| /* |
| * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| // A ClassLoaderData identifies the full set of class types that a class |
| // loader's name resolution strategy produces for a given configuration of the |
| // class loader. |
| // Class types in the ClassLoaderData may be defined by from class file binaries |
| // provided by the class loader, or from other class loader it interacts with |
| // according to its name resolution strategy. |
| // |
| // Class loaders that implement a deterministic name resolution strategy |
| // (including with respect to their delegation behavior), such as the boot, the |
| // platform, and the system loaders of the JDK's built-in class loader |
| // hierarchy, always produce the same linkset for a given configuration. |
| // |
| // ClassLoaderData carries information related to a linkset (e.g., |
| // metaspace holding its klass definitions). |
| // The System Dictionary and related data structures (e.g., placeholder table, |
| // loader constraints table) as well as the runtime representation of classes |
| // only reference ClassLoaderData. |
| // |
| // Instances of java.lang.ClassLoader holds a pointer to a ClassLoaderData that |
| // that represent the loader's "linking domain" in the JVM. |
| // |
| // The bootstrap loader (represented by NULL) also has a ClassLoaderData, |
| // the singleton class the_null_class_loader_data(). |
| |
| #include "precompiled.hpp" |
| #include "classfile/classLoaderData.hpp" |
| #include "classfile/classLoaderData.inline.hpp" |
| #include "classfile/javaClasses.hpp" |
| #include "classfile/metadataOnStackMark.hpp" |
| #include "classfile/moduleEntry.hpp" |
| #include "classfile/packageEntry.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "code/codeCache.hpp" |
| #include "gc/shared/gcLocker.hpp" |
| #include "logging/log.hpp" |
| #include "memory/metadataFactory.hpp" |
| #include "memory/metaspaceShared.hpp" |
| #include "memory/oopFactory.hpp" |
| #include "oops/objArrayOop.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.inline.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/jniHandles.hpp" |
| #include "runtime/mutex.hpp" |
| #include "runtime/safepoint.hpp" |
| #include "runtime/synchronizer.hpp" |
| #include "utilities/growableArray.hpp" |
| #include "utilities/macros.hpp" |
| #include "utilities/ostream.hpp" |
| #if INCLUDE_TRACE |
| #include "trace/tracing.hpp" |
| #endif |
| |
| ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL; |
| |
| ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) : |
| _class_loader(h_class_loader()), |
| _is_anonymous(is_anonymous), |
| // An anonymous class loader data doesn't have anything to keep |
| // it from being unloaded during parsing of the anonymous class. |
| // The null-class-loader should always be kept alive. |
| _keep_alive(is_anonymous || h_class_loader.is_null()), |
| _metaspace(NULL), _unloading(false), _klasses(NULL), |
| _modules(NULL), _packages(NULL), |
| _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL), |
| _next(NULL), _dependencies(dependencies), _shared_class_loader_id(-1), |
| _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true, |
| Monitor::_safepoint_check_never)) { |
| // empty |
| } |
| |
| void ClassLoaderData::init_dependencies(TRAPS) { |
| assert(!Universe::is_fully_initialized(), "should only be called when initializing"); |
| assert(is_the_null_class_loader_data(), "should only call this for the null class loader"); |
| _dependencies.init(CHECK); |
| } |
| |
| void ClassLoaderData::Dependencies::init(TRAPS) { |
| // Create empty dependencies array to add to. CMS requires this to be |
| // an oop so that it can track additions via card marks. We think. |
| _list_head = oopFactory::new_objectArray(2, CHECK); |
| } |
| |
| bool ClassLoaderData::claim() { |
| if (_claimed == 1) { |
| return false; |
| } |
| |
| return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0; |
| } |
| |
| void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { |
| if (must_claim && !claim()) { |
| return; |
| } |
| |
| f->do_oop(&_class_loader); |
| _dependencies.oops_do(f); |
| _handles->oops_do(f); |
| if (klass_closure != NULL) { |
| classes_do(klass_closure); |
| } |
| } |
| |
| void ClassLoaderData::Dependencies::oops_do(OopClosure* f) { |
| f->do_oop((oop*)&_list_head); |
| } |
| |
| void ClassLoaderData::classes_do(KlassClosure* klass_closure) { |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| klass_closure->do_klass(k); |
| assert(k != k->next_link(), "no loops!"); |
| } |
| } |
| |
| void ClassLoaderData::classes_do(void f(Klass * const)) { |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| f(k); |
| } |
| } |
| |
| void ClassLoaderData::methods_do(void f(Method*)) { |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| if (k->is_instance_klass()) { |
| InstanceKlass::cast(k)->methods_do(f); |
| } |
| } |
| } |
| |
| void ClassLoaderData::loaded_classes_do(KlassClosure* klass_closure) { |
| // Lock to avoid classes being modified/added/removed during iteration |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| // Do not filter ArrayKlass oops here... |
| if (k->is_array_klass() || (k->is_instance_klass() && InstanceKlass::cast(k)->is_loaded())) { |
| klass_closure->do_klass(k); |
| } |
| } |
| } |
| |
| void ClassLoaderData::classes_do(void f(InstanceKlass*)) { |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| if (k->is_instance_klass()) { |
| f(InstanceKlass::cast(k)); |
| } |
| assert(k != k->next_link(), "no loops!"); |
| } |
| } |
| |
| void ClassLoaderData::modules_do(void f(ModuleEntry*)) { |
| if (_modules != NULL) { |
| for (int i = 0; i < _modules->table_size(); i++) { |
| for (ModuleEntry* entry = _modules->bucket(i); |
| entry != NULL; |
| entry = entry->next()) { |
| f(entry); |
| } |
| } |
| } |
| } |
| |
| void ClassLoaderData::packages_do(void f(PackageEntry*)) { |
| if (_packages != NULL) { |
| for (int i = 0; i < _packages->table_size(); i++) { |
| for (PackageEntry* entry = _packages->bucket(i); |
| entry != NULL; |
| entry = entry->next()) { |
| f(entry); |
| } |
| } |
| } |
| } |
| |
| void ClassLoaderData::record_dependency(const Klass* k, TRAPS) { |
| assert(k != NULL, "invariant"); |
| |
| ClassLoaderData * const from_cld = this; |
| ClassLoaderData * const to_cld = k->class_loader_data(); |
| |
| // Dependency to the null class loader data doesn't need to be recorded |
| // because the null class loader data never goes away. |
| if (to_cld->is_the_null_class_loader_data()) { |
| return; |
| } |
| |
| oop to; |
| if (to_cld->is_anonymous()) { |
| // Anonymous class dependencies are through the mirror. |
| to = k->java_mirror(); |
| } else { |
| to = to_cld->class_loader(); |
| |
| // If from_cld is anonymous, even if it's class_loader is a parent of 'to' |
| // we still have to add it. The class_loader won't keep from_cld alive. |
| if (!from_cld->is_anonymous()) { |
| // Check that this dependency isn't from the same or parent class_loader |
| oop from = from_cld->class_loader(); |
| |
| oop curr = from; |
| while (curr != NULL) { |
| if (curr == to) { |
| return; // this class loader is in the parent list, no need to add it. |
| } |
| curr = java_lang_ClassLoader::parent(curr); |
| } |
| } |
| } |
| |
| // It's a dependency we won't find through GC, add it. This is relatively rare |
| // Must handle over GC point. |
| Handle dependency(THREAD, to); |
| from_cld->_dependencies.add(dependency, CHECK); |
| } |
| |
| |
| void ClassLoaderData::Dependencies::add(Handle dependency, TRAPS) { |
| // Check first if this dependency is already in the list. |
| // Save a pointer to the last to add to under the lock. |
| objArrayOop ok = _list_head; |
| objArrayOop last = NULL; |
| while (ok != NULL) { |
| last = ok; |
| if (ok->obj_at(0) == dependency()) { |
| // Don't need to add it |
| return; |
| } |
| ok = (objArrayOop)ok->obj_at(1); |
| } |
| |
| // Must handle over GC points |
| assert (last != NULL, "dependencies should be initialized"); |
| objArrayHandle last_handle(THREAD, last); |
| |
| // Create a new dependency node with fields for (class_loader or mirror, next) |
| objArrayOop deps = oopFactory::new_objectArray(2, CHECK); |
| deps->obj_at_put(0, dependency()); |
| |
| // Must handle over GC points |
| objArrayHandle new_dependency(THREAD, deps); |
| |
| // Add the dependency under lock |
| locked_add(last_handle, new_dependency, THREAD); |
| } |
| |
| void ClassLoaderData::Dependencies::locked_add(objArrayHandle last_handle, |
| objArrayHandle new_dependency, |
| Thread* THREAD) { |
| |
| // Have to lock and put the new dependency on the end of the dependency |
| // array so the card mark for CMS sees that this dependency is new. |
| // Can probably do this lock free with some effort. |
| ObjectLocker ol(Handle(THREAD, _list_head), THREAD); |
| |
| oop loader_or_mirror = new_dependency->obj_at(0); |
| |
| // Since the dependencies are only added, add to the end. |
| objArrayOop end = last_handle(); |
| objArrayOop last = NULL; |
| while (end != NULL) { |
| last = end; |
| // check again if another thread added it to the end. |
| if (end->obj_at(0) == loader_or_mirror) { |
| // Don't need to add it |
| return; |
| } |
| end = (objArrayOop)end->obj_at(1); |
| } |
| assert (last != NULL, "dependencies should be initialized"); |
| // fill in the first element with the oop in new_dependency. |
| if (last->obj_at(0) == NULL) { |
| last->obj_at_put(0, new_dependency->obj_at(0)); |
| } else { |
| last->obj_at_put(1, new_dependency()); |
| } |
| } |
| |
| void ClassLoaderDataGraph::clear_claimed_marks() { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->clear_claimed(); |
| } |
| } |
| |
| void ClassLoaderData::add_class(Klass* k, bool publicize /* true */) { |
| { |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| Klass* old_value = _klasses; |
| k->set_next_link(old_value); |
| // Make sure linked class is stable, since the class list is walked without a lock |
| OrderAccess::storestore(); |
| // link the new item into the list |
| _klasses = k; |
| } |
| |
| if (publicize && k->class_loader_data() != NULL) { |
| ResourceMark rm; |
| log_trace(classloaderdata)("Adding k: " PTR_FORMAT " %s to CLD: " |
| PTR_FORMAT " loader: " PTR_FORMAT " %s", |
| p2i(k), |
| k->external_name(), |
| p2i(k->class_loader_data()), |
| p2i((void *)k->class_loader()), |
| loader_name()); |
| } |
| } |
| |
| // This is called by InstanceKlass::deallocate_contents() to remove the |
| // scratch_class for redefine classes. We need a lock because there it may not |
| // be called at a safepoint if there's an error. |
| void ClassLoaderData::remove_class(Klass* scratch_class) { |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| Klass* prev = NULL; |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| if (k == scratch_class) { |
| if (prev == NULL) { |
| _klasses = k->next_link(); |
| } else { |
| Klass* next = k->next_link(); |
| prev->set_next_link(next); |
| } |
| return; |
| } |
| prev = k; |
| assert(k != k->next_link(), "no loops!"); |
| } |
| ShouldNotReachHere(); // should have found this class!! |
| } |
| |
| void ClassLoaderData::unload() { |
| _unloading = true; |
| |
| // Tell serviceability tools these classes are unloading |
| classes_do(InstanceKlass::notify_unload_class); |
| |
| if (log_is_enabled(Debug, classloaderdata)) { |
| ResourceMark rm; |
| outputStream* log = LogHandle(classloaderdata)::debug_stream(); |
| log->print(": unload loader data " INTPTR_FORMAT, p2i(this)); |
| log->print(" for instance " INTPTR_FORMAT " of %s", p2i((void *)class_loader()), |
| loader_name()); |
| if (is_anonymous()) { |
| log->print(" for anonymous class " INTPTR_FORMAT " ", p2i(_klasses)); |
| } |
| log->cr(); |
| } |
| } |
| |
| PackageEntryTable* ClassLoaderData::packages() { |
| // Lazily create the package entry table at first request. |
| if (_packages == NULL) { |
| MutexLockerEx m1(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| // Check again if _packages has been allocated while we were getting this lock. |
| if (_packages != NULL) { |
| return _packages; |
| } |
| // Ensure _packages is stable, since it is examined without a lock |
| OrderAccess::storestore(); |
| _packages = new PackageEntryTable(PackageEntryTable::_packagetable_entry_size); |
| } |
| return _packages; |
| } |
| |
| ModuleEntryTable* ClassLoaderData::modules() { |
| // Lazily create the module entry table at first request. |
| if (_modules == NULL) { |
| MutexLocker m1(Module_lock); |
| // Check again if _modules has been allocated while we were getting this lock. |
| if (_modules != NULL) { |
| return _modules; |
| } |
| |
| ModuleEntryTable* temp_table = new ModuleEntryTable(ModuleEntryTable::_moduletable_entry_size); |
| // Each loader has one unnamed module entry. Create it before |
| // any classes, loaded by this loader, are defined in case |
| // they end up being defined in loader's unnamed module. |
| temp_table->create_unnamed_module(this); |
| |
| { |
| MutexLockerEx m1(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| // Ensure _modules is stable, since it is examined without a lock |
| OrderAccess::storestore(); |
| _modules = temp_table; |
| } |
| } |
| return _modules; |
| } |
| |
| oop ClassLoaderData::keep_alive_object() const { |
| assert(!keep_alive(), "Don't use with CLDs that are artificially kept alive"); |
| return is_anonymous() ? _klasses->java_mirror() : class_loader(); |
| } |
| |
| bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const { |
| bool alive = keep_alive() // null class loader and incomplete anonymous klasses. |
| || is_alive_closure->do_object_b(keep_alive_object()); |
| |
| return alive; |
| } |
| |
| |
| ClassLoaderData::~ClassLoaderData() { |
| // Release C heap structures for all the classes. |
| classes_do(InstanceKlass::release_C_heap_structures); |
| |
| // Release C heap allocated hashtable for all the packages. |
| if (_packages != NULL) { |
| // Destroy the table itself |
| delete _packages; |
| _packages = NULL; |
| } |
| |
| // Release C heap allocated hashtable for all the modules. |
| if (_modules != NULL) { |
| // Destroy the table itself |
| delete _modules; |
| _modules = NULL; |
| } |
| |
| // release the metaspace |
| Metaspace *m = _metaspace; |
| if (m != NULL) { |
| _metaspace = NULL; |
| delete m; |
| } |
| // release the handles |
| if (_handles != NULL) { |
| JNIHandleBlock::release_block(_handles); |
| _handles = NULL; |
| } |
| |
| // Clear all the JNI handles for methods |
| // These aren't deallocated and are going to look like a leak, but that's |
| // needed because we can't really get rid of jmethodIDs because we don't |
| // know when native code is going to stop using them. The spec says that |
| // they're "invalid" but existing programs likely rely on their being |
| // NULL after class unloading. |
| if (_jmethod_ids != NULL) { |
| Method::clear_jmethod_ids(this); |
| } |
| // Delete lock |
| delete _metaspace_lock; |
| |
| // Delete free list |
| if (_deallocate_list != NULL) { |
| delete _deallocate_list; |
| } |
| } |
| |
| /** |
| * Returns true if this class loader data is for the platform class loader. |
| */ |
| bool ClassLoaderData::is_platform_class_loader_data() const { |
| return SystemDictionary::is_platform_class_loader(class_loader()); |
| } |
| |
| Metaspace* ClassLoaderData::metaspace_non_null() { |
| assert(!DumpSharedSpaces, "wrong metaspace!"); |
| // If the metaspace has not been allocated, create a new one. Might want |
| // to create smaller arena for Reflection class loaders also. |
| // The reason for the delayed allocation is because some class loaders are |
| // simply for delegating with no metadata of their own. |
| if (_metaspace == NULL) { |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| // Check again if metaspace has been allocated while we were getting this lock. |
| if (_metaspace != NULL) { |
| return _metaspace; |
| } |
| if (this == the_null_class_loader_data()) { |
| assert (class_loader() == NULL, "Must be"); |
| set_metaspace(new Metaspace(_metaspace_lock, Metaspace::BootMetaspaceType)); |
| } else if (is_anonymous()) { |
| if (class_loader() != NULL) { |
| log_trace(classloaderdata)("is_anonymous: %s", class_loader()->klass()->internal_name()); |
| } |
| set_metaspace(new Metaspace(_metaspace_lock, Metaspace::AnonymousMetaspaceType)); |
| } else if (class_loader()->is_a(SystemDictionary::reflect_DelegatingClassLoader_klass())) { |
| if (class_loader() != NULL) { |
| log_trace(classloaderdata)("is_reflection: %s", class_loader()->klass()->internal_name()); |
| } |
| set_metaspace(new Metaspace(_metaspace_lock, Metaspace::ReflectionMetaspaceType)); |
| } else { |
| set_metaspace(new Metaspace(_metaspace_lock, Metaspace::StandardMetaspaceType)); |
| } |
| } |
| return _metaspace; |
| } |
| |
| JNIHandleBlock* ClassLoaderData::handles() const { return _handles; } |
| void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; } |
| |
| jobject ClassLoaderData::add_handle(Handle h) { |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| if (handles() == NULL) { |
| set_handles(JNIHandleBlock::allocate_block()); |
| } |
| return handles()->allocate_handle(h()); |
| } |
| |
| void ClassLoaderData::remove_handle(jobject h) { |
| _handles->release_handle(h); |
| } |
| |
| // Add this metadata pointer to be freed when it's safe. This is only during |
| // class unloading because Handles might point to this metadata field. |
| void ClassLoaderData::add_to_deallocate_list(Metadata* m) { |
| // Metadata in shared region isn't deleted. |
| if (!m->is_shared()) { |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| if (_deallocate_list == NULL) { |
| _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true); |
| } |
| _deallocate_list->append_if_missing(m); |
| } |
| } |
| |
| // Deallocate free metadata on the free list. How useful the PermGen was! |
| void ClassLoaderData::free_deallocate_list() { |
| // Don't need lock, at safepoint |
| assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint"); |
| if (_deallocate_list == NULL) { |
| return; |
| } |
| // Go backwards because this removes entries that are freed. |
| for (int i = _deallocate_list->length() - 1; i >= 0; i--) { |
| Metadata* m = _deallocate_list->at(i); |
| if (!m->on_stack()) { |
| _deallocate_list->remove_at(i); |
| // There are only three types of metadata that we deallocate directly. |
| // Cast them so they can be used by the template function. |
| if (m->is_method()) { |
| MetadataFactory::free_metadata(this, (Method*)m); |
| } else if (m->is_constantPool()) { |
| MetadataFactory::free_metadata(this, (ConstantPool*)m); |
| } else if (m->is_klass()) { |
| MetadataFactory::free_metadata(this, (InstanceKlass*)m); |
| } else { |
| ShouldNotReachHere(); |
| } |
| } else { |
| // Metadata is alive. |
| // If scratch_class is on stack then it shouldn't be on this list! |
| assert(!m->is_klass() || !((InstanceKlass*)m)->is_scratch_class(), |
| "scratch classes on this list should be dead"); |
| // Also should assert that other metadata on the list was found in handles. |
| } |
| } |
| } |
| |
| // These anonymous class loaders are to contain classes used for JSR292 |
| ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) { |
| // Add a new class loader data to the graph. |
| return ClassLoaderDataGraph::add(loader, true, THREAD); |
| } |
| |
| const char* ClassLoaderData::loader_name() { |
| // Handles null class loader |
| return SystemDictionary::loader_name(class_loader()); |
| } |
| |
| #ifndef PRODUCT |
| // Define to dump klasses |
| #undef CLD_DUMP_KLASSES |
| |
| void ClassLoaderData::dump(outputStream * const out) { |
| ResourceMark rm; |
| out->print("ClassLoaderData CLD: " PTR_FORMAT ", loader: " PTR_FORMAT ", loader_klass: " PTR_FORMAT " %s {", |
| p2i(this), p2i((void *)class_loader()), |
| p2i(class_loader() != NULL ? class_loader()->klass() : NULL), loader_name()); |
| if (claimed()) out->print(" claimed "); |
| if (is_unloading()) out->print(" unloading "); |
| out->print(" handles " INTPTR_FORMAT, p2i(handles())); |
| out->cr(); |
| if (metaspace_or_null() != NULL) { |
| out->print_cr("metaspace: " INTPTR_FORMAT, p2i(metaspace_or_null())); |
| metaspace_or_null()->dump(out); |
| } else { |
| out->print_cr("metaspace: NULL"); |
| } |
| |
| #ifdef CLD_DUMP_KLASSES |
| if (Verbose) { |
| ResourceMark rm; |
| Klass* k = _klasses; |
| while (k != NULL) { |
| out->print_cr("klass " PTR_FORMAT ", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(), |
| k->has_modified_oops(), k->has_accumulated_modified_oops()); |
| assert(k != k->next_link(), "no loops!"); |
| k = k->next_link(); |
| } |
| } |
| #endif // CLD_DUMP_KLASSES |
| #undef CLD_DUMP_KLASSES |
| if (_jmethod_ids != NULL) { |
| Method::print_jmethod_ids(this, out); |
| } |
| out->print_cr("}"); |
| } |
| #endif // PRODUCT |
| |
| void ClassLoaderData::verify() { |
| oop cl = class_loader(); |
| |
| guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same"); |
| guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be"); |
| |
| // Verify the integrity of the allocated space. |
| if (metaspace_or_null() != NULL) { |
| metaspace_or_null()->verify(); |
| } |
| |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| guarantee(k->class_loader_data() == this, "Must be the same"); |
| k->verify(); |
| assert(k != k->next_link(), "no loops!"); |
| } |
| } |
| |
| bool ClassLoaderData::contains_klass(Klass* klass) { |
| for (Klass* k = _klasses; k != NULL; k = k->next_link()) { |
| if (k == klass) return true; |
| } |
| return false; |
| } |
| |
| |
| // GC root of class loader data created. |
| ClassLoaderData* ClassLoaderDataGraph::_head = NULL; |
| ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL; |
| ClassLoaderData* ClassLoaderDataGraph::_saved_unloading = NULL; |
| ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL; |
| |
| bool ClassLoaderDataGraph::_should_purge = false; |
| bool ClassLoaderDataGraph::_metaspace_oom = false; |
| |
| // Add a new class loader data node to the list. Assign the newly created |
| // ClassLoaderData into the java/lang/ClassLoader object as a hidden field |
| ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) { |
| // We need to allocate all the oops for the ClassLoaderData before allocating the |
| // actual ClassLoaderData object. |
| ClassLoaderData::Dependencies dependencies(CHECK_NULL); |
| |
| NoSafepointVerifier no_safepoints; // we mustn't GC until we've installed the |
| // ClassLoaderData in the graph since the CLD |
| // contains unhandled oops |
| |
| ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous, dependencies); |
| |
| |
| if (!is_anonymous) { |
| ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader()); |
| // First, Atomically set it |
| ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL); |
| if (old != NULL) { |
| delete cld; |
| // Returns the data. |
| return old; |
| } |
| } |
| |
| // We won the race, and therefore the task of adding the data to the list of |
| // class loader data |
| ClassLoaderData** list_head = &_head; |
| ClassLoaderData* next = _head; |
| |
| do { |
| cld->set_next(next); |
| ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next); |
| if (exchanged == next) { |
| if (log_is_enabled(Debug, classloaderdata)) { |
| PauseNoSafepointVerifier pnsv(&no_safepoints); // Need safe points for JavaCalls::call_virtual |
| log_creation(loader, cld, CHECK_NULL); |
| } |
| return cld; |
| } |
| next = exchanged; |
| } while (true); |
| } |
| |
| void ClassLoaderDataGraph::log_creation(Handle loader, ClassLoaderData* cld, TRAPS) { |
| Handle string; |
| if (loader.not_null()) { |
| // Include the result of loader.toString() in the output. This allows |
| // the user of the log to identify the class loader instance. |
| JavaValue result(T_OBJECT); |
| KlassHandle spec_klass(THREAD, SystemDictionary::ClassLoader_klass()); |
| JavaCalls::call_virtual(&result, |
| loader, |
| spec_klass, |
| vmSymbols::toString_name(), |
| vmSymbols::void_string_signature(), |
| CHECK); |
| assert(result.get_type() == T_OBJECT, "just checking"); |
| string = (oop)result.get_jobject(); |
| } |
| |
| ResourceMark rm; |
| outputStream* log = LogHandle(classloaderdata)::debug_stream(); |
| log->print("create class loader data " INTPTR_FORMAT, p2i(cld)); |
| log->print(" for instance " INTPTR_FORMAT " of %s", p2i((void *)cld->class_loader()), |
| cld->loader_name()); |
| |
| if (string.not_null()) { |
| log->print(": "); |
| java_lang_String::print(string(), log); |
| } |
| log->cr(); |
| } |
| |
| |
| void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->oops_do(f, klass_closure, must_claim); |
| } |
| } |
| |
| void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| if (cld->keep_alive()) { |
| cld->oops_do(f, klass_closure, must_claim); |
| } |
| } |
| } |
| |
| void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { |
| if (ClassUnloading) { |
| keep_alive_oops_do(f, klass_closure, must_claim); |
| } else { |
| oops_do(f, klass_closure, must_claim); |
| } |
| } |
| |
| void ClassLoaderDataGraph::cld_do(CLDClosure* cl) { |
| for (ClassLoaderData* cld = _head; cl != NULL && cld != NULL; cld = cld->next()) { |
| cl->do_cld(cld); |
| } |
| } |
| |
| void ClassLoaderDataGraph::roots_cld_do(CLDClosure* strong, CLDClosure* weak) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->_next) { |
| CLDClosure* closure = cld->keep_alive() ? strong : weak; |
| if (closure != NULL) { |
| closure->do_cld(cld); |
| } |
| } |
| } |
| |
| void ClassLoaderDataGraph::keep_alive_cld_do(CLDClosure* cl) { |
| roots_cld_do(cl, NULL); |
| } |
| |
| void ClassLoaderDataGraph::always_strong_cld_do(CLDClosure* cl) { |
| if (ClassUnloading) { |
| keep_alive_cld_do(cl); |
| } else { |
| cld_do(cl); |
| } |
| } |
| |
| void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->classes_do(klass_closure); |
| } |
| } |
| |
| void ClassLoaderDataGraph::classes_do(void f(Klass* const)) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->classes_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::methods_do(void f(Method*)) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->methods_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::modules_do(void f(ModuleEntry*)) { |
| assert_locked_or_safepoint(Module_lock); |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->modules_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::modules_unloading_do(void f(ModuleEntry*)) { |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!"); |
| // Only walk the head until any clds not purged from prior unloading |
| // (CMS doesn't purge right away). |
| for (ClassLoaderData* cld = _unloading; cld != _saved_unloading; cld = cld->next()) { |
| assert(cld->is_unloading(), "invariant"); |
| cld->modules_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::packages_do(void f(PackageEntry*)) { |
| assert_locked_or_safepoint(Module_lock); |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->packages_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::packages_unloading_do(void f(PackageEntry*)) { |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!"); |
| // Only walk the head until any clds not purged from prior unloading |
| // (CMS doesn't purge right away). |
| for (ClassLoaderData* cld = _unloading; cld != _saved_unloading; cld = cld->next()) { |
| assert(cld->is_unloading(), "invariant"); |
| cld->packages_do(f); |
| } |
| } |
| |
| void ClassLoaderDataGraph::loaded_classes_do(KlassClosure* klass_closure) { |
| for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { |
| cld->loaded_classes_do(klass_closure); |
| } |
| } |
| |
| void ClassLoaderDataGraph::classes_unloading_do(void f(Klass* const)) { |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!"); |
| // Only walk the head until any clds not purged from prior unloading |
| // (CMS doesn't purge right away). |
| for (ClassLoaderData* cld = _unloading; cld != _saved_unloading; cld = cld->next()) { |
| assert(cld->is_unloading(), "invariant"); |
| cld->classes_do(f); |
| } |
| } |
| |
| GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() { |
| assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?"); |
| |
| GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>(); |
| |
| // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true); |
| ClassLoaderData* curr = _head; |
| while (curr != _saved_head) { |
| if (!curr->claimed()) { |
| array->push(curr); |
| |
| if (log_is_enabled(Debug, classloaderdata)) { |
| outputStream* log = LogHandle(classloaderdata)::debug_stream(); |
| log->print("found new CLD: "); |
| curr->print_value_on(log); |
| log->cr(); |
| } |
| } |
| |
| curr = curr->_next; |
| } |
| |
| return array; |
| } |
| |
| bool ClassLoaderDataGraph::unload_list_contains(const void* x) { |
| assert(SafepointSynchronize::is_at_safepoint(), "only safe to call at safepoint"); |
| for (ClassLoaderData* cld = _unloading; cld != NULL; cld = cld->next()) { |
| if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| #ifndef PRODUCT |
| bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) { |
| for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { |
| if (loader_data == data) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| #endif // PRODUCT |
| |
| |
| // Move class loader data from main list to the unloaded list for unloading |
| // and deallocation later. |
| bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure, |
| bool clean_previous_versions) { |
| |
| ClassLoaderData* data = _head; |
| ClassLoaderData* prev = NULL; |
| bool seen_dead_loader = false; |
| |
| // Mark metadata seen on the stack only so we can delete unneeded entries. |
| // Only walk all metadata, including the expensive code cache walk, for Full GC |
| // and only if class redefinition and if there's previous versions of |
| // Klasses to delete. |
| bool walk_all_metadata = clean_previous_versions && |
| JvmtiExport::has_redefined_a_class() && |
| InstanceKlass::has_previous_versions(); |
| MetadataOnStackMark md_on_stack(walk_all_metadata); |
| |
| // Save previous _unloading pointer for CMS which may add to unloading list before |
| // purging and we don't want to rewalk the previously unloaded class loader data. |
| _saved_unloading = _unloading; |
| |
| data = _head; |
| while (data != NULL) { |
| if (data->is_alive(is_alive_closure)) { |
| if (data->packages_defined()) { |
| data->packages()->purge_all_package_exports(); |
| } |
| if (data->modules_defined()) { |
| data->modules()->purge_all_module_reads(); |
| } |
| // clean metaspace |
| if (walk_all_metadata) { |
| data->classes_do(InstanceKlass::purge_previous_versions); |
| } |
| data->free_deallocate_list(); |
| prev = data; |
| data = data->next(); |
| continue; |
| } |
| seen_dead_loader = true; |
| ClassLoaderData* dead = data; |
| dead->unload(); |
| data = data->next(); |
| // Remove from loader list. |
| // This class loader data will no longer be found |
| // in the ClassLoaderDataGraph. |
| if (prev != NULL) { |
| prev->set_next(data); |
| } else { |
| assert(dead == _head, "sanity check"); |
| _head = data; |
| } |
| dead->set_next(_unloading); |
| _unloading = dead; |
| } |
| |
| if (seen_dead_loader) { |
| post_class_unload_events(); |
| } |
| |
| return seen_dead_loader; |
| } |
| |
| void ClassLoaderDataGraph::purge() { |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!"); |
| ClassLoaderData* list = _unloading; |
| _unloading = NULL; |
| ClassLoaderData* next = list; |
| bool classes_unloaded = false; |
| while (next != NULL) { |
| ClassLoaderData* purge_me = next; |
| next = purge_me->next(); |
| delete purge_me; |
| classes_unloaded = true; |
| } |
| if (classes_unloaded) { |
| Metaspace::purge(); |
| set_metaspace_oom(false); |
| } |
| } |
| |
| void ClassLoaderDataGraph::post_class_unload_events(void) { |
| #if INCLUDE_TRACE |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!"); |
| if (Tracing::enabled()) { |
| if (Tracing::is_event_enabled(TraceClassUnloadEvent)) { |
| assert(_unloading != NULL, "need class loader data unload list!"); |
| _class_unload_time = Ticks::now(); |
| classes_unloading_do(&class_unload_event); |
| } |
| Tracing::on_unloading_classes(); |
| } |
| #endif |
| } |
| |
| // CDS support |
| |
| // Global metaspaces for writing information to the shared archive. When |
| // application CDS is supported, we may need one per metaspace, so this |
| // sort of looks like it. |
| Metaspace* ClassLoaderData::_ro_metaspace = NULL; |
| Metaspace* ClassLoaderData::_rw_metaspace = NULL; |
| static bool _shared_metaspaces_initialized = false; |
| |
| // Initialize shared metaspaces (change to call from somewhere not lazily) |
| void ClassLoaderData::initialize_shared_metaspaces() { |
| assert(DumpSharedSpaces, "only use this for dumping shared spaces"); |
| assert(this == ClassLoaderData::the_null_class_loader_data(), |
| "only supported for null loader data for now"); |
| assert (!_shared_metaspaces_initialized, "only initialize once"); |
| MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); |
| _ro_metaspace = new Metaspace(_metaspace_lock, Metaspace::ROMetaspaceType); |
| _rw_metaspace = new Metaspace(_metaspace_lock, Metaspace::ReadWriteMetaspaceType); |
| _shared_metaspaces_initialized = true; |
| } |
| |
| Metaspace* ClassLoaderData::ro_metaspace() { |
| assert(_ro_metaspace != NULL, "should already be initialized"); |
| return _ro_metaspace; |
| } |
| |
| Metaspace* ClassLoaderData::rw_metaspace() { |
| assert(_rw_metaspace != NULL, "should already be initialized"); |
| return _rw_metaspace; |
| } |
| |
| ClassLoaderDataGraphKlassIteratorAtomic::ClassLoaderDataGraphKlassIteratorAtomic() |
| : _next_klass(NULL) { |
| ClassLoaderData* cld = ClassLoaderDataGraph::_head; |
| Klass* klass = NULL; |
| |
| // Find the first klass in the CLDG. |
| while (cld != NULL) { |
| klass = cld->_klasses; |
| if (klass != NULL) { |
| _next_klass = klass; |
| return; |
| } |
| cld = cld->next(); |
| } |
| } |
| |
| Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass_in_cldg(Klass* klass) { |
| Klass* next = klass->next_link(); |
| if (next != NULL) { |
| return next; |
| } |
| |
| // No more klasses in the current CLD. Time to find a new CLD. |
| ClassLoaderData* cld = klass->class_loader_data(); |
| while (next == NULL) { |
| cld = cld->next(); |
| if (cld == NULL) { |
| break; |
| } |
| next = cld->_klasses; |
| } |
| |
| return next; |
| } |
| |
| Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass() { |
| Klass* head = _next_klass; |
| |
| while (head != NULL) { |
| Klass* next = next_klass_in_cldg(head); |
| |
| Klass* old_head = (Klass*)Atomic::cmpxchg_ptr(next, &_next_klass, head); |
| |
| if (old_head == head) { |
| return head; // Won the CAS. |
| } |
| |
| head = old_head; |
| } |
| |
| // Nothing more for the iterator to hand out. |
| assert(head == NULL, "head is " PTR_FORMAT ", expected not null:", p2i(head)); |
| return NULL; |
| } |
| |
| ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() { |
| _data = ClassLoaderDataGraph::_head; |
| } |
| |
| ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {} |
| |
| #ifndef PRODUCT |
| // callable from debugger |
| extern "C" int print_loader_data_graph() { |
| ClassLoaderDataGraph::dump_on(tty); |
| return 0; |
| } |
| |
| void ClassLoaderDataGraph::verify() { |
| for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { |
| data->verify(); |
| } |
| } |
| |
| void ClassLoaderDataGraph::dump_on(outputStream * const out) { |
| for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { |
| data->dump(out); |
| } |
| MetaspaceAux::dump(out); |
| } |
| #endif // PRODUCT |
| |
| void ClassLoaderData::print_value_on(outputStream* out) const { |
| if (class_loader() == NULL) { |
| out->print("NULL class_loader"); |
| } else { |
| out->print("class loader " INTPTR_FORMAT, p2i(this)); |
| class_loader()->print_value_on(out); |
| } |
| } |
| |
| #if INCLUDE_TRACE |
| |
| Ticks ClassLoaderDataGraph::_class_unload_time; |
| |
| void ClassLoaderDataGraph::class_unload_event(Klass* const k) { |
| assert(k != NULL, "invariant"); |
| |
| // post class unload event |
| EventClassUnload event(UNTIMED); |
| event.set_endtime(_class_unload_time); |
| event.set_unloadedClass(k); |
| oop defining_class_loader = k->class_loader(); |
| event.set_definingClassLoader(defining_class_loader != NULL ? |
| defining_class_loader->klass() : (Klass*)NULL); |
| event.commit(); |
| } |
| |
| #endif // INCLUDE_TRACE |