1 /* 2 * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_INCLUDE_CDS_H 26 #define SHARE_INCLUDE_CDS_H 27 28 // This file declares the CDS data structures that are used by the HotSpot Serviceability Agent 29 // (see C sources inside src/jdk.hotspot.agent). 30 // 31 // We should use only standard C types. Do not use custom types such as bool, intx, 32 // etc, to avoid introducing unnecessary dependencies to other HotSpot type declarations. 33 // 34 // Also, this is a C header file. Do not use C++ here. 35 36 #define NUM_CDS_REGIONS 8 // this must be the same as MetaspaceShared::n_regions 37 #define CDS_ARCHIVE_MAGIC 0xf00baba2 38 #define CDS_DYNAMIC_ARCHIVE_MAGIC 0xf00baba8 39 #define CURRENT_CDS_ARCHIVE_VERSION 6 40 #define INVALID_CDS_ARCHIVE_VERSION -1 41 42 #define JVM_IDENT_MAX 256 43 44 struct CDSFileMapRegion { 45 int _crc; // crc checksum of the current space 46 size_t _file_offset; // sizeof(this) rounded to vm page size 47 union { 48 char* _base; // copy-on-write base address 49 size_t _offset; // offset from the compressed oop encoding base, only used 50 // by archive heap space 51 } _addr; 52 size_t _used; // for setting space top on read 53 int _read_only; // read only space? 54 int _allow_exec; // executable code in space? 55 void* _oopmap; // bitmap for relocating embedded oops 56 size_t _oopmap_size_in_bits; 57 }; 58 59 struct CDSFileMapHeaderBase { 60 unsigned int _magic; // identify file type 61 int _crc; // header crc checksum 62 int _version; // must be CURRENT_CDS_ARCHIVE_VERSION 63 char _jvm_ident[JVM_IDENT_MAX]; // identifier of the JVM with which this archive was generated 64 struct CDSFileMapRegion _space[NUM_CDS_REGIONS]; 65 }; 66 67 typedef struct CDSFileMapHeaderBase CDSFileMapHeaderBase; 68 69 #endif // SHARE_INCLUDE_CDS_H