--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/objArrayKlass.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,503 @@
+/*
+ * Copyright (c) 1997, 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/moduleEntry.hpp"
+#include "classfile/packageEntry.hpp"
+#include "classfile/symbolTable.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "gc/shared/collectedHeap.inline.hpp"
+#include "gc/shared/specialized_oop_closures.hpp"
+#include "memory/iterator.inline.hpp"
+#include "memory/metadataFactory.hpp"
+#include "memory/metaspaceClosure.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.inline.hpp"
+#include "oops/arrayKlass.inline.hpp"
+#include "oops/instanceKlass.hpp"
+#include "oops/klass.inline.hpp"
+#include "oops/objArrayKlass.inline.hpp"
+#include "oops/objArrayOop.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "oops/symbol.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "utilities/copy.hpp"
+#include "utilities/macros.hpp"
+
+ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) {
+  assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
+      "array klasses must be same size as InstanceKlass");
+
+  int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
+
+  return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name);
+}
+
+Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
+                                                int n, Klass* element_klass, TRAPS) {
+
+  // Eagerly allocate the direct array supertype.
+  Klass* super_klass = NULL;
+  if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) {
+    Klass* element_super = element_klass->super();
+    if (element_super != NULL) {
+      // The element type has a direct super.  E.g., String[] has direct super of Object[].
+      super_klass = element_super->array_klass_or_null();
+      bool supers_exist = super_klass != NULL;
+      // Also, see if the element has secondary supertypes.
+      // We need an array type for each.
+      Array<Klass*>* element_supers = element_klass->secondary_supers();
+      for( int i = element_supers->length()-1; i >= 0; i-- ) {
+        Klass* elem_super = element_supers->at(i);
+        if (elem_super->array_klass_or_null() == NULL) {
+          supers_exist = false;
+          break;
+        }
+      }
+      if (!supers_exist) {
+        // Oops.  Not allocated yet.  Back out, allocate it, and retry.
+        Klass* ek = NULL;
+        {
+          MutexUnlocker mu(MultiArray_lock);
+          MutexUnlocker mc(Compile_lock);   // for vtables
+          super_klass = element_super->array_klass(CHECK_0);
+          for( int i = element_supers->length()-1; i >= 0; i-- ) {
+            Klass* elem_super = element_supers->at(i);
+            elem_super->array_klass(CHECK_0);
+          }
+          // Now retry from the beginning
+          ek = element_klass->array_klass(n, CHECK_0);
+        }  // re-lock
+        return ek;
+      }
+    } else {
+      // The element type is already Object.  Object[] has direct super of Object.
+      super_klass = SystemDictionary::Object_klass();
+    }
+  }
+
+  // Create type name for klass.
+  Symbol* name = NULL;
+  if (!element_klass->is_instance_klass() ||
+      (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) {
+
+    ResourceMark rm(THREAD);
+    char *name_str = element_klass->name()->as_C_string();
+    int len = element_klass->name()->utf8_length();
+    char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
+    int idx = 0;
+    new_str[idx++] = '[';
+    if (element_klass->is_instance_klass()) { // it could be an array or simple type
+      new_str[idx++] = 'L';
+    }
+    memcpy(&new_str[idx], name_str, len * sizeof(char));
+    idx += len;
+    if (element_klass->is_instance_klass()) {
+      new_str[idx++] = ';';
+    }
+    new_str[idx++] = '\0';
+    name = SymbolTable::new_permanent_symbol(new_str, CHECK_0);
+    if (element_klass->is_instance_klass()) {
+      InstanceKlass* ik = InstanceKlass::cast(element_klass);
+      ik->set_array_name(name);
+    }
+  }
+
+  // Initialize instance variables
+  ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0);
+
+  // Add all classes to our internal class loader list here,
+  // including classes in the bootstrap (NULL) class loader.
+  // GC walks these as strong roots.
+  loader_data->add_class(oak);
+
+  ModuleEntry* module = oak->module();
+  assert(module != NULL, "No module entry for array");
+
+  // Call complete_create_array_klass after all instance variables has been initialized.
+  ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0);
+
+  return oak;
+}
+
+ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name) {
+  this->set_dimension(n);
+  this->set_element_klass(element_klass);
+  // decrement refcount because object arrays are not explicitly freed.  The
+  // InstanceKlass array_name() keeps the name counted while the klass is
+  // loaded.
+  name->decrement_refcount();
+
+  Klass* bk;
+  if (element_klass->is_objArray_klass()) {
+    bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
+  } else {
+    bk = element_klass;
+  }
+  assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
+  this->set_bottom_klass(bk);
+  this->set_class_loader_data(bk->class_loader_data());
+
+  this->set_layout_helper(array_layout_helper(T_OBJECT));
+  assert(this->is_array_klass(), "sanity");
+  assert(this->is_objArray_klass(), "sanity");
+}
+
+int ObjArrayKlass::oop_size(oop obj) const {
+  assert(obj->is_objArray(), "must be object array");
+  return objArrayOop(obj)->object_size();
+}
+
+objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
+  if (length >= 0) {
+    if (length <= arrayOopDesc::max_array_length(T_OBJECT)) {
+      int size = objArrayOopDesc::object_size(length);
+      return (objArrayOop)CollectedHeap::array_allocate(this, size, length, THREAD);
+    } else {
+      report_java_out_of_memory("Requested array size exceeds VM limit");
+      JvmtiExport::post_array_size_exhausted();
+      THROW_OOP_0(Universe::out_of_memory_error_array_size());
+    }
+  } else {
+    THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
+  }
+}
+
+static int multi_alloc_counter = 0;
+
+oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
+  int length = *sizes;
+  // Call to lower_dimension uses this pointer, so most be called before a
+  // possible GC
+  Klass* ld_klass = lower_dimension();
+  // If length < 0 allocate will throw an exception.
+  objArrayOop array = allocate(length, CHECK_NULL);
+  objArrayHandle h_array (THREAD, array);
+  if (rank > 1) {
+    if (length != 0) {
+      for (int index = 0; index < length; index++) {
+        ArrayKlass* ak = ArrayKlass::cast(ld_klass);
+        oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
+        h_array->obj_at_put(index, sub_array);
+      }
+    } else {
+      // Since this array dimension has zero length, nothing will be
+      // allocated, however the lower dimension values must be checked
+      // for illegal values.
+      for (int i = 0; i < rank - 1; ++i) {
+        sizes += 1;
+        if (*sizes < 0) {
+          THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
+        }
+      }
+    }
+  }
+  return h_array();
+}
+
+// Either oop or narrowOop depending on UseCompressedOops.
+template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src,
+                               arrayOop d, T* dst, int length, TRAPS) {
+
+  BarrierSet* bs = Universe::heap()->barrier_set();
+  // For performance reasons, we assume we are that the write barrier we
+  // are using has optimized modes for arrays of references.  At least one
+  // of the asserts below will fail if this is not the case.
+  assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt");
+  assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well.");
+
+  if (s == d) {
+    // since source and destination are equal we do not need conversion checks.
+    assert(length > 0, "sanity check");
+    bs->write_ref_array_pre(dst, length);
+    Copy::conjoint_oops_atomic(src, dst, length);
+  } else {
+    // We have to make sure all elements conform to the destination array
+    Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
+    Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
+    if (stype == bound || stype->is_subtype_of(bound)) {
+      // elements are guaranteed to be subtypes, so no check necessary
+      bs->write_ref_array_pre(dst, length);
+      Copy::conjoint_oops_atomic(src, dst, length);
+    } else {
+      // slow case: need individual subtype checks
+      // note: don't use obj_at_put below because it includes a redundant store check
+      T* from = src;
+      T* end = from + length;
+      for (T* p = dst; from < end; from++, p++) {
+        // XXX this is going to be slow.
+        T element = *from;
+        // even slower now
+        bool element_is_null = oopDesc::is_null(element);
+        oop new_val = element_is_null ? oop(NULL)
+                                      : oopDesc::decode_heap_oop_not_null(element);
+        if (element_is_null ||
+            (new_val->klass())->is_subtype_of(bound)) {
+          bs->write_ref_field_pre(p, new_val);
+          *p = element;
+        } else {
+          // We must do a barrier to cover the partial copy.
+          const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize);
+          // pointer delta is scaled to number of elements (length field in
+          // objArrayOop) which we assume is 32 bit.
+          assert(pd == (size_t)(int)pd, "length field overflow");
+          bs->write_ref_array((HeapWord*)dst, pd);
+          THROW(vmSymbols::java_lang_ArrayStoreException());
+          return;
+        }
+      }
+    }
+  }
+  bs->write_ref_array((HeapWord*)dst, length);
+}
+
+void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
+                               int dst_pos, int length, TRAPS) {
+  assert(s->is_objArray(), "must be obj array");
+
+  if (!d->is_objArray()) {
+    THROW(vmSymbols::java_lang_ArrayStoreException());
+  }
+
+  // Check is all offsets and lengths are non negative
+  if (src_pos < 0 || dst_pos < 0 || length < 0) {
+    THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
+  }
+  // Check if the ranges are valid
+  if  ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length())
+     || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) {
+    THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
+  }
+
+  // Special case. Boundary cases must be checked first
+  // This allows the following call: copy_array(s, s.length(), d.length(), 0).
+  // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
+  // points to the right of the last element.
+  if (length==0) {
+    return;
+  }
+  if (UseCompressedOops) {
+    narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos);
+    narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos);
+    do_copy<narrowOop>(s, src, d, dst, length, CHECK);
+  } else {
+    oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos);
+    oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos);
+    do_copy<oop> (s, src, d, dst, length, CHECK);
+  }
+}
+
+
+Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
+
+  assert(dimension() <= n, "check order of chain");
+  int dim = dimension();
+  if (dim == n) return this;
+
+  // lock-free read needs acquire semantics
+  if (higher_dimension_acquire() == NULL) {
+    if (or_null)  return NULL;
+
+    ResourceMark rm;
+    JavaThread *jt = (JavaThread *)THREAD;
+    {
+      MutexLocker mc(Compile_lock, THREAD);   // for vtables
+      // Ensure atomic creation of higher dimensions
+      MutexLocker mu(MultiArray_lock, THREAD);
+
+      // Check if another thread beat us
+      if (higher_dimension() == NULL) {
+
+        // Create multi-dim klass object and link them together
+        Klass* k =
+          ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
+        ObjArrayKlass* ak = ObjArrayKlass::cast(k);
+        ak->set_lower_dimension(this);
+        // use 'release' to pair with lock-free load
+        release_set_higher_dimension(ak);
+        assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
+      }
+    }
+  } else {
+    CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
+  }
+
+  ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
+  if (or_null) {
+    return ak->array_klass_or_null(n);
+  }
+  return ak->array_klass(n, THREAD);
+}
+
+Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
+  return array_klass_impl(or_null, dimension() +  1, THREAD);
+}
+
+bool ObjArrayKlass::can_be_primary_super_slow() const {
+  if (!bottom_klass()->can_be_primary_super())
+    // array of interfaces
+    return false;
+  else
+    return Klass::can_be_primary_super_slow();
+}
+
+GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) {
+  // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
+  Array<Klass*>* elem_supers = element_klass()->secondary_supers();
+  int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
+  int num_secondaries = num_extra_slots + 2 + num_elem_supers;
+  if (num_secondaries == 2) {
+    // Must share this for correct bootstrapping!
+    set_secondary_supers(Universe::the_array_interfaces_array());
+    return NULL;
+  } else {
+    GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
+    secondaries->push(SystemDictionary::Cloneable_klass());
+    secondaries->push(SystemDictionary::Serializable_klass());
+    for (int i = 0; i < num_elem_supers; i++) {
+      Klass* elem_super = (Klass*) elem_supers->at(i);
+      Klass* array_super = elem_super->array_klass_or_null();
+      assert(array_super != NULL, "must already have been created");
+      secondaries->push(array_super);
+    }
+    return secondaries;
+  }
+}
+
+bool ObjArrayKlass::compute_is_subtype_of(Klass* k) {
+  if (!k->is_objArray_klass())
+    return ArrayKlass::compute_is_subtype_of(k);
+
+  ObjArrayKlass* oak = ObjArrayKlass::cast(k);
+  return element_klass()->is_subtype_of(oak->element_klass());
+}
+
+void ObjArrayKlass::initialize(TRAPS) {
+  bottom_klass()->initialize(THREAD);  // dispatches to either InstanceKlass or TypeArrayKlass
+}
+
+void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
+  ArrayKlass::metaspace_pointers_do(it);
+  it->push(&_element_klass);
+  it->push(&_bottom_klass);
+}
+
+// JVM support
+
+jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
+  // The modifier for an objectArray is the same as its element
+  if (element_klass() == NULL) {
+    assert(Universe::is_bootstrapping(), "partial objArray only at startup");
+    return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
+  }
+  // Return the flags of the bottom element type.
+  jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
+
+  return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
+                        | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
+}
+
+ModuleEntry* ObjArrayKlass::module() const {
+  assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
+  // The array is defined in the module of its bottom class
+  return bottom_klass()->module();
+}
+
+PackageEntry* ObjArrayKlass::package() const {
+  assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
+  return bottom_klass()->package();
+}
+
+// Printing
+
+void ObjArrayKlass::print_on(outputStream* st) const {
+#ifndef PRODUCT
+  Klass::print_on(st);
+  st->print(" - instance klass: ");
+  element_klass()->print_value_on(st);
+  st->cr();
+#endif //PRODUCT
+}
+
+void ObjArrayKlass::print_value_on(outputStream* st) const {
+  assert(is_klass(), "must be klass");
+
+  element_klass()->print_value_on(st);
+  st->print("[]");
+}
+
+#ifndef PRODUCT
+
+void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
+  ArrayKlass::oop_print_on(obj, st);
+  assert(obj->is_objArray(), "must be objArray");
+  objArrayOop oa = objArrayOop(obj);
+  int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
+  for(int index = 0; index < print_len; index++) {
+    st->print(" - %3d : ", index);
+    oa->obj_at(index)->print_value_on(st);
+    st->cr();
+  }
+  int remaining = oa->length() - print_len;
+  if (remaining > 0) {
+    st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
+  }
+}
+
+#endif //PRODUCT
+
+void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
+  assert(obj->is_objArray(), "must be objArray");
+  st->print("a ");
+  element_klass()->print_value_on(st);
+  int len = objArrayOop(obj)->length();
+  st->print("[%d] ", len);
+  obj->print_address_on(st);
+}
+
+const char* ObjArrayKlass::internal_name() const {
+  return external_name();
+}
+
+
+// Verification
+
+void ObjArrayKlass::verify_on(outputStream* st) {
+  ArrayKlass::verify_on(st);
+  guarantee(element_klass()->is_klass(), "should be klass");
+  guarantee(bottom_klass()->is_klass(), "should be klass");
+  Klass* bk = bottom_klass();
+  guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(),  "invalid bottom klass");
+}
+
+void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
+  ArrayKlass::oop_verify_on(obj, st);
+  guarantee(obj->is_objArray(), "must be objArray");
+  objArrayOop oa = objArrayOop(obj);
+  for(int index = 0; index < oa->length(); index++) {
+    guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
+  }
+}