| /* |
| * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_RUNTIME_PERFMEMORY_HPP |
| #define SHARE_VM_RUNTIME_PERFMEMORY_HPP |
| |
| #include "utilities/exceptions.hpp" |
| |
| /* |
| * PerfData Version Constants |
| * - Major Version - change whenever the structure of PerfDataEntry changes |
| * - Minor Version - change whenever the data within the PerfDataEntry |
| * structure changes. for example, new unit or variability |
| * values are added or new PerfData subtypes are added. |
| */ |
| #define PERFDATA_MAJOR_VERSION 2 |
| #define PERFDATA_MINOR_VERSION 0 |
| |
| /* Byte order of the PerfData memory region. The byte order is exposed in |
| * the PerfData memory region as the data in the memory region may have |
| * been generated by a little endian JVM implementation. Tracking the byte |
| * order in the PerfData memory region allows Java applications to adapt |
| * to the native byte order for monitoring purposes. This indicator is |
| * also useful when a snapshot of the PerfData memory region is shipped |
| * to a machine with a native byte order different from that of the |
| * originating machine. |
| */ |
| #define PERFDATA_BIG_ENDIAN 0 |
| #define PERFDATA_LITTLE_ENDIAN 1 |
| |
| /* |
| * The PerfDataPrologue structure is known by the PerfDataBuffer Java class |
| * libraries that read the PerfData memory region. The size and the position |
| * of the fields must be changed along with their counterparts in the |
| * PerfDataBuffer Java class. The first four bytes of this structure |
| * should never change, or compatibility problems between the monitoring |
| * applications and HotSpot VMs will result. The reserved fields are |
| * available for future enhancements. |
| */ |
| typedef struct { |
| jint magic; // magic number - 0xcafec0c0 |
| jbyte byte_order; // byte order of the buffer |
| jbyte major_version; // major and minor version numbers |
| jbyte minor_version; |
| jbyte accessible; // ready to access |
| jint used; // number of PerfData memory bytes used |
| jint overflow; // number of bytes of overflow |
| jlong mod_time_stamp; // time stamp of last structural modification |
| jint entry_offset; // offset of the first PerfDataEntry |
| jint num_entries; // number of allocated PerfData entries |
| } PerfDataPrologue; |
| |
| /* The PerfDataEntry structure defines the fixed portion of an entry |
| * in the PerfData memory region. The PerfDataBuffer Java libraries |
| * are aware of this structure and need to be changed when this |
| * structure changes. |
| */ |
| typedef struct { |
| |
| jint entry_length; // entry length in bytes |
| jint name_offset; // offset of the data item name |
| jint vector_length; // length of the vector. If 0, then scalar |
| jbyte data_type; // type of the data item - |
| // 'B','Z','J','I','S','C','D','F','V','L','[' |
| jbyte flags; // flags indicating misc attributes |
| jbyte data_units; // unit of measure for the data type |
| jbyte data_variability; // variability classification of data type |
| jint data_offset; // offset of the data item |
| |
| /* |
| body of PerfData memory entry is variable length |
| |
| jbyte[name_length] data_name; // name of the data item |
| jbyte[pad_length] data_pad; // alignment of data item |
| j<data_type>[data_length] data_item; // array of appropriate types. |
| // data_length is > 1 only when the |
| // data_type is T_ARRAY. |
| */ |
| } PerfDataEntry; |
| |
| // Prefix of performance data file. |
| extern const char PERFDATA_NAME[]; |
| |
| // UINT_CHARS contains the number of characters holding a process id |
| // (i.e. pid). pid is defined as unsigned "int" so the maximum possible pid value |
| // would be 2^32 - 1 (4294967295) which can be represented as a 10 characters |
| // string. |
| static const size_t UINT_CHARS = 10; |
| |
| /* the PerfMemory class manages creation, destruction, |
| * and allocation of the PerfData region. |
| */ |
| class PerfMemory : AllStatic { |
| friend class VMStructs; |
| private: |
| static char* _start; |
| static char* _end; |
| static char* _top; |
| static size_t _capacity; |
| static PerfDataPrologue* _prologue; |
| static jint _initialized; |
| |
| static void create_memory_region(size_t sizep); |
| static void delete_memory_region(); |
| |
| public: |
| enum PerfMemoryMode { |
| PERF_MODE_RO = 0, |
| PERF_MODE_RW = 1 |
| }; |
| |
| static char* alloc(size_t size); |
| static char* start() { return _start; } |
| static char* end() { return _end; } |
| static size_t used() { return (size_t) (_top - _start); } |
| static size_t capacity() { return _capacity; } |
| static bool is_initialized() { return _initialized != 0; } |
| static bool contains(char* addr) { |
| return ((_start != NULL) && (addr >= _start) && (addr < _end)); |
| } |
| static void mark_updated(); |
| |
| // methods for attaching to and detaching from the PerfData |
| // memory segment of another JVM process on the same system. |
| static void attach(const char* user, int vmid, PerfMemoryMode mode, |
| char** addrp, size_t* size, TRAPS); |
| static void detach(char* addr, size_t bytes, TRAPS); |
| |
| static void initialize(); |
| static void destroy(); |
| static void set_accessible(bool value) { |
| if (UsePerfData) { |
| _prologue->accessible = value; |
| } |
| } |
| |
| // returns the complete file path of hsperfdata. |
| // the caller is expected to free the allocated memory. |
| static char* get_perfdata_file_path(); |
| }; |
| |
| void perfMemory_init(); |
| void perfMemory_exit(); |
| |
| #endif // SHARE_VM_RUNTIME_PERFMEMORY_HPP |