aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #ifndef SHARE_VM_OOPS_OBJARRAYOOP_HPP
aoqi@0: #define SHARE_VM_OOPS_OBJARRAYOOP_HPP
aoqi@0: 
aoqi@0: #include "oops/arrayOop.hpp"
aoqi@0: 
aoqi@0: // An objArrayOop is an array containing oops.
aoqi@0: // Evaluating "String arg[10]" will create an objArrayOop.
aoqi@0: 
aoqi@0: class objArrayOopDesc : public arrayOopDesc {
aoqi@0:   friend class ObjArrayKlass;
aoqi@0:   friend class Runtime1;
aoqi@0:   friend class psPromotionManager;
aoqi@0:   friend class CSetMarkOopClosure;
aoqi@0:   friend class G1ParScanPartialArrayClosure;
aoqi@0: 
aoqi@0:   template <class T> T* obj_at_addr(int index) const {
aoqi@0:     assert(is_within_bounds(index), "index out of bounds");
aoqi@0:     return &((T*)base())[index];
aoqi@0:   }
aoqi@0: 
aoqi@0: private:
aoqi@0:   // Give size of objArrayOop in HeapWords minus the header
aoqi@0:   static int array_size(int length) {
aoqi@0:     const int OopsPerHeapWord = HeapWordSize/heapOopSize;
aoqi@0:     assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0),
aoqi@0:            "Else the following (new) computation would be in error");
aoqi@0: #ifdef ASSERT
aoqi@0:     // The old code is left in for sanity-checking; it'll
aoqi@0:     // go away pretty soon. XXX
aoqi@0:     // Without UseCompressedOops, this is simply:
aoqi@0:     // oop->length() * HeapWordsPerOop;
aoqi@0:     // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.
aoqi@0:     // The oop elements are aligned up to wordSize
aoqi@0:     const int HeapWordsPerOop = heapOopSize/HeapWordSize;
aoqi@0:     int old_res;
aoqi@0:     if (HeapWordsPerOop > 0) {
aoqi@0:       old_res = length * HeapWordsPerOop;
aoqi@0:     } else {
aoqi@0:       old_res = align_size_up(length, OopsPerHeapWord)/OopsPerHeapWord;
aoqi@0:     }
aoqi@0: #endif  // ASSERT
aoqi@0:     int res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord;
aoqi@0:     assert(res == old_res, "Inconsistency between old and new.");
aoqi@0:     return res;
aoqi@0:   }
aoqi@0: 
aoqi@0:  public:
aoqi@0:   // Returns the offset of the first element.
aoqi@0:   static int base_offset_in_bytes() {
aoqi@0:     return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // base is the address following the header.
aoqi@0:   HeapWord* base() const      { return (HeapWord*) arrayOopDesc::base(T_OBJECT); }
aoqi@0: 
aoqi@0:   // Accessing
aoqi@0:   oop obj_at(int index) const {
aoqi@0:     // With UseCompressedOops decode the narrow oop in the objArray to an
aoqi@0:     // uncompressed oop.  Otherwise this is simply a "*" operator.
aoqi@0:     if (UseCompressedOops) {
aoqi@0:       return load_decode_heap_oop(obj_at_addr<narrowOop>(index));
aoqi@0:     } else {
aoqi@0:       return load_decode_heap_oop(obj_at_addr<oop>(index));
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   void obj_at_put(int index, oop value) {
aoqi@0:     if (UseCompressedOops) {
aoqi@0:       oop_store(obj_at_addr<narrowOop>(index), value);
aoqi@0:     } else {
aoqi@0:       oop_store(obj_at_addr<oop>(index), value);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // Sizing
aoqi@0:   static int header_size()    { return arrayOopDesc::header_size(T_OBJECT); }
aoqi@0:   int object_size()           { return object_size(length()); }
aoqi@0: 
aoqi@0:   static int object_size(int length) {
aoqi@0:     // This returns the object size in HeapWords.
aoqi@0:     uint asz = array_size(length);
aoqi@0:     uint osz = align_object_size(header_size() + asz);
aoqi@0:     assert(osz >= asz,   "no overflow");
aoqi@0:     assert((int)osz > 0, "no overflow");
aoqi@0:     return (int)osz;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // special iterators for index ranges, returns size of object
aoqi@0: #define ObjArrayOop_OOP_ITERATE_DECL(OopClosureType, nv_suffix)     \
aoqi@0:   int oop_iterate_range(OopClosureType* blk, int start, int end);
aoqi@0: 
aoqi@0:   ALL_OOP_OOP_ITERATE_CLOSURES_1(ObjArrayOop_OOP_ITERATE_DECL)
aoqi@0:   ALL_OOP_OOP_ITERATE_CLOSURES_2(ObjArrayOop_OOP_ITERATE_DECL)
aoqi@0: };
aoqi@0: 
aoqi@0: #endif // SHARE_VM_OOPS_OBJARRAYOOP_HPP