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.
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   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.
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   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
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  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 9 // 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 9
  40 #define INVALID_CDS_ARCHIVE_VERSION -1
  41 
  42 struct CDSFileMapRegion {
  43   int     _crc;               // CRC checksum of this region.
  44   int     _read_only;         // read only region?
  45   int     _allow_exec;        // executable code in this region?
  46   int     _is_heap_region;    // Used in debug build only.
  47   int     _mapped_from_file;  // Is this region mapped from a file?
  48                               // If false, this region was initialized using os::read().
  49   size_t  _file_offset;       // Data for this region starts at this offset in the archive file.
  50   size_t  _mapping_offset;    // This region should be mapped at this offset from the base address
  51                               // - for non-heap regions, the base address is SharedBaseAddress
  52                               // - for heap regions, the base address is the compressed oop encoding base
  53   size_t  _used;              // Number of bytes actually used by this region (excluding padding bytes added
  54                               // for alignment purposed.
  55   size_t  _oopmap_offset;     // Bitmap for relocating embedded oops (offset from SharedBaseAddress).
  56   size_t  _oopmap_size_in_bits;
  57   char*   _mapped_base;       // Actually mapped address (NULL if this region is not mapped).
  58 };
  59 
  60 struct CDSFileMapHeaderBase {
  61   unsigned int _magic;           // identify file type
  62   int          _crc;             // header crc checksum
  63   int          _version;         // must be CURRENT_CDS_ARCHIVE_VERSION
  64   struct CDSFileMapRegion _space[NUM_CDS_REGIONS];
  65 };
  66 
  67 typedef struct CDSFileMapHeaderBase CDSFileMapHeaderBase;
  68 
  69 #endif // SHARE_INCLUDE_CDS_H