diff -r 000000000000 -r f90c822e73f8 src/share/vm/runtime/perfMemory.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/runtime/perfMemory.hpp Wed Apr 27 01:25:04 2016 +0800 @@ -0,0 +1,169 @@ +/* + * 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_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; + } + } + + // filename of backing store or NULL if none. + static char* backing_store_filename(); + + // 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