void PlaceholderTable::classes_do(KlassClosure* f) {
for (int index = 0; index < table_size(); index++) {
for (PlaceholderEntry* probe = bucket(index);
probe != NULL;
probe = probe->next()) {
probe->classes_do(f);
}
}
}
// do all entries in the placeholder table
void PlaceholderTable::entries_do(void f(Symbol*)) {
for (int index = 0; index < table_size(); index++) {
for (PlaceholderEntry* probe = bucket(index);
probe != NULL;
probe = probe->next()) {
f(probe->klassname());
}
}
}
// do all entries in the placeholder table
void PlaceholderTable::entries_do(void f(symbolOop, oop)) {
for (int index = 0; index < table_size(); index++) {
for (PlaceholderEntry* probe = bucket(index);
probe != NULL;
probe = probe->next()) {
f(probe->klass(), probe->loader());
}
}
}
// placeholder used to track class loading internal states
// placeholder existence now for loading superclass/superinterface
// superthreadQ tracks class circularity, while loading superclass/superinterface
// loadInstanceThreadQ tracks load_instance_class calls
// definer() tracks the single thread that owns define token
// defineThreadQ tracks waiters on defining thread's results
// 1st claimant creates placeholder
// find_and_add adds SeenThread entry for appropriate queue
// All claimants remove SeenThread after completing action
// On removal: if definer and all queues empty, remove entry
// Note: you can be in both placeholders and systemDictionary
// see parse_stream for redefine classes
// Therefore - must always check SD first
// Ignores the case where entry is not found
void PlaceholderTable::find_and_remove(int index, unsigned int hash,
symbolHandle name, Handle loader, Thread* thread) {
assert_locked_or_safepoint(SystemDictionary_lock);
PlaceholderEntry *probe = get_entry(index, hash, name, loader);
if (probe != NULL) {
// No other threads using this entry
if ((probe->superThreadQ() == NULL) && (probe->loadInstanceThreadQ() == NULL)
&& (probe->defineThreadQ() == NULL) && (probe->definer() == NULL)) {
remove_entry(index, hash, name, loader);
}
}
}
void PlaceholderTable::print() {
for (int pindex = 0; pindex < table_size(); pindex++) {
for (PlaceholderEntry* probe = bucket(pindex);
probe != NULL;
probe = probe->next()) {
if (Verbose) tty->print("%4d: ", pindex);
tty->print(" place holder ");
probe->print();
tty->cr();
}
}
}
void PlaceholderTable::verify() {
int element_count = 0;
for (int pindex = 0; pindex < table_size(); pindex++) {
for (PlaceholderEntry* probe = bucket(pindex);
probe != NULL;
probe = probe->next()) {
probe->verify();
element_count++; // both klasses and place holders count
}
}
guarantee(number_of_entries() == element_count,
"Verify of system dictionary failed");
}
// find_and_add returns probe pointer - old or new
// If no entry exists, add a placeholder entry
// If entry exists, reuse entry
// For both, push SeenThread for classloadAction
// if havesupername: this is used for circularity for instanceklass loading
PlaceholderEntry* PlaceholderTable::find_and_add(int index, unsigned int hash, symbolHandle name, Handle loader, classloadAction action, symbolHandle supername, Thread* thread) {
PlaceholderEntry* probe = get_entry(index, hash, name, loader);
if (probe == NULL) {
// Nothing found, add place holder
add_entry(index, hash, name, loader, (action == LOAD_SUPER), supername);
probe = get_entry(index, hash, name, loader);
} else {
if (action == LOAD_SUPER) {
probe->set_havesupername(true);
probe->set_supername(supername());
}
}
if (probe) probe->add_seen_thread(thread, action);
return probe;
}
// Remove a placeholder object.
void PlaceholderTable::remove_entry(int index, unsigned int hash,
Symbol* class_name,
ClassLoaderData* loader_data) {
assert_locked_or_safepoint(SystemDictionary_lock);
PlaceholderEntry** p = bucket_addr(index);
while (*p) {
PlaceholderEntry *probe = *p;
if (probe->hash() == hash && probe->equals(class_name, loader_data)) {
// Delete entry
*p = probe->next();
free_entry(probe);
return;
}
p = probe->next_addr();
}
}
PlaceholderEntry* PlaceholderTable::new_entry(int hash, symbolOop name,
oop loader, bool havesupername,
symbolOop supername) {
PlaceholderEntry* entry = (PlaceholderEntry*)Hashtable::new_entry(hash, name);
entry->set_loader(loader);
entry->set_havesupername(havesupername);
entry->set_supername(supername);
entry->set_superThreadQ(NULL);
entry->set_loadInstanceThreadQ(NULL);
entry->set_defineThreadQ(NULL);
entry->set_definer(NULL);
entry->set_instanceKlass(NULL);
return entry;
}
PlaceholderEntry* PlaceholderTable::new_entry(int hash, Symbol* name,
ClassLoaderData* loader_data,
bool havesupername,
Symbol* supername) {
PlaceholderEntry* entry = (PlaceholderEntry*)Hashtable<Symbol*, mtClass>::new_entry(hash, name);
// Hashtable with Symbol* literal must increment and decrement refcount.
name->increment_refcount();
entry->set_loader_data(loader_data);
entry->set_havesupername(havesupername);
entry->set_supername(supername);
entry->set_superThreadQ(NULL);
entry->set_loadInstanceThreadQ(NULL);
entry->set_defineThreadQ(NULL);
entry->set_definer(NULL);
entry->set_instance_klass(NULL);
return entry;
}
// placeholder is used to track class loading internal states
// placeholder existence now for loading superclass/superinterface
// superthreadQ tracks class circularity, while loading superclass/superinterface
// loadInstanceThreadQ tracks load_instance_class calls
// definer() tracks the single thread that owns define token
// defineThreadQ tracks waiters on defining thread's results
// 1st claimant creates placeholder
// find_and_add adds SeenThread entry for appropriate queue
// All claimants remove SeenThread after completing action
// On removal: if definer and all queues empty, remove entry
// Note: you can be in both placeholders and systemDictionary
// Therefore - must always check SD first
// Ignores the case where entry is not found
void PlaceholderTable::find_and_remove(int index, unsigned int hash,
Symbol* name, ClassLoaderData* loader_data,
classloadAction action,
Thread* thread) {
assert_locked_or_safepoint(SystemDictionary_lock);
PlaceholderEntry *probe = get_entry(index, hash, name, loader_data);
if (probe != NULL) {
probe->remove_seen_thread(thread, action);
// If no other threads using this entry, and this thread is not using this entry for other states
if ((probe->superThreadQ() == NULL) && (probe->loadInstanceThreadQ() == NULL)
&& (probe->defineThreadQ() == NULL) && (probe->definer() == NULL)) {
remove_entry(index, hash, name, loader_data);
}
}
}
Symbol* PlaceholderTable::find_entry(int index, unsigned int hash,
Symbol* class_name,
ClassLoaderData* loader_data) {
PlaceholderEntry* probe = get_entry(index, hash, class_name, loader_data);
return (probe? probe->klassname(): (Symbol*)NULL);
}
symbolOop PlaceholderTable::find_entry(int index, unsigned int hash,
symbolHandle class_name,
Handle class_loader) {
PlaceholderEntry* probe = get_entry(index, hash, class_name, class_loader);
return (probe? probe->klass(): symbolOop(NULL));
}
