled()) { |
| 241 | ResourceMark rm; |
| 242 | LogStream ls(lt); |
| 243 | ls.print("create "); |
| 244 | cld->print_value_on(&ls); |
| 245 | ls.cr(); |
| 246 | } |
| 247 | return cld; |
| 248 | } |
| 249 | |
| 250 | ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool has_class_mirror_holder) { |
| 251 | MutexLocker ml(ClassLoaderDataGraph_lock); |
| 252 | ClassLoaderData* loader_data = add_to_graph(loader, has_class_mirror_holder); |
| 253 | return loader_data; |
| 254 | } |
| 255 | |
| 256 | void ClassLoaderDataGraph::cld_unloading_do(CLDClosure* cl) { |
| 257 | assert_locked_or_safepoint_weak(ClassLoaderDataGraph_lock); |
| 258 | for (ClassLoaderData* cld = _unloading; cld != NULL__null; cld = cld->next()) { |
| 259 | assert(cld->is_unloading(), "invariant")do { if (!(cld->is_unloading())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 259, "assert(" "cld->is_unloading()" ") failed", "invariant" ); ::breakpoint(); } } while (0); |
| 260 | cl->do_cld(cld); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | // These are functions called by the GC, which require all of the CLDs, including the |
| 265 | // unloading ones. |
| 266 | void ClassLoaderDataGraph::cld_do(CLDClosure* cl) { |
| 267 | assert_locked_or_safepoint_weak(ClassLoaderDataGraph_lock); |
| 268 | for (ClassLoaderData* cld = _head; cld != NULL__null; cld = cld->_next) { |
| 269 | cl->do_cld(cld); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | void ClassLoaderDataGraph::roots_cld_do(CLDClosure* strong, CLDClosure* weak) { |
| 274 | assert_locked_or_safepoint_weak(ClassLoaderDataGraph_lock); |
| 275 | for (ClassLoaderData* cld = _head; cld != NULL__null; cld = cld->_next) { |
| 276 | CLDClosure* closure = cld->keep_alive() ? strong : weak; |
| 277 | if (closure != NULL__null) { |
| 278 | closure->do_cld(cld); |
| 279 | } |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | void ClassLoaderDataGraph::always_strong_cld_do(CLDClosure* cl) { |
| 284 | assert_locked_or_safepoint_weak(ClassLoaderDataGraph_lock); |
| 285 | if (ClassUnloading) { |
| 286 | roots_cld_do(cl, NULL__null); |
| 287 | } else { |
| 288 | cld_do(cl); |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | // Closure for locking and iterating through classes. Only lock outside of safepoint. |
| 293 | LockedClassesDo::LockedClassesDo(classes_do_func_t f) : _function(f), |
| 294 | _do_lock(!SafepointSynchronize::is_at_safepoint()) { |
| 295 | if (_do_lock) { |
| 296 | ClassLoaderDataGraph_lock->lock(); |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | LockedClassesDo::LockedClassesDo() : _function(NULL__null), |
| 301 | _do_lock(!SafepointSynchronize::is_at_safepoint()) { |
| 302 | // callers provide their own do_klass |
| 303 | if (_do_lock) { |
| 304 | ClassLoaderDataGraph_lock->lock(); |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | LockedClassesDo::~LockedClassesDo() { |
| 309 | if (_do_lock) { |
| 310 | ClassLoaderDataGraph_lock->unlock(); |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | |
| 315 | // Iterating over the CLDG needs to be locked because |
| 316 | // unloading can remove entries concurrently soon. |
| 317 | class ClassLoaderDataGraphIterator : public StackObj { |
| 318 | ClassLoaderData* _next; |
| 319 | Thread* _thread; |
| 320 | HandleMark _hm; // clean up handles when this is done. |
| 321 | Handle _holder; |
| 322 | NoSafepointVerifier _nsv; // No safepoints allowed in this scope |
| 323 | // unless verifying at a safepoint. |
| 324 | |
| 325 | public: |
| 326 | ClassLoaderDataGraphIterator() : _next(ClassLoaderDataGraph::_head), _thread(Thread::current()), _hm(_thread) { |
| 327 | _thread = Thread::current(); |
| 328 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 329 | } |
| 330 | |
| 331 | ClassLoaderData* get_next() { |
| 332 | ClassLoaderData* cld = _next; |
| 333 | // Skip already unloaded CLD for concurrent unloading. |
| 334 | while (cld != NULL__null && !cld->is_alive()) { |
| 335 | cld = cld->next(); |
| 336 | } |
| 337 | if (cld != NULL__null) { |
| 338 | // Keep cld that is being returned alive. |
| 339 | _holder = Handle(_thread, cld->holder()); |
| 340 | _next = cld->next(); |
| 341 | } else { |
| 342 | _next = NULL__null; |
| 343 | } |
| 344 | return cld; |
| 345 | } |
| 346 | }; |
| 347 | |
| 348 | void ClassLoaderDataGraph::loaded_cld_do(CLDClosure* cl) { |
| 349 | ClassLoaderDataGraphIterator iter; |
| 350 | while (ClassLoaderData* cld = iter.get_next()) { |
| 351 | cl->do_cld(cld); |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | // These functions assume that the caller has locked the ClassLoaderDataGraph_lock |
| 356 | // if they are not calling the function from a safepoint. |
| 357 | void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) { |
| 358 | ClassLoaderDataGraphIterator iter; |
| 359 | while (ClassLoaderData* cld = iter.get_next()) { |
| 360 | cld->classes_do(klass_closure); |
| 361 | } |
| 362 | } |
| 363 | |
| 364 | void ClassLoaderDataGraph::classes_do(void f(Klass* const)) { |
| 365 | ClassLoaderDataGraphIterator iter; |
| 366 | while (ClassLoaderData* cld = iter.get_next()) { |
| 367 | cld->classes_do(f); |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | void ClassLoaderDataGraph::methods_do(void f(Method*)) { |
| 372 | ClassLoaderDataGraphIterator iter; |
| 373 | while (ClassLoaderData* cld = iter.get_next()) { |
| 374 | cld->methods_do(f); |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | void ClassLoaderDataGraph::modules_do(void f(ModuleEntry*)) { |
| 379 | assert_locked_or_safepoint(Module_lock); |
| 380 | ClassLoaderDataGraphIterator iter; |
| 381 | while (ClassLoaderData* cld = iter.get_next()) { |
| 382 | cld->modules_do(f); |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | void ClassLoaderDataGraph::modules_unloading_do(void f(ModuleEntry*)) { |
| 387 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 388 | for (ClassLoaderData* cld = _unloading; cld != NULL__null; cld = cld->next()) { |
| 389 | assert(cld->is_unloading(), "invariant")do { if (!(cld->is_unloading())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 389, "assert(" "cld->is_unloading()" ") failed", "invariant" ); ::breakpoint(); } } while (0); |
| 390 | cld->modules_do(f); |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | void ClassLoaderDataGraph::packages_do(void f(PackageEntry*)) { |
| 395 | assert_locked_or_safepoint(Module_lock); |
| 396 | ClassLoaderDataGraphIterator iter; |
| 397 | while (ClassLoaderData* cld = iter.get_next()) { |
| 398 | cld->packages_do(f); |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | void ClassLoaderDataGraph::packages_unloading_do(void f(PackageEntry*)) { |
| 403 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 404 | for (ClassLoaderData* cld = _unloading; cld != NULL__null; cld = cld->next()) { |
| 405 | assert(cld->is_unloading(), "invariant")do { if (!(cld->is_unloading())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 405, "assert(" "cld->is_unloading()" ") failed", "invariant" ); ::breakpoint(); } } while (0); |
| 406 | cld->packages_do(f); |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | void ClassLoaderDataGraph::loaded_classes_do(KlassClosure* klass_closure) { |
| 411 | ClassLoaderDataGraphIterator iter; |
| 412 | while (ClassLoaderData* cld = iter.get_next()) { |
| 413 | cld->loaded_classes_do(klass_closure); |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | void ClassLoaderDataGraph::classes_unloading_do(void f(Klass* const)) { |
| 418 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 419 | for (ClassLoaderData* cld = _unloading; cld != NULL__null; cld = cld->next()) { |
| 420 | assert(cld->is_unloading(), "invariant")do { if (!(cld->is_unloading())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 420, "assert(" "cld->is_unloading()" ") failed", "invariant" ); ::breakpoint(); } } while (0); |
| 421 | cld->classes_do(f); |
| 422 | } |
| 423 | } |
| 424 | |
| 425 | #define FOR_ALL_DICTIONARY(X)ClassLoaderDataGraphIterator iter; while (ClassLoaderData* X = iter.get_next()) if (X->dictionary() != __null) ClassLoaderDataGraphIterator iter; \ |
| 426 | while (ClassLoaderData* X = iter.get_next()) \ |
| 427 | if (X->dictionary() != NULL__null) |
| 428 | |
| 429 | void ClassLoaderDataGraph::verify_dictionary() { |
| 430 | FOR_ALL_DICTIONARY(cld)ClassLoaderDataGraphIterator iter; while (ClassLoaderData* cld = iter.get_next()) if (cld->dictionary() != __null) { |
| 431 | cld->dictionary()->verify(); |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | void ClassLoaderDataGraph::print_dictionary(outputStream* st) { |
| 436 | FOR_ALL_DICTIONARY(cld)ClassLoaderDataGraphIterator iter; while (ClassLoaderData* cld = iter.get_next()) if (cld->dictionary() != __null) { |
| 437 | st->print("Dictionary for "); |
| 438 | cld->print_value_on(st); |
| 439 | st->cr(); |
| 440 | cld->dictionary()->print_on(st); |
| 441 | st->cr(); |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | void ClassLoaderDataGraph::print_table_statistics(outputStream* st) { |
| 446 | FOR_ALL_DICTIONARY(cld)ClassLoaderDataGraphIterator iter; while (ClassLoaderData* cld = iter.get_next()) if (cld->dictionary() != __null) { |
| 447 | ResourceMark rm; |
| 448 | stringStream tempst; |
| 449 | tempst.print("System Dictionary for %s class loader", cld->loader_name_and_id()); |
| 450 | cld->dictionary()->print_table_statistics(st, tempst.as_string()); |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | #ifndef PRODUCT |
| 455 | bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) { |
| 456 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 457 | for (ClassLoaderData* data = _head; data != NULL__null; data = data->next()) { |
| 458 | if (loader_data == data) { |
| 459 | return true; |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | return false; |
| 464 | } |
| 465 | #endif // PRODUCT |
| 466 | |
| 467 | bool ClassLoaderDataGraph::is_valid(ClassLoaderData* loader_data) { |
| 468 | DEBUG_ONLY( if (!VMError::is_error_reported()) { assert_locked_or_safepoint(ClassLoaderDataGraph_lock); } )if (!VMError::is_error_reported()) { assert_locked_or_safepoint (ClassLoaderDataGraph_lock); } |
| 469 | if (loader_data != NULL__null) { |
| 470 | if (loader_data == ClassLoaderData::the_null_class_loader_data()) { |
| 471 | return true; |
| 472 | } |
| 473 | for (ClassLoaderData* data = _head; data != NULL__null; data = data->next()) { |
| 474 | if (loader_data == data) { |
| 475 | return true; |
| 476 | } |
| 477 | } |
| 478 | } |
| 479 | return false; |
| 480 | } |
| 481 | |
| 482 | // Move class loader data from main list to the unloaded list for unloading |
| 483 | // and deallocation later. |
| 484 | bool ClassLoaderDataGraph::do_unloading() { |
| 485 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 486 | |
| 487 | ClassLoaderData* data = _head; |
Value stored to 'data' during its initialization is never read | |
| 488 | ClassLoaderData* prev = NULL__null; |
| 489 | bool seen_dead_loader = false; |
| 490 | uint loaders_processed = 0; |
| 491 | uint loaders_removed = 0; |
| 492 | |
| 493 | data = _head; |
| 494 | while (data != NULL__null) { |
| 495 | if (data->is_alive()) { |
| 496 | prev = data; |
| 497 | data = data->next(); |
| 498 | loaders_processed++; |
| 499 | continue; |
| 500 | } |
| 501 | seen_dead_loader = true; |
| 502 | loaders_removed++; |
| 503 | ClassLoaderData* dead = data; |
| 504 | dead->unload(); |
| 505 | data = data->next(); |
| 506 | // Remove from loader list. |
| 507 | // This class loader data will no longer be found |
| 508 | // in the ClassLoaderDataGraph. |
| 509 | if (prev != NULL__null) { |
| 510 | prev->set_next(data); |
| 511 | } else { |
| 512 | assert(dead == _head, "sanity check")do { if (!(dead == _head)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 512, "assert(" "dead == _head" ") failed", "sanity check"); ::breakpoint(); } } while (0); |
| 513 | _head = data; |
| 514 | } |
| 515 | dead->set_next(_unloading); |
| 516 | _unloading = dead; |
| 517 | } |
| 518 | |
| 519 | log_debug(class, loader, data)(!(LogImpl<(LogTag::_class), (LogTag::_loader), (LogTag::_data ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Debug))) ? (void)0 : LogImpl<(LogTag ::_class), (LogTag::_loader), (LogTag::_data), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Debug>("do_unloading: loaders processed %u, loaders removed %u", loaders_processed, loaders_removed); |
| 520 | |
| 521 | return seen_dead_loader; |
| 522 | } |
| 523 | |
| 524 | // There's at least one dead class loader. Purge refererences of healthy module |
| 525 | // reads lists and package export lists to modules belonging to dead loaders. |
| 526 | void ClassLoaderDataGraph::clean_module_and_package_info() { |
| 527 | assert_locked_or_safepoint(ClassLoaderDataGraph_lock); |
| 528 | |
| 529 | ClassLoaderData* data = _head; |
| 530 | while (data != NULL__null) { |
| 531 | // Walk a ModuleEntry's reads, and a PackageEntry's exports |
| 532 | // lists to determine if there are modules on those lists that are now |
| 533 | // dead and should be removed. A module's life cycle is equivalent |
| 534 | // to its defining class loader's life cycle. Since a module is |
| 535 | // considered dead if its class loader is dead, these walks must |
| 536 | // occur after each class loader's aliveness is determined. |
| 537 | if (data->packages() != NULL__null) { |
| 538 | data->packages()->purge_all_package_exports(); |
| 539 | } |
| 540 | if (data->modules_defined()) { |
| 541 | data->modules()->purge_all_module_reads(); |
| 542 | } |
| 543 | data = data->next(); |
| 544 | } |
| 545 | } |
| 546 | |
| 547 | void ClassLoaderDataGraph::purge(bool at_safepoint) { |
| 548 | ClassLoaderData* list = _unloading; |
| 549 | _unloading = NULL__null; |
| 550 | ClassLoaderData* next = list; |
| 551 | bool classes_unloaded = false; |
| 552 | while (next != NULL__null) { |
| 553 | ClassLoaderData* purge_me = next; |
| 554 | next = purge_me->next(); |
| 555 | delete purge_me; |
| 556 | classes_unloaded = true; |
| 557 | } |
| 558 | if (classes_unloaded) { |
| 559 | Metaspace::purge(); |
| 560 | set_metaspace_oom(false); |
| 561 | } |
| 562 | DependencyContext::purge_dependency_contexts(); |
| 563 | |
| 564 | // If we're purging metadata at a safepoint, clean remaining |
| 565 | // metaspaces if we need to. |
| 566 | if (at_safepoint) { |
| 567 | _safepoint_cleanup_needed = true; // tested and reset next. |
| 568 | if (should_clean_metaspaces_and_reset()) { |
| 569 | walk_metadata_and_clean_metaspaces(); |
| 570 | } |
| 571 | } else { |
| 572 | // Tell service thread this is a good time to check to see if we should |
| 573 | // clean loaded CLDGs. This causes another safepoint. |
| 574 | MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); |
| 575 | _safepoint_cleanup_needed = true; |
| 576 | Service_lock->notify_all(); |
| 577 | } |
| 578 | } |
| 579 | |
| 580 | int ClassLoaderDataGraph::resize_dictionaries() { |
| 581 | assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 581, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "must be at safepoint!"); ::breakpoint(); } } while (0); |
| 582 | int resized = 0; |
| 583 | assert (Dictionary::does_any_dictionary_needs_resizing(), "some dictionary should need resizing")do { if (!(Dictionary::does_any_dictionary_needs_resizing())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 583, "assert(" "Dictionary::does_any_dictionary_needs_resizing()" ") failed", "some dictionary should need resizing"); ::breakpoint (); } } while (0); |
| 584 | FOR_ALL_DICTIONARY(cld)ClassLoaderDataGraphIterator iter; while (ClassLoaderData* cld = iter.get_next()) if (cld->dictionary() != __null) { |
| 585 | if (cld->dictionary()->resize_if_needed()) { |
| 586 | resized++; |
| 587 | } |
| 588 | } |
| 589 | return resized; |
| 590 | } |
| 591 | |
| 592 | ClassLoaderDataGraphKlassIteratorAtomic::ClassLoaderDataGraphKlassIteratorAtomic() |
| 593 | : _next_klass(NULL__null) { |
| 594 | assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 594, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "must be at safepoint!"); ::breakpoint(); } } while (0); |
| 595 | ClassLoaderData* cld = ClassLoaderDataGraph::_head; |
| 596 | Klass* klass = NULL__null; |
| 597 | |
| 598 | // Find the first klass in the CLDG. |
| 599 | while (cld != NULL__null) { |
| 600 | assert_locked_or_safepoint(cld->metaspace_lock()); |
| 601 | klass = cld->_klasses; |
| 602 | if (klass != NULL__null) { |
| 603 | _next_klass = klass; |
| 604 | return; |
| 605 | } |
| 606 | cld = cld->next(); |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass_in_cldg(Klass* klass) { |
| 611 | Klass* next = klass->next_link(); |
| 612 | if (next != NULL__null) { |
| 613 | return next; |
| 614 | } |
| 615 | |
| 616 | // No more klasses in the current CLD. Time to find a new CLD. |
| 617 | ClassLoaderData* cld = klass->class_loader_data(); |
| 618 | assert_locked_or_safepoint(cld->metaspace_lock()); |
| 619 | while (next == NULL__null) { |
| 620 | cld = cld->next(); |
| 621 | if (cld == NULL__null) { |
| 622 | break; |
| 623 | } |
| 624 | next = cld->_klasses; |
| 625 | } |
| 626 | |
| 627 | return next; |
| 628 | } |
| 629 | |
| 630 | Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass() { |
| 631 | Klass* head = _next_klass; |
| 632 | |
| 633 | while (head != NULL__null) { |
| 634 | Klass* next = next_klass_in_cldg(head); |
| 635 | |
| 636 | Klass* old_head = Atomic::cmpxchg(&_next_klass, head, next); |
| 637 | |
| 638 | if (old_head == head) { |
| 639 | return head; // Won the CAS. |
| 640 | } |
| 641 | |
| 642 | head = old_head; |
| 643 | } |
| 644 | |
| 645 | // Nothing more for the iterator to hand out. |
| 646 | assert(head == NULL, "head is " PTR_FORMAT ", expected not null:", p2i(head))do { if (!(head == __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/classfile/classLoaderDataGraph.cpp" , 646, "assert(" "head == __null" ") failed", "head is " "0x%016" "l" "x" ", expected not null:", p2i(head)); ::breakpoint(); } } while (0); |
| 647 | return NULL__null; |
| 648 | } |
| 649 | |
| 650 | void ClassLoaderDataGraph::verify() { |
| 651 | ClassLoaderDataGraphIterator iter; |
| 652 | while (ClassLoaderData* cld = iter.get_next()) { |
| 653 | cld->verify(); |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | #ifndef PRODUCT |
| 658 | // callable from debugger |
| 659 | extern "C" int print_loader_data_graph() { |
| 660 | ResourceMark rm; |
| 661 | MutexLocker ml(ClassLoaderDataGraph_lock); |
| 662 | ClassLoaderDataGraph::print_on(tty); |
| 663 | return 0; |
| 664 | } |
| 665 | |
| 666 | void ClassLoaderDataGraph::print_on(outputStream * const out) { |
| 667 | ClassLoaderDataGraphIterator iter; |
| 668 | while (ClassLoaderData* cld = iter.get_next()) { |
| 669 | cld->print_on(out); |
| 670 | } |
| 671 | } |
| 672 | #endif // PRODUCT |
| 673 | |
| 674 | void ClassLoaderDataGraph::print() { print_on(tty); } |