1 /*
2 * Copyright (c) 1998, 2015, 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.
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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/sizes.hpp"
31
32 // This file provides the basic support for exception handling in the VM.
33 // Note: We do not use C++ exceptions to avoid compiler dependencies and
34 // unpredictable performance.
35 //
36 // Scheme: Exceptions are stored with the thread. There is never more
37 // than one pending exception per thread. All functions that can throw
38 // an exception carry a THREAD argument (usually the last argument and
39 // declared with the TRAPS macro). Throwing an exception means setting
40 // a pending exception in the thread. Upon return from a function that
41 // can throw an exception, we must check if an exception is pending.
42 // The CHECK macros do this in a convenient way. Carrying around the
43 // thread provides also convenient access to it (e.g. for Handle
44 // creation, w/o the need for recomputation).
45
46
47
48 // Forward declarations to be independent of the include structure.
49 // This allows us to have exceptions.hpp included in top.hpp.
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 protected:
63 char _yieldpoint_poll;
64 char _yieldpoint_spill[wordSize - 1];
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), _yieldpoint_poll(3) {}
95
96 void set_yieldpoint(bool should_take_yieldpoint) {
97 _yieldpoint_poll = should_take_yieldpoint ? 0 : 3;
98 }
99
100 bool yieldpoint() {
101 return _yieldpoint_poll == 3;
102 }
103 };
104
105
106 // Exceptions is a helper class that encapsulates all operations
107 // that require access to the thread interface and which are
108 // relatively rare. The Exceptions operations should only be
109 // used directly if the macros below are insufficient.
110
111 class Exceptions {
112 static bool special_exception(Thread *thread, const char* file, int line, Handle exception);
113 static bool special_exception(Thread* thread, const char* file, int line, Symbol* name, const char* message);
114
115 // Count out of memory errors that are interesting in error diagnosis
116 static volatile int _out_of_memory_error_java_heap_errors;
117 static volatile int _out_of_memory_error_metaspace_errors;
118 static volatile int _out_of_memory_error_class_metaspace_errors;
119 public:
120 // this enum is defined to indicate whether it is safe to
121 // ignore the encoding scheme of the original message string.
122 typedef enum {
123 safe_to_utf8 = 0,
124 unsafe_to_utf8 = 1
125 } ExceptionMsgToUtf8Mode;
126 // Throw exceptions: w/o message, w/ message & with formatted message.
127 static void _throw_oop(Thread* thread, const char* file, int line, oop exception);
128 static void _throw(Thread* thread, const char* file, int line, Handle exception, const char* msg = NULL);
129
130 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message);
131 static void _throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message,
132 Handle loader, Handle protection_domain);
133
134 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause);
135 static void _throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
136 Handle h_loader, Handle h_protection_domain);
137
138 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause);
139 static void _throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause,
140 Handle h_loader, Handle h_protection_domain);
141
142 static void _throw_args(Thread* thread, const char* file, int line,
143 Symbol* name, Symbol* signature,
144 JavaCallArguments* args);
145
146 // There is no THROW... macro for this method. Caller should remember
147 // to do a return after calling it.
148 static void fthrow(Thread* thread, const char* file, int line, Symbol* name,
149 const char* format, ...) ATTRIBUTE_PRINTF(5, 6);
150
151 // Create and initialize a new exception
152 static Handle new_exception(Thread* thread, Symbol* name,
153 Symbol* signature, JavaCallArguments* args,
154 Handle loader, Handle protection_domain);
155
156 static Handle new_exception(Thread* thread, Symbol* name,
157 Symbol* signature, JavaCallArguments* args,
158 Handle cause,
159 Handle loader, Handle protection_domain);
160
161 static Handle new_exception(Thread* thread, Symbol* name,
162 Handle cause,
163 Handle loader, Handle protection_domain,
164 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
165
166 static Handle new_exception(Thread* thread, Symbol* name,
167 const char* message, Handle cause,
168 Handle loader, Handle protection_domain,
169 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
170
171 static Handle new_exception(Thread* thread, Symbol* name,
172 const char* message,
173 ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8);
174
175 static void throw_stack_overflow_exception(Thread* thread, const char* file, int line, methodHandle method);
176
177 // Exception counting for error files of interesting exceptions that may have
178 // caused a problem for the jvm
179 static volatile int _stack_overflow_errors;
180
181 static bool has_exception_counts();
182 static void count_out_of_memory_exceptions(Handle exception);
183 static void print_exception_counts_on_error(outputStream* st);
184
185 // for AbortVMOnException flag
186 NOT_PRODUCT(static void debug_check_abort(Handle exception, const char* message = NULL);)
187 NOT_PRODUCT(static void debug_check_abort(const char *value_string, const char* message = NULL);)
188 };
189
190
191 // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions.
192 // Convention: Use the TRAPS macro as the last argument of such a function; e.g.:
193 //
194 // int this_function_may_trap(int x, float y, TRAPS)
195
196 #define THREAD __the_thread__
197 #define TRAPS Thread* THREAD
198
199
200 // The CHECK... macros should be used to pass along a THREAD reference and to check for pending
201 // exceptions. In special situations it is necessary to handle pending exceptions explicitly,
202 // in these cases the PENDING_EXCEPTION helper macros should be used.
203 //
204 // Macro naming conventions: Macros that end with _ require a result value to be returned. They
205 // are for functions with non-void result type. The result value is usually ignored because of
206 // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for
207 // _(0) since this is a frequent case. Example:
208 //
209 // int result = this_function_may_trap(x_arg, y_arg, CHECK_0);
210 //
211 // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a
212 // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state-
213 // ments!
214
215 #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception())
216 #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception())
217 #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception())
218
219 #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (void)(0
220 #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (void)(0
221 #define CHECK_0 CHECK_(0)
222 #define CHECK_NH CHECK_(Handle())
223 #define CHECK_NULL CHECK_(NULL)
224 #define CHECK_false CHECK_(false)
225 #define CHECK_JNI_ERR CHECK_(JNI_ERR)
226
227 #define CHECK_AND_CLEAR THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return; } (void)(0
228 #define CHECK_AND_CLEAR_(result) THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return result; } (void)(0
229 #define CHECK_AND_CLEAR_0 CHECK_AND_CLEAR_(0)
230 #define CHECK_AND_CLEAR_NH CHECK_AND_CLEAR_(Handle())
231 #define CHECK_AND_CLEAR_NULL CHECK_AND_CLEAR_(NULL)
232 #define CHECK_AND_CLEAR_false CHECK_AND_CLEAR_(false)
233
234 // The THROW... macros should be used to throw an exception. They require a THREAD variable to be
235 // visible within the scope containing the THROW. Usually this is achieved by declaring the function
236 // with a TRAPS argument.
237
238 #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__
239
240 #define THROW_OOP(e) \
241 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; }
242
243 #define THROW_HANDLE(e) \
244 { Exceptions::_throw(THREAD_AND_LOCATION, e); return; }
245
246 #define THROW(name) \
247 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return; }
248
249 #define THROW_MSG(name, message) \
250 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; }
251
252 #define THROW_CAUSE(name, cause) \
253 { Exceptions::_throw_cause(THREAD_AND_LOCATION, name, cause); return; }
254
255 #define THROW_MSG_LOADER(name, message, loader, protection_domain) \
256 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return; }
257
258 #define THROW_ARG(name, signature, args) \
259 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; }
260
261 #define THROW_OOP_(e, result) \
262 { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; }
263
264 #define THROW_HANDLE_(e, result) \
265 { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; }
266
267 #define THROW_(name, result) \
268 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; }
269
270 #define THROW_MSG_(name, message, result) \
271 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; }
272
273 #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \
274 { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; }
275
276 #define THROW_ARG_(name, signature, args, result) \
277 { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; }
278
279 #define THROW_MSG_CAUSE(name, message, cause) \
280 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return; }
281
282 #define THROW_MSG_CAUSE_(name, message, cause, result) \
283 { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; }
284
285
286 #define THROW_OOP_0(e) THROW_OOP_(e, 0)
287 #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0)
288 #define THROW_0(name) THROW_(name, 0)
289 #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0)
290 #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0)
291 #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0)
292 #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0)
293 #define THROW_MSG_CAUSE_NULL(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, NULL)
294
295 #define THROW_NULL(name) THROW_(name, NULL)
296 #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, NULL)
297
298 // The CATCH macro checks that no exception has been thrown by a function; it is used at
299 // call sites about which is statically known that the callee cannot throw an exception
300 // even though it is declared with TRAPS.
301
302 #define CATCH \
303 THREAD); if (HAS_PENDING_EXCEPTION) { \
304 oop ex = PENDING_EXCEPTION; \
305 CLEAR_PENDING_EXCEPTION; \
306 ex->print(); \
307 ShouldNotReachHere(); \
308 } (void)(0
309
310 // ExceptionMark is a stack-allocated helper class for local exception handling.
311 // It is used with the EXCEPTION_MARK macro.
312
313 class ExceptionMark {
314 private:
315 Thread* _thread;
316
317 public:
318 ExceptionMark(Thread*& thread);
319 ~ExceptionMark();
320 };
321
322
323
324 // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no
325 // pending exception exists upon entering its scope and tests that no pending exception
326 // exists when leaving the scope.
327
328 // See also preserveException.hpp for PRESERVE_EXCEPTION_MARK macro,
329 // which preserves pre-existing exceptions and does not allow new
330 // exceptions.
331
332 #define EXCEPTION_MARK Thread* THREAD = NULL; ExceptionMark __em(THREAD);
333
334 #endif // SHARE_VM_UTILITIES_EXCEPTIONS_HPP