Mercurial > hg > graal-compiler
view src/share/vm/classfile/classLoaderData.cpp @ 6792:137868b7aa6f
7196199: java/text/Bidi/Bug6665028.java failed: Bidi run count incorrect
Summary: Save whole XMM/YMM registers in safepoint interrupt handler.
Reviewed-by: roland, twisti
author | kvn |
---|---|
date | Mon, 17 Sep 2012 19:39:07 -0700 |
parents | da91efe96a93 |
children | 90273fc0a981 |
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/* * Copyright (c) 2012, 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 // extension, 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/systemDictionary.hpp" #include "code/codeCache.hpp" #include "memory/metadataFactory.hpp" #include "memory/metaspaceShared.hpp" #include "prims/jvmtiRedefineClasses.hpp" #include "runtime/jniHandles.hpp" #include "runtime/mutex.hpp" #include "runtime/safepoint.hpp" #include "runtime/synchronizer.hpp" #include "utilities/growableArray.hpp" #include "utilities/ostream.hpp" ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL; ClassLoaderData::ClassLoaderData(Handle h_class_loader) : _class_loader(h_class_loader()), _metaspace(NULL), _unloading(false), _klasses(NULL), _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL), _next(NULL), _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) { // empty } 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); _handles->oops_do(f); if (klass_closure != NULL) { classes_do(klass_closure); } } void ClassLoaderData::classes_do(KlassClosure* klass_closure) { for (Klass* k = _klasses; k != NULL; k = k->next_link()) { klass_closure->do_klass(k); } } void ClassLoaderData::classes_do(void f(InstanceKlass*)) { for (Klass* k = _klasses; k != NULL; k = k->next_link()) { if (k->oop_is_instance()) { f(InstanceKlass::cast(k)); } } } void ClassLoaderData::record_dependency(Klass* k, TRAPS) { ClassLoaderData * const from_cld = this; ClassLoaderData * const to_cld = k->class_loader_data(); // Records dependency between non-null class loaders only. if (to_cld->is_the_null_class_loader_data() || from_cld->is_the_null_class_loader_data()) { return; } // Check that this dependency isn't from the same or parent class_loader oop to = to_cld->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 from_cld->add_dependency(to_cld, CHECK); } bool ClassLoaderData::has_dependency(ClassLoaderData* dependency) { oop loader = dependency->class_loader(); // Get objArrayOop out of the class_loader oop and see if this dependency // is there. Don't safepoint! These are all oops. // Dependency list is (oop class_loader, objArrayOop next) objArrayOop ok = (objArrayOop)java_lang_ClassLoader::dependencies(class_loader()); while (ok != NULL) { if (ok->obj_at(0) == loader) { return true; } ok = (objArrayOop)ok->obj_at(1); } return false; } void ClassLoaderData::add_dependency(ClassLoaderData* dependency, TRAPS) { // Minimize the number of duplicates in the list. if (has_dependency(dependency)) { return; } // Create a new dependency node with fields for (class_loader, next) objArrayOop deps = oopFactory::new_objectArray(2, CHECK); deps->obj_at_put(0, dependency->class_loader()); // Add this lock free, using compare and exchange, need barriers for GC // Do the barrier first. HeapWord* addr = java_lang_ClassLoader::dependencies_addr(class_loader()); while (true) { oop old_dependency = java_lang_ClassLoader::dependencies(class_loader()); deps->obj_at_put(1, old_dependency); oop newold = oopDesc::atomic_compare_exchange_oop((oop)deps, addr, old_dependency, true); if (newold == old_dependency) { update_barrier_set((void*)addr, (oop)deps); // we won the race to add this dependency break; } } } void ClassLoaderDataGraph::clear_claimed_marks() { for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { cld->clear_claimed(); } } void ClassLoaderData::add_class(Klass* k) { MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); Klass* old_value = _klasses; k->set_next_link(old_value); // link the new item into the list _klasses = k; if (TraceClassLoaderData && k->class_loader_data() != NULL) { ResourceMark rm; tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: " PTR_FORMAT " loader: " PTR_FORMAT " %s", k, k->external_name(), k->class_loader_data(), k->class_loader(), k->class_loader() != NULL ? k->class_loader()->klass()->external_name() : "NULL" ); } } // 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; } ShouldNotReachHere(); // should have found this class!! } ClassLoaderData::~ClassLoaderData() { Metaspace *m = _metaspace; if (m != NULL) { _metaspace = NULL; // release the metaspace 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; } } Metaspace* ClassLoaderData::metaspace_non_null() { // 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 (class_loader() == NULL) { assert(this == the_null_class_loader_data(), "Must be"); size_t word_size = Metaspace::first_chunk_word_size(); set_metaspace(new Metaspace(_metaspace_lock, word_size)); } else { set_metaspace(new Metaspace(_metaspace_lock)); // default size for now. } } 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()); } // 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(); } } } } #ifndef PRODUCT void ClassLoaderData::print_loader(ClassLoaderData *loader_data, outputStream* out) { oop class_loader = loader_data->class_loader(); out->print("%s", SystemDictionary::loader_name(class_loader)); } // 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 {", this, class_loader(), class_loader() != NULL ? class_loader()->klass() : NULL, class_loader() != NULL ? class_loader()->klass()->external_name() : "NULL"); if (claimed()) out->print(" claimed "); if (is_unloading()) out->print(" unloading "); out->print(" handles " INTPTR_FORMAT, handles()); out->cr(); if (metaspace_or_null() != NULL) { out->print_cr("metaspace: " PTR_FORMAT, 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()); 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), "Must be the same"); guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data(), "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(); } } // GC root of class loader data created. ClassLoaderData* ClassLoaderDataGraph::_head = NULL; ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL; ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL; // 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(ClassLoaderData** cld_addr, Handle loader_data) { // Not assigned a class loader data yet. // Create one. ClassLoaderData* *list_head = &_head; ClassLoaderData* next = _head; ClassLoaderData* cld = new ClassLoaderData(loader_data); // 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 do { cld->set_next(next); ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next); if (exchanged == next) { if (TraceClassLoaderData) { tty->print("[ClassLoaderData: "); tty->print("create class loader data "PTR_FORMAT, cld); tty->print(" for instance "PTR_FORMAT" of ", cld->class_loader()); loader_data->klass()->name()->print_symbol_on(tty); tty->print_cr("]"); } return cld; } next = exchanged; } while (true); } 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::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { if (ClassUnloading) { ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim); } else { ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim); } } void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) { for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { cld->classes_do(klass_closure); } } 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 (TraceClassLoaderData) { tty->print("[ClassLoaderData] found new CLD: "); curr->print_value_on(tty); tty->cr(); } } curr = curr->_next; } return array; } #ifndef PRODUCT // for debugging and hsfind(x) bool ClassLoaderDataGraph::contains(address x) { // I think we need the _metaspace_lock taken here because the class loader // data graph could be changing while we are walking it (new entries added, // new entries being unloaded, etc). if (DumpSharedSpaces) { // There are only two metaspaces to worry about. ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data(); return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x)); } if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) { return true; } for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) { return true; } } // Could also be on an unloading list which is okay, ie. still allocated // for a little while. for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) { if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) { return true; } } return false; } 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) { ClassLoaderData* data = _head; ClassLoaderData* prev = NULL; bool seen_dead_loader = false; // mark metadata seen on the stack and code cache so we can delete // unneeded entries. bool has_redefined_a_class = JvmtiExport::has_redefined_a_class(); MetadataOnStackMark md_on_stack; while (data != NULL) { if (data->class_loader() == NULL || is_alive->do_object_b(data->class_loader())) { assert(data->claimed(), "class loader data must have been claimed"); if (has_redefined_a_class) { 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->mark_for_unload(); if (TraceClassLoaderData) { tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, dead); tty->print(" for instance "PTR_FORMAT" of ", dead->class_loader()); dead->class_loader()->klass()->name()->print_symbol_on(tty); tty->print_cr("]"); } data = data->next(); // Remove from loader list. if (prev != NULL) { prev->set_next(data); } else { assert(dead == _head, "sanity check"); _head = data; } dead->set_next(_unloading); _unloading = dead; } return seen_dead_loader; } void ClassLoaderDataGraph::purge() { ClassLoaderData* list = _unloading; _unloading = NULL; ClassLoaderData* next = list; while (next != NULL) { ClassLoaderData* purge_me = next; next = purge_me->next(); delete purge_me; } } // 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, SharedReadOnlySize/wordSize); _rw_metaspace = new Metaspace(_metaspace_lock, SharedReadWriteSize/wordSize); _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; } 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); } void ClassLoaderData::print_value_on(outputStream* out) const { if (class_loader() == NULL) { out->print_cr("NULL class_loader"); } else { out->print("class loader "PTR_FORMAT, this); class_loader()->print_value_on(out); } } #endif // PRODUCT