1 /*
2 * Copyright (c) 1998, 2016, 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_VM_UTILITIES_EXCEPTIONS_HPP
26 #define SHARE_VM_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
56 // The ThreadShadow class is a helper class to access the _pending_exception
57 // field of the Thread class w/o having access to the Thread's interface (for
58 // include hierachy reasons).
59
60 class ThreadShadow: public CHeapObj<mtThread> {
61 friend class VMStructs;
62 friend class JVMCIVMStructs;
63
64 protected:
65 oop _pending_exception; // Thread has gc actions.
66 const char* _exception_file; // file information for exception (debugging only)
67 int _exception_line; // line information for exception (debugging only)
68 friend void check_ThreadShadow(); // checks _pending_exception offset
69
70 // The following virtual exists only to force creation of a vtable.
71 // We need ThreadShadow to have a vtable, even in product builds,
72 // so that its layout will start at an offset of zero relative to Thread.
73 // Some C++ compilers are so "clever" that they put the ThreadShadow
74 // base class at offset 4 in Thread (after Thread's vtable), if they
75 // notice that Thread has a vtable but ThreadShadow does not.
76 virtual void unused_initial_virtual() { }
77
78 public:
79 oop pending_exception() const { return _pending_exception; }
80 bool has_pending_exception() const { return _pending_exception != NULL; }
81 const char* exception_file() const { return _exception_file; }
82 int exception_line() const { return _exception_line; }
83
84 // Code generation support
85 static ByteSize pending_exception_offset() { return byte_offset_of(ThreadShadow, _pending_exception); }
86
87 // use THROW whenever possible!
88 void set_pending_exception(oop exception, const char* file, int line);
89
90 // use CLEAR_PENDING_EXCEPTION whenever possible!
91 void clear_pending_exception();
92
93 ThreadShadow() : _pending_exception(NULL),
94 _exception_file(NULL), _exception_line(0) {}
95 };
96
97
98 // Exceptions is a helper class that encapsulates all operations
99 // that require access to the thread interface and which are
100 // relatively rare. The Exceptions operations should only be
101 // used directly if the macros below are insufficient.
102
103 class Exceptions {
104 static bool special_exception(Thread *thread, const char* file, int line, Handle exception);
105 static bool special_exception(Thread* thread, const char* file, int line, Symbol* name, const char* message);
106
107 // Count out of memory errors that are interesting in error diagnosis
108 static volatile int _out_of_memory_error_java_heap_errors;
109 static volatile int _out_of_memory_error_metaspace_errors;
110 static volatile int _out_of_memory_error_class_metaspace_errors;
111 public:
112 // this enum is defined to indicate whether it is safe to
113 // ignore the encoding scheme of the original message string.
114 typedef enum {
115 safe_to_utf8 = 0,
116 unsafe_to_utf8 = 1
117 } ExceptionMsgToUtf8Mode;
118 // Throw exceptions: w/o message, w/ message & with formatted message.
119 static void _throw_oop(Thread* thread, const char* file, int line, oop exception);
120 static void _throw(Thread* thread, const char* file, int line, Handle exception, const char* msg = NULL);
121
122 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message);
123 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message,
124 Handle loader, Handle protection_domain);
125
126 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause);
127 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
128 Handle h_loader, Handle h_protection_domain);
129
130 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause);
131 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause,
132 Handle h_loader, Handle h_protection_domain);
133
134 static void _throw_args(Thread* thread, const char* file, int line,
135 Symbol* name, Symbol* signature,
136 JavaCallArguments* args);
137
138 // There is no THROW... macro for this method. Caller should remember
139 // to do a return after calling it.
140 static void fthrow(Thread* thread, const char* file, int line, Symbol* name,
141 const char* format, ...) ATTRIBUTE_PRINTF(5, 6);
142
143 // Create and initialize a new exception
144 static Handle new_exception(Thread* thread, Symbol* name,
145 Symbol* signature, JavaCallArguments* args,
146 Handle loader, Handle protection_domain);
147
148 static Handle new_exception(Thread* thread, Symbol* name,
149 Symbol* signature, JavaCallArguments* args,
150 Handle cause,
151 Handle loader, Handle protection_domain);
152
153 static Handle new_exception(Thread* thread, Symbol* name,
154 Handle cause,
155 Handle loader, Handle protection_domain,
156 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
157
158 static Handle new_exception(Thread* thread, Symbol* name,
159 const char* message, Handle cause,
160 Handle loader, Handle protection_domain,
161 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
162
163 static Handle new_exception(Thread* thread, Symbol* name,
164 const char* message,
165 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
166
167 static void throw_stack_overflow_exception(Thread* thread, const char* file, int line, const methodHandle& method);
168
169 static void wrap_dynamic_exception(Thread* thread);
170
171 // Exception counting for error files of interesting exceptions that may have
172 // caused a problem for the jvm
173 static volatile int _stack_overflow_errors;
174
175 static bool has_exception_counts();
176 static void count_out_of_memory_exceptions(Handle exception);
177 static void print_exception_counts_on_error(outputStream* st);
178
179 // for AbortVMOnException flag
180 static void debug_check_abort(Handle exception, const char* message = NULL);
181 static void debug_check_abort_helper(Handle exception, const char* message = NULL);
182 static void debug_check_abort(const char *value_string, const char* message = NULL);
183
184 // for logging exceptions
185 static void log_exception(Handle exception, stringStream tempst);
186 };
187
188
189 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
190 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
191 //
192 // int this_function_may_trap(int x, float y, TRAPS)
193
194 #define THREAD __the_thread__
195 #define TRAPS Thread* THREAD
196
197
198 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
199 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
200 // in these cases the PENDING_EXCEPTION helper macros should be used.
201 //
202 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
203 // are for functions with non-void result type. The result value is usually ignored because of
204 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
205 // _(0) since this is a frequent case. Example:
206 //
207 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
208 //
209 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
210 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
211 // ments!
212
213 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception())
214 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception())
215 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception())
216
217 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (void)(0
218 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0
219 #define CHECK_0 CHECK_(0)
220 #define CHECK_NH CHECK_(Handle())
221 #define CHECK_NULL CHECK_(NULL)
222 #define CHECK_false CHECK_(false)
223 #define CHECK_JNI_ERR CHECK_(JNI_ERR)
224
225 #define CHECK_AND_CLEAR THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return; } (void)(0
226 #define CHECK_AND_CLEAR_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0
227 #define CHECK_AND_CLEAR_0 CHECK_AND_CLEAR_(0)
228 #define CHECK_AND_CLEAR_NH CHECK_AND_CLEAR_(Handle())
229 #define CHECK_AND_CLEAR_NULL CHECK_AND_CLEAR_(NULL)
230 #define CHECK_AND_CLEAR_false CHECK_AND_CLEAR_(false)
231
232 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
233 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
234 // with a TRAPS argument.
235
236 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__
237
238 #define THROW_OOP(e) \
239 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; }
240
241 #define THROW_HANDLE(e) \
242 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; }
243
244 #define THROW(name) \
245 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return; }
246
247 #define THROW_MSG(name, message) \
248 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; }
249
250 #define THROW_CAUSE(name, cause) \
251 { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; }
252
253 #define THROW_MSG_LOADER(name, message, loader, protection_domain) \
254 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return; }
255
256 #define THROW_ARG(name, signature, args) \
257 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; }
258
259 #define THROW_OOP_(e, result) \
260 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; }
261
262 #define THROW_HANDLE_(e, result) \
263 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; }
264
265 #define THROW_(name, result) \
266 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; }
267
268 #define THROW_MSG_(name, message, result) \
269 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
270
271 #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \
272 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; }
273
274 #define THROW_ARG_(name, signature, args, result) \
275 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
276
277 #define THROW_MSG_CAUSE(name, message, cause) \
278 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; }
279
280 #define THROW_MSG_CAUSE_(name, message, cause, result) \
281 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
282
283
284 #define THROW_OOP_0(e) THROW_OOP_(e, 0)
285 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0)
286 #define THROW_0(name) THROW_(name, 0)
287 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0)
288 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0)
289 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0)
290 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
291 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, NULL)
292
293 #define THROW_NULL(name) THROW_(name, NULL)
294 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, NULL)
295
296 // The CATCH macro checks that no exception has been thrown by a function; it is used at
297 // call sites about which is statically known that the callee cannot throw an exception
298 // even though it is declared with TRAPS.
299
300 #define CATCH \
301 THREAD); if (HAS_PENDING_EXCEPTION) { \
302 oop ex = PENDING_EXCEPTION; \
303 CLEAR_PENDING_EXCEPTION; \
304 ex->print(); \
305 ShouldNotReachHere(); \
306 } (void)(0
307
308 // ExceptionMark is a stack-allocated helper class for local exception handling.
309 // It is used with the EXCEPTION_MARK macro.
310
311 class ExceptionMark {
312 private:
313 Thread* _thread;
314
315 public:
316 ExceptionMark(Thread*& thread);
317 ~ExceptionMark();
318 };
319
320
321
322 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
323 // pending exception exists upon entering its scope and tests that no pending exception
324 // exists when leaving the scope.
325
326 // See also preserveException.hpp for PRESERVE_EXCEPTION_MARK macro,
327 // which preserves pre-existing exceptions and does not allow new
328 // exceptions.
329
330 #define EXCEPTION_MARK Thread* THREAD = NULL; ExceptionMark __em(THREAD);
331
332 #endif // SHARE_VM_UTILITIES_EXCEPTIONS_HPP