jdk8-mips64-public/hotspot: src/share/vm/runtime/perfMemory.hpp@fa83ab460c54

6988353: refactor contended sync subsystem
Summary: reduce complexity by factoring synchronizer.cpp
Reviewed-by: dholmes, never, coleenp

     1 /*

     2  * Copyright (c) 2001, 2008, 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  */

    25 /*

    26  * PerfData Version Constants

    27  *   - Major Version - change whenever the structure of PerfDataEntry changes

    28  *   - Minor Version - change whenever the data within the PerfDataEntry

    29  *                     structure changes. for example, new unit or variability

    30  *                     values are added or new PerfData subtypes are added.

    31  */

    32 #define PERFDATA_MAJOR_VERSION 2

    33 #define PERFDATA_MINOR_VERSION 0

    35 /* Byte order of the PerfData memory region. The byte order is exposed in

    36  * the PerfData memory region as the data in the memory region may have

    37  * been generated by a little endian JVM implementation. Tracking the byte

    38  * order in the PerfData memory region allows Java applications to adapt

    39  * to the native byte order for monitoring purposes. This indicator is

    40  * also useful when a snapshot of the PerfData memory region is shipped

    41  * to a machine with a native byte order different from that of the

    42  * originating machine.

    43  */

    44 #define PERFDATA_BIG_ENDIAN     0

    45 #define PERFDATA_LITTLE_ENDIAN  1

    47 /*

    48  * The PerfDataPrologue structure is known by the PerfDataBuffer Java class

    49  * libraries that read the PerfData memory region. The size and the position

    50  * of the fields must be changed along with their counterparts in the

    51  * PerfDataBuffer Java class. The first four bytes of this structure

    52  * should never change, or compatibility problems between the monitoring

    53  * applications and Hotspot VMs will result. The reserved fields are

    54  * available for future enhancements.

    55  */

    56 typedef struct {

    57   jint   magic;              // magic number - 0xcafec0c0

    58   jbyte  byte_order;         // byte order of the buffer

    59   jbyte  major_version;      // major and minor version numbers

    60   jbyte  minor_version;

    61   jbyte  accessible;         // ready to access

    62   jint   used;               // number of PerfData memory bytes used

    63   jint   overflow;           // number of bytes of overflow

    64   jlong  mod_time_stamp;     // time stamp of last structural modification

    65   jint   entry_offset;       // offset of the first PerfDataEntry

    66   jint   num_entries;        // number of allocated PerfData entries

    67 } PerfDataPrologue;

    69 /* The PerfDataEntry structure defines the fixed portion of an entry

    70  * in the PerfData memory region. The PerfDataBuffer Java libraries

    71  * are aware of this structure and need to be changed when this

    72  * structure changes.

    73  */

    74 typedef struct {

    76   jint entry_length;      // entry length in bytes

    77   jint name_offset;       // offset of the data item name

    78   jint vector_length;     // length of the vector. If 0, then scalar

    79   jbyte data_type;        // type of the data item -

    80                           // 'B','Z','J','I','S','C','D','F','V','L','['

    81   jbyte flags;            // flags indicating misc attributes

    82   jbyte data_units;       // unit of measure for the data type

    83   jbyte data_variability; // variability classification of data type

    84   jint  data_offset;      // offset of the data item

    86 /*

    87   body of PerfData memory entry is variable length

    89   jbyte[name_length] data_name;        // name of the data item

    90   jbyte[pad_length] data_pad;          // alignment of data item

    91   j<data_type>[data_length] data_item; // array of appropriate types.

    92                                        // data_length is > 1 only when the

    93                                        // data_type is T_ARRAY.

    94 */

    95 } PerfDataEntry;

    97 // Prefix of performance data file.

    98 extern const char PERFDATA_NAME[];

   100 // UINT_CHARS contains the number of characters holding a process id

   101 // (i.e. pid). pid is defined as unsigned "int" so the maximum possible pid value

   102 // would be 2^32 - 1 (4294967295) which can be represented as a 10 characters

   103 // string.

   104 static const size_t UINT_CHARS = 10;

   106 /* the PerfMemory class manages creation, destruction,

   107  * and allocation of the PerfData region.

   108  */

   109 class PerfMemory : AllStatic {

   110     friend class VMStructs;

   111   private:

   112     static char*  _start;

   113     static char*  _end;

   114     static char*  _top;

   115     static size_t _capacity;

   116     static PerfDataPrologue*  _prologue;

   117     static jint   _initialized;

   119     static void create_memory_region(size_t sizep);

   120     static void delete_memory_region();

   122   public:

   123     enum PerfMemoryMode {

   124       PERF_MODE_RO = 0,

   125       PERF_MODE_RW = 1

   126     };

   128     static char* alloc(size_t size);

   129     static char* start() { return _start; }

   130     static char* end() { return _end; }

   131     static size_t used() { return (size_t) (_top - _start); }

   132     static size_t capacity() { return _capacity; }

   133     static bool is_initialized() { return _initialized != 0; }

   134     static bool contains(char* addr) {

   135       return ((_start != NULL) && (addr >= _start) && (addr < _end));

   136     }

   137     static void mark_updated();

   139     // methods for attaching to and detaching from the PerfData

   140     // memory segment of another JVM process on the same system.

   141     static void attach(const char* user, int vmid, PerfMemoryMode mode,

   142                        char** addrp, size_t* size, TRAPS);

   143     static void detach(char* addr, size_t bytes, TRAPS);

   145     static void initialize();

   146     static void destroy();

   147     static void set_accessible(bool value) {

   148       if (UsePerfData) {

   149         _prologue->accessible = value;

   150       }

   151     }

   153     // filename of backing store or NULL if none.

   154     static char* backing_store_filename();

   156     // returns the complete file path of hsperfdata.

   157     // the caller is expected to free the allocated memory.

   158     static char* get_perfdata_file_path();

   159 };

   161 void perfMemory_init();

   162 void perfMemory_exit();

Mercurial > jdk8-mips64-public > hotspot / file revision