duke@435: /*
stefank@2314:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_OOPS_OBJARRAYOOP_HPP
stefank@2314: #define SHARE_VM_OOPS_OBJARRAYOOP_HPP
stefank@2314: 
stefank@2314: #include "oops/arrayOop.hpp"
stefank@2314: 
duke@435: // An objArrayOop is an array containing oops.
duke@435: // Evaluating "String arg[10]" will create an objArrayOop.
duke@435: 
duke@435: class objArrayOopDesc : public arrayOopDesc {
coleenp@548:   friend class objArrayKlass;
coleenp@548:   friend class Runtime1;
coleenp@548:   friend class psPromotionManager;
ysr@777:   friend class CSMarkOopClosure;
ysr@777:   friend class G1ParScanPartialArrayClosure;
coleenp@548: 
coleenp@548:   template <class T> T* obj_at_addr(int index) const {
coleenp@548:     assert(is_within_bounds(index), "index out of bounds");
coleenp@548:     return &((T*)base())[index];
coleenp@548:   }
coleenp@548: 
ysr@1526: private:
ysr@1526:   // Give size of objArrayOop in HeapWords minus the header
ysr@1526:   static int array_size(int length) {
ysr@1526:     const int OopsPerHeapWord = HeapWordSize/heapOopSize;
ysr@1526:     assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0),
ysr@1526:            "Else the following (new) computation would be in error");
ysr@1526: #ifdef ASSERT
ysr@1526:     // The old code is left in for sanity-checking; it'll
ysr@1526:     // go away pretty soon. XXX
ysr@1526:     // Without UseCompressedOops, this is simply:
ysr@1526:     // oop->length() * HeapWordsPerOop;
ysr@1526:     // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.
ysr@1526:     // The oop elements are aligned up to wordSize
ysr@1526:     const int HeapWordsPerOop = heapOopSize/HeapWordSize;
ysr@1526:     int old_res;
ysr@1526:     if (HeapWordsPerOop > 0) {
ysr@1526:       old_res = length * HeapWordsPerOop;
ysr@1526:     } else {
ysr@1526:       old_res = align_size_up(length, OopsPerHeapWord)/OopsPerHeapWord;
ysr@1526:     }
ysr@1526: #endif  // ASSERT
ysr@1530:     int res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord;
ysr@1526:     assert(res == old_res, "Inconsistency between old and new.");
ysr@1526:     return res;
ysr@1526:   }
ysr@1526: 
duke@435:  public:
twisti@1330:   // Returns the offset of the first element.
twisti@1330:   static int base_offset_in_bytes() {
twisti@1330:     return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
twisti@1330:   }
twisti@1330: 
coleenp@548:   // base is the address following the header.
coleenp@548:   HeapWord* base() const      { return (HeapWord*) arrayOopDesc::base(T_OBJECT); }
coleenp@548: 
duke@435:   // Accessing
coleenp@548:   oop obj_at(int index) const {
coleenp@548:     // With UseCompressedOops decode the narrow oop in the objArray to an
coleenp@548:     // uncompressed oop.  Otherwise this is simply a "*" operator.
coleenp@548:     if (UseCompressedOops) {
coleenp@548:       return load_decode_heap_oop(obj_at_addr<narrowOop>(index));
coleenp@548:     } else {
coleenp@548:       return load_decode_heap_oop(obj_at_addr<oop>(index));
coleenp@548:     }
coleenp@548:   }
duke@435: 
coleenp@548:   void obj_at_put(int index, oop value) {
coleenp@548:     if (UseCompressedOops) {
coleenp@548:       oop_store(obj_at_addr<narrowOop>(index), value);
coleenp@548:     } else {
coleenp@548:       oop_store(obj_at_addr<oop>(index), value);
coleenp@548:     }
coleenp@548:   }
duke@435:   // Sizing
coleenp@548:   static int header_size()    { return arrayOopDesc::header_size(T_OBJECT); }
coleenp@548:   int object_size()           { return object_size(length()); }
duke@435: 
coleenp@548:   static int object_size(int length) {
coleenp@548:     // This returns the object size in HeapWords.
ysr@1530:     uint asz = array_size(length);
ysr@1530:     uint osz = align_object_size(header_size() + asz);
ysr@1530:     assert(osz >= asz,   "no overflow");
ysr@1530:     assert((int)osz > 0, "no overflow");
ysr@1530:     return (int)osz;
duke@435:   }
coleenp@548: 
coleenp@548:   // special iterators for index ranges, returns size of object
coleenp@548: #define ObjArrayOop_OOP_ITERATE_DECL(OopClosureType, nv_suffix)     \
coleenp@548:   int oop_iterate_range(OopClosureType* blk, int start, int end);
coleenp@548: 
coleenp@548:   ALL_OOP_OOP_ITERATE_CLOSURES_1(ObjArrayOop_OOP_ITERATE_DECL)
ysr@777:   ALL_OOP_OOP_ITERATE_CLOSURES_2(ObjArrayOop_OOP_ITERATE_DECL)
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_OOPS_OBJARRAYOOP_HPP