src/hotspot/share/classfile/dictionary.cpp
changeset 47216 71c04702a3d5
parent 47103 a993ec29ec75
child 47761 1b0566927c7a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/dictionary.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,516 @@
+/*
+ * Copyright (c) 2003, 2017, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/classLoaderData.inline.hpp"
+#include "classfile/sharedClassUtil.hpp"
+#include "classfile/dictionary.hpp"
+#include "classfile/protectionDomainCache.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/systemDictionaryShared.hpp"
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/iterator.hpp"
+#include "memory/metaspaceClosure.hpp"
+#include "memory/resourceArea.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "utilities/hashtable.inline.hpp"
+
+size_t Dictionary::entry_size() {
+  if (DumpSharedSpaces) {
+    return SystemDictionaryShared::dictionary_entry_size();
+  } else {
+    return sizeof(DictionaryEntry);
+  }
+}
+
+Dictionary::Dictionary(ClassLoaderData* loader_data, int table_size)
+  : _loader_data(loader_data), Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size()) {
+};
+
+
+Dictionary::Dictionary(ClassLoaderData* loader_data,
+                       int table_size, HashtableBucket<mtClass>* t,
+                       int number_of_entries)
+  : _loader_data(loader_data), Hashtable<InstanceKlass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
+};
+
+Dictionary::~Dictionary() {
+  DictionaryEntry* probe = NULL;
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
+      probe = *p;
+      *p = probe->next();
+      free_entry(probe);
+    }
+  }
+  assert(number_of_entries() == 0, "should have removed all entries");
+  assert(new_entry_free_list() == NULL, "entry present on Dictionary's free list");
+  free_buckets();
+}
+
+DictionaryEntry* Dictionary::new_entry(unsigned int hash, InstanceKlass* klass) {
+  DictionaryEntry* entry = (DictionaryEntry*)Hashtable<InstanceKlass*, mtClass>::allocate_new_entry(hash, klass);
+  entry->set_pd_set(NULL);
+  assert(klass->is_instance_klass(), "Must be");
+  if (DumpSharedSpaces) {
+    SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
+  }
+  return entry;
+}
+
+
+void Dictionary::free_entry(DictionaryEntry* entry) {
+  // avoid recursion when deleting linked list
+  // pd_set is accessed during a safepoint.
+  while (entry->pd_set() != NULL) {
+    ProtectionDomainEntry* to_delete = entry->pd_set();
+    entry->set_pd_set(to_delete->next());
+    delete to_delete;
+  }
+  // Unlink from the Hashtable prior to freeing
+  unlink_entry(entry);
+  FREE_C_HEAP_ARRAY(char, entry);
+}
+
+
+bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
+#ifdef ASSERT
+  if (protection_domain == instance_klass()->protection_domain()) {
+    // Ensure this doesn't show up in the pd_set (invariant)
+    bool in_pd_set = false;
+    for (ProtectionDomainEntry* current = pd_set_acquire();
+                                current != NULL;
+                                current = current->next()) {
+      if (current->protection_domain() == protection_domain) {
+        in_pd_set = true;
+        break;
+      }
+    }
+    if (in_pd_set) {
+      assert(false, "A klass's protection domain should not show up "
+                    "in its sys. dict. PD set");
+    }
+  }
+#endif /* ASSERT */
+
+  if (protection_domain == instance_klass()->protection_domain()) {
+    // Succeeds trivially
+    return true;
+  }
+
+  for (ProtectionDomainEntry* current = pd_set_acquire();
+                              current != NULL;
+                              current = current->next()) {
+    if (current->protection_domain() == protection_domain) return true;
+  }
+  return false;
+}
+
+
+void DictionaryEntry::add_protection_domain(Dictionary* dict, Handle protection_domain) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  if (!contains_protection_domain(protection_domain())) {
+    ProtectionDomainCacheEntry* entry = SystemDictionary::cache_get(protection_domain);
+    ProtectionDomainEntry* new_head =
+                new ProtectionDomainEntry(entry, pd_set());
+    // Warning: Preserve store ordering.  The SystemDictionary is read
+    //          without locks.  The new ProtectionDomainEntry must be
+    //          complete before other threads can be allowed to see it
+    //          via a store to _pd_set.
+    release_set_pd_set(new_head);
+  }
+  LogTarget(Trace, protectiondomain) lt;
+  if (lt.is_enabled()) {
+    LogStream ls(lt);
+    print_count(&ls);
+  }
+}
+
+
+void Dictionary::do_unloading() {
+  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
+
+  // The NULL class loader doesn't initiate loading classes from other class loaders
+  if (loader_data() == ClassLoaderData::the_null_class_loader_data()) {
+    return;
+  }
+
+  // Remove unloaded entries and classes from this dictionary
+  DictionaryEntry* probe = NULL;
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
+      probe = *p;
+      InstanceKlass* ik = probe->instance_klass();
+      ClassLoaderData* k_def_class_loader_data = ik->class_loader_data();
+
+      // If the klass that this loader initiated is dead,
+      // (determined by checking the defining class loader)
+      // remove this entry.
+      if (k_def_class_loader_data->is_unloading()) {
+        assert(k_def_class_loader_data != loader_data(),
+               "cannot have live defining loader and unreachable klass");
+        *p = probe->next();
+        free_entry(probe);
+        continue;
+      }
+      p = probe->next_addr();
+    }
+  }
+}
+
+void Dictionary::remove_classes_in_error_state() {
+  assert(DumpSharedSpaces, "supported only when dumping");
+  DictionaryEntry* probe = NULL;
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry** p = bucket_addr(index); *p != NULL; ) {
+      probe = *p;
+      InstanceKlass* ik = probe->instance_klass();
+      if (ik->is_in_error_state()) { // purge this entry
+        *p = probe->next();
+        free_entry(probe);
+        ResourceMark rm;
+        tty->print_cr("Preload Warning: Removed error class: %s", ik->external_name());
+        continue;
+      }
+
+      p = probe->next_addr();
+    }
+  }
+}
+
+//   Just the classes from defining class loaders
+void Dictionary::classes_do(void f(InstanceKlass*)) {
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry* probe = bucket(index);
+                          probe != NULL;
+                          probe = probe->next()) {
+      InstanceKlass* k = probe->instance_klass();
+      if (loader_data() == k->class_loader_data()) {
+        f(k);
+      }
+    }
+  }
+}
+
+// Added for initialize_itable_for_klass to handle exceptions
+//   Just the classes from defining class loaders
+void Dictionary::classes_do(void f(InstanceKlass*, TRAPS), TRAPS) {
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry* probe = bucket(index);
+                          probe != NULL;
+                          probe = probe->next()) {
+      InstanceKlass* k = probe->instance_klass();
+      if (loader_data() == k->class_loader_data()) {
+        f(k, CHECK);
+      }
+    }
+  }
+}
+
+// All classes, and their class loaders, including initiating class loaders
+void Dictionary::all_entries_do(void f(InstanceKlass*, ClassLoaderData*)) {
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry* probe = bucket(index);
+                          probe != NULL;
+                          probe = probe->next()) {
+      InstanceKlass* k = probe->instance_klass();
+      f(k, loader_data());
+    }
+  }
+}
+
+// Used to scan and relocate the classes during CDS archive dump.
+void Dictionary::classes_do(MetaspaceClosure* it) {
+  assert(DumpSharedSpaces, "dump-time only");
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry* probe = bucket(index);
+                          probe != NULL;
+                          probe = probe->next()) {
+      it->push(probe->klass_addr());
+      ((SharedDictionaryEntry*)probe)->metaspace_pointers_do(it);
+    }
+  }
+}
+
+
+
+// Add a loaded class to the dictionary.
+// Readers of the SystemDictionary aren't always locked, so _buckets
+// is volatile. The store of the next field in the constructor is
+// also cast to volatile;  we do this to ensure store order is maintained
+// by the compilers.
+
+void Dictionary::add_klass(int index, unsigned int hash, Symbol* class_name,
+                           InstanceKlass* obj) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  assert(obj != NULL, "adding NULL obj");
+  assert(obj->name() == class_name, "sanity check on name");
+
+  DictionaryEntry* entry = new_entry(hash, obj);
+  add_entry(index, entry);
+}
+
+
+// This routine does not lock the dictionary.
+//
+// Since readers don't hold a lock, we must make sure that system
+// dictionary entries are only removed at a safepoint (when only one
+// thread is running), and are added to in a safe way (all links must
+// be updated in an MT-safe manner).
+//
+// Callers should be aware that an entry could be added just after
+// _buckets[index] is read here, so the caller will not see the new entry.
+DictionaryEntry* Dictionary::get_entry(int index, unsigned int hash,
+                                       Symbol* class_name) {
+  for (DictionaryEntry* entry = bucket(index);
+                        entry != NULL;
+                        entry = entry->next()) {
+    if (entry->hash() == hash && entry->equals(class_name)) {
+      if (!DumpSharedSpaces || SystemDictionaryShared::is_builtin(entry)) {
+        return entry;
+      }
+    }
+  }
+  return NULL;
+}
+
+
+InstanceKlass* Dictionary::find(int index, unsigned int hash, Symbol* name,
+                                Handle protection_domain) {
+  DictionaryEntry* entry = get_entry(index, hash, name);
+  if (entry != NULL && entry->is_valid_protection_domain(protection_domain)) {
+    return entry->instance_klass();
+  } else {
+    return NULL;
+  }
+}
+
+
+InstanceKlass* Dictionary::find_class(int index, unsigned int hash,
+                                      Symbol* name) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  assert (index == index_for(name), "incorrect index?");
+
+  DictionaryEntry* entry = get_entry(index, hash, name);
+  return (entry != NULL) ? entry->instance_klass() : NULL;
+}
+
+
+// Variant of find_class for shared classes.  No locking required, as
+// that table is static.
+
+InstanceKlass* Dictionary::find_shared_class(int index, unsigned int hash,
+                                             Symbol* name) {
+  assert (index == index_for(name), "incorrect index?");
+
+  DictionaryEntry* entry = get_entry(index, hash, name);
+  return (entry != NULL) ? entry->instance_klass() : NULL;
+}
+
+
+void Dictionary::add_protection_domain(int index, unsigned int hash,
+                                       InstanceKlass* klass,
+                                       Handle protection_domain,
+                                       TRAPS) {
+  Symbol*  klass_name = klass->name();
+  DictionaryEntry* entry = get_entry(index, hash, klass_name);
+
+  assert(entry != NULL,"entry must be present, we just created it");
+  assert(protection_domain() != NULL,
+         "real protection domain should be present");
+
+  entry->add_protection_domain(this, protection_domain);
+
+  assert(entry->contains_protection_domain(protection_domain()),
+         "now protection domain should be present");
+}
+
+
+bool Dictionary::is_valid_protection_domain(int index, unsigned int hash,
+                                            Symbol* name,
+                                            Handle protection_domain) {
+  DictionaryEntry* entry = get_entry(index, hash, name);
+  return entry->is_valid_protection_domain(protection_domain);
+}
+
+
+void Dictionary::reorder_dictionary_for_sharing() {
+
+  // Copy all the dictionary entries into a single master list.
+
+  DictionaryEntry* master_list = NULL;
+  for (int i = 0; i < table_size(); ++i) {
+    DictionaryEntry* p = bucket(i);
+    while (p != NULL) {
+      DictionaryEntry* next = p->next();
+      InstanceKlass*ik = p->instance_klass();
+      // we cannot include signed classes in the archive because the certificates
+      // used during dump time may be different than those used during
+      // runtime (due to expiration, etc).
+      if (ik->signers() != NULL) {
+        ResourceMark rm;
+        tty->print_cr("Preload Warning: Skipping %s from signed JAR",
+                       ik->name()->as_C_string());
+        free_entry(p);
+      } else {
+        p->set_next(master_list);
+        master_list = p;
+      }
+      p = next;
+    }
+    set_entry(i, NULL);
+  }
+
+  // Add the dictionary entries back to the list in the correct buckets.
+  while (master_list != NULL) {
+    DictionaryEntry* p = master_list;
+    master_list = master_list->next();
+    p->set_next(NULL);
+    Symbol* class_name = p->instance_klass()->name();
+    // Since the null class loader data isn't copied to the CDS archive,
+    // compute the hash with NULL for loader data.
+    unsigned int hash = compute_hash(class_name);
+    int index = hash_to_index(hash);
+    p->set_hash(hash);
+    p->set_next(bucket(index));
+    set_entry(index, p);
+  }
+}
+
+
+SymbolPropertyTable::SymbolPropertyTable(int table_size)
+  : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
+{
+}
+SymbolPropertyTable::SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t,
+                                         int number_of_entries)
+  : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry), t, number_of_entries)
+{
+}
+
+
+SymbolPropertyEntry* SymbolPropertyTable::find_entry(int index, unsigned int hash,
+                                                     Symbol* sym,
+                                                     intptr_t sym_mode) {
+  assert(index == index_for(sym, sym_mode), "incorrect index?");
+  for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
+    if (p->hash() == hash && p->symbol() == sym && p->symbol_mode() == sym_mode) {
+      return p;
+    }
+  }
+  return NULL;
+}
+
+
+SymbolPropertyEntry* SymbolPropertyTable::add_entry(int index, unsigned int hash,
+                                                    Symbol* sym, intptr_t sym_mode) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  assert(index == index_for(sym, sym_mode), "incorrect index?");
+  assert(find_entry(index, hash, sym, sym_mode) == NULL, "no double entry");
+
+  SymbolPropertyEntry* p = new_entry(hash, sym, sym_mode);
+  Hashtable<Symbol*, mtSymbol>::add_entry(index, p);
+  return p;
+}
+
+void SymbolPropertyTable::oops_do(OopClosure* f) {
+  for (int index = 0; index < table_size(); index++) {
+    for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
+      if (p->method_type() != NULL) {
+        f->do_oop(p->method_type_addr());
+      }
+    }
+  }
+}
+
+void SymbolPropertyTable::methods_do(void f(Method*)) {
+  for (int index = 0; index < table_size(); index++) {
+    for (SymbolPropertyEntry* p = bucket(index); p != NULL; p = p->next()) {
+      Method* prop = p->method();
+      if (prop != NULL) {
+        f((Method*)prop);
+      }
+    }
+  }
+}
+
+
+// ----------------------------------------------------------------------------
+
+void Dictionary::print_on(outputStream* st) const {
+  ResourceMark rm;
+
+  assert(loader_data() != NULL, "loader data should not be null");
+  st->print_cr("Java dictionary (table_size=%d, classes=%d)",
+               table_size(), number_of_entries());
+  st->print_cr("^ indicates that initiating loader is different from defining loader");
+
+  for (int index = 0; index < table_size(); index++) {
+    for (DictionaryEntry* probe = bucket(index);
+                          probe != NULL;
+                          probe = probe->next()) {
+      Klass* e = probe->instance_klass();
+      bool is_defining_class =
+         (loader_data() == e->class_loader_data());
+      st->print("%4d: %s%s, loader ", index, is_defining_class ? " " : "^", e->external_name());
+      ClassLoaderData* loader_data = e->class_loader_data();
+      if (loader_data == NULL) {
+        // Shared class not restored yet in shared dictionary
+        st->print("<shared, not restored>");
+      } else {
+        loader_data->print_value_on(st);
+      }
+      st->cr();
+    }
+  }
+  tty->cr();
+}
+
+void DictionaryEntry::verify() {
+  Klass* e = instance_klass();
+  guarantee(e->is_instance_klass(),
+                          "Verify of dictionary failed");
+  e->verify();
+  verify_protection_domain_set();
+}
+
+void Dictionary::verify() {
+  guarantee(number_of_entries() >= 0, "Verify of dictionary failed");
+
+  ClassLoaderData* cld = loader_data();
+  // class loader must be present;  a null class loader is the
+  // boostrap loader
+  guarantee(cld != NULL || DumpSharedSpaces ||
+            cld->class_loader() == NULL ||
+            cld->class_loader()->is_instance(),
+            "checking type of class_loader");
+
+  ResourceMark rm;
+  stringStream tempst;
+  tempst.print("System Dictionary for %s", cld->loader_name());
+  verify_table<DictionaryEntry>(tempst.as_string());
+}