Tue, 27 Nov 2012 14:20:21 +0100
8003935: Simplify the needed includes for using Thread::current()
Reviewed-by: dholmes, rbackman, coleenp
1 /*
2 * Copyright (c) 1998, 2012, 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 */
25 #include "precompiled.hpp"
26 #include "interpreter/bytecodes.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "interpreter/rewriter.hpp"
29 #include "memory/gcLocker.hpp"
30 #include "memory/metadataFactory.hpp"
31 #include "memory/oopFactory.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/generateOopMap.hpp"
34 #include "oops/objArrayOop.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "prims/methodComparator.hpp"
37 #include "prims/methodHandles.hpp"
39 // Computes a CPC map (new_index -> original_index) for constant pool entries
40 // that are referred to by the interpreter at runtime via the constant pool cache.
41 // Also computes a CP map (original_index -> new_index).
42 // Marks entries in CP which require additional processing.
43 void Rewriter::compute_index_maps() {
44 const int length = _pool->length();
45 init_maps(length);
46 bool saw_mh_symbol = false;
47 for (int i = 0; i < length; i++) {
48 int tag = _pool->tag_at(i).value();
49 switch (tag) {
50 case JVM_CONSTANT_InterfaceMethodref:
51 case JVM_CONSTANT_Fieldref : // fall through
52 case JVM_CONSTANT_Methodref : // fall through
53 add_cp_cache_entry(i);
54 break;
55 case JVM_CONSTANT_String:
56 case JVM_CONSTANT_Object:
57 case JVM_CONSTANT_MethodHandle : // fall through
58 case JVM_CONSTANT_MethodType : // fall through
59 add_resolved_references_entry(i);
60 break;
61 case JVM_CONSTANT_Utf8:
62 if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle())
63 saw_mh_symbol = true;
64 break;
65 }
66 }
68 // Record limits of resolved reference map for constant pool cache indices
69 record_map_limits();
71 guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1),
72 "all cp cache indexes fit in a u2");
74 if (saw_mh_symbol)
75 _method_handle_invokers.initialize(length, (int)0);
76 }
78 // Unrewrite the bytecodes if an error occurs.
79 void Rewriter::restore_bytecodes() {
80 int len = _methods->length();
82 for (int i = len-1; i >= 0; i--) {
83 Method* method = _methods->at(i);
84 scan_method(method, true);
85 }
86 }
88 // Creates a constant pool cache given a CPC map
89 void Rewriter::make_constant_pool_cache(TRAPS) {
90 const int length = _cp_cache_map.length();
91 ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
92 ConstantPoolCache* cache =
93 ConstantPoolCache::allocate(loader_data, length, CHECK);
95 // initialize object cache in constant pool
96 _pool->initialize_resolved_references(loader_data, _resolved_references_map,
97 _resolved_reference_limit,
98 CHECK);
100 No_Safepoint_Verifier nsv;
101 cache->initialize(_cp_cache_map, _invokedynamic_references_map);
102 _pool->set_cache(cache);
103 cache->set_constant_pool(_pool());
104 }
108 // The new finalization semantics says that registration of
109 // finalizable objects must be performed on successful return from the
110 // Object.<init> constructor. We could implement this trivially if
111 // <init> were never rewritten but since JVMTI allows this to occur, a
112 // more complicated solution is required. A special return bytecode
113 // is used only by Object.<init> to signal the finalization
114 // registration point. Additionally local 0 must be preserved so it's
115 // available to pass to the registration function. For simplicty we
116 // require that local 0 is never overwritten so it's available as an
117 // argument for registration.
119 void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) {
120 RawBytecodeStream bcs(method);
121 while (!bcs.is_last_bytecode()) {
122 Bytecodes::Code opcode = bcs.raw_next();
123 switch (opcode) {
124 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
126 case Bytecodes::_istore:
127 case Bytecodes::_lstore:
128 case Bytecodes::_fstore:
129 case Bytecodes::_dstore:
130 case Bytecodes::_astore:
131 if (bcs.get_index() != 0) continue;
133 // fall through
134 case Bytecodes::_istore_0:
135 case Bytecodes::_lstore_0:
136 case Bytecodes::_fstore_0:
137 case Bytecodes::_dstore_0:
138 case Bytecodes::_astore_0:
139 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
140 "can't overwrite local 0 in Object.<init>");
141 break;
142 }
143 }
144 }
147 // Rewrite a classfile-order CP index into a native-order CPC index.
148 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) {
149 address p = bcp + offset;
150 if (!reverse) {
151 int cp_index = Bytes::get_Java_u2(p);
152 int cache_index = cp_entry_to_cp_cache(cp_index);
153 Bytes::put_native_u2(p, cache_index);
154 if (!_method_handle_invokers.is_empty())
155 maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse);
156 } else {
157 int cache_index = Bytes::get_native_u2(p);
158 int pool_index = cp_cache_entry_pool_index(cache_index);
159 Bytes::put_Java_u2(p, pool_index);
160 if (!_method_handle_invokers.is_empty())
161 maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse);
162 }
163 }
166 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
167 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
168 if (!reverse) {
169 if ((*opc) == (u1)Bytecodes::_invokevirtual ||
170 // allow invokespecial as an alias, although it would be very odd:
171 (*opc) == (u1)Bytecodes::_invokespecial) {
172 assert(_pool->tag_at(cp_index).is_method(), "wrong index");
173 // Determine whether this is a signature-polymorphic method.
174 if (cp_index >= _method_handle_invokers.length()) return;
175 int status = _method_handle_invokers[cp_index];
176 assert(status >= -1 && status <= 1, "oob tri-state");
177 if (status == 0) {
178 if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
179 MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(),
180 _pool->name_ref_at(cp_index))) {
181 // we may need a resolved_refs entry for the appendix
182 add_invokedynamic_resolved_references_entries(cp_index, cache_index);
183 status = +1;
184 } else {
185 status = -1;
186 }
187 _method_handle_invokers[cp_index] = status;
188 }
189 // We use a special internal bytecode for such methods (if non-static).
190 // The basic reason for this is that such methods need an extra "appendix" argument
191 // to transmit the call site's intended call type.
192 if (status > 0) {
193 (*opc) = (u1)Bytecodes::_invokehandle;
194 }
195 }
196 } else {
197 // Do not need to look at cp_index.
198 if ((*opc) == (u1)Bytecodes::_invokehandle) {
199 (*opc) = (u1)Bytecodes::_invokevirtual;
200 // Ignore corner case of original _invokespecial instruction.
201 // This is safe because (a) the signature polymorphic method was final, and
202 // (b) the implementation of MethodHandle will not call invokespecial on it.
203 }
204 }
205 }
208 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
209 address p = bcp + offset;
210 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
211 if (!reverse) {
212 int cp_index = Bytes::get_Java_u2(p);
213 int cache_index = add_invokedynamic_cp_cache_entry(cp_index);
214 add_invokedynamic_resolved_references_entries(cp_index, cache_index);
215 // Replace the trailing four bytes with a CPC index for the dynamic
216 // call site. Unlike other CPC entries, there is one per bytecode,
217 // not just one per distinct CP entry. In other words, the
218 // CPC-to-CP relation is many-to-one for invokedynamic entries.
219 // This means we must use a larger index size than u2 to address
220 // all these entries. That is the main reason invokedynamic
221 // must have a five-byte instruction format. (Of course, other JVM
222 // implementations can use the bytes for other purposes.)
223 Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index));
224 // Note: We use native_u4 format exclusively for 4-byte indexes.
225 } else {
226 // callsite index
227 int cache_index = ConstantPool::decode_invokedynamic_index(
228 Bytes::get_native_u4(p));
229 int cp_index = cp_cache_entry_pool_index(cache_index);
230 assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
231 // zero out 4 bytes
232 Bytes::put_Java_u4(p, 0);
233 Bytes::put_Java_u2(p, cp_index);
234 }
235 }
238 // Rewrite some ldc bytecodes to _fast_aldc
239 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
240 bool reverse) {
241 if (!reverse) {
242 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
243 address p = bcp + offset;
244 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
245 constantTag tag = _pool->tag_at(cp_index).value();
246 if (tag.is_method_handle() || tag.is_method_type() || tag.is_string() || tag.is_object()) {
247 int ref_index = cp_entry_to_resolved_references(cp_index);
248 if (is_wide) {
249 (*bcp) = Bytecodes::_fast_aldc_w;
250 assert(ref_index == (u2)ref_index, "index overflow");
251 Bytes::put_native_u2(p, ref_index);
252 } else {
253 (*bcp) = Bytecodes::_fast_aldc;
254 assert(ref_index == (u1)ref_index, "index overflow");
255 (*p) = (u1)ref_index;
256 }
257 }
258 } else {
259 Bytecodes::Code rewritten_bc =
260 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
261 if ((*bcp) == rewritten_bc) {
262 address p = bcp + offset;
263 int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
264 int pool_index = resolved_references_entry_to_pool_index(ref_index);
265 if (is_wide) {
266 (*bcp) = Bytecodes::_ldc_w;
267 assert(pool_index == (u2)pool_index, "index overflow");
268 Bytes::put_Java_u2(p, pool_index);
269 } else {
270 (*bcp) = Bytecodes::_ldc;
271 assert(pool_index == (u1)pool_index, "index overflow");
272 (*p) = (u1)pool_index;
273 }
274 }
275 }
276 }
279 // Rewrites a method given the index_map information
280 void Rewriter::scan_method(Method* method, bool reverse) {
282 int nof_jsrs = 0;
283 bool has_monitor_bytecodes = false;
285 {
286 // We cannot tolerate a GC in this block, because we've
287 // cached the bytecodes in 'code_base'. If the Method*
288 // moves, the bytecodes will also move.
289 No_Safepoint_Verifier nsv;
290 Bytecodes::Code c;
292 // Bytecodes and their length
293 const address code_base = method->code_base();
294 const int code_length = method->code_size();
296 int bc_length;
297 for (int bci = 0; bci < code_length; bci += bc_length) {
298 address bcp = code_base + bci;
299 int prefix_length = 0;
300 c = (Bytecodes::Code)(*bcp);
302 // Since we have the code, see if we can get the length
303 // directly. Some more complicated bytecodes will report
304 // a length of zero, meaning we need to make another method
305 // call to calculate the length.
306 bc_length = Bytecodes::length_for(c);
307 if (bc_length == 0) {
308 bc_length = Bytecodes::length_at(method, bcp);
310 // length_at will put us at the bytecode after the one modified
311 // by 'wide'. We don't currently examine any of the bytecodes
312 // modified by wide, but in case we do in the future...
313 if (c == Bytecodes::_wide) {
314 prefix_length = 1;
315 c = (Bytecodes::Code)bcp[1];
316 }
317 }
319 assert(bc_length != 0, "impossible bytecode length");
321 switch (c) {
322 case Bytecodes::_lookupswitch : {
323 #ifndef CC_INTERP
324 Bytecode_lookupswitch bc(method, bcp);
325 (*bcp) = (
326 bc.number_of_pairs() < BinarySwitchThreshold
327 ? Bytecodes::_fast_linearswitch
328 : Bytecodes::_fast_binaryswitch
329 );
330 #endif
331 break;
332 }
333 case Bytecodes::_fast_linearswitch:
334 case Bytecodes::_fast_binaryswitch: {
335 #ifndef CC_INTERP
336 (*bcp) = Bytecodes::_lookupswitch;
337 #endif
338 break;
339 }
340 case Bytecodes::_getstatic : // fall through
341 case Bytecodes::_putstatic : // fall through
342 case Bytecodes::_getfield : // fall through
343 case Bytecodes::_putfield : // fall through
344 case Bytecodes::_invokevirtual : // fall through
345 case Bytecodes::_invokespecial : // fall through
346 case Bytecodes::_invokestatic :
347 case Bytecodes::_invokeinterface:
348 case Bytecodes::_invokehandle : // if reverse=true
349 rewrite_member_reference(bcp, prefix_length+1, reverse);
350 break;
351 case Bytecodes::_invokedynamic:
352 rewrite_invokedynamic(bcp, prefix_length+1, reverse);
353 break;
354 case Bytecodes::_ldc:
355 case Bytecodes::_fast_aldc: // if reverse=true
356 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
357 break;
358 case Bytecodes::_ldc_w:
359 case Bytecodes::_fast_aldc_w: // if reverse=true
360 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
361 break;
362 case Bytecodes::_jsr : // fall through
363 case Bytecodes::_jsr_w : nof_jsrs++; break;
364 case Bytecodes::_monitorenter : // fall through
365 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
366 }
367 }
368 }
370 // Update access flags
371 if (has_monitor_bytecodes) {
372 method->set_has_monitor_bytecodes();
373 }
375 // The present of a jsr bytecode implies that the method might potentially
376 // have to be rewritten, so we run the oopMapGenerator on the method
377 if (nof_jsrs > 0) {
378 method->set_has_jsrs();
379 // Second pass will revisit this method.
380 assert(method->has_jsrs(), "didn't we just set this?");
381 }
382 }
384 // After constant pool is created, revisit methods containing jsrs.
385 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) {
386 ResourceMark rm(THREAD);
387 ResolveOopMapConflicts romc(method);
388 methodHandle original_method = method;
389 method = romc.do_potential_rewrite(CHECK_(methodHandle()));
390 // Update monitor matching info.
391 if (romc.monitor_safe()) {
392 method->set_guaranteed_monitor_matching();
393 }
395 return method;
396 }
398 void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) {
399 ResourceMark rm(THREAD);
400 Rewriter rw(klass, klass->constants(), klass->methods(), CHECK);
401 // (That's all, folks.)
402 }
405 void Rewriter::rewrite(instanceKlassHandle klass, constantPoolHandle cpool, Array<Method*>* methods, TRAPS) {
406 ResourceMark rm(THREAD);
407 Rewriter rw(klass, cpool, methods, CHECK);
408 // (That's all, folks.)
409 }
412 Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, Array<Method*>* methods, TRAPS)
413 : _klass(klass),
414 _pool(cpool),
415 _methods(methods)
416 {
417 assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
419 // determine index maps for Method* rewriting
420 compute_index_maps();
422 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
423 bool did_rewrite = false;
424 int i = _methods->length();
425 while (i-- > 0) {
426 Method* method = _methods->at(i);
427 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
428 // rewrite the return bytecodes of Object.<init> to register the
429 // object for finalization if needed.
430 methodHandle m(THREAD, method);
431 rewrite_Object_init(m, CHECK);
432 did_rewrite = true;
433 break;
434 }
435 }
436 assert(did_rewrite, "must find Object::<init> to rewrite it");
437 }
439 // rewrite methods, in two passes
440 int len = _methods->length();
442 for (int i = len-1; i >= 0; i--) {
443 Method* method = _methods->at(i);
444 scan_method(method);
445 }
447 // allocate constant pool cache, now that we've seen all the bytecodes
448 make_constant_pool_cache(THREAD);
450 // Restore bytecodes to their unrewritten state if there are exceptions
451 // rewriting bytecodes or allocating the cpCache
452 if (HAS_PENDING_EXCEPTION) {
453 restore_bytecodes();
454 return;
455 }
456 }
458 // Relocate jsr/rets in a method. This can't be done with the rewriter
459 // stage because it can throw other exceptions, leaving the bytecodes
460 // pointing at constant pool cache entries.
461 // Link and check jvmti dependencies while we're iterating over the methods.
462 // JSR292 code calls with a different set of methods, so two entry points.
463 void Rewriter::relocate_and_link(instanceKlassHandle this_oop, TRAPS) {
464 relocate_and_link(this_oop, this_oop->methods(), THREAD);
465 }
467 void Rewriter::relocate_and_link(instanceKlassHandle this_oop,
468 Array<Method*>* methods, TRAPS) {
469 int len = methods->length();
470 for (int i = len-1; i >= 0; i--) {
471 methodHandle m(THREAD, methods->at(i));
473 if (m->has_jsrs()) {
474 m = rewrite_jsrs(m, CHECK);
475 // Method might have gotten rewritten.
476 methods->at_put(i, m());
477 }
479 // Set up method entry points for compiler and interpreter .
480 m->link_method(m, CHECK);
482 // This is for JVMTI and unrelated to relocator but the last thing we do
483 #ifdef ASSERT
484 if (StressMethodComparator) {
485 static int nmc = 0;
486 for (int j = i; j >= 0 && j >= i-4; j--) {
487 if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
488 bool z = MethodComparator::methods_EMCP(m(),
489 methods->at(j));
490 if (j == i && !z) {
491 tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
492 assert(z, "method must compare equal to itself");
493 }
494 }
495 }
496 #endif //ASSERT
497 }
498 }