annotate src/share/vm/utilities/exceptions.hpp @ 844:bd02caa94611

6862919: Update copyright year Summary: Update copyright for files that have been modified in 2009, up to 07/09 Reviewed-by: tbell, ohair
author xdono
date Tue, 28 Jul 2009 12:12:40 -0700
parents e5b0439ef4ae
children fcb148c6b605
rev   line source
duke@0 1 /*
xdono@844 2 * Copyright 1998-2009 Sun Microsystems, Inc. All Rights Reserved.
duke@0 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@0 4 *
duke@0 5 * This code is free software; you can redistribute it and/or modify it
duke@0 6 * under the terms of the GNU General Public License version 2 only, as
duke@0 7 * published by the Free Software Foundation.
duke@0 8 *
duke@0 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@0 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@0 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@0 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@0 13 * accompanied this code).
duke@0 14 *
duke@0 15 * You should have received a copy of the GNU General Public License version
duke@0 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@0 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@0 18 *
duke@0 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@0 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@0 21 * have any questions.
duke@0 22 *
duke@0 23 */
duke@0 24
duke@0 25 // This file provides the basic support for exception handling in the VM.
duke@0 26 // Note: We do not use C++ exceptions to avoid compiler dependencies and
duke@0 27 // unpredictable performance.
duke@0 28 //
duke@0 29 // Scheme: Exceptions are stored with the thread. There is never more
duke@0 30 // than one pending exception per thread. All functions that can throw
duke@0 31 // an exception carry a THREAD argument (usually the last argument and
duke@0 32 // declared with the TRAPS macro). Throwing an exception means setting
duke@0 33 // a pending exception in the thread. Upon return from a function that
duke@0 34 // can throw an exception, we must check if an exception is pending.
duke@0 35 // The CHECK macros do this in a convenient way. Carrying around the
duke@0 36 // thread provides also convenient access to it (e.g. for Handle
duke@0 37 // creation, w/o the need for recomputation).
duke@0 38
duke@0 39
duke@0 40
duke@0 41 // Forward declarations to be independent of the include structure.
duke@0 42 // This allows us to have exceptions.hpp included in top.hpp.
duke@0 43
duke@0 44 class Thread;
duke@0 45 class Handle;
duke@0 46 class symbolHandle;
duke@0 47 class symbolOopDesc;
duke@0 48 class JavaCallArguments;
duke@0 49
duke@0 50 // The ThreadShadow class is a helper class to access the _pending_exception
duke@0 51 // field of the Thread class w/o having access to the Thread's interface (for
duke@0 52 // include hierachy reasons).
duke@0 53
duke@0 54 class ThreadShadow: public CHeapObj {
duke@0 55 protected:
duke@0 56 oop _pending_exception; // Thread has gc actions.
duke@0 57 const char* _exception_file; // file information for exception (debugging only)
duke@0 58 int _exception_line; // line information for exception (debugging only)
duke@0 59 friend void check_ThreadShadow(); // checks _pending_exception offset
duke@0 60
duke@0 61 // The following virtual exists only to force creation of a vtable.
duke@0 62 // We need ThreadShadow to have a vtable, even in product builds,
duke@0 63 // so that its layout will start at an offset of zero relative to Thread.
duke@0 64 // Some C++ compilers are so "clever" that they put the ThreadShadow
duke@0 65 // base class at offset 4 in Thread (after Thread's vtable), if they
duke@0 66 // notice that Thread has a vtable but ThreadShadow does not.
duke@0 67 virtual void unused_initial_virtual() { }
duke@0 68
duke@0 69 public:
duke@0 70 oop pending_exception() const { return _pending_exception; }
duke@0 71 bool has_pending_exception() const { return _pending_exception != NULL; }
duke@0 72 const char* exception_file() const { return _exception_file; }
duke@0 73 int exception_line() const { return _exception_line; }
duke@0 74
duke@0 75 // Code generation support
duke@0 76 static ByteSize pending_exception_offset() { return byte_offset_of(ThreadShadow, _pending_exception); }
duke@0 77
duke@0 78 // use THROW whenever possible!
duke@0 79 void set_pending_exception(oop exception, const char* file, int line);
duke@0 80
duke@0 81 // use CLEAR_PENDING_EXCEPTION whenever possible!
duke@0 82 void clear_pending_exception();
duke@0 83
duke@0 84 ThreadShadow() : _pending_exception(NULL),
duke@0 85 _exception_file(NULL), _exception_line(0) {}
duke@0 86 };
duke@0 87
duke@0 88
duke@0 89 // Exceptions is a helper class that encapsulates all operations
duke@0 90 // that require access to the thread interface and which are
duke@0 91 // relatively rare. The Exceptions operations should only be
duke@0 92 // used directly if the macros below are insufficient.
duke@0 93
duke@0 94 class Exceptions {
duke@0 95 static bool special_exception(Thread *thread, const char* file, int line, Handle exception);
duke@0 96 static bool special_exception(Thread* thread, const char* file, int line, symbolHandle name, const char* message);
duke@0 97 public:
duke@0 98 // this enum is defined to indicate whether it is safe to
duke@0 99 // ignore the encoding scheme of the original message string.
duke@0 100 typedef enum {
duke@0 101 safe_to_utf8 = 0,
duke@0 102 unsafe_to_utf8 = 1
duke@0 103 } ExceptionMsgToUtf8Mode;
duke@0 104 // Throw exceptions: w/o message, w/ message & with formatted message.
duke@0 105 static void _throw_oop(Thread* thread, const char* file, int line, oop exception);
duke@0 106 static void _throw(Thread* thread, const char* file, int line, Handle exception);
duke@0 107 static void _throw_msg(Thread* thread, const char* file, int line,
duke@0 108 symbolHandle name, const char* message, Handle loader,
duke@0 109 Handle protection_domain);
duke@0 110 static void _throw_msg(Thread* thread, const char* file, int line,
duke@0 111 symbolOop name, const char* message);
duke@0 112 static void _throw_msg(Thread* thread, const char* file, int line,
duke@0 113 symbolHandle name, const char* message);
duke@0 114 static void _throw_args(Thread* thread, const char* file, int line,
duke@0 115 symbolHandle name, symbolHandle signature,
duke@0 116 JavaCallArguments* args);
duke@0 117 static void _throw_msg_cause(Thread* thread, const char* file,
duke@0 118 int line, symbolHandle h_name, const char* message,
duke@0 119 Handle h_cause, Handle h_loader, Handle h_protection_domain);
duke@0 120 static void _throw_msg_cause(Thread* thread, const char* file, int line,
duke@0 121 symbolHandle name, const char* message, Handle cause);
duke@0 122
duke@0 123 // There is no THROW... macro for this method. Caller should remember
duke@0 124 // to do a return after calling it.
duke@0 125 static void fthrow(Thread* thread, const char* file, int line, symbolHandle name,
duke@0 126 const char* format, ...);
duke@0 127
duke@0 128 // Create and initialize a new exception
duke@0 129 static Handle new_exception(Thread* thread, symbolHandle name,
duke@0 130 symbolHandle signature, JavaCallArguments* args,
duke@0 131 Handle cause, Handle loader,
duke@0 132 Handle protection_domain);
duke@0 133
duke@0 134 static Handle new_exception(Thread* thread, symbolHandle name,
duke@0 135 const char* message, Handle cause, Handle loader,
duke@0 136 Handle protection_domain,
duke@0 137 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
duke@0 138
duke@0 139 static Handle new_exception(Thread* thread, symbolOop name,
duke@0 140 const char* message,
duke@0 141 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
duke@0 142
duke@0 143 static void throw_stack_overflow_exception(Thread* thread, const char* file, int line);
duke@0 144
duke@0 145 // for AbortVMOnException flag
duke@0 146 NOT_PRODUCT(static void debug_check_abort(Handle exception);)
duke@0 147 NOT_PRODUCT(static void debug_check_abort(const char *value_string);)
duke@0 148 };
duke@0 149
duke@0 150
duke@0 151 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
duke@0 152 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
duke@0 153 //
duke@0 154 // int this_function_may_trap(int x, float y, TRAPS)
duke@0 155
duke@0 156 #define THREAD __the_thread__
duke@0 157 #define TRAPS Thread* THREAD
duke@0 158
duke@0 159
duke@0 160 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
duke@0 161 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
duke@0 162 // in these cases the PENDING_EXCEPTION helper macros should be used.
duke@0 163 //
duke@0 164 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
duke@0 165 // are for functions with non-void result type. The result value is usually ignored because of
duke@0 166 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
duke@0 167 // _(0) since this is a frequent case. Example:
duke@0 168 //
duke@0 169 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
duke@0 170 //
duke@0 171 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
duke@0 172 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
duke@0 173 // ments!
duke@0 174
duke@0 175 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception())
duke@0 176 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception())
duke@0 177 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception())
duke@0 178
duke@0 179 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (0
duke@0 180 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (0
duke@0 181 #define CHECK_0 CHECK_(0)
duke@0 182 #define CHECK_NH CHECK_(Handle())
duke@0 183 #define CHECK_NULL CHECK_(NULL)
duke@0 184 #define CHECK_false CHECK_(false)
duke@0 185
duke@0 186 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
duke@0 187 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
duke@0 188 // with a TRAPS argument.
duke@0 189
duke@0 190 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__
duke@0 191
duke@0 192 #define THROW_OOP(e) \
duke@0 193 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; }
duke@0 194
duke@0 195 #define THROW_HANDLE(e) \
duke@0 196 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; }
duke@0 197
duke@0 198 #define THROW(name) \
duke@0 199 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return; }
duke@0 200
duke@0 201 #define THROW_MSG(name, message) \
duke@0 202 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; }
duke@0 203
duke@0 204 #define THROW_MSG_LOADER(name, message, loader, protection_domain) \
duke@0 205 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return; }
duke@0 206
duke@0 207 #define THROW_ARG(name, signature, args) \
duke@0 208 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; }
duke@0 209
duke@0 210 #define THROW_OOP_(e, result) \
duke@0 211 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; }
duke@0 212
duke@0 213 #define THROW_HANDLE_(e, result) \
duke@0 214 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; }
duke@0 215
duke@0 216 #define THROW_(name, result) \
duke@0 217 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; }
duke@0 218
duke@0 219 #define THROW_MSG_(name, message, result) \
duke@0 220 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
duke@0 221
duke@0 222 #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \
duke@0 223 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; }
duke@0 224
duke@0 225 #define THROW_ARG_(name, signature, args, result) \
duke@0 226 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
duke@0 227
duke@0 228 #define THROW_MSG_CAUSE_(name, message, cause, result) \
duke@0 229 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
duke@0 230
duke@0 231
duke@0 232 #define THROW_OOP_0(e) THROW_OOP_(e, 0)
duke@0 233 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0)
duke@0 234 #define THROW_0(name) THROW_(name, 0)
duke@0 235 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0)
duke@0 236 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0)
duke@0 237 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0)
duke@0 238 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
duke@0 239
jrose@710 240 #define THROW_NULL(name) THROW_(name, NULL)
jrose@710 241 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, NULL)
jrose@710 242
duke@0 243 // The CATCH macro checks that no exception has been thrown by a function; it is used at
duke@0 244 // call sites about which is statically known that the callee cannot throw an exception
duke@0 245 // even though it is declared with TRAPS.
duke@0 246
duke@0 247 #define CATCH \
duke@0 248 THREAD); if (HAS_PENDING_EXCEPTION) { \
duke@0 249 oop ex = PENDING_EXCEPTION; \
duke@0 250 CLEAR_PENDING_EXCEPTION; \
duke@0 251 ex->print(); \
duke@0 252 ShouldNotReachHere(); \
duke@0 253 } (0
duke@0 254
duke@0 255
duke@0 256 // ExceptionMark is a stack-allocated helper class for local exception handling.
duke@0 257 // It is used with the EXCEPTION_MARK macro.
duke@0 258
duke@0 259 class ExceptionMark {
duke@0 260 private:
duke@0 261 Thread* _thread;
duke@0 262
duke@0 263 public:
duke@0 264 ExceptionMark(Thread*& thread);
duke@0 265 ~ExceptionMark();
duke@0 266 };
duke@0 267
duke@0 268
duke@0 269
duke@0 270 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
duke@0 271 // pending exception exists upon entering its scope and tests that no pending exception
duke@0 272 // exists when leaving the scope.
duke@0 273
duke@0 274 // See also preserveException.hpp for PRESERVE_EXCEPTION_MARK macro,
duke@0 275 // which preserves pre-existing exceptions and does not allow new
duke@0 276 // exceptions.
duke@0 277
duke@0 278 #define EXCEPTION_MARK Thread* THREAD; ExceptionMark __em(THREAD);