Tue, 28 Jul 2009 12:12:40 -0700
6862919: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 07/09
Reviewed-by: tbell, ohair
1 /*
2 * Copyright 1998-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_rewriter.cpp.incl"
28 // Computes a CPC map (new_index -> original_index) for constant pool entries
29 // that are referred to by the interpreter at runtime via the constant pool cache.
30 // Also computes a CP map (original_index -> new_index).
31 // Marks entries in CP which require additional processing.
32 void Rewriter::compute_index_maps() {
33 const int length = _pool->length();
34 init_cp_map(length);
35 for (int i = 0; i < length; i++) {
36 int tag = _pool->tag_at(i).value();
37 switch (tag) {
38 case JVM_CONSTANT_InterfaceMethodref:
39 case JVM_CONSTANT_Fieldref : // fall through
40 case JVM_CONSTANT_Methodref : // fall through
41 add_cp_cache_entry(i);
42 break;
43 }
44 }
46 guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1),
47 "all cp cache indexes fit in a u2");
48 }
51 int Rewriter::add_extra_cp_cache_entry(int main_entry) {
52 // Hack: We put it on the map as an encoded value.
53 // The only place that consumes this is ConstantPoolCacheEntry::set_initial_state
54 int encoded = constantPoolCacheOopDesc::encode_secondary_index(main_entry);
55 int plain_secondary_index = _cp_cache_map.append(encoded);
56 return constantPoolCacheOopDesc::encode_secondary_index(plain_secondary_index);
57 }
61 // Creates a constant pool cache given a CPC map
62 // This creates the constant pool cache initially in a state
63 // that is unsafe for concurrent GC processing but sets it to
64 // a safe mode before the constant pool cache is returned.
65 void Rewriter::make_constant_pool_cache(TRAPS) {
66 const int length = _cp_cache_map.length();
67 constantPoolCacheOop cache =
68 oopFactory::new_constantPoolCache(length, methodOopDesc::IsUnsafeConc, CHECK);
69 cache->initialize(_cp_cache_map);
70 _pool->set_cache(cache);
71 cache->set_constant_pool(_pool());
72 }
76 // The new finalization semantics says that registration of
77 // finalizable objects must be performed on successful return from the
78 // Object.<init> constructor. We could implement this trivially if
79 // <init> were never rewritten but since JVMTI allows this to occur, a
80 // more complicated solution is required. A special return bytecode
81 // is used only by Object.<init> to signal the finalization
82 // registration point. Additionally local 0 must be preserved so it's
83 // available to pass to the registration function. For simplicty we
84 // require that local 0 is never overwritten so it's available as an
85 // argument for registration.
87 void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) {
88 RawBytecodeStream bcs(method);
89 while (!bcs.is_last_bytecode()) {
90 Bytecodes::Code opcode = bcs.raw_next();
91 switch (opcode) {
92 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
94 case Bytecodes::_istore:
95 case Bytecodes::_lstore:
96 case Bytecodes::_fstore:
97 case Bytecodes::_dstore:
98 case Bytecodes::_astore:
99 if (bcs.get_index() != 0) continue;
101 // fall through
102 case Bytecodes::_istore_0:
103 case Bytecodes::_lstore_0:
104 case Bytecodes::_fstore_0:
105 case Bytecodes::_dstore_0:
106 case Bytecodes::_astore_0:
107 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
108 "can't overwrite local 0 in Object.<init>");
109 break;
110 }
111 }
112 }
115 // Rewrite a classfile-order CP index into a native-order CPC index.
116 int Rewriter::rewrite_member_reference(address bcp, int offset) {
117 address p = bcp + offset;
118 int cp_index = Bytes::get_Java_u2(p);
119 int cache_index = cp_entry_to_cp_cache(cp_index);
120 Bytes::put_native_u2(p, cache_index);
121 return cp_index;
122 }
125 void Rewriter::rewrite_invokedynamic(address bcp, int offset, int delete_me) {
126 address p = bcp + offset;
127 assert(p[-1] == Bytecodes::_invokedynamic, "");
128 int cp_index = Bytes::get_Java_u2(p);
129 int cpc = maybe_add_cp_cache_entry(cp_index); // add lazily
130 int cpc2 = add_extra_cp_cache_entry(cpc);
132 // Replace the trailing four bytes with a CPC index for the dynamic
133 // call site. Unlike other CPC entries, there is one per bytecode,
134 // not just one per distinct CP entry. In other words, the
135 // CPC-to-CP relation is many-to-one for invokedynamic entries.
136 // This means we must use a larger index size than u2 to address
137 // all these entries. That is the main reason invokedynamic
138 // must have a five-byte instruction format. (Of course, other JVM
139 // implementations can use the bytes for other purposes.)
140 Bytes::put_native_u4(p, cpc2);
141 // Note: We use native_u4 format exclusively for 4-byte indexes.
142 }
145 // Rewrites a method given the index_map information
146 void Rewriter::scan_method(methodOop method) {
148 int nof_jsrs = 0;
149 bool has_monitor_bytecodes = false;
151 {
152 // We cannot tolerate a GC in this block, because we've
153 // cached the bytecodes in 'code_base'. If the methodOop
154 // moves, the bytecodes will also move.
155 No_Safepoint_Verifier nsv;
156 Bytecodes::Code c;
158 // Bytecodes and their length
159 const address code_base = method->code_base();
160 const int code_length = method->code_size();
162 int bc_length;
163 for (int bci = 0; bci < code_length; bci += bc_length) {
164 address bcp = code_base + bci;
165 int prefix_length = 0;
166 c = (Bytecodes::Code)(*bcp);
168 // Since we have the code, see if we can get the length
169 // directly. Some more complicated bytecodes will report
170 // a length of zero, meaning we need to make another method
171 // call to calculate the length.
172 bc_length = Bytecodes::length_for(c);
173 if (bc_length == 0) {
174 bc_length = Bytecodes::length_at(bcp);
176 // length_at will put us at the bytecode after the one modified
177 // by 'wide'. We don't currently examine any of the bytecodes
178 // modified by wide, but in case we do in the future...
179 if (c == Bytecodes::_wide) {
180 prefix_length = 1;
181 c = (Bytecodes::Code)bcp[1];
182 }
183 }
185 assert(bc_length != 0, "impossible bytecode length");
187 switch (c) {
188 case Bytecodes::_lookupswitch : {
189 #ifndef CC_INTERP
190 Bytecode_lookupswitch* bc = Bytecode_lookupswitch_at(bcp);
191 bc->set_code(
192 bc->number_of_pairs() < BinarySwitchThreshold
193 ? Bytecodes::_fast_linearswitch
194 : Bytecodes::_fast_binaryswitch
195 );
196 #endif
197 break;
198 }
199 case Bytecodes::_getstatic : // fall through
200 case Bytecodes::_putstatic : // fall through
201 case Bytecodes::_getfield : // fall through
202 case Bytecodes::_putfield : // fall through
203 case Bytecodes::_invokevirtual : // fall through
204 case Bytecodes::_invokespecial : // fall through
205 case Bytecodes::_invokestatic :
206 case Bytecodes::_invokeinterface:
207 rewrite_member_reference(bcp, prefix_length+1);
208 break;
209 case Bytecodes::_invokedynamic:
210 rewrite_invokedynamic(bcp, prefix_length+1, int(sizeof"@@@@DELETE ME"));
211 break;
212 case Bytecodes::_jsr : // fall through
213 case Bytecodes::_jsr_w : nof_jsrs++; break;
214 case Bytecodes::_monitorenter : // fall through
215 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
216 }
217 }
218 }
220 // Update access flags
221 if (has_monitor_bytecodes) {
222 method->set_has_monitor_bytecodes();
223 }
225 // The present of a jsr bytecode implies that the method might potentially
226 // have to be rewritten, so we run the oopMapGenerator on the method
227 if (nof_jsrs > 0) {
228 method->set_has_jsrs();
229 // Second pass will revisit this method.
230 assert(method->has_jsrs(), "");
231 }
232 }
234 // After constant pool is created, revisit methods containing jsrs.
235 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) {
236 ResolveOopMapConflicts romc(method);
237 methodHandle original_method = method;
238 method = romc.do_potential_rewrite(CHECK_(methodHandle()));
239 if (method() != original_method()) {
240 // Insert invalid bytecode into original methodOop and set
241 // interpreter entrypoint, so that a executing this method
242 // will manifest itself in an easy recognizable form.
243 address bcp = original_method->bcp_from(0);
244 *bcp = (u1)Bytecodes::_shouldnotreachhere;
245 int kind = Interpreter::method_kind(original_method);
246 original_method->set_interpreter_kind(kind);
247 }
249 // Update monitor matching info.
250 if (romc.monitor_safe()) {
251 method->set_guaranteed_monitor_matching();
252 }
254 return method;
255 }
258 void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) {
259 ResourceMark rm(THREAD);
260 Rewriter rw(klass, CHECK);
261 // (That's all, folks.)
262 }
264 Rewriter::Rewriter(instanceKlassHandle klass, TRAPS)
265 : _klass(klass),
266 // gather starting points
267 _pool( THREAD, klass->constants()),
268 _methods(THREAD, klass->methods())
269 {
270 assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
272 // determine index maps for methodOop rewriting
273 compute_index_maps();
275 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
276 int i = _methods->length();
277 while (i-- > 0) {
278 methodOop method = (methodOop)_methods->obj_at(i);
279 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
280 // rewrite the return bytecodes of Object.<init> to register the
281 // object for finalization if needed.
282 methodHandle m(THREAD, method);
283 rewrite_Object_init(m, CHECK);
284 break;
285 }
286 }
287 }
289 // rewrite methods, in two passes
290 int i, len = _methods->length();
292 for (i = len; --i >= 0; ) {
293 methodOop method = (methodOop)_methods->obj_at(i);
294 scan_method(method);
295 }
297 // allocate constant pool cache, now that we've seen all the bytecodes
298 make_constant_pool_cache(CHECK);
300 for (i = len; --i >= 0; ) {
301 methodHandle m(THREAD, (methodOop)_methods->obj_at(i));
303 if (m->has_jsrs()) {
304 m = rewrite_jsrs(m, CHECK);
305 // Method might have gotten rewritten.
306 _methods->obj_at_put(i, m());
307 }
309 // Set up method entry points for compiler and interpreter.
310 m->link_method(m, CHECK);
311 }
312 }