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::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()) {
cld->classes_do(f);
}
}
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);
}
}
}
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;
}
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;
}
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();
}
}
// 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);
No_Safepoint_Verifier 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 (TraceClassLoaderData) {
ResourceMark rm;
tty->print("[ClassLoaderData: ");
tty->print("create class loader data " INTPTR_FORMAT, p2i(cld));
tty->print(" for instance " INTPTR_FORMAT " of %s", p2i((void *)cld->class_loader()),
cld->loader_name());
tty->print_cr("]");
}
return cld;
}
next = exchanged;
} while (true);
}
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;
}
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;
}
// Move class loader data from main list to the unloaded list for unloading
// and deallocation later.
bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
ClassLoaderData* data = _head;
ClassLoaderData* prev = NULL;
bool seen_dead_loader = false;
// 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;
// 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->is_alive(is_alive_closure)) {
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->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;
}
// 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;
}
void ClassLoaderDataGraph::verify() {
for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
data->verify();
}
}
void ClassLoaderDataGraph::cld_do(CLDClosure* cl) {
for (ClassLoaderData* cld = _head; cl != NULL && cld != NULL; cld = cld->next()) {
cl->do_cld(cld);
}
}
void ClassLoaderDataGraph::clear_claimed_marks() {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
cld->clear_claimed();
}
}
// 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)) {
// 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::methods_do(void f(Method*)) {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
cld->methods_do(f);
}
}
void ClassLoaderDataGraph::classes_do(void f(Klass* const)) {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
cld->classes_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::dump_on(outputStream * const out) {
for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
data->dump(out);
}
MetaspaceAux::dump(out);
}
void ClassLoaderDataGraph::classes_unloading_do(void f(Klass* const)) {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
for (ClassLoaderData* cld = _unloading; cld != NULL; cld = cld->next()) {
cld->classes_do(f);
}
}
