1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2016 SAP SE. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "asm/codeBuffer.hpp" 28 #include "asm/macroAssembler.inline.hpp" 29 #include "memory/metaspaceShared.hpp" 30 31 // Generate the self-patching vtable method: 32 // 33 // This method will be called (as any other Klass virtual method) with 34 // the Klass itself as the first argument. Example: 35 // 36 // oop obj; 37 // int size = obj->klass()->klass_part()->oop_size(this); 38 // 39 // for which the virtual method call is Klass::oop_size();. 40 // 41 // The dummy method is called with the Klass object as the first 42 // operand, and an object as the second argument. 43 // 44 45 //===================================================================== 46 47 // All of the dummy methods in the vtable are essentially identical, 48 // differing only by an ordinal constant, and they bear no releationship 49 // to the original method which the caller intended. Also, there needs 50 // to be 'vtbl_list_size' instances of the vtable in order to 51 // differentiate between the 'vtable_list_size' original Klass objects. 52 53 #undef __ 54 #define __ masm-> 55 56 void MetaspaceShared::generate_vtable_methods(void** vtbl_list, 57 void** vtable, 58 char** md_top, 59 char* md_end, 60 char** mc_top, 61 char* mc_end) { 62 63 intptr_t vtable_bytes = (num_virtuals * vtbl_list_size) * sizeof(void*); 64 *(intptr_t *)(*md_top) = vtable_bytes; 65 *md_top += sizeof(intptr_t); 66 void** dummy_vtable = (void**)*md_top; 67 *vtable = dummy_vtable; 68 *md_top += vtable_bytes; 69 70 // Get ready to generate dummy methods. 71 72 CodeBuffer cb((unsigned char*)*mc_top, mc_end - *mc_top); 73 MacroAssembler* masm = new MacroAssembler(&cb); 74 75 __ unimplemented(); 76 }