1 /* 2 * Copyright (c) 1998, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_UTILITIES_EXCEPTIONS_HPP 26 #define SHARE_UTILITIES_EXCEPTIONS_HPP 27 28 #include "memory/allocation.hpp" 29 #include "oops/oopsHierarchy.hpp" 30 #include "utilities/ostream.hpp" 31 #include "utilities/sizes.hpp" 32 33 // This file provides the basic support for exception handling in the VM. 34 // Note: We do not use C++ exceptions to avoid compiler dependencies and 35 // unpredictable performance. 36 // 37 // Scheme: Exceptions are stored with the thread. There is never more 38 // than one pending exception per thread. All functions that can throw 39 // an exception carry a THREAD argument (usually the last argument and 40 // declared with the TRAPS macro). Throwing an exception means setting 41 // a pending exception in the thread. Upon return from a function that 42 // can throw an exception, we must check if an exception is pending. 43 // The CHECK macros do this in a convenient way. Carrying around the 44 // thread provides also convenient access to it (e.g. for Handle 45 // creation, w/o the need for recomputation). 46 47 48 49 // Forward declarations to be independent of the include structure. 50 51 class Thread; 52 class Handle; 53 class Symbol; 54 class JavaCallArguments; 55 class methodHandle; 56 57 // The ThreadShadow class is a helper class to access the _pending_exception 58 // field of the Thread class w/o having access to the Thread's interface (for 59 // include hierachy reasons). 60 61 class ThreadShadow: public CHeapObj<mtThread> { 62 friend class VMStructs; 63 friend class JVMCIVMStructs; 64 65 protected: 66 oop _pending_exception; // Thread has gc actions. 67 const char* _exception_file; // file information for exception (debugging only) 68 int _exception_line; // line information for exception (debugging only) 69 friend void check_ThreadShadow(); // checks _pending_exception offset 70 71 // The following virtual exists only to force creation of a vtable. 72 // We need ThreadShadow to have a vtable, even in product builds, 73 // so that its layout will start at an offset of zero relative to Thread. 74 // Some C++ compilers are so "clever" that they put the ThreadShadow 75 // base class at offset 4 in Thread (after Thread's vtable), if they 76 // notice that Thread has a vtable but ThreadShadow does not. 77 virtual void unused_initial_virtual() { } 78 79 public: 80 oop pending_exception() const { return _pending_exception; } 81 bool has_pending_exception() const { return _pending_exception != NULL; } 82 const char* exception_file() const { return _exception_file; } 83 int exception_line() const { return _exception_line; } 84 85 // Code generation support 86 static ByteSize pending_exception_offset() { return byte_offset_of(ThreadShadow, _pending_exception); } 87 88 // use THROW whenever possible! 89 void set_pending_exception(oop exception, const char* file, int line); 90 91 // use CLEAR_PENDING_EXCEPTION whenever possible! 92 void clear_pending_exception(); 93 94 ThreadShadow() : _pending_exception(NULL), 95 _exception_file(NULL), _exception_line(0) {} 96 }; 97 98 99 // Exceptions is a helper class that encapsulates all operations 100 // that require access to the thread interface and which are 101 // relatively rare. The Exceptions operations should only be 102 // used directly if the macros below are insufficient. 103 104 class Exceptions { 105 static bool special_exception(Thread *thread, const char* file, int line, Handle exception); 106 static bool special_exception(Thread* thread, const char* file, int line, Symbol* name, const char* message); 107 108 // Count out of memory errors that are interesting in error diagnosis 109 static volatile int _out_of_memory_error_java_heap_errors; 110 static volatile int _out_of_memory_error_metaspace_errors; 111 static volatile int _out_of_memory_error_class_metaspace_errors; 112 113 // Count linkage errors 114 static volatile int _linkage_errors; 115 public: 116 // this enum is defined to indicate whether it is safe to 117 // ignore the encoding scheme of the original message string. 118 typedef enum { 119 safe_to_utf8 = 0, 120 unsafe_to_utf8 = 1 121 } ExceptionMsgToUtf8Mode; 122 // Throw exceptions: w/o message, w/ message & with formatted message. 123 static void _throw_oop(Thread* thread, const char* file, int line, oop exception); 124 static void _throw(Thread* thread, const char* file, int line, Handle exception, const char* msg = NULL); 125 126 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message); 127 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message, 128 Handle loader, Handle protection_domain); 129 130 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause); 131 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause, 132 Handle h_loader, Handle h_protection_domain); 133 134 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause); 135 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause, 136 Handle h_loader, Handle h_protection_domain); 137 138 static void _throw_args(Thread* thread, const char* file, int line, 139 Symbol* name, Symbol* signature, 140 JavaCallArguments* args); 141 142 // There is no THROW... macro for this method. Caller should remember 143 // to do a return after calling it. 144 static void fthrow(Thread* thread, const char* file, int line, Symbol* name, 145 const char* format, ...) ATTRIBUTE_PRINTF(5, 6); 146 147 // Create and initialize a new exception 148 static Handle new_exception(Thread* thread, Symbol* name, 149 Symbol* signature, JavaCallArguments* args, 150 Handle loader, Handle protection_domain); 151 152 static Handle new_exception(Thread* thread, Symbol* name, 153 Symbol* signature, JavaCallArguments* args, 154 Handle cause, 155 Handle loader, Handle protection_domain); 156 157 static Handle new_exception(Thread* thread, Symbol* name, 158 Handle cause, 159 Handle loader, Handle protection_domain, 160 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8); 161 162 static Handle new_exception(Thread* thread, Symbol* name, 163 const char* message, Handle cause, 164 Handle loader, Handle protection_domain, 165 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8); 166 167 static Handle new_exception(Thread* thread, Symbol* name, 168 const char* message, 169 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8); 170 171 static void throw_stack_overflow_exception(Thread* thread, const char* file, int line, const methodHandle& method); 172 173 static void wrap_dynamic_exception(Thread* thread); 174 175 // Exception counting for error files of interesting exceptions that may have 176 // caused a problem for the jvm 177 static volatile int _stack_overflow_errors; 178 179 static bool has_exception_counts(); 180 static void count_out_of_memory_exceptions(Handle exception); 181 static void print_exception_counts_on_error(outputStream* st); 182 183 // for AbortVMOnException flag 184 static void debug_check_abort(Handle exception, const char* message = NULL); 185 static void debug_check_abort_helper(Handle exception, const char* message = NULL); 186 static void debug_check_abort(const char *value_string, const char* message = NULL); 187 188 // for logging exceptions 189 static void log_exception(Handle exception, stringStream tempst); 190 }; 191 192 193 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions. 194 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.: 195 // 196 // int this_function_may_trap(int x, float y, TRAPS) 197 198 #define THREAD __the_thread__ 199 #define TRAPS Thread* THREAD 200 201 202 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending 203 // exceptions. In special situations it is necessary to handle pending exceptions explicitly, 204 // in these cases the PENDING_EXCEPTION helper macros should be used. 205 // 206 // Macro naming conventions: Macros that end with _ require a result value to be returned. They 207 // are for functions with non-void result type. The result value is usually ignored because of 208 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for 209 // _(0) since this is a frequent case. Example: 210 // 211 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0); 212 // 213 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a 214 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state- 215 // ments! Also make sure it is not used on a function call that is part of a return statement! 216 217 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception()) 218 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception()) 219 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception()) 220 221 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (void)(0 222 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0 223 #define CHECK_0 CHECK_(0) 224 #define CHECK_NH CHECK_(Handle()) 225 #define CHECK_NULL CHECK_(NULL) 226 #define CHECK_false CHECK_(false) 227 #define CHECK_JNI_ERR CHECK_(JNI_ERR) 228 229 #define CHECK_AND_CLEAR THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return; } (void)(0 230 #define CHECK_AND_CLEAR_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0 231 #define CHECK_AND_CLEAR_0 CHECK_AND_CLEAR_(0) 232 #define CHECK_AND_CLEAR_NH CHECK_AND_CLEAR_(Handle()) 233 #define CHECK_AND_CLEAR_NULL CHECK_AND_CLEAR_(NULL) 234 #define CHECK_AND_CLEAR_false CHECK_AND_CLEAR_(false) 235 236 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be 237 // visible within the scope containing the THROW. Usually this is achieved by declaring the function 238 // with a TRAPS argument. 239 240 #ifdef THIS_FILE 241 #define THREAD_AND_LOCATION THREAD, THIS_FILE, __LINE__ 242 #else 243 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__ 244 #endif 245 246 #define THROW_OOP(e) \ 247 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; } 248 249 #define THROW_HANDLE(e) \ 250 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; } 251 252 #define THROW(name) \ 253 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return; } 254 255 #define THROW_MSG(name, message) \ 256 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; } 257 258 #define THROW_CAUSE(name, cause) \ 259 { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; } 260 261 #define THROW_MSG_LOADER(name, message, loader, protection_domain) \ 262 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return; } 263 264 #define THROW_ARG(name, signature, args) \ 265 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; } 266 267 #define THROW_OOP_(e, result) \ 268 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; } 269 270 #define THROW_HANDLE_(e, result) \ 271 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; } 272 273 #define THROW_(name, result) \ 274 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; } 275 276 #define THROW_MSG_(name, message, result) \ 277 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; } 278 279 #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \ 280 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; } 281 282 #define THROW_ARG_(name, signature, args, result) \ 283 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; } 284 285 #define THROW_MSG_CAUSE(name, message, cause) \ 286 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; } 287 288 #define THROW_MSG_CAUSE_(name, message, cause, result) \ 289 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; } 290 291 292 #define THROW_OOP_0(e) THROW_OOP_(e, 0) 293 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0) 294 #define THROW_0(name) THROW_(name, 0) 295 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0) 296 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0) 297 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0) 298 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0) 299 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, NULL) 300 301 #define THROW_NULL(name) THROW_(name, NULL) 302 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, NULL) 303 304 // The CATCH macro checks that no exception has been thrown by a function; it is used at 305 // call sites about which is statically known that the callee cannot throw an exception 306 // even though it is declared with TRAPS. 307 308 #define CATCH \ 309 THREAD); if (HAS_PENDING_EXCEPTION) { \ 310 oop ex = PENDING_EXCEPTION; \ 311 CLEAR_PENDING_EXCEPTION; \ 312 ex->print(); \ 313 ShouldNotReachHere(); \ 314 } (void)(0 315 316 // ExceptionMark is a stack-allocated helper class for local exception handling. 317 // It is used with the EXCEPTION_MARK macro. 318 319 class ExceptionMark { 320 private: 321 Thread* _thread; 322 323 public: 324 ExceptionMark(Thread*& thread); 325 ~ExceptionMark(); 326 }; 327 328 329 330 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no 331 // pending exception exists upon entering its scope and tests that no pending exception 332 // exists when leaving the scope. 333 334 // See also preserveException.hpp for PRESERVE_EXCEPTION_MARK macro, 335 // which preserves pre-existing exceptions and does not allow new 336 // exceptions. 337 338 #define EXCEPTION_MARK Thread* THREAD = NULL; ExceptionMark __em(THREAD); 339 340 #endif // SHARE_UTILITIES_EXCEPTIONS_HPP