view src/share/vm/oops/typeArrayKlass.cpp @ 3917:eca1193ca245

4965777: GC changes to support use of discovered field for pending references Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose. Reviewed-by: jcoomes, mchung, stefank
author ysr
date Wed, 07 Sep 2011 13:55:42 -0700
parents c9ca3f51cf41
children a92cdbac8b9e
line wrap: on
line source

/*
 * Copyright (c) 1997, 2011, 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/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "gc_interface/collectedHeap.hpp"
#include "gc_interface/collectedHeap.inline.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "memory/universe.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klassOop.hpp"
#include "oops/objArrayKlassKlass.hpp"
#include "oops/oop.inline.hpp"
#include "oops/typeArrayKlass.hpp"
#include "oops/typeArrayOop.hpp"
#include "runtime/handles.inline.hpp"

bool typeArrayKlass::compute_is_subtype_of(klassOop k) {
  if (!k->klass_part()->oop_is_typeArray()) {
    return arrayKlass::compute_is_subtype_of(k);
  }

  typeArrayKlass* tak = typeArrayKlass::cast(k);
  if (dimension() != tak->dimension()) return false;

  return element_type() == tak->element_type();
}

klassOop typeArrayKlass::create_klass(BasicType type, int scale,
                                      const char* name_str, TRAPS) {
  typeArrayKlass o;

  Symbol* sym = NULL;
  if (name_str != NULL) {
    sym = SymbolTable::new_symbol(name_str, CHECK_NULL);
  }
  KlassHandle klassklass (THREAD, Universe::typeArrayKlassKlassObj());

  arrayKlassHandle k = base_create_array_klass(o.vtbl_value(), header_size(), klassklass, CHECK_NULL);
  typeArrayKlass* ak = typeArrayKlass::cast(k());
  ak->set_name(sym);
  ak->set_layout_helper(array_layout_helper(type));
  assert(scale == (1 << ak->log2_element_size()), "scale must check out");
  assert(ak->oop_is_javaArray(), "sanity");
  assert(ak->oop_is_typeArray(), "sanity");
  ak->set_max_length(arrayOopDesc::max_array_length(type));
  assert(k()->size() > header_size(), "bad size");

  // Call complete_create_array_klass after all instance variables have been initialized.
  KlassHandle super (THREAD, k->super());
  complete_create_array_klass(k, super, CHECK_NULL);

  return k();
}

typeArrayOop typeArrayKlass::allocate(int length, TRAPS) {
  assert(log2_element_size() >= 0, "bad scale");
  if (length >= 0) {
    if (length <= max_length()) {
      size_t size = typeArrayOopDesc::object_size(layout_helper(), length);
      KlassHandle h_k(THREAD, as_klassOop());
      typeArrayOop t;
      CollectedHeap* ch = Universe::heap();
      t = (typeArrayOop)CollectedHeap::array_allocate(h_k, (int)size, length, CHECK_NULL);
      assert(t->is_parsable(), "Don't publish unless parsable");
      return t;
    } else {
      report_java_out_of_memory("Requested array size exceeds VM limit");
      THROW_OOP_0(Universe::out_of_memory_error_array_size());
    }
  } else {
    THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
  }
}

typeArrayOop typeArrayKlass::allocate_permanent(int length, TRAPS) {
  if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
  int size = typeArrayOopDesc::object_size(layout_helper(), length);
  KlassHandle h_k(THREAD, as_klassOop());
  typeArrayOop t = (typeArrayOop)
    CollectedHeap::permanent_array_allocate(h_k, size, length, CHECK_NULL);
  assert(t->is_parsable(), "Can't publish until parsable");
  return t;
}

oop typeArrayKlass::multi_allocate(int rank, jint* last_size, TRAPS) {
  // For typeArrays this is only called for the last dimension
  assert(rank == 1, "just checking");
  int length = *last_size;
  return allocate(length, THREAD);
}


void typeArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
  assert(s->is_typeArray(), "must be type array");

  // Check destination
  if (!d->is_typeArray() || element_type() != typeArrayKlass::cast(d->klass())->element_type()) {
    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());
  }
  // Check zero copy
  if (length == 0)
    return;

  // This is an attempt to make the copy_array fast.
  int l2es = log2_element_size();
  int ihs = array_header_in_bytes() / wordSize;
  char* src = (char*) ((oop*)s + ihs) + ((size_t)src_pos << l2es);
  char* dst = (char*) ((oop*)d + ihs) + ((size_t)dst_pos << l2es);
  Copy::conjoint_memory_atomic(src, dst, (size_t)length << l2es);
}


// create a klass of array holding typeArrays
klassOop typeArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  typeArrayKlassHandle h_this(THREAD, as_klassOop());
  return array_klass_impl(h_this, or_null, n, THREAD);
}

klassOop typeArrayKlass::array_klass_impl(typeArrayKlassHandle h_this, bool or_null, int n, TRAPS) {
  int dimension = h_this->dimension();
  assert(dimension <= n, "check order of chain");
    if (dimension == n)
      return h_this();

  objArrayKlassHandle  h_ak(THREAD, h_this->higher_dimension());
  if (h_ak.is_null()) {
    if (or_null)  return NULL;

    ResourceMark rm;
    JavaThread *jt = (JavaThread *)THREAD;
    {
      MutexLocker mc(Compile_lock, THREAD);   // for vtables
      // Atomic create higher dimension and link into list
      MutexLocker mu(MultiArray_lock, THREAD);

      h_ak = objArrayKlassHandle(THREAD, h_this->higher_dimension());
      if (h_ak.is_null()) {
        klassOop oak = objArrayKlassKlass::cast(
          Universe::objArrayKlassKlassObj())->allocate_objArray_klass(
          dimension + 1, h_this, CHECK_NULL);
        h_ak = objArrayKlassHandle(THREAD, oak);
        h_ak->set_lower_dimension(h_this());
        OrderAccess::storestore();
        h_this->set_higher_dimension(h_ak());
        assert(h_ak->oop_is_objArray(), "incorrect initialization of objArrayKlass");
      }
    }
  } else {
    CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  }
  if (or_null) {
    return h_ak->array_klass_or_null(n);
  }
  return h_ak->array_klass(n, CHECK_NULL);
}

klassOop typeArrayKlass::array_klass_impl(bool or_null, TRAPS) {
  return array_klass_impl(or_null, dimension() +  1, THREAD);
}

int typeArrayKlass::oop_size(oop obj) const {
  assert(obj->is_typeArray(),"must be a type array");
  typeArrayOop t = typeArrayOop(obj);
  return t->object_size();
}

void typeArrayKlass::oop_follow_contents(oop obj) {
  assert(obj->is_typeArray(),"must be a type array");
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::typeArrayKlass never moves.
}

#ifndef SERIALGC
void typeArrayKlass::oop_follow_contents(ParCompactionManager* cm, oop obj) {
  assert(obj->is_typeArray(),"must be a type array");
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::typeArrayKlass never moves.
}
#endif // SERIALGC

int typeArrayKlass::oop_adjust_pointers(oop obj) {
  assert(obj->is_typeArray(),"must be a type array");
  typeArrayOop t = typeArrayOop(obj);
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::typeArrayKlass never moves.
  return t->object_size();
}

int typeArrayKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
  assert(obj->is_typeArray(),"must be a type array");
  typeArrayOop t = typeArrayOop(obj);
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::typeArrayKlass never moves.
  return t->object_size();
}

int typeArrayKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
  assert(obj->is_typeArray(),"must be a type array");
  typeArrayOop t = typeArrayOop(obj);
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::typeArrayKlass never moves.
  return t->object_size();
}

#ifndef SERIALGC
void typeArrayKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  assert(obj->is_typeArray(),"must be a type array");
}

int
typeArrayKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  assert(obj->is_typeArray(),"must be a type array");
  return typeArrayOop(obj)->object_size();
}
#endif // SERIALGC

void typeArrayKlass::initialize(TRAPS) {
  // Nothing to do. Having this function is handy since objArrayKlasses can be
  // initialized by calling initialize on their bottom_klass, see objArrayKlass::initialize
}

const char* typeArrayKlass::external_name(BasicType type) {
  switch (type) {
    case T_BOOLEAN: return "[Z";
    case T_CHAR:    return "[C";
    case T_FLOAT:   return "[F";
    case T_DOUBLE:  return "[D";
    case T_BYTE:    return "[B";
    case T_SHORT:   return "[S";
    case T_INT:     return "[I";
    case T_LONG:    return "[J";
    default: ShouldNotReachHere();
  }
  return NULL;
}

#ifndef PRODUCT
// Printing

static void print_boolean_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    st->print_cr(" - %3d: %s", index, (ta->bool_at(index) == 0) ? "false" : "true");
  }
}


static void print_char_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    jchar c = ta->char_at(index);
    st->print_cr(" - %3d: %x %c", index, c, isprint(c) ? c : ' ');
  }
}


static void print_float_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    st->print_cr(" - %3d: %g", index, ta->float_at(index));
  }
}


static void print_double_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    st->print_cr(" - %3d: %g", index, ta->double_at(index));
  }
}


static void print_byte_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    jbyte c = ta->byte_at(index);
    st->print_cr(" - %3d: %x %c", index, c, isprint(c) ? c : ' ');
  }
}


static void print_short_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    int v = ta->ushort_at(index);
    st->print_cr(" - %3d: 0x%x\t %d", index, v, v);
  }
}


static void print_int_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    jint v = ta->int_at(index);
    st->print_cr(" - %3d: 0x%x %d", index, v, v);
  }
}


static void print_long_array(typeArrayOop ta, int print_len, outputStream* st) {
  for (int index = 0; index < print_len; index++) {
    jlong v = ta->long_at(index);
    st->print_cr(" - %3d: 0x%x 0x%x", index, high(v), low(v));
  }
}


void typeArrayKlass::oop_print_on(oop obj, outputStream* st) {
  arrayKlass::oop_print_on(obj, st);
  typeArrayOop ta = typeArrayOop(obj);
  int print_len = MIN2((intx) ta->length(), MaxElementPrintSize);
  switch (element_type()) {
    case T_BOOLEAN: print_boolean_array(ta, print_len, st); break;
    case T_CHAR:    print_char_array(ta, print_len, st);    break;
    case T_FLOAT:   print_float_array(ta, print_len, st);   break;
    case T_DOUBLE:  print_double_array(ta, print_len, st);  break;
    case T_BYTE:    print_byte_array(ta, print_len, st);    break;
    case T_SHORT:   print_short_array(ta, print_len, st);   break;
    case T_INT:     print_int_array(ta, print_len, st);     break;
    case T_LONG:    print_long_array(ta, print_len, st);    break;
    default: ShouldNotReachHere();
  }
  int remaining = ta->length() - print_len;
  if (remaining > 0) {
    tty->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
  }
}

#endif // PRODUCT

const char* typeArrayKlass::internal_name() const {
  return Klass::external_name();
}