coleenp@4037: /*
coleenp@4490:  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
coleenp@4037:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4037:  *
coleenp@4037:  * This code is free software; you can redistribute it and/or modify it
coleenp@4037:  * under the terms of the GNU General Public License version 2 only, as
coleenp@4037:  * published by the Free Software Foundation.
coleenp@4037:  *
coleenp@4037:  * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4037:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4037:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
coleenp@4037:  * version 2 for more details (a copy is included in the LICENSE file that
coleenp@4037:  * accompanied this code).
coleenp@4037:  *
coleenp@4037:  * You should have received a copy of the GNU General Public License version
coleenp@4037:  * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4037:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4037:  *
coleenp@4037:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4037:  * or visit www.oracle.com if you need additional information or have any
coleenp@4037:  * questions.
coleenp@4037:  *
coleenp@4037:  */
coleenp@4037: 
coleenp@4037: // A ClassLoaderData identifies the full set of class types that a class
coleenp@4037: // loader's name resolution strategy produces for a given configuration of the
coleenp@4037: // class loader.
coleenp@4037: // Class types in the ClassLoaderData may be defined by from class file binaries
coleenp@4037: // provided by the class loader, or from other class loader it interacts with
coleenp@4037: // according to its name resolution strategy.
coleenp@4037: //
coleenp@4037: // Class loaders that implement a deterministic name resolution strategy
coleenp@4037: // (including with respect to their delegation behavior), such as the boot, the
coleenp@4037: // extension, and the system loaders of the JDK's built-in class loader
coleenp@4037: // hierarchy, always produce the same linkset for a given configuration.
coleenp@4037: //
coleenp@4037: // ClassLoaderData carries information related to a linkset (e.g.,
coleenp@4037: // metaspace holding its klass definitions).
coleenp@4037: // The System Dictionary and related data structures (e.g., placeholder table,
coleenp@4037: // loader constraints table) as well as the runtime representation of classes
coleenp@4037: // only reference ClassLoaderData.
coleenp@4037: //
coleenp@4037: // Instances of java.lang.ClassLoader holds a pointer to a ClassLoaderData that
coleenp@4037: // that represent the loader's "linking domain" in the JVM.
coleenp@4037: //
coleenp@4037: // The bootstrap loader (represented by NULL) also has a ClassLoaderData,
coleenp@4037: // the singleton class the_null_class_loader_data().
coleenp@4037: 
coleenp@4037: #include "precompiled.hpp"
coleenp@4037: #include "classfile/classLoaderData.hpp"
coleenp@4037: #include "classfile/classLoaderData.inline.hpp"
coleenp@4037: #include "classfile/javaClasses.hpp"
coleenp@4490: #include "classfile/metadataOnStackMark.hpp"
coleenp@4037: #include "classfile/systemDictionary.hpp"
coleenp@4037: #include "code/codeCache.hpp"
mgerdin@5013: #include "memory/gcLocker.hpp"
coleenp@4037: #include "memory/metadataFactory.hpp"
coleenp@4037: #include "memory/metaspaceShared.hpp"
coleenp@4490: #include "memory/oopFactory.hpp"
coleenp@4037: #include "runtime/jniHandles.hpp"
coleenp@4037: #include "runtime/mutex.hpp"
coleenp@4037: #include "runtime/safepoint.hpp"
coleenp@4037: #include "runtime/synchronizer.hpp"
coleenp@4037: #include "utilities/growableArray.hpp"
coleenp@4037: #include "utilities/ostream.hpp"
coleenp@4037: 
sla@5237: #if INCLUDE_TRACE
sla@5237:  #include "trace/tracing.hpp"
sla@5237: #endif
sla@5237: 
sla@5237: 
coleenp@4037: ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
coleenp@4037: 
mgerdin@5016: ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) :
coleenp@4345:   _class_loader(h_class_loader()),
coleenp@4345:   _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
coleenp@4345:   _metaspace(NULL), _unloading(false), _klasses(NULL),
coleenp@4304:   _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
mgerdin@5016:   _next(NULL), _dependencies(dependencies),
coleenp@4037:   _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
coleenp@4037:     // empty
coleenp@4037: }
coleenp@4037: 
coleenp@4304: void ClassLoaderData::init_dependencies(TRAPS) {
mgerdin@5016:   assert(!Universe::is_fully_initialized(), "should only be called when initializing");
mgerdin@5016:   assert(is_the_null_class_loader_data(), "should only call this for the null class loader");
mgerdin@4903:   _dependencies.init(CHECK);
mgerdin@4903: }
mgerdin@4903: 
mgerdin@4903: void ClassLoaderData::Dependencies::init(TRAPS) {
coleenp@4304:   // Create empty dependencies array to add to. CMS requires this to be
coleenp@4304:   // an oop so that it can track additions via card marks.  We think.
mgerdin@4903:   _list_head = oopFactory::new_objectArray(2, CHECK);
coleenp@4304: }
coleenp@4304: 
coleenp@4037: bool ClassLoaderData::claim() {
coleenp@4037:   if (_claimed == 1) {
coleenp@4037:     return false;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037:   if (must_claim && !claim()) {
coleenp@4037:     return;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   f->do_oop(&_class_loader);
mgerdin@4903:   _dependencies.oops_do(f);
coleenp@4037:   _handles->oops_do(f);
coleenp@4037:   if (klass_closure != NULL) {
coleenp@4037:     classes_do(klass_closure);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
mgerdin@4903: void ClassLoaderData::Dependencies::oops_do(OopClosure* f) {
mgerdin@4903:   f->do_oop((oop*)&_list_head);
mgerdin@4903: }
mgerdin@4903: 
coleenp@4037: void ClassLoaderData::classes_do(KlassClosure* klass_closure) {
coleenp@4037:   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037:     klass_closure->do_klass(k);
coleenp@4751:     assert(k != k->next_link(), "no loops!");
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
sla@5237: void ClassLoaderData::classes_do(void f(Klass * const)) {
sla@5237:   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
sla@5237:     f(k);
sla@5237:   }
sla@5237: }
sla@5237: 
coleenp@4037: void ClassLoaderData::classes_do(void f(InstanceKlass*)) {
coleenp@4037:   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037:     if (k->oop_is_instance()) {
coleenp@4037:       f(InstanceKlass::cast(k));
coleenp@4037:     }
coleenp@4751:     assert(k != k->next_link(), "no loops!");
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderData::record_dependency(Klass* k, TRAPS) {
coleenp@4037:   ClassLoaderData * const from_cld = this;
coleenp@4037:   ClassLoaderData * const to_cld = k->class_loader_data();
coleenp@4037: 
coleenp@4304:   // Dependency to the null class loader data doesn't need to be recorded
coleenp@4304:   // because the null class loader data never goes away.
coleenp@4304:   if (to_cld->is_the_null_class_loader_data()) {
coleenp@4037:     return;
coleenp@4037:   }
coleenp@4037: 
coleenp@4304:   oop to;
coleenp@4304:   if (to_cld->is_anonymous()) {
coleenp@4304:     // Anonymous class dependencies are through the mirror.
coleenp@4304:     to = k->java_mirror();
coleenp@4304:   } else {
coleenp@4304:     to = to_cld->class_loader();
coleenp@4037: 
coleenp@4304:     // If from_cld is anonymous, even if it's class_loader is a parent of 'to'
coleenp@4304:     // we still have to add it.  The class_loader won't keep from_cld alive.
coleenp@4304:     if (!from_cld->is_anonymous()) {
coleenp@4304:       // Check that this dependency isn't from the same or parent class_loader
coleenp@4304:       oop from = from_cld->class_loader();
coleenp@4304: 
coleenp@4304:       oop curr = from;
coleenp@4304:       while (curr != NULL) {
coleenp@4304:         if (curr == to) {
coleenp@4304:           return; // this class loader is in the parent list, no need to add it.
coleenp@4304:         }
coleenp@4304:         curr = java_lang_ClassLoader::parent(curr);
coleenp@4304:       }
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   // It's a dependency we won't find through GC, add it. This is relatively rare
coleenp@4304:   // Must handle over GC point.
coleenp@4304:   Handle dependency(THREAD, to);
mgerdin@4903:   from_cld->_dependencies.add(dependency, CHECK);
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
mgerdin@4903: void ClassLoaderData::Dependencies::add(Handle dependency, TRAPS) {
coleenp@4304:   // Check first if this dependency is already in the list.
coleenp@4304:   // Save a pointer to the last to add to under the lock.
mgerdin@4903:   objArrayOop ok = _list_head;
coleenp@4304:   objArrayOop last = NULL;
coleenp@4037:   while (ok != NULL) {
coleenp@4304:     last = ok;
coleenp@4304:     if (ok->obj_at(0) == dependency()) {
coleenp@4304:       // Don't need to add it
coleenp@4304:       return;
coleenp@4037:     }
coleenp@4037:     ok = (objArrayOop)ok->obj_at(1);
coleenp@4037:   }
coleenp@4304: 
stefank@4353:   // Must handle over GC points
stefank@4353:   assert (last != NULL, "dependencies should be initialized");
stefank@4353:   objArrayHandle last_handle(THREAD, last);
stefank@4353: 
coleenp@4304:   // Create a new dependency node with fields for (class_loader or mirror, next)
coleenp@4304:   objArrayOop deps = oopFactory::new_objectArray(2, CHECK);
coleenp@4304:   deps->obj_at_put(0, dependency());
coleenp@4304: 
stefank@4353:   // Must handle over GC points
coleenp@4304:   objArrayHandle new_dependency(THREAD, deps);
coleenp@4304: 
coleenp@4304:   // Add the dependency under lock
mgerdin@4903:   locked_add(last_handle, new_dependency, THREAD);
coleenp@4037: }
coleenp@4037: 
mgerdin@4903: void ClassLoaderData::Dependencies::locked_add(objArrayHandle last_handle,
mgerdin@4903:                                                objArrayHandle new_dependency,
mgerdin@4903:                                                Thread* THREAD) {
coleenp@4304: 
coleenp@4304:   // Have to lock and put the new dependency on the end of the dependency
coleenp@4304:   // array so the card mark for CMS sees that this dependency is new.
coleenp@4304:   // Can probably do this lock free with some effort.
mgerdin@4903:   ObjectLocker ol(Handle(THREAD, _list_head), THREAD);
coleenp@4304: 
coleenp@4304:   oop loader_or_mirror = new_dependency->obj_at(0);
coleenp@4304: 
coleenp@4304:   // Since the dependencies are only added, add to the end.
coleenp@4304:   objArrayOop end = last_handle();
coleenp@4304:   objArrayOop last = NULL;
coleenp@4304:   while (end != NULL) {
coleenp@4304:     last = end;
coleenp@4304:     // check again if another thread added it to the end.
coleenp@4304:     if (end->obj_at(0) == loader_or_mirror) {
coleenp@4304:       // Don't need to add it
coleenp@4304:       return;
coleenp@4304:     }
coleenp@4304:     end = (objArrayOop)end->obj_at(1);
coleenp@4037:   }
coleenp@4304:   assert (last != NULL, "dependencies should be initialized");
coleenp@4304:   // fill in the first element with the oop in new_dependency.
coleenp@4304:   if (last->obj_at(0) == NULL) {
coleenp@4304:     last->obj_at_put(0, new_dependency->obj_at(0));
coleenp@4304:   } else {
coleenp@4304:     last->obj_at_put(1, new_dependency());
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::clear_claimed_marks() {
coleenp@4037:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037:     cld->clear_claimed();
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderData::add_class(Klass* k) {
coleenp@4037:   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
coleenp@4037:   Klass* old_value = _klasses;
coleenp@4037:   k->set_next_link(old_value);
coleenp@4037:   // link the new item into the list
coleenp@4037:   _klasses = k;
coleenp@4037: 
coleenp@4304:   if (TraceClassLoaderData && Verbose && k->class_loader_data() != NULL) {
coleenp@4037:     ResourceMark rm;
coleenp@4037:     tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: "
coleenp@4037:                   PTR_FORMAT " loader: " PTR_FORMAT " %s",
coleenp@4037:                   k,
coleenp@4037:                   k->external_name(),
coleenp@4037:                   k->class_loader_data(),
hseigel@5784:                   (void *)k->class_loader(),
coleenp@4304:                   loader_name());
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // This is called by InstanceKlass::deallocate_contents() to remove the
coleenp@4037: // scratch_class for redefine classes.  We need a lock because there it may not
coleenp@4037: // be called at a safepoint if there's an error.
coleenp@4037: void ClassLoaderData::remove_class(Klass* scratch_class) {
coleenp@4037:   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
coleenp@4037:   Klass* prev = NULL;
coleenp@4037:   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037:     if (k == scratch_class) {
coleenp@4037:       if (prev == NULL) {
coleenp@4037:         _klasses = k->next_link();
coleenp@4037:       } else {
coleenp@4037:         Klass* next = k->next_link();
coleenp@4037:         prev->set_next_link(next);
coleenp@4037:       }
coleenp@4037:       return;
coleenp@4037:     }
coleenp@4037:     prev = k;
coleenp@4751:     assert(k != k->next_link(), "no loops!");
coleenp@4037:   }
coleenp@4037:   ShouldNotReachHere();   // should have found this class!!
coleenp@4037: }
coleenp@4037: 
coleenp@4304: void ClassLoaderData::unload() {
coleenp@4304:   _unloading = true;
coleenp@4304: 
coleenp@4981:   // Tell serviceability tools these classes are unloading
coleenp@4981:   classes_do(InstanceKlass::notify_unload_class);
coleenp@4981: 
coleenp@4304:   if (TraceClassLoaderData) {
coleenp@4304:     ResourceMark rm;
coleenp@4304:     tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this);
hseigel@5784:     tty->print(" for instance "PTR_FORMAT" of %s", (void *)class_loader(),
coleenp@4304:                loader_name());
coleenp@4304:     if (is_anonymous()) {
coleenp@4304:       tty->print(" for anonymous class  "PTR_FORMAT " ", _klasses);
coleenp@4304:     }
coleenp@4304:     tty->print_cr("]");
coleenp@4304:   }
coleenp@4304: }
coleenp@4304: 
coleenp@4304: bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
coleenp@4304:   bool alive =
coleenp@4304:     is_anonymous() ?
coleenp@4304:        is_alive_closure->do_object_b(_klasses->java_mirror()) :
coleenp@4304:        class_loader() == NULL || is_alive_closure->do_object_b(class_loader());
coleenp@4304:   assert(!alive || claimed(), "must be claimed");
coleenp@4304:   return alive;
coleenp@4304: }
coleenp@4304: 
coleenp@4304: 
coleenp@4037: ClassLoaderData::~ClassLoaderData() {
coleenp@4981:   // Release C heap structures for all the classes.
coleenp@4981:   classes_do(InstanceKlass::release_C_heap_structures);
coleenp@4981: 
coleenp@4037:   Metaspace *m = _metaspace;
coleenp@4037:   if (m != NULL) {
coleenp@4037:     _metaspace = NULL;
coleenp@4037:     // release the metaspace
coleenp@4037:     delete m;
coleenp@4037:     // release the handles
coleenp@4037:     if (_handles != NULL) {
coleenp@4037:       JNIHandleBlock::release_block(_handles);
coleenp@4037:       _handles = NULL;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   // Clear all the JNI handles for methods
coleenp@4037:   // These aren't deallocated and are going to look like a leak, but that's
coleenp@4037:   // needed because we can't really get rid of jmethodIDs because we don't
coleenp@4037:   // know when native code is going to stop using them.  The spec says that
coleenp@4037:   // they're "invalid" but existing programs likely rely on their being
coleenp@4037:   // NULL after class unloading.
coleenp@4037:   if (_jmethod_ids != NULL) {
coleenp@4037:     Method::clear_jmethod_ids(this);
coleenp@4037:   }
coleenp@4037:   // Delete lock
coleenp@4037:   delete _metaspace_lock;
coleenp@4037: 
coleenp@4037:   // Delete free list
coleenp@4037:   if (_deallocate_list != NULL) {
coleenp@4037:     delete _deallocate_list;
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
twisti@4866: /**
twisti@4866:  * Returns true if this class loader data is for the extension class loader.
twisti@4866:  */
twisti@4866: bool ClassLoaderData::is_ext_class_loader_data() const {
twisti@4866:   return SystemDictionary::is_ext_class_loader(class_loader());
twisti@4866: }
twisti@4866: 
coleenp@4037: Metaspace* ClassLoaderData::metaspace_non_null() {
jmasa@4457:   assert(!DumpSharedSpaces, "wrong metaspace!");
coleenp@4037:   // If the metaspace has not been allocated, create a new one.  Might want
coleenp@4037:   // to create smaller arena for Reflection class loaders also.
coleenp@4037:   // The reason for the delayed allocation is because some class loaders are
coleenp@4037:   // simply for delegating with no metadata of their own.
coleenp@4037:   if (_metaspace == NULL) {
coleenp@4037:     MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
coleenp@4037:     // Check again if metaspace has been allocated while we were getting this lock.
coleenp@4037:     if (_metaspace != NULL) {
coleenp@4037:       return _metaspace;
coleenp@4037:     }
coleenp@4304:     if (this == the_null_class_loader_data()) {
coleenp@4304:       assert (class_loader() == NULL, "Must be");
jmasa@4382:       set_metaspace(new Metaspace(_metaspace_lock, Metaspace::BootMetaspaceType));
jmasa@4382:     } else if (is_anonymous()) {
jmasa@4382:       if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
jmasa@4382:         tty->print_cr("is_anonymous: %s", class_loader()->klass()->internal_name());
jmasa@4382:       }
jmasa@4382:       set_metaspace(new Metaspace(_metaspace_lock, Metaspace::AnonymousMetaspaceType));
jmasa@4382:     } else if (class_loader()->is_a(SystemDictionary::reflect_DelegatingClassLoader_klass())) {
jmasa@4382:       if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
jmasa@4382:         tty->print_cr("is_reflection: %s", class_loader()->klass()->internal_name());
jmasa@4382:       }
jmasa@4382:       set_metaspace(new Metaspace(_metaspace_lock, Metaspace::ReflectionMetaspaceType));
coleenp@4037:     } else {
jmasa@4382:       set_metaspace(new Metaspace(_metaspace_lock, Metaspace::StandardMetaspaceType));
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   return _metaspace;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: JNIHandleBlock* ClassLoaderData::handles() const           { return _handles; }
coleenp@4037: void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; }
coleenp@4037: 
coleenp@4037: jobject ClassLoaderData::add_handle(Handle h) {
coleenp@4037:   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
coleenp@4037:   if (handles() == NULL) {
coleenp@4037:     set_handles(JNIHandleBlock::allocate_block());
coleenp@4037:   }
coleenp@4037:   return handles()->allocate_handle(h());
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Add this metadata pointer to be freed when it's safe.  This is only during
coleenp@4037: // class unloading because Handles might point to this metadata field.
coleenp@4037: void ClassLoaderData::add_to_deallocate_list(Metadata* m) {
coleenp@4037:   // Metadata in shared region isn't deleted.
coleenp@4037:   if (!m->is_shared()) {
coleenp@4037:     MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
coleenp@4037:     if (_deallocate_list == NULL) {
coleenp@4037:       _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true);
coleenp@4037:     }
coleenp@4037:     _deallocate_list->append_if_missing(m);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Deallocate free metadata on the free list.  How useful the PermGen was!
coleenp@4037: void ClassLoaderData::free_deallocate_list() {
coleenp@4037:   // Don't need lock, at safepoint
coleenp@4037:   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
coleenp@4037:   if (_deallocate_list == NULL) {
coleenp@4037:     return;
coleenp@4037:   }
coleenp@4037:   // Go backwards because this removes entries that are freed.
coleenp@4037:   for (int i = _deallocate_list->length() - 1; i >= 0; i--) {
coleenp@4037:     Metadata* m = _deallocate_list->at(i);
coleenp@4037:     if (!m->on_stack()) {
coleenp@4037:       _deallocate_list->remove_at(i);
coleenp@4037:       // There are only three types of metadata that we deallocate directly.
coleenp@4037:       // Cast them so they can be used by the template function.
coleenp@4037:       if (m->is_method()) {
coleenp@4037:         MetadataFactory::free_metadata(this, (Method*)m);
coleenp@4037:       } else if (m->is_constantPool()) {
coleenp@4037:         MetadataFactory::free_metadata(this, (ConstantPool*)m);
coleenp@4037:       } else if (m->is_klass()) {
coleenp@4037:         MetadataFactory::free_metadata(this, (InstanceKlass*)m);
coleenp@4037:       } else {
coleenp@4037:         ShouldNotReachHere();
coleenp@4037:       }
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4304: // These anonymous class loaders are to contain classes used for JSR292
coleenp@4304: ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) {
coleenp@4304:   // Add a new class loader data to the graph.
mgerdin@5013:   return ClassLoaderDataGraph::add(loader, true, CHECK_NULL);
coleenp@4037: }
coleenp@4037: 
coleenp@4304: const char* ClassLoaderData::loader_name() {
coleenp@4304:   // Handles null class loader
coleenp@4304:   return SystemDictionary::loader_name(class_loader());
coleenp@4304: }
coleenp@4304: 
coleenp@4304: #ifndef PRODUCT
coleenp@4037: // Define to dump klasses
coleenp@4037: #undef CLD_DUMP_KLASSES
coleenp@4037: 
coleenp@4037: void ClassLoaderData::dump(outputStream * const out) {
coleenp@4037:   ResourceMark rm;
coleenp@4037:   out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {",
hseigel@5784:       this, (void *)class_loader(),
coleenp@4304:       class_loader() != NULL ? class_loader()->klass() : NULL, loader_name());
coleenp@4037:   if (claimed()) out->print(" claimed ");
coleenp@4037:   if (is_unloading()) out->print(" unloading ");
coleenp@4037:   out->print(" handles " INTPTR_FORMAT, handles());
coleenp@4037:   out->cr();
coleenp@4037:   if (metaspace_or_null() != NULL) {
coleenp@4037:     out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null());
coleenp@4037:     metaspace_or_null()->dump(out);
coleenp@4037:   } else {
coleenp@4037:     out->print_cr("metaspace: NULL");
coleenp@4037:   }
coleenp@4037: 
coleenp@4037: #ifdef CLD_DUMP_KLASSES
coleenp@4037:   if (Verbose) {
coleenp@4037:     ResourceMark rm;
coleenp@4037:     Klass* k = _klasses;
coleenp@4037:     while (k != NULL) {
coleenp@4037:       out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(),
coleenp@4037:           k->has_modified_oops(), k->has_accumulated_modified_oops());
coleenp@4751:       assert(k != k->next_link(), "no loops!");
coleenp@4037:       k = k->next_link();
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: #endif  // CLD_DUMP_KLASSES
coleenp@4037: #undef CLD_DUMP_KLASSES
coleenp@4037:   if (_jmethod_ids != NULL) {
coleenp@4037:     Method::print_jmethod_ids(this, out);
coleenp@4037:   }
coleenp@4037:   out->print_cr("}");
coleenp@4037: }
coleenp@4037: #endif // PRODUCT
coleenp@4037: 
coleenp@4037: void ClassLoaderData::verify() {
coleenp@4037:   oop cl = class_loader();
coleenp@4037: 
coleenp@4304:   guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same");
coleenp@4304:   guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be");
coleenp@4037: 
coleenp@4037:   // Verify the integrity of the allocated space.
coleenp@4037:   if (metaspace_or_null() != NULL) {
coleenp@4037:     metaspace_or_null()->verify();
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037:     guarantee(k->class_loader_data() == this, "Must be the same");
coleenp@4037:     k->verify();
coleenp@4751:     assert(k != k->next_link(), "no loops!");
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4304: 
coleenp@4037: // GC root of class loader data created.
coleenp@4037: ClassLoaderData* ClassLoaderDataGraph::_head = NULL;
coleenp@4037: ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL;
coleenp@4037: ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
coleenp@4037: 
coleenp@4037: // Add a new class loader data node to the list.  Assign the newly created
coleenp@4037: // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
mgerdin@5013: ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) {
mgerdin@5016:   // We need to allocate all the oops for the ClassLoaderData before allocating the
mgerdin@5016:   // actual ClassLoaderData object.
mgerdin@5016:   ClassLoaderData::Dependencies dependencies(CHECK_NULL);
coleenp@4345: 
mgerdin@5016:   No_Safepoint_Verifier no_safepoints; // we mustn't GC until we've installed the
mgerdin@5016:                                        // ClassLoaderData in the graph since the CLD
mgerdin@5016:                                        // contains unhandled oops
coleenp@4037: 
mgerdin@5016:   ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous, dependencies);
mgerdin@5016: 
mgerdin@4903: 
mgerdin@5013:   if (!is_anonymous) {
mgerdin@5013:     ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader());
coleenp@4304:     // First, Atomically set it
coleenp@4304:     ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
coleenp@4304:     if (old != NULL) {
coleenp@4304:       delete cld;
coleenp@4304:       // Returns the data.
coleenp@4304:       return old;
coleenp@4304:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   // We won the race, and therefore the task of adding the data to the list of
coleenp@4037:   // class loader data
mgerdin@5013:   ClassLoaderData** list_head = &_head;
mgerdin@5013:   ClassLoaderData* next = _head;
mgerdin@5013: 
coleenp@4037:   do {
coleenp@4037:     cld->set_next(next);
coleenp@4037:     ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next);
coleenp@4037:     if (exchanged == next) {
coleenp@4037:       if (TraceClassLoaderData) {
coleenp@4304:         ResourceMark rm;
coleenp@4037:         tty->print("[ClassLoaderData: ");
coleenp@4037:         tty->print("create class loader data "PTR_FORMAT, cld);
hseigel@5784:         tty->print(" for instance "PTR_FORMAT" of %s", (void *)cld->class_loader(),
coleenp@4304:                    cld->loader_name());
coleenp@4037:         tty->print_cr("]");
coleenp@4037:       }
coleenp@4037:       return cld;
coleenp@4037:     }
coleenp@4037:     next = exchanged;
coleenp@4037:   } while (true);
coleenp@4304: 
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037:     cld->oops_do(f, klass_closure, must_claim);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4304: void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4304:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4304:     if (cld->keep_alive()) {
coleenp@4304:       cld->oops_do(f, klass_closure, must_claim);
coleenp@4304:     }
coleenp@4304:   }
coleenp@4304: }
coleenp@4304: 
coleenp@4037: void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037:   if (ClassUnloading) {
coleenp@4037:     ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim);
coleenp@4304:     // keep any special CLDs alive.
coleenp@4304:     ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim);
coleenp@4037:   } else {
coleenp@4037:     ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
coleenp@4037:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037:     cld->classes_do(klass_closure);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
sla@5237: void ClassLoaderDataGraph::classes_do(void f(Klass* const)) {
sla@5237:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
sla@5237:     cld->classes_do(f);
sla@5237:   }
sla@5237: }
sla@5237: 
sla@5237: void ClassLoaderDataGraph::classes_unloading_do(void f(Klass* const)) {
sla@5237:   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
sla@5237:   for (ClassLoaderData* cld = _unloading; cld != NULL; cld = cld->next()) {
sla@5237:     cld->classes_do(f);
sla@5237:   }
sla@5237: }
sla@5237: 
coleenp@4037: GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
coleenp@4037:   assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?");
coleenp@4037: 
coleenp@4037:   GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>();
coleenp@4037: 
coleenp@4037:   // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true);
coleenp@4037:   ClassLoaderData* curr = _head;
coleenp@4037:   while (curr != _saved_head) {
coleenp@4037:     if (!curr->claimed()) {
coleenp@4037:       array->push(curr);
coleenp@4037: 
coleenp@4037:       if (TraceClassLoaderData) {
coleenp@4037:         tty->print("[ClassLoaderData] found new CLD: ");
coleenp@4037:         curr->print_value_on(tty);
coleenp@4037:         tty->cr();
coleenp@4037:       }
coleenp@4037:     }
coleenp@4037: 
coleenp@4037:     curr = curr->_next;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   return array;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: #ifndef PRODUCT
coleenp@4037: // for debugging and hsfind(x)
coleenp@4037: bool ClassLoaderDataGraph::contains(address x) {
coleenp@4037:   // I think we need the _metaspace_lock taken here because the class loader
coleenp@4037:   // data graph could be changing while we are walking it (new entries added,
coleenp@4037:   // new entries being unloaded, etc).
coleenp@4037:   if (DumpSharedSpaces) {
coleenp@4037:     // There are only two metaspaces to worry about.
coleenp@4037:     ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
coleenp@4037:     return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x));
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) {
coleenp@4037:     return true;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037:     if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
coleenp@4037:       return true;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   // Could also be on an unloading list which is okay, ie. still allocated
coleenp@4037:   // for a little while.
coleenp@4037:   for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
coleenp@4037:     if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
coleenp@4037:       return true;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   return false;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
coleenp@4037:   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037:     if (loader_data == data) {
coleenp@4037:       return true;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   return false;
coleenp@4037: }
coleenp@4037: #endif // PRODUCT
coleenp@4037: 
coleenp@4304: 
coleenp@4037: // Move class loader data from main list to the unloaded list for unloading
coleenp@4037: // and deallocation later.
coleenp@4304: bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
coleenp@4037:   ClassLoaderData* data = _head;
coleenp@4037:   ClassLoaderData* prev = NULL;
coleenp@4037:   bool seen_dead_loader = false;
coleenp@4037:   // mark metadata seen on the stack and code cache so we can delete
coleenp@4037:   // unneeded entries.
coleenp@4037:   bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
coleenp@4037:   MetadataOnStackMark md_on_stack;
coleenp@4037:   while (data != NULL) {
coleenp@4304:     if (data->keep_alive() || data->is_alive(is_alive_closure)) {
coleenp@4037:       if (has_redefined_a_class) {
coleenp@4037:         data->classes_do(InstanceKlass::purge_previous_versions);
coleenp@4037:       }
coleenp@4037:       data->free_deallocate_list();
coleenp@4037:       prev = data;
coleenp@4037:       data = data->next();
coleenp@4037:       continue;
coleenp@4037:     }
coleenp@4037:     seen_dead_loader = true;
coleenp@4037:     ClassLoaderData* dead = data;
coleenp@4304:     dead->unload();
coleenp@4037:     data = data->next();
coleenp@4037:     // Remove from loader list.
jmasa@5015:     // This class loader data will no longer be found
jmasa@5015:     // in the ClassLoaderDataGraph.
coleenp@4037:     if (prev != NULL) {
coleenp@4037:       prev->set_next(data);
coleenp@4037:     } else {
coleenp@4037:       assert(dead == _head, "sanity check");
coleenp@4037:       _head = data;
coleenp@4037:     }
coleenp@4037:     dead->set_next(_unloading);
coleenp@4037:     _unloading = dead;
coleenp@4037:   }
sla@5237: 
sla@5237:   if (seen_dead_loader) {
sla@5237:     post_class_unload_events();
sla@5237:   }
sla@5237: 
coleenp@4037:   return seen_dead_loader;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::purge() {
coleenp@4037:   ClassLoaderData* list = _unloading;
coleenp@4037:   _unloading = NULL;
coleenp@4037:   ClassLoaderData* next = list;
coleenp@4037:   while (next != NULL) {
coleenp@4037:     ClassLoaderData* purge_me = next;
coleenp@4037:     next = purge_me->next();
coleenp@4037:     delete purge_me;
coleenp@4037:   }
jmasa@5007:   Metaspace::purge();
coleenp@4037: }
coleenp@4037: 
sla@5237: void ClassLoaderDataGraph::post_class_unload_events(void) {
sla@5237: #if INCLUDE_TRACE
sla@5237:   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
sla@5237:   if (Tracing::enabled()) {
sla@5237:     if (Tracing::is_event_enabled(TraceClassUnloadEvent)) {
sla@5237:       assert(_unloading != NULL, "need class loader data unload list!");
sla@5237:       _class_unload_time = Tracing::time();
sla@5237:       classes_unloading_do(&class_unload_event);
sla@5237:     }
sla@5237:     Tracing::on_unloading_classes();
sla@5237:   }
sla@5237: #endif
sla@5237: }
sla@5237: 
coleenp@4037: // CDS support
coleenp@4037: 
coleenp@4037: // Global metaspaces for writing information to the shared archive.  When
coleenp@4037: // application CDS is supported, we may need one per metaspace, so this
coleenp@4037: // sort of looks like it.
coleenp@4037: Metaspace* ClassLoaderData::_ro_metaspace = NULL;
coleenp@4037: Metaspace* ClassLoaderData::_rw_metaspace = NULL;
coleenp@4037: static bool _shared_metaspaces_initialized = false;
coleenp@4037: 
coleenp@4037: // Initialize shared metaspaces (change to call from somewhere not lazily)
coleenp@4037: void ClassLoaderData::initialize_shared_metaspaces() {
coleenp@4037:   assert(DumpSharedSpaces, "only use this for dumping shared spaces");
coleenp@4037:   assert(this == ClassLoaderData::the_null_class_loader_data(),
coleenp@4037:          "only supported for null loader data for now");
coleenp@4037:   assert (!_shared_metaspaces_initialized, "only initialize once");
coleenp@4037:   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
jmasa@4382:   _ro_metaspace = new Metaspace(_metaspace_lock, Metaspace::ROMetaspaceType);
jmasa@4382:   _rw_metaspace = new Metaspace(_metaspace_lock, Metaspace::ReadWriteMetaspaceType);
coleenp@4037:   _shared_metaspaces_initialized = true;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: Metaspace* ClassLoaderData::ro_metaspace() {
coleenp@4037:   assert(_ro_metaspace != NULL, "should already be initialized");
coleenp@4037:   return _ro_metaspace;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: Metaspace* ClassLoaderData::rw_metaspace() {
coleenp@4037:   assert(_rw_metaspace != NULL, "should already be initialized");
coleenp@4037:   return _rw_metaspace;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
coleenp@4037:   _data = ClassLoaderDataGraph::_head;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
coleenp@4037: 
coleenp@4037: #ifndef PRODUCT
coleenp@4037: // callable from debugger
coleenp@4037: extern "C" int print_loader_data_graph() {
coleenp@4037:   ClassLoaderDataGraph::dump_on(tty);
coleenp@4037:   return 0;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::verify() {
coleenp@4037:   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037:     data->verify();
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void ClassLoaderDataGraph::dump_on(outputStream * const out) {
coleenp@4037:   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037:     data->dump(out);
coleenp@4037:   }
coleenp@4037:   MetaspaceAux::dump(out);
coleenp@4037: }
acorn@4497: #endif // PRODUCT
coleenp@4037: 
coleenp@4037: void ClassLoaderData::print_value_on(outputStream* out) const {
coleenp@4037:   if (class_loader() == NULL) {
acorn@4497:     out->print("NULL class_loader");
coleenp@4037:   } else {
coleenp@4037:     out->print("class loader "PTR_FORMAT, this);
coleenp@4037:     class_loader()->print_value_on(out);
coleenp@4037:   }
coleenp@4037: }
sla@5237: 
sla@5237: #if INCLUDE_TRACE
sla@5237: 
sla@5237: TracingTime ClassLoaderDataGraph::_class_unload_time;
sla@5237: 
sla@5237: void ClassLoaderDataGraph::class_unload_event(Klass* const k) {
sla@5237: 
sla@5237:   // post class unload event
sla@5237:   EventClassUnload event(UNTIMED);
sla@5237:   event.set_endtime(_class_unload_time);
sla@5237:   event.set_unloadedClass(k);
sla@5237:   oop defining_class_loader = k->class_loader();
sla@5237:   event.set_definingClassLoader(defining_class_loader != NULL ?
sla@5237:                                 defining_class_loader->klass() : (Klass*)NULL);
sla@5237:   event.commit();
sla@5237: }
sla@5237: 
sla@5237: #endif /* INCLUDE_TRACE */