Tue, 15 Nov 2011 20:17:33 +0100
7110152: assert(size_in_words <= (julong)max_jint) failed: no overflow
Summary: Reduce what arrayOopDesc::max_array_length() returns to avoid int overflow
Reviewed-by: kvn, dholmes, tonyp
1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
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23 */
25 #ifndef SHARE_VM_OOPS_CONSTMETHODOOP_HPP
26 #define SHARE_VM_OOPS_CONSTMETHODOOP_HPP
28 #include "oops/oop.hpp"
29 #include "oops/typeArrayOop.hpp"
31 // An constMethodOop represents portions of a Java method which
32 // do not vary.
33 //
34 // Memory layout (each line represents a word). Note that most
35 // applications load thousands of methods, so keeping the size of this
36 // structure small has a big impact on footprint.
37 //
38 // |------------------------------------------------------|
39 // | header |
40 // | klass |
41 // |------------------------------------------------------|
42 // | fingerprint 1 |
43 // | fingerprint 2 |
44 // | method (oop) |
45 // | stackmap_data (oop) |
46 // | exception_table (oop) |
47 // | constMethod_size |
48 // | interp_kind | flags | code_size |
49 // | name index | signature index |
50 // | method_idnum | generic_signature_index |
51 // |------------------------------------------------------|
52 // | |
53 // | byte codes |
54 // | |
55 // |------------------------------------------------------|
56 // | compressed linenumber table |
57 // | (see class CompressedLineNumberReadStream) |
58 // | (note that length is unknown until decompressed) |
59 // | (access flags bit tells whether table is present) |
60 // | (indexed from start of constMethodOop) |
61 // | (elements not necessarily sorted!) |
62 // |------------------------------------------------------|
63 // | localvariable table elements + length (length last) |
64 // | (length is u2, elements are 6-tuples of u2) |
65 // | (see class LocalVariableTableElement) |
66 // | (access flags bit tells whether table is present) |
67 // | (indexed from end of contMethodOop) |
68 // |------------------------------------------------------|
69 // | checked exceptions elements + length (length last) |
70 // | (length is u2, elements are u2) |
71 // | (see class CheckedExceptionElement) |
72 // | (access flags bit tells whether table is present) |
73 // | (indexed from end of constMethodOop) |
74 // |------------------------------------------------------|
77 // Utitily class decribing elements in checked exceptions table inlined in methodOop.
78 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC {
79 public:
80 u2 class_cp_index;
81 };
84 // Utitily class decribing elements in local variable table inlined in methodOop.
85 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC {
86 public:
87 u2 start_bci;
88 u2 length;
89 u2 name_cp_index;
90 u2 descriptor_cp_index;
91 u2 signature_cp_index;
92 u2 slot;
93 };
96 class constMethodOopDesc : public oopDesc {
97 friend class constMethodKlass;
98 friend class VMStructs;
99 private:
100 enum {
101 _has_linenumber_table = 1,
102 _has_checked_exceptions = 2,
103 _has_localvariable_table = 4
104 };
106 // Bit vector of signature
107 // Callers interpret 0=not initialized yet and
108 // -1=too many args to fix, must parse the slow way.
109 // The real initial value is special to account for nonatomicity of 64 bit
110 // loads and stores. This value may updated and read without a lock by
111 // multiple threads, so is volatile.
112 volatile uint64_t _fingerprint;
113 volatile bool _is_conc_safe; // if true, safe for concurrent GC processing
115 public:
116 oop* oop_block_beg() const { return adr_method(); }
117 oop* oop_block_end() const { return adr_exception_table() + 1; }
119 private:
120 //
121 // The oop block. See comment in klass.hpp before making changes.
122 //
124 // Backpointer to non-const methodOop (needed for some JVMTI operations)
125 methodOop _method;
127 // Raw stackmap data for the method
128 typeArrayOop _stackmap_data;
130 // The exception handler table. 4-tuples of ints [start_pc, end_pc,
131 // handler_pc, catch_type index] For methods with no exceptions the
132 // table is pointing to Universe::the_empty_int_array
133 typeArrayOop _exception_table;
135 //
136 // End of the oop block.
137 //
139 int _constMethod_size;
140 jbyte _interpreter_kind;
141 jbyte _flags;
143 // Size of Java bytecodes allocated immediately after methodOop.
144 u2 _code_size;
145 u2 _name_index; // Method name (index in constant pool)
146 u2 _signature_index; // Method signature (index in constant pool)
147 u2 _method_idnum; // unique identification number for the method within the class
148 // initially corresponds to the index into the methods array.
149 // but this may change with redefinition
150 u2 _generic_signature_index; // Generic signature (index in constant pool, 0 if absent)
152 public:
153 // Inlined tables
154 void set_inlined_tables_length(int checked_exceptions_len,
155 int compressed_line_number_size,
156 int localvariable_table_len);
158 bool has_linenumber_table() const
159 { return (_flags & _has_linenumber_table) != 0; }
161 bool has_checked_exceptions() const
162 { return (_flags & _has_checked_exceptions) != 0; }
164 bool has_localvariable_table() const
165 { return (_flags & _has_localvariable_table) != 0; }
167 void set_interpreter_kind(int kind) { _interpreter_kind = kind; }
168 int interpreter_kind(void) const { return _interpreter_kind; }
170 // backpointer to non-const methodOop
171 methodOop method() const { return _method; }
172 void set_method(methodOop m) { oop_store_without_check((oop*)&_method, (oop) m); }
175 // stackmap table data
176 typeArrayOop stackmap_data() const { return _stackmap_data; }
177 void set_stackmap_data(typeArrayOop sd) {
178 oop_store_without_check((oop*)&_stackmap_data, (oop)sd);
179 }
180 bool has_stackmap_table() const { return _stackmap_data != NULL; }
182 // exception handler table
183 typeArrayOop exception_table() const { return _exception_table; }
184 void set_exception_table(typeArrayOop e) { oop_store_without_check((oop*) &_exception_table, (oop) e); }
185 bool has_exception_handler() const { return exception_table() != NULL && exception_table()->length() > 0; }
187 void init_fingerprint() {
188 const uint64_t initval = CONST64(0x8000000000000000);
189 _fingerprint = initval;
190 }
192 uint64_t fingerprint() const {
193 // Since reads aren't atomic for 64 bits, if any of the high or low order
194 // word is the initial value, return 0. See init_fingerprint for initval.
195 uint high_fp = (uint)(_fingerprint >> 32);
196 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
197 return 0L;
198 } else {
199 return _fingerprint;
200 }
201 }
203 uint64_t set_fingerprint(uint64_t new_fingerprint) {
204 #ifdef ASSERT
205 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
206 uint64_t oldfp = fingerprint();
207 #endif // ASSERT
208 _fingerprint = new_fingerprint;
209 assert(oldfp == 0L || new_fingerprint == oldfp,
210 "fingerprint cannot change");
211 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
212 "fingerprint should call init to set initial value");
213 return new_fingerprint;
214 }
216 // name
217 int name_index() const { return _name_index; }
218 void set_name_index(int index) { _name_index = index; }
220 // signature
221 int signature_index() const { return _signature_index; }
222 void set_signature_index(int index) { _signature_index = index; }
224 // generics support
225 int generic_signature_index() const { return _generic_signature_index; }
226 void set_generic_signature_index(int index) { _generic_signature_index = index; }
228 // Sizing
229 static int header_size() {
230 return sizeof(constMethodOopDesc)/HeapWordSize;
231 }
233 // Object size needed
234 static int object_size(int code_size, int compressed_line_number_size,
235 int local_variable_table_length,
236 int checked_exceptions_length);
238 int object_size() const { return _constMethod_size; }
239 void set_constMethod_size(int size) { _constMethod_size = size; }
240 // Is object parsable by gc
241 bool object_is_parsable() { return object_size() > 0; }
243 // code size
244 int code_size() const { return _code_size; }
245 void set_code_size(int size) {
246 assert(max_method_code_size < (1 << 16),
247 "u2 is too small to hold method code size in general");
248 assert(0 <= size && size <= max_method_code_size, "invalid code size");
249 _code_size = size;
250 }
252 // linenumber table - note that length is unknown until decompression,
253 // see class CompressedLineNumberReadStream.
254 u_char* compressed_linenumber_table() const; // not preserved by gc
255 u2* checked_exceptions_length_addr() const;
256 u2* localvariable_table_length_addr() const;
258 // checked exceptions
259 int checked_exceptions_length() const;
260 CheckedExceptionElement* checked_exceptions_start() const;
262 // localvariable table
263 int localvariable_table_length() const;
264 LocalVariableTableElement* localvariable_table_start() const;
266 // byte codes
267 void set_code(address code) {
268 if (code_size() > 0) {
269 memcpy(code_base(), code, code_size());
270 }
271 }
272 address code_base() const { return (address) (this+1); }
273 address code_end() const { return code_base() + code_size(); }
274 bool contains(address bcp) const { return code_base() <= bcp
275 && bcp < code_end(); }
276 // Offset to bytecodes
277 static ByteSize codes_offset()
278 { return in_ByteSize(sizeof(constMethodOopDesc)); }
280 // interpreter support
281 static ByteSize exception_table_offset()
282 { return byte_offset_of(constMethodOopDesc, _exception_table); }
284 // Garbage collection support
285 oop* adr_method() const { return (oop*)&_method; }
286 oop* adr_stackmap_data() const { return (oop*)&_stackmap_data; }
287 oop* adr_exception_table() const { return (oop*)&_exception_table; }
288 bool is_conc_safe() { return _is_conc_safe; }
289 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
291 // Unique id for the method
292 static const u2 MAX_IDNUM;
293 static const u2 UNSET_IDNUM;
294 u2 method_idnum() const { return _method_idnum; }
295 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
297 private:
298 // Since the size of the compressed line number table is unknown, the
299 // offsets of the other variable sized sections are computed backwards
300 // from the end of the constMethodOop.
302 // First byte after constMethodOop
303 address constMethod_end() const
304 { return (address)((oop*)this + _constMethod_size); }
306 // Last short in constMethodOop
307 u2* last_u2_element() const
308 { return (u2*)constMethod_end() - 1; }
309 };
311 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP