1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/vmStructs.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,121 @@
1.4 +/*
1.5 + * Copyright 2000-2001 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// This table encapsulates the debugging information required by the
1.29 +// serviceability agent in order to run. Specifically, we need to
1.30 +// understand the layout of certain C data structures (offsets, in
1.31 +// bytes, of their fields.)
1.32 +//
1.33 +// There are alternatives for the design of this mechanism, including
1.34 +// parsing platform-specific debugging symbols from a debug build into
1.35 +// a program database. While this current mechanism can be considered
1.36 +// to be a workaround for the inability to debug arbitrary C and C++
1.37 +// programs at the present time, it does have certain advantages.
1.38 +// First, it is platform-independent, which will vastly simplify the
1.39 +// initial bringup of the system both now and on future platforms.
1.40 +// Second, it is embedded within the VM, as opposed to being in a
1.41 +// separate program database; experience has shown that whenever
1.42 +// portions of a system are decoupled, version skew is problematic.
1.43 +// Third, generating a program database, for example for a product
1.44 +// build, would probably require two builds to be done: the desired
1.45 +// product build as well as an intermediary build with the PRODUCT
1.46 +// flag turned on but also compiled with -g, leading to a doubling of
1.47 +// the time required to get a serviceability agent-debuggable product
1.48 +// build. Fourth, and very significantly, this table probably
1.49 +// preserves more information about field types than stabs do; for
1.50 +// example, it preserves the fact that a field is a "jlong" rather
1.51 +// than transforming the type according to the typedef in jni_md.h,
1.52 +// which allows the Java-side code to identify "Java-sized" fields in
1.53 +// C++ data structures. If the symbol parsing mechanism was redone
1.54 +// using stabs, it might still be necessary to have a table somewhere
1.55 +// containing this information.
1.56 +//
1.57 +// Do not change the sizes or signedness of the integer values in
1.58 +// these data structures; they are fixed over in the serviceability
1.59 +// agent's Java code (for bootstrapping).
1.60 +
1.61 +typedef struct {
1.62 + const char* typeName; // The type name containing the given field (example: "Klass")
1.63 + const char* fieldName; // The field name within the type (example: "_name")
1.64 + const char* typeString; // Quoted name of the type of this field (example: "symbolOopDesc*";
1.65 + // parsed in Java to ensure type correctness
1.66 + int32_t isStatic; // Indicates whether following field is an offset or an address
1.67 + uint64_t offset; // Offset of field within structure; only used for nonstatic fields
1.68 + void* address; // Address of field; only used for static fields
1.69 + // ("offset" can not be reused because of apparent SparcWorks compiler bug
1.70 + // in generation of initializer data)
1.71 +} VMStructEntry;
1.72 +
1.73 +typedef struct {
1.74 + const char* typeName; // Type name (example: "methodOopDesc")
1.75 + const char* superclassName; // Superclass name, or null if none (example: "oopDesc")
1.76 + int32_t isOopType; // Does this type represent an oop typedef? (i.e., "methodOop" or
1.77 + // "klassOop", but NOT "methodOopDesc")
1.78 + int32_t isIntegerType; // Does this type represent an integer type (of arbitrary size)?
1.79 + int32_t isUnsigned; // If so, is it unsigned?
1.80 + uint64_t size; // Size, in bytes, of the type
1.81 +} VMTypeEntry;
1.82 +
1.83 +typedef struct {
1.84 + const char* name; // Name of constant (example: "_thread_in_native")
1.85 + int32_t value; // Value of constant
1.86 +} VMIntConstantEntry;
1.87 +
1.88 +typedef struct {
1.89 + const char* name; // Name of constant (example: "_thread_in_native")
1.90 + uint64_t value; // Value of constant
1.91 +} VMLongConstantEntry;
1.92 +
1.93 +// This class is a friend of most classes, to be able to access
1.94 +// private fields
1.95 +class VMStructs {
1.96 +public:
1.97 + // The last entry is identified over in the serviceability agent by
1.98 + // the fact that it has a NULL fieldName
1.99 + static VMStructEntry localHotSpotVMStructs[];
1.100 +
1.101 + // The last entry is identified over in the serviceability agent by
1.102 + // the fact that it has a NULL typeName
1.103 + static VMTypeEntry localHotSpotVMTypes[];
1.104 +
1.105 + // Table of integer constants required by the serviceability agent.
1.106 + // The last entry is identified over in the serviceability agent by
1.107 + // the fact that it has a NULL typeName
1.108 + static VMIntConstantEntry localHotSpotVMIntConstants[];
1.109 +
1.110 + // Table of long constants required by the serviceability agent.
1.111 + // The last entry is identified over in the serviceability agent by
1.112 + // the fact that it has a NULL typeName
1.113 + static VMLongConstantEntry localHotSpotVMLongConstants[];
1.114 +
1.115 + // This is used to run any checking code necessary for validation of
1.116 + // the data structure (debug build only)
1.117 + static void init();
1.118 +
1.119 +private:
1.120 + // Look up a type in localHotSpotVMTypes using strcmp() (debug build only).
1.121 + // Returns 1 if found, 0 if not.
1.122 + // debug_only(static int findType(const char* typeName);)
1.123 + static int findType(const char* typeName);
1.124 +};
