hotspot/src/share/vm/ci/ciObjectFactory.cpp
changeset 1 489c9b5090e2
child 360 21d113ecbf6a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/ci/ciObjectFactory.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,647 @@
+/*
+ * Copyright 1999-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_ciObjectFactory.cpp.incl"
+
+// ciObjectFactory
+//
+// This class handles requests for the creation of new instances
+// of ciObject and its subclasses.  It contains a caching mechanism
+// which ensures that for each oop, at most one ciObject is created.
+// This invariant allows more efficient implementation of ciObject.
+//
+// Implementation note: the oop->ciObject mapping is represented as
+// a table stored in an array.  Even though objects are moved
+// by the garbage collector, the compactor preserves their relative
+// order; address comparison of oops (in perm space) is safe so long
+// as we prohibit GC during our comparisons.  We currently use binary
+// search to find the oop in the table, and inserting a new oop
+// into the table may be costly.  If this cost ends up being
+// problematic the underlying data structure can be switched to some
+// sort of balanced binary tree.
+
+GrowableArray<ciObject*>* ciObjectFactory::_shared_ci_objects = NULL;
+ciSymbol*                 ciObjectFactory::_shared_ci_symbols[vmSymbols::SID_LIMIT];
+int                       ciObjectFactory::_shared_ident_limit = 0;
+volatile bool             ciObjectFactory::_initialized = false;
+
+
+// ------------------------------------------------------------------
+// ciObjectFactory::ciObjectFactory
+ciObjectFactory::ciObjectFactory(Arena* arena,
+                                 int expected_size) {
+
+  for (int i = 0; i < NON_PERM_BUCKETS; i++) {
+    _non_perm_bucket[i] = NULL;
+  }
+  _non_perm_count = 0;
+
+  _next_ident = _shared_ident_limit;
+  _arena = arena;
+  _ci_objects = new (arena) GrowableArray<ciObject*>(arena, expected_size, 0, NULL);
+
+  // If the shared ci objects exist append them to this factory's objects
+
+  if (_shared_ci_objects != NULL) {
+    _ci_objects->appendAll(_shared_ci_objects);
+  }
+
+  _unloaded_methods = new (arena) GrowableArray<ciMethod*>(arena, 4, 0, NULL);
+  _unloaded_klasses = new (arena) GrowableArray<ciKlass*>(arena, 8, 0, NULL);
+  _return_addresses =
+    new (arena) GrowableArray<ciReturnAddress*>(arena, 8, 0, NULL);
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::ciObjectFactory
+void ciObjectFactory::initialize() {
+  ASSERT_IN_VM;
+  JavaThread* thread = JavaThread::current();
+  HandleMark  handle_mark(thread);
+
+  // This Arena is long lived and exists in the resource mark of the
+  // compiler thread that initializes the initial ciObjectFactory which
+  // creates the shared ciObjects that all later ciObjectFactories use.
+  Arena* arena = new Arena();
+  ciEnv initial(arena);
+  ciEnv* env = ciEnv::current();
+  env->_factory->init_shared_objects();
+
+  _initialized = true;
+
+}
+
+void ciObjectFactory::init_shared_objects() {
+
+  _next_ident = 1;  // start numbering CI objects at 1
+
+  {
+    // Create the shared symbols, but not in _shared_ci_objects.
+    int i;
+    for (i = vmSymbols::FIRST_SID; i < vmSymbols::SID_LIMIT; i++) {
+      symbolHandle sym_handle = vmSymbolHandles::symbol_handle_at((vmSymbols::SID) i);
+      assert(vmSymbols::find_sid(sym_handle()) == i, "1-1 mapping");
+      ciSymbol* sym = new (_arena) ciSymbol(sym_handle);
+      init_ident_of(sym);
+      _shared_ci_symbols[i] = sym;
+    }
+#ifdef ASSERT
+    for (i = vmSymbols::FIRST_SID; i < vmSymbols::SID_LIMIT; i++) {
+      symbolHandle sym_handle = vmSymbolHandles::symbol_handle_at((vmSymbols::SID) i);
+      ciSymbol* sym = vm_symbol_at((vmSymbols::SID) i);
+      assert(sym->get_oop() == sym_handle(), "oop must match");
+    }
+    assert(ciSymbol::void_class_signature()->get_oop() == vmSymbols::void_class_signature(), "spot check");
+#endif
+  }
+
+  _ci_objects = new (_arena) GrowableArray<ciObject*>(_arena, 64, 0, NULL);
+
+  for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
+    BasicType t = (BasicType)i;
+    if (type2name(t) != NULL && t != T_OBJECT && t != T_ARRAY) {
+      ciType::_basic_types[t] = new (_arena) ciType(t);
+      init_ident_of(ciType::_basic_types[t]);
+    }
+  }
+
+  ciEnv::_null_object_instance = new (_arena) ciNullObject();
+  init_ident_of(ciEnv::_null_object_instance);
+  ciEnv::_method_klass_instance =
+    get(Universe::methodKlassObj())->as_method_klass();
+  ciEnv::_symbol_klass_instance =
+    get(Universe::symbolKlassObj())->as_symbol_klass();
+  ciEnv::_klass_klass_instance =
+    get(Universe::klassKlassObj())->as_klass_klass();
+  ciEnv::_instance_klass_klass_instance =
+    get(Universe::instanceKlassKlassObj())
+      ->as_instance_klass_klass();
+  ciEnv::_type_array_klass_klass_instance =
+    get(Universe::typeArrayKlassKlassObj())
+      ->as_type_array_klass_klass();
+  ciEnv::_obj_array_klass_klass_instance =
+    get(Universe::objArrayKlassKlassObj())
+      ->as_obj_array_klass_klass();
+  ciEnv::_ArrayStoreException =
+    get(SystemDictionary::ArrayStoreException_klass())
+      ->as_instance_klass();
+  ciEnv::_Class =
+    get(SystemDictionary::class_klass())
+      ->as_instance_klass();
+  ciEnv::_ClassCastException =
+    get(SystemDictionary::ClassCastException_klass())
+      ->as_instance_klass();
+  ciEnv::_Object =
+    get(SystemDictionary::object_klass())
+      ->as_instance_klass();
+  ciEnv::_Throwable =
+    get(SystemDictionary::throwable_klass())
+      ->as_instance_klass();
+  ciEnv::_Thread =
+    get(SystemDictionary::thread_klass())
+      ->as_instance_klass();
+  ciEnv::_OutOfMemoryError =
+    get(SystemDictionary::OutOfMemoryError_klass())
+      ->as_instance_klass();
+  ciEnv::_String =
+    get(SystemDictionary::string_klass())
+      ->as_instance_klass();
+
+  for (int len = -1; len != _ci_objects->length(); ) {
+    len = _ci_objects->length();
+    for (int i2 = 0; i2 < len; i2++) {
+      ciObject* obj = _ci_objects->at(i2);
+      if (obj->is_loaded() && obj->is_instance_klass()) {
+        obj->as_instance_klass()->compute_nonstatic_fields();
+      }
+    }
+  }
+
+  ciEnv::_unloaded_cisymbol = (ciSymbol*) ciObjectFactory::get(vmSymbols::dummy_symbol_oop());
+  // Create dummy instanceKlass and objArrayKlass object and assign them idents
+  ciEnv::_unloaded_ciinstance_klass = new (_arena) ciInstanceKlass(ciEnv::_unloaded_cisymbol, NULL, NULL);
+  init_ident_of(ciEnv::_unloaded_ciinstance_klass);
+  ciEnv::_unloaded_ciobjarrayklass = new (_arena) ciObjArrayKlass(ciEnv::_unloaded_cisymbol, ciEnv::_unloaded_ciinstance_klass, 1);
+  init_ident_of(ciEnv::_unloaded_ciobjarrayklass);
+  assert(ciEnv::_unloaded_ciobjarrayklass->is_obj_array_klass(), "just checking");
+
+  get(Universe::boolArrayKlassObj());
+  get(Universe::charArrayKlassObj());
+  get(Universe::singleArrayKlassObj());
+  get(Universe::doubleArrayKlassObj());
+  get(Universe::byteArrayKlassObj());
+  get(Universe::shortArrayKlassObj());
+  get(Universe::intArrayKlassObj());
+  get(Universe::longArrayKlassObj());
+
+
+
+  assert(_non_perm_count == 0, "no shared non-perm objects");
+
+  // The shared_ident_limit is the first ident number that will
+  // be used for non-shared objects.  That is, numbers less than
+  // this limit are permanently assigned to shared CI objects,
+  // while the higher numbers are recycled afresh by each new ciEnv.
+
+  _shared_ident_limit = _next_ident;
+  _shared_ci_objects = _ci_objects;
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::get
+//
+// Get the ciObject corresponding to some oop.  If the ciObject has
+// already been created, it is returned.  Otherwise, a new ciObject
+// is created.
+ciObject* ciObjectFactory::get(oop key) {
+  ASSERT_IN_VM;
+
+#ifdef ASSERT
+  oop last = NULL;
+  for (int j = 0; j< _ci_objects->length(); j++) {
+    oop o = _ci_objects->at(j)->get_oop();
+    assert(last < o, "out of order");
+    last = o;
+  }
+#endif // ASSERT
+  int len = _ci_objects->length();
+  int index = find(key, _ci_objects);
+#ifdef ASSERT
+  for (int i=0; i<_ci_objects->length(); i++) {
+    if (_ci_objects->at(i)->get_oop() == key) {
+      assert(index == i, " bad lookup");
+    }
+  }
+#endif
+  if (!is_found_at(index, key, _ci_objects)) {
+
+    // Check in the non-perm area before putting it in the list.
+    NonPermObject* &bucket = find_non_perm(key);
+    if (bucket != NULL) {
+      return bucket->object();
+    }
+
+    // Check in the shared symbol area before putting it in the list.
+    if (key->is_symbol()) {
+      vmSymbols::SID sid = vmSymbols::find_sid((symbolOop)key);
+      if (sid != vmSymbols::NO_SID) {
+        // do not pollute the main cache with it
+        return vm_symbol_at(sid);
+      }
+    }
+
+    // The ciObject does not yet exist.  Create it and insert it
+    // into the cache.
+    Handle keyHandle(key);
+    ciObject* new_object = create_new_object(keyHandle());
+    assert(keyHandle() == new_object->get_oop(), "must be properly recorded");
+    init_ident_of(new_object);
+    if (!keyHandle->is_perm()) {
+      // Not a perm-space object.
+      insert_non_perm(bucket, keyHandle(), new_object);
+      return new_object;
+    }
+    new_object->set_perm();
+    if (len != _ci_objects->length()) {
+      // creating the new object has recursively entered new objects
+      // into the table.  We need to recompute our index.
+      index = find(keyHandle(), _ci_objects);
+    }
+    assert(!is_found_at(index, keyHandle(), _ci_objects), "no double insert");
+    insert(index, new_object, _ci_objects);
+    return new_object;
+  }
+  return _ci_objects->at(index);
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::create_new_object
+//
+// Create a new ciObject from an oop.
+//
+// Implementation note: this functionality could be virtual behavior
+// of the oop itself.  For now, we explicitly marshal the object.
+ciObject* ciObjectFactory::create_new_object(oop o) {
+  EXCEPTION_CONTEXT;
+
+  if (o->is_symbol()) {
+    symbolHandle h_o(THREAD, (symbolOop)o);
+    return new (arena()) ciSymbol(h_o);
+  } else if (o->is_klass()) {
+    KlassHandle h_k(THREAD, (klassOop)o);
+    Klass* k = ((klassOop)o)->klass_part();
+    if (k->oop_is_instance()) {
+      return new (arena()) ciInstanceKlass(h_k);
+    } else if (k->oop_is_objArray()) {
+      return new (arena()) ciObjArrayKlass(h_k);
+    } else if (k->oop_is_typeArray()) {
+      return new (arena()) ciTypeArrayKlass(h_k);
+    } else if (k->oop_is_method()) {
+      return new (arena()) ciMethodKlass(h_k);
+    } else if (k->oop_is_symbol()) {
+      return new (arena()) ciSymbolKlass(h_k);
+    } else if (k->oop_is_klass()) {
+      if (k->oop_is_objArrayKlass()) {
+        return new (arena()) ciObjArrayKlassKlass(h_k);
+      } else if (k->oop_is_typeArrayKlass()) {
+        return new (arena()) ciTypeArrayKlassKlass(h_k);
+      } else if (k->oop_is_instanceKlass()) {
+        return new (arena()) ciInstanceKlassKlass(h_k);
+      } else {
+        assert(o == Universe::klassKlassObj(), "bad klassKlass");
+        return new (arena()) ciKlassKlass(h_k);
+      }
+    }
+  } else if (o->is_method()) {
+    methodHandle h_m(THREAD, (methodOop)o);
+    return new (arena()) ciMethod(h_m);
+  } else if (o->is_methodData()) {
+    methodDataHandle h_md(THREAD, (methodDataOop)o);
+    return new (arena()) ciMethodData(h_md);
+  } else if (o->is_instance()) {
+    instanceHandle h_i(THREAD, (instanceOop)o);
+    return new (arena()) ciInstance(h_i);
+  } else if (o->is_objArray()) {
+    objArrayHandle h_oa(THREAD, (objArrayOop)o);
+    return new (arena()) ciObjArray(h_oa);
+  } else if (o->is_typeArray()) {
+    typeArrayHandle h_ta(THREAD, (typeArrayOop)o);
+    return new (arena()) ciTypeArray(h_ta);
+  }
+
+  // The oop is of some type not supported by the compiler interface.
+  ShouldNotReachHere();
+  return NULL;
+}
+
+//------------------------------------------------------------------
+// ciObjectFactory::get_unloaded_method
+//
+// Get the ciMethod representing an unloaded/unfound method.
+//
+// Implementation note: unloaded methods are currently stored in
+// an unordered array, requiring a linear-time lookup for each
+// unloaded method.  This may need to change.
+ciMethod* ciObjectFactory::get_unloaded_method(ciInstanceKlass* holder,
+                                               ciSymbol*        name,
+                                               ciSymbol*        signature) {
+  for (int i=0; i<_unloaded_methods->length(); i++) {
+    ciMethod* entry = _unloaded_methods->at(i);
+    if (entry->holder()->equals(holder) &&
+        entry->name()->equals(name) &&
+        entry->signature()->as_symbol()->equals(signature)) {
+      // We've found a match.
+      return entry;
+    }
+  }
+
+  // This is a new unloaded method.  Create it and stick it in
+  // the cache.
+  ciMethod* new_method = new (arena()) ciMethod(holder, name, signature);
+
+  init_ident_of(new_method);
+  _unloaded_methods->append(new_method);
+
+  return new_method;
+}
+
+//------------------------------------------------------------------
+// ciObjectFactory::get_unloaded_klass
+//
+// Get a ciKlass representing an unloaded klass.
+//
+// Implementation note: unloaded klasses are currently stored in
+// an unordered array, requiring a linear-time lookup for each
+// unloaded klass.  This may need to change.
+ciKlass* ciObjectFactory::get_unloaded_klass(ciKlass* accessing_klass,
+                                             ciSymbol* name,
+                                             bool create_if_not_found) {
+  EXCEPTION_CONTEXT;
+  oop loader = NULL;
+  oop domain = NULL;
+  if (accessing_klass != NULL) {
+    loader = accessing_klass->loader();
+    domain = accessing_klass->protection_domain();
+  }
+  for (int i=0; i<_unloaded_klasses->length(); i++) {
+    ciKlass* entry = _unloaded_klasses->at(i);
+    if (entry->name()->equals(name) &&
+        entry->loader() == loader &&
+        entry->protection_domain() == domain) {
+      // We've found a match.
+      return entry;
+    }
+  }
+
+  if (!create_if_not_found)
+    return NULL;
+
+  // This is a new unloaded klass.  Create it and stick it in
+  // the cache.
+  ciKlass* new_klass = NULL;
+
+  // Two cases: this is an unloaded objArrayKlass or an
+  // unloaded instanceKlass.  Deal with both.
+  if (name->byte_at(0) == '[') {
+    // Decompose the name.'
+    jint dimension = 0;
+    symbolOop element_name = NULL;
+    BasicType element_type= FieldType::get_array_info(name->get_symbolOop(),
+                                                      &dimension,
+                                                      &element_name,
+                                                      THREAD);
+    if (HAS_PENDING_EXCEPTION) {
+      CLEAR_PENDING_EXCEPTION;
+      CURRENT_THREAD_ENV->record_out_of_memory_failure();
+      return ciEnv::_unloaded_ciobjarrayklass;
+    }
+    assert(element_type != T_ARRAY, "unsuccessful decomposition");
+    ciKlass* element_klass = NULL;
+    if (element_type == T_OBJECT) {
+      ciEnv *env = CURRENT_THREAD_ENV;
+      ciSymbol* ci_name = env->get_object(element_name)->as_symbol();
+      element_klass =
+        env->get_klass_by_name(accessing_klass, ci_name, false)->as_instance_klass();
+    } else {
+      assert(dimension > 1, "one dimensional type arrays are always loaded.");
+
+      // The type array itself takes care of one of the dimensions.
+      dimension--;
+
+      // The element klass is a typeArrayKlass.
+      element_klass = ciTypeArrayKlass::make(element_type);
+    }
+    new_klass = new (arena()) ciObjArrayKlass(name, element_klass, dimension);
+  } else {
+    jobject loader_handle = NULL;
+    jobject domain_handle = NULL;
+    if (accessing_klass != NULL) {
+      loader_handle = accessing_klass->loader_handle();
+      domain_handle = accessing_klass->protection_domain_handle();
+    }
+    new_klass = new (arena()) ciInstanceKlass(name, loader_handle, domain_handle);
+  }
+  init_ident_of(new_klass);
+  _unloaded_klasses->append(new_klass);
+
+  return new_klass;
+}
+
+//------------------------------------------------------------------
+// ciObjectFactory::get_empty_methodData
+//
+// Get the ciMethodData representing the methodData for a method with
+// none.
+ciMethodData* ciObjectFactory::get_empty_methodData() {
+  ciMethodData* new_methodData = new (arena()) ciMethodData();
+  init_ident_of(new_methodData);
+  return new_methodData;
+}
+
+//------------------------------------------------------------------
+// ciObjectFactory::get_return_address
+//
+// Get a ciReturnAddress for a specified bci.
+ciReturnAddress* ciObjectFactory::get_return_address(int bci) {
+  for (int i=0; i<_return_addresses->length(); i++) {
+    ciReturnAddress* entry = _return_addresses->at(i);
+    if (entry->bci() == bci) {
+      // We've found a match.
+      return entry;
+    }
+  }
+
+  ciReturnAddress* new_ret_addr = new (arena()) ciReturnAddress(bci);
+  init_ident_of(new_ret_addr);
+  _return_addresses->append(new_ret_addr);
+  return new_ret_addr;
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::init_ident_of
+void ciObjectFactory::init_ident_of(ciObject* obj) {
+  obj->set_ident(_next_ident++);
+}
+
+
+// ------------------------------------------------------------------
+// ciObjectFactory::find
+//
+// Use binary search to find the position of this oop in the cache.
+// If there is no entry in the cache corresponding to this oop, return
+// the position at which the oop should be inserted.
+int ciObjectFactory::find(oop key, GrowableArray<ciObject*>* objects) {
+  int min = 0;
+  int max = objects->length()-1;
+
+  // print_contents();
+
+  while (max >= min) {
+    int mid = (max + min) / 2;
+    oop value = objects->at(mid)->get_oop();
+    if (value < key) {
+      min = mid + 1;
+    } else if (value > key) {
+      max = mid - 1;
+    } else {
+      return mid;
+    }
+  }
+  return min;
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::is_found_at
+//
+// Verify that the binary seach found the given key.
+bool ciObjectFactory::is_found_at(int index, oop key, GrowableArray<ciObject*>* objects) {
+  return (index < objects->length() &&
+          objects->at(index)->get_oop() == key);
+}
+
+
+// ------------------------------------------------------------------
+// ciObjectFactory::insert
+//
+// Insert a ciObject into the table at some index.
+void ciObjectFactory::insert(int index, ciObject* obj, GrowableArray<ciObject*>* objects) {
+  int len = objects->length();
+  if (len == index) {
+    objects->append(obj);
+  } else {
+    objects->append(objects->at(len-1));
+    int pos;
+    for (pos = len-2; pos >= index; pos--) {
+      objects->at_put(pos+1,objects->at(pos));
+    }
+    objects->at_put(index, obj);
+  }
+#ifdef ASSERT
+  oop last = NULL;
+  for (int j = 0; j< objects->length(); j++) {
+    oop o = objects->at(j)->get_oop();
+    assert(last < o, "out of order");
+    last = o;
+  }
+#endif // ASSERT
+}
+
+static ciObjectFactory::NonPermObject* emptyBucket = NULL;
+
+// ------------------------------------------------------------------
+// ciObjectFactory::find_non_perm
+//
+// Use a small hash table, hashed on the klass of the key.
+// If there is no entry in the cache corresponding to this oop, return
+// the null tail of the bucket into which the oop should be inserted.
+ciObjectFactory::NonPermObject* &ciObjectFactory::find_non_perm(oop key) {
+  // Be careful:  is_perm might change from false to true.
+  // Thus, there might be a matching perm object in the table.
+  // If there is, this probe must find it.
+  if (key->is_perm() && _non_perm_count == 0) {
+    return emptyBucket;
+  } else if (key->is_instance()) {
+    if (key->klass() == SystemDictionary::class_klass()) {
+      // class mirror instances are always perm
+      return emptyBucket;
+    }
+    // fall through to probe
+  } else if (key->is_array()) {
+    // fall through to probe
+  } else {
+    // not an array or instance
+    return emptyBucket;
+  }
+
+  ciObject* klass = get(key->klass());
+  NonPermObject* *bp = &_non_perm_bucket[(unsigned) klass->hash() % NON_PERM_BUCKETS];
+  for (NonPermObject* p; (p = (*bp)) != NULL; bp = &p->next()) {
+    if (is_equal(p, key))  break;
+  }
+  return (*bp);
+}
+
+
+
+// ------------------------------------------------------------------
+// Code for for NonPermObject
+//
+inline ciObjectFactory::NonPermObject::NonPermObject(ciObjectFactory::NonPermObject* &bucket, oop key, ciObject* object) {
+  assert(ciObjectFactory::is_initialized(), "");
+  _object = object;
+  _next = bucket;
+  bucket = this;
+}
+
+
+
+// ------------------------------------------------------------------
+// ciObjectFactory::insert_non_perm
+//
+// Insert a ciObject into the non-perm table.
+void ciObjectFactory::insert_non_perm(ciObjectFactory::NonPermObject* &where, oop key, ciObject* obj) {
+  assert(&where != &emptyBucket, "must not try to fill empty bucket");
+  NonPermObject* p = new (arena()) NonPermObject(where, key, obj);
+  assert(where == p && is_equal(p, key) && p->object() == obj, "entry must match");
+  assert(find_non_perm(key) == p, "must find the same spot");
+  ++_non_perm_count;
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::vm_symbol_at
+// Get the ciSymbol corresponding to some index in vmSymbols.
+ciSymbol* ciObjectFactory::vm_symbol_at(int index) {
+  assert(index >= vmSymbols::FIRST_SID && index < vmSymbols::SID_LIMIT, "oob");
+  return _shared_ci_symbols[index];
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::print_contents_impl
+void ciObjectFactory::print_contents_impl() {
+  int len = _ci_objects->length();
+  tty->print_cr("ciObjectFactory (%d) oop contents:", len);
+  for (int i=0; i<len; i++) {
+    _ci_objects->at(i)->print();
+    tty->cr();
+  }
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::print_contents
+void ciObjectFactory::print_contents() {
+  print();
+  tty->cr();
+  GUARDED_VM_ENTRY(print_contents_impl();)
+}
+
+// ------------------------------------------------------------------
+// ciObjectFactory::print
+//
+// Print debugging information about the object factory
+void ciObjectFactory::print() {
+  tty->print("<ciObjectFactory oops=%d unloaded_methods=%d unloaded_klasses=%d>",
+             _ci_objects->length(), _unloaded_methods->length(),
+             _unloaded_klasses->length());
+}