4170N/A * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 0N/A * published by the Free Software Foundation. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1472N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 0N/A// This table encapsulates the debugging information required by the 0N/A// serviceability agent in order to run. Specifically, we need to 0N/A// understand the layout of certain C data structures (offsets, in 0N/A// bytes, of their fields.) 0N/A// There are alternatives for the design of this mechanism, including 0N/A// parsing platform-specific debugging symbols from a debug build into 0N/A// a program database. While this current mechanism can be considered 0N/A// to be a workaround for the inability to debug arbitrary C and C++ 0N/A// programs at the present time, it does have certain advantages. 0N/A// First, it is platform-independent, which will vastly simplify the 0N/A// initial bringup of the system both now and on future platforms. 0N/A// Second, it is embedded within the VM, as opposed to being in a 0N/A// separate program database; experience has shown that whenever 0N/A// portions of a system are decoupled, version skew is problematic. 0N/A// Third, generating a program database, for example for a product 0N/A// build, would probably require two builds to be done: the desired 0N/A// product build as well as an intermediary build with the PRODUCT 0N/A// flag turned on but also compiled with -g, leading to a doubling of 0N/A// the time required to get a serviceability agent-debuggable product 0N/A// build. Fourth, and very significantly, this table probably 0N/A// preserves more information about field types than stabs do; for 0N/A// example, it preserves the fact that a field is a "jlong" rather 0N/A// than transforming the type according to the typedef in jni_md.h, 0N/A// which allows the Java-side code to identify "Java-sized" fields in 0N/A// C++ data structures. If the symbol parsing mechanism was redone 0N/A// using stabs, it might still be necessary to have a table somewhere 0N/A// containing this information. 0N/A// Do not change the sizes or signedness of the integer values in 0N/A// these data structures; they are fixed over in the serviceability 0N/A// agent's Java code (for bootstrapping). 0N/A const char*
typeName;
// The type name containing the given field (example: "Klass") 0N/A const char*
fieldName;
// The field name within the type (example: "_name") 2062N/A const char*
typeString;
// Quoted name of the type of this field (example: "Symbol*"; 0N/A // parsed in Java to ensure type correctness 0N/A void*
address;
// Address of field; only used for static fields 0N/A // ("offset" can not be reused because of apparent SparcWorks compiler bug 0N/A // in generation of initializer data) 0N/A const char*
typeName;
// Type name (example: "methodOopDesc") 0N/A // "klassOop", but NOT "methodOopDesc") 0N/A const char*
name;
// Name of constant (example: "_thread_in_native") 0N/A const char*
name;
// Name of constant (example: "_thread_in_native") 0N/A// This class is a friend of most classes, to be able to access 0N/A // The last entry is identified over in the serviceability agent by 0N/A // the fact that it has a NULL fieldName 0N/A // The last entry is identified over in the serviceability agent by 0N/A // the fact that it has a NULL typeName 0N/A // Table of integer constants required by the serviceability agent. 0N/A // The last entry is identified over in the serviceability agent by 0N/A // the fact that it has a NULL typeName 0N/A // Table of long constants required by the serviceability agent. 0N/A // The last entry is identified over in the serviceability agent by 0N/A // the fact that it has a NULL typeName 0N/A // This is used to run any checking code necessary for validation of 0N/A // the data structure (debug build only) 0N/A // Look up a type in localHotSpotVMTypes using strcmp() (debug build only). 0N/A // Returns 1 if found, 0 if not. 0N/A // debug_only(static int findType(const char* typeName);) 1879N/A#
endif // SHARE_VM_RUNTIME_VMSTRUCTS_HPP