1 /*
   2  * Copyright (c) 1997, 2021, 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 #include "precompiled.hpp"
  26 #include "cds/cppVtables.hpp"
  27 #include "cds/metaspaceShared.hpp"
  28 #include "classfile/classLoaderDataGraph.hpp"
  29 #include "classfile/metadataOnStackMark.hpp"
  30 #include "classfile/symbolTable.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmClasses.hpp"
  33 #include "code/codeCache.hpp"
  34 #include "code/debugInfoRec.hpp"
  35 #include "compiler/compilationPolicy.hpp"
  36 #include "gc/shared/collectedHeap.inline.hpp"
  37 #include "interpreter/bytecodeStream.hpp"
  38 #include "interpreter/bytecodeTracer.hpp"
  39 #include "interpreter/bytecodes.hpp"
  40 #include "interpreter/interpreter.hpp"
  41 #include "interpreter/oopMapCache.hpp"
  42 #include "logging/log.hpp"
  43 #include "logging/logTag.hpp"
  44 #include "logging/logStream.hpp"
  45 #include "memory/allocation.inline.hpp"
  46 #include "memory/metadataFactory.hpp"
  47 #include "memory/metaspaceClosure.hpp"
  48 #include "memory/oopFactory.hpp"
  49 #include "memory/resourceArea.hpp"
  50 #include "memory/universe.hpp"
  51 #include "oops/constMethod.hpp"
  52 #include "oops/constantPool.hpp"
  53 #include "oops/klass.inline.hpp"
  54 #include "oops/method.inline.hpp"
  55 #include "oops/methodData.hpp"
  56 #include "oops/objArrayKlass.hpp"
  57 #include "oops/objArrayOop.inline.hpp"
  58 #include "oops/oop.inline.hpp"
  59 #include "oops/symbol.hpp"
  60 #include "prims/jvmtiExport.hpp"
  61 #include "prims/methodHandles.hpp"
  62 #include "runtime/arguments.hpp"
  63 #include "runtime/atomic.hpp"
  64 #include "runtime/frame.inline.hpp"
  65 #include "runtime/handles.inline.hpp"
  66 #include "runtime/init.hpp"
  67 #include "runtime/orderAccess.hpp"
  68 #include "runtime/relocator.hpp"
  69 #include "runtime/safepointVerifiers.hpp"
  70 #include "runtime/sharedRuntime.hpp"
  71 #include "runtime/signature.hpp"
  72 #include "runtime/vm_version.hpp"
  73 #include "services/memTracker.hpp"
  74 #include "utilities/align.hpp"
  75 #include "utilities/quickSort.hpp"
  76 #include "utilities/vmError.hpp"
  77 #include "utilities/xmlstream.hpp"
  78 
  79 // Implementation of Method
  80 
  81 Method* Method::allocate(ClassLoaderData* loader_data,
  82                          int byte_code_size,
  83                          AccessFlags access_flags,
  84                          InlineTableSizes* sizes,
  85                          ConstMethod::MethodType method_type,
  86                          TRAPS) {
  87   assert(!access_flags.is_native() || byte_code_size == 0,
  88          "native methods should not contain byte codes");
  89   ConstMethod* cm = ConstMethod::allocate(loader_data,
  90                                           byte_code_size,
  91                                           sizes,
  92                                           method_type,
  93                                           CHECK_NULL);
  94   int size = Method::size(access_flags.is_native());
  95   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  96 }
  97 
  98 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  99   NoSafepointVerifier no_safepoint;
 100   set_constMethod(xconst);
 101   set_access_flags(access_flags);
 102   set_intrinsic_id(vmIntrinsics::_none);
 103   set_force_inline(false);
 104   set_hidden(false);
 105   set_dont_inline(false);
 106   set_has_injected_profile(false);
 107   set_method_data(NULL);
 108   clear_method_counters();
 109   set_vtable_index(Method::garbage_vtable_index);
 110 
 111   // Fix and bury in Method*
 112   set_interpreter_entry(NULL); // sets i2i entry and from_int
 113   set_adapter_entry(NULL);
 114   Method::clear_code(); // from_c/from_i get set to c2i/i2i
 115 
 116   if (access_flags.is_native()) {
 117     clear_native_function();
 118     set_signature_handler(NULL);
 119   }
 120 
 121   NOT_PRODUCT(set_compiled_invocation_count(0);)
 122 }
 123 
 124 // Release Method*.  The nmethod will be gone when we get here because
 125 // we've walked the code cache.
 126 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 127   MetadataFactory::free_metadata(loader_data, constMethod());
 128   set_constMethod(NULL);
 129   MetadataFactory::free_metadata(loader_data, method_data());
 130   set_method_data(NULL);
 131   MetadataFactory::free_metadata(loader_data, method_counters());
 132   clear_method_counters();
 133   // The nmethod will be gone when we get here.
 134   if (code() != NULL) _code = NULL;
 135 }
 136 
 137 void Method::release_C_heap_structures() {
 138   if (method_data()) {
 139 #if INCLUDE_JVMCI
 140     FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
 141 #endif
 142     // Destroy MethodData
 143     method_data()->~MethodData();
 144   }
 145 }
 146 
 147 address Method::get_i2c_entry() {
 148   assert(adapter() != NULL, "must have");
 149   return adapter()->get_i2c_entry();
 150 }
 151 
 152 address Method::get_c2i_entry() {
 153   assert(adapter() != NULL, "must have");
 154   return adapter()->get_c2i_entry();
 155 }
 156 
 157 address Method::get_c2i_unverified_entry() {
 158   assert(adapter() != NULL, "must have");
 159   return adapter()->get_c2i_unverified_entry();
 160 }
 161 
 162 address Method::get_c2i_no_clinit_check_entry() {
 163   assert(VM_Version::supports_fast_class_init_checks(), "");
 164   assert(adapter() != NULL, "must have");
 165   return adapter()->get_c2i_no_clinit_check_entry();
 166 }
 167 
 168 char* Method::name_and_sig_as_C_string() const {
 169   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 170 }
 171 
 172 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 173   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 174 }
 175 
 176 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 177   const char* klass_name = klass->external_name();
 178   int klass_name_len  = (int)strlen(klass_name);
 179   int method_name_len = method_name->utf8_length();
 180   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 181   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 182   strcpy(dest, klass_name);
 183   dest[klass_name_len] = '.';
 184   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 185   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 186   dest[len] = 0;
 187   return dest;
 188 }
 189 
 190 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 191   Symbol* klass_name = klass->name();
 192   klass_name->as_klass_external_name(buf, size);
 193   int len = (int)strlen(buf);
 194 
 195   if (len < size - 1) {
 196     buf[len++] = '.';
 197 
 198     method_name->as_C_string(&(buf[len]), size - len);
 199     len = (int)strlen(buf);
 200 
 201     signature->as_C_string(&(buf[len]), size - len);
 202   }
 203 
 204   return buf;
 205 }
 206 
 207 const char* Method::external_name() const {
 208   return external_name(constants()->pool_holder(), name(), signature());
 209 }
 210 
 211 void Method::print_external_name(outputStream *os) const {
 212   print_external_name(os, constants()->pool_holder(), name(), signature());
 213 }
 214 
 215 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
 216   stringStream ss;
 217   print_external_name(&ss, klass, method_name, signature);
 218   return ss.as_string();
 219 }
 220 
 221 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
 222   signature->print_as_signature_external_return_type(os);
 223   os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
 224   signature->print_as_signature_external_parameters(os);
 225   os->print(")");
 226 }
 227 
 228 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 229   if (log_is_enabled(Debug, exceptions)) {
 230     ResourceMark rm(THREAD);
 231     log_debug(exceptions)("Looking for catch handler for exception of type \"%s\" in method \"%s\"",
 232                           ex_klass == NULL ? "NULL" : ex_klass->external_name(), mh->name()->as_C_string());
 233   }
 234   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 235   // access exception table
 236   ExceptionTable table(mh());
 237   int length = table.length();
 238   // iterate through all entries sequentially
 239   constantPoolHandle pool(THREAD, mh->constants());
 240   for (int i = 0; i < length; i ++) {
 241     //reacquire the table in case a GC happened
 242     ExceptionTable table(mh());
 243     int beg_bci = table.start_pc(i);
 244     int end_bci = table.end_pc(i);
 245     assert(beg_bci <= end_bci, "inconsistent exception table");
 246     log_debug(exceptions)("  - checking exception table entry for BCI %d to %d",
 247                          beg_bci, end_bci);
 248 
 249     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 250       // exception handler bci range covers throw_bci => investigate further
 251       log_debug(exceptions)("    - entry covers throw point BCI %d", throw_bci);
 252 
 253       int handler_bci = table.handler_pc(i);
 254       int klass_index = table.catch_type_index(i);
 255       if (klass_index == 0) {
 256         if (log_is_enabled(Info, exceptions)) {
 257           ResourceMark rm(THREAD);
 258           log_info(exceptions)("Found catch-all handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 259                                ex_klass == NULL ? "NULL" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 260         }
 261         return handler_bci;
 262       } else if (ex_klass == NULL) {
 263         // Is this even possible?
 264         if (log_is_enabled(Info, exceptions)) {
 265           ResourceMark rm(THREAD);
 266           log_info(exceptions)("NULL exception class is implicitly caught by handler in method \"%s\" at BCI: %d",
 267                                mh()->name()->as_C_string(), handler_bci);
 268         }
 269         return handler_bci;
 270       } else {
 271         if (log_is_enabled(Debug, exceptions)) {
 272           ResourceMark rm(THREAD);
 273           log_debug(exceptions)("    - resolving catch type \"%s\"",
 274                                pool->klass_name_at(klass_index)->as_C_string());
 275         }
 276         // we know the exception class => get the constraint class
 277         // this may require loading of the constraint class; if verification
 278         // fails or some other exception occurs, return handler_bci
 279         Klass* k = pool->klass_at(klass_index, THREAD);
 280         if (HAS_PENDING_EXCEPTION) {
 281           if (log_is_enabled(Debug, exceptions)) {
 282             ResourceMark rm(THREAD);
 283             log_debug(exceptions)("    - exception \"%s\" occurred resolving catch type",
 284                                  PENDING_EXCEPTION->klass()->external_name());
 285           }
 286           return handler_bci;
 287         }
 288         assert(k != NULL, "klass not loaded");
 289         if (ex_klass->is_subtype_of(k)) {
 290           if (log_is_enabled(Info, exceptions)) {
 291             ResourceMark rm(THREAD);
 292             log_info(exceptions)("Found matching handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 293                                  ex_klass == NULL ? "NULL" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 294           }
 295           return handler_bci;
 296         }
 297       }
 298     }
 299   }
 300 
 301   if (log_is_enabled(Debug, exceptions)) {
 302     ResourceMark rm(THREAD);
 303     log_debug(exceptions)("No catch handler found for exception of type \"%s\" in method \"%s\"",
 304                           ex_klass->external_name(), mh->name()->as_C_string());
 305   }
 306 
 307   return -1;
 308 }
 309 
 310 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 311   methodHandle h_this(Thread::current(), this);
 312   // Only GC uses the OopMapCache during thread stack root scanning
 313   // any other uses generate an oopmap but do not save it in the cache.
 314   if (Universe::heap()->is_gc_active()) {
 315     method_holder()->mask_for(h_this, bci, mask);
 316   } else {
 317     OopMapCache::compute_one_oop_map(h_this, bci, mask);
 318   }
 319   return;
 320 }
 321 
 322 
 323 int Method::bci_from(address bcp) const {
 324   if (is_native() && bcp == 0) {
 325     return 0;
 326   }
 327 #ifdef ASSERT
 328   {
 329     ResourceMark rm;
 330     assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
 331            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 332            p2i(bcp), name_and_sig_as_C_string());
 333   }
 334 #endif
 335   return bcp - code_base();
 336 }
 337 
 338 
 339 int Method::validate_bci(int bci) const {
 340   return (bci == 0 || bci < code_size()) ? bci : -1;
 341 }
 342 
 343 // Return bci if it appears to be a valid bcp
 344 // Return -1 otherwise.
 345 // Used by profiling code, when invalid data is a possibility.
 346 // The caller is responsible for validating the Method* itself.
 347 int Method::validate_bci_from_bcp(address bcp) const {
 348   // keep bci as -1 if not a valid bci
 349   int bci = -1;
 350   if (bcp == 0 || bcp == code_base()) {
 351     // code_size() may return 0 and we allow 0 here
 352     // the method may be native
 353     bci = 0;
 354   } else if (contains(bcp)) {
 355     bci = bcp - code_base();
 356   }
 357   // Assert that if we have dodged any asserts, bci is negative.
 358   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 359   return bci;
 360 }
 361 
 362 address Method::bcp_from(int bci) const {
 363   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 364          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 365   address bcp = code_base() + bci;
 366   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 367   return bcp;
 368 }
 369 
 370 address Method::bcp_from(address bcp) const {
 371   if (is_native() && bcp == NULL) {
 372     return code_base();
 373   } else {
 374     return bcp;
 375   }
 376 }
 377 
 378 int Method::size(bool is_native) {
 379   // If native, then include pointers for native_function and signature_handler
 380   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 381   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 382   return align_metadata_size(header_size() + extra_words);
 383 }
 384 
 385 Symbol* Method::klass_name() const {
 386   return method_holder()->name();
 387 }
 388 
 389 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 390   log_trace(cds)("Iter(Method): %p", this);
 391 
 392   if (!method_holder()->is_rewritten()) {
 393     it->push(&_constMethod, MetaspaceClosure::_writable);
 394   } else {
 395     it->push(&_constMethod);
 396   }
 397   it->push(&_method_data);
 398   it->push(&_method_counters);
 399 }
 400 
 401 // Attempt to return method to original state.  Clear any pointers
 402 // (to objects outside the shared spaces).  We won't be able to predict
 403 // where they should point in a new JVM.  Further initialize some
 404 // entries now in order allow them to be write protected later.
 405 
 406 void Method::remove_unshareable_info() {
 407   unlink_method();
 408   JFR_ONLY(REMOVE_METHOD_ID(this);)
 409 }
 410 
 411 void Method::set_vtable_index(int index) {
 412   if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 413     // At runtime initialize_vtable is rerun as part of link_class_impl()
 414     // for a shared class loaded by the non-boot loader to obtain the loader
 415     // constraints based on the runtime classloaders' context.
 416     return; // don't write into the shared class
 417   } else {
 418     _vtable_index = index;
 419   }
 420 }
 421 
 422 void Method::set_itable_index(int index) {
 423   if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 424     // At runtime initialize_itable is rerun as part of link_class_impl()
 425     // for a shared class loaded by the non-boot loader to obtain the loader
 426     // constraints based on the runtime classloaders' context. The dumptime
 427     // itable index should be the same as the runtime index.
 428     assert(_vtable_index == itable_index_max - index,
 429            "archived itable index is different from runtime index");
 430     return; // don’t write into the shared class
 431   } else {
 432     _vtable_index = itable_index_max - index;
 433   }
 434   assert(valid_itable_index(), "");
 435 }
 436 
 437 // The RegisterNatives call being attempted tried to register with a method that
 438 // is not native.  Ask JVM TI what prefixes have been specified.  Then check
 439 // to see if the native method is now wrapped with the prefixes.  See the
 440 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
 441 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
 442 #if INCLUDE_JVMTI
 443   ResourceMark rm(THREAD);
 444   Method* method;
 445   int name_len = name->utf8_length();
 446   char* name_str = name->as_utf8();
 447   int prefix_count;
 448   char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
 449   for (int i = 0; i < prefix_count; i++) {
 450     char* prefix = prefixes[i];
 451     int prefix_len = (int)strlen(prefix);
 452 
 453     // try adding this prefix to the method name and see if it matches another method name
 454     int trial_len = name_len + prefix_len;
 455     char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
 456     strcpy(trial_name_str, prefix);
 457     strcat(trial_name_str, name_str);
 458     TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
 459     if (trial_name == NULL) {
 460       continue; // no such symbol, so this prefix wasn't used, try the next prefix
 461     }
 462     method = k->lookup_method(trial_name, signature);
 463     if (method == NULL) {
 464       continue; // signature doesn't match, try the next prefix
 465     }
 466     if (method->is_native()) {
 467       method->set_is_prefixed_native();
 468       return method; // wahoo, we found a prefixed version of the method, return it
 469     }
 470     // found as non-native, so prefix is good, add it, probably just need more prefixes
 471     name_len = trial_len;
 472     name_str = trial_name_str;
 473   }
 474 #endif // INCLUDE_JVMTI
 475   return NULL; // not found
 476 }
 477 
 478 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
 479   Method* method = k->lookup_method(name, signature);
 480   if (method == NULL) {
 481     ResourceMark rm(THREAD);
 482     stringStream st;
 483     st.print("Method '");
 484     print_external_name(&st, k, name, signature);
 485     st.print("' name or signature does not match");
 486     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 487   }
 488   if (!method->is_native()) {
 489     // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
 490     method = find_prefixed_native(k, name, signature, THREAD);
 491     if (method == NULL) {
 492       ResourceMark rm(THREAD);
 493       stringStream st;
 494       st.print("Method '");
 495       print_external_name(&st, k, name, signature);
 496       st.print("' is not declared as native");
 497       THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 498     }
 499   }
 500 
 501   if (entry != NULL) {
 502     method->set_native_function(entry, native_bind_event_is_interesting);
 503   } else {
 504     method->clear_native_function();
 505   }
 506   if (log_is_enabled(Debug, jni, resolve)) {
 507     ResourceMark rm(THREAD);
 508     log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
 509                             method->method_holder()->external_name(),
 510                             method->name()->as_C_string());
 511   }
 512   return true;
 513 }
 514 
 515 bool Method::was_executed_more_than(int n) {
 516   // Invocation counter is reset when the Method* is compiled.
 517   // If the method has compiled code we therefore assume it has
 518   // be excuted more than n times.
 519   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 520     // interpreter doesn't bump invocation counter of trivial methods
 521     // compiler does not bump invocation counter of compiled methods
 522     return true;
 523   }
 524   else if ((method_counters() != NULL &&
 525             method_counters()->invocation_counter()->carry()) ||
 526            (method_data() != NULL &&
 527             method_data()->invocation_counter()->carry())) {
 528     // The carry bit is set when the counter overflows and causes
 529     // a compilation to occur.  We don't know how many times
 530     // the counter has been reset, so we simply assume it has
 531     // been executed more than n times.
 532     return true;
 533   } else {
 534     return invocation_count() > n;
 535   }
 536 }
 537 
 538 void Method::print_invocation_count() {
 539   //---<  compose+print method return type, klass, name, and signature  >---
 540   if (is_static()) tty->print("static ");
 541   if (is_final()) tty->print("final ");
 542   if (is_synchronized()) tty->print("synchronized ");
 543   if (is_native()) tty->print("native ");
 544   tty->print("%s::", method_holder()->external_name());
 545   name()->print_symbol_on(tty);
 546   signature()->print_symbol_on(tty);
 547 
 548   if (WizardMode) {
 549     // dump the size of the byte codes
 550     tty->print(" {%d}", code_size());
 551   }
 552   tty->cr();
 553 
 554   // Counting based on signed int counters tends to overflow with
 555   // longer-running workloads on fast machines. The counters under
 556   // consideration here, however, are limited in range by counting
 557   // logic. See InvocationCounter:count_limit for example.
 558   // No "overflow precautions" need to be implemented here.
 559   tty->print_cr ("  interpreter_invocation_count: " INT32_FORMAT_W(11), interpreter_invocation_count());
 560   tty->print_cr ("  invocation_counter:           " INT32_FORMAT_W(11), invocation_count());
 561   tty->print_cr ("  backedge_counter:             " INT32_FORMAT_W(11), backedge_count());
 562 
 563   if (method_data() != NULL) {
 564     tty->print_cr ("  decompile_count:              " UINT32_FORMAT_W(11), method_data()->decompile_count());
 565   }
 566 
 567 #ifndef PRODUCT
 568   if (CountCompiledCalls) {
 569     tty->print_cr ("  compiled_invocation_count:    " INT64_FORMAT_W(11), compiled_invocation_count());
 570   }
 571 #endif
 572 }
 573 
 574 // Build a MethodData* object to hold information about this method
 575 // collected in the interpreter.
 576 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 577   // Do not profile the method if metaspace has hit an OOM previously
 578   // allocating profiling data. Callers clear pending exception so don't
 579   // add one here.
 580   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 581     return;
 582   }
 583 
 584   // Grab a lock here to prevent multiple
 585   // MethodData*s from being created.
 586   MutexLocker ml(THREAD, MethodData_lock);
 587   if (method->method_data() == NULL) {
 588     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 589     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 590     if (HAS_PENDING_EXCEPTION) {
 591       CompileBroker::log_metaspace_failure();
 592       ClassLoaderDataGraph::set_metaspace_oom(true);
 593       return;   // return the exception (which is cleared)
 594     }
 595 
 596     method->set_method_data(method_data);
 597     if (PrintMethodData && (Verbose || WizardMode)) {
 598       ResourceMark rm(THREAD);
 599       tty->print("build_interpreter_method_data for ");
 600       method->print_name(tty);
 601       tty->cr();
 602       // At the end of the run, the MDO, full of data, will be dumped.
 603     }
 604   }
 605 }
 606 
 607 MethodCounters* Method::build_method_counters(Thread* current, Method* m) {
 608   // Do not profile the method if metaspace has hit an OOM previously
 609   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 610     return NULL;
 611   }
 612 
 613   methodHandle mh(current, m);
 614   MethodCounters* counters;
 615   if (current->is_Java_thread()) {
 616     JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
 617     // Use the TRAPS version for a JavaThread so it will adjust the GC threshold
 618     // if needed.
 619     counters = MethodCounters::allocate_with_exception(mh, THREAD);
 620     if (HAS_PENDING_EXCEPTION) {
 621       CLEAR_PENDING_EXCEPTION;
 622     }
 623   } else {
 624     // Call metaspace allocation that doesn't throw exception if the
 625     // current thread isn't a JavaThread, ie. the VMThread.
 626     counters = MethodCounters::allocate_no_exception(mh);
 627   }
 628 
 629   if (counters == NULL) {
 630     CompileBroker::log_metaspace_failure();
 631     ClassLoaderDataGraph::set_metaspace_oom(true);
 632     return NULL;
 633   }
 634 
 635   if (!mh->init_method_counters(counters)) {
 636     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 637   }
 638 
 639   if (LogTouchedMethods) {
 640     mh->log_touched(current);
 641   }
 642 
 643   return mh->method_counters();
 644 }
 645 
 646 bool Method::init_method_counters(MethodCounters* counters) {
 647   // Try to install a pointer to MethodCounters, return true on success.
 648   return Atomic::replace_if_null(&_method_counters, counters);
 649 }
 650 
 651 int Method::extra_stack_words() {
 652   // not an inline function, to avoid a header dependency on Interpreter
 653   return extra_stack_entries() * Interpreter::stackElementSize;
 654 }
 655 
 656 // Derive size of parameters, return type, and fingerprint,
 657 // all in one pass, which is run at load time.
 658 // We need the first two, and might as well grab the third.
 659 void Method::compute_from_signature(Symbol* sig) {
 660   // At this point, since we are scanning the signature,
 661   // we might as well compute the whole fingerprint.
 662   Fingerprinter fp(sig, is_static());
 663   set_size_of_parameters(fp.size_of_parameters());
 664   constMethod()->set_result_type(fp.return_type());
 665   constMethod()->set_fingerprint(fp.fingerprint());
 666 }
 667 
 668 bool Method::is_vanilla_constructor() const {
 669   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 670   // which only calls the superclass vanilla constructor and possibly does stores of
 671   // zero constants to local fields:
 672   //
 673   //   aload_0
 674   //   invokespecial
 675   //   indexbyte1
 676   //   indexbyte2
 677   //
 678   // followed by an (optional) sequence of:
 679   //
 680   //   aload_0
 681   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 682   //   putfield
 683   //   indexbyte1
 684   //   indexbyte2
 685   //
 686   // followed by:
 687   //
 688   //   return
 689 
 690   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 691   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 692   int size = code_size();
 693   // Check if size match
 694   if (size == 0 || size % 5 != 0) return false;
 695   address cb = code_base();
 696   int last = size - 1;
 697   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 698     // Does not call superclass default constructor
 699     return false;
 700   }
 701   // Check optional sequence
 702   for (int i = 4; i < last; i += 5) {
 703     if (cb[i] != Bytecodes::_aload_0) return false;
 704     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 705     if (cb[i+2] != Bytecodes::_putfield) return false;
 706   }
 707   return true;
 708 }
 709 
 710 
 711 bool Method::compute_has_loops_flag() {
 712   BytecodeStream bcs(methodHandle(Thread::current(), this));
 713   Bytecodes::Code bc;
 714 
 715   while ((bc = bcs.next()) >= 0) {
 716     switch (bc) {
 717       case Bytecodes::_ifeq:
 718       case Bytecodes::_ifnull:
 719       case Bytecodes::_iflt:
 720       case Bytecodes::_ifle:
 721       case Bytecodes::_ifne:
 722       case Bytecodes::_ifnonnull:
 723       case Bytecodes::_ifgt:
 724       case Bytecodes::_ifge:
 725       case Bytecodes::_if_icmpeq:
 726       case Bytecodes::_if_icmpne:
 727       case Bytecodes::_if_icmplt:
 728       case Bytecodes::_if_icmpgt:
 729       case Bytecodes::_if_icmple:
 730       case Bytecodes::_if_icmpge:
 731       case Bytecodes::_if_acmpeq:
 732       case Bytecodes::_if_acmpne:
 733       case Bytecodes::_goto:
 734       case Bytecodes::_jsr:
 735         if (bcs.dest() < bcs.next_bci()) _access_flags.set_has_loops();
 736         break;
 737 
 738       case Bytecodes::_goto_w:
 739       case Bytecodes::_jsr_w:
 740         if (bcs.dest_w() < bcs.next_bci()) _access_flags.set_has_loops();
 741         break;
 742 
 743       case Bytecodes::_lookupswitch: {
 744         Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
 745         if (lookupswitch.default_offset() < 0) {
 746           _access_flags.set_has_loops();
 747         } else {
 748           for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
 749             LookupswitchPair pair = lookupswitch.pair_at(i);
 750             if (pair.offset() < 0) {
 751               _access_flags.set_has_loops();
 752               break;
 753             }
 754           }
 755         }
 756         break;
 757       }
 758       case Bytecodes::_tableswitch: {
 759         Bytecode_tableswitch tableswitch(this, bcs.bcp());
 760         if (tableswitch.default_offset() < 0) {
 761           _access_flags.set_has_loops();
 762         } else {
 763           for (int i = 0; i < tableswitch.length(); ++i) {
 764             if (tableswitch.dest_offset_at(i) < 0) {
 765               _access_flags.set_has_loops();
 766             }
 767           }
 768         }
 769         break;
 770       }
 771       default:
 772         break;
 773     }
 774   }
 775   _access_flags.set_loops_flag_init();
 776   return _access_flags.has_loops();
 777 }
 778 
 779 bool Method::is_final_method(AccessFlags class_access_flags) const {
 780   // or "does_not_require_vtable_entry"
 781   // default method or overpass can occur, is not final (reuses vtable entry)
 782   // private methods in classes get vtable entries for backward class compatibility.
 783   if (is_overpass() || is_default_method())  return false;
 784   return is_final() || class_access_flags.is_final();
 785 }
 786 
 787 bool Method::is_final_method() const {
 788   return is_final_method(method_holder()->access_flags());
 789 }
 790 
 791 bool Method::is_default_method() const {
 792   if (method_holder() != NULL &&
 793       method_holder()->is_interface() &&
 794       !is_abstract() && !is_private()) {
 795     return true;
 796   } else {
 797     return false;
 798   }
 799 }
 800 
 801 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 802   if (is_final_method(class_access_flags))  return true;
 803 #ifdef ASSERT
 804   ResourceMark rm;
 805   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 806   if (class_access_flags.is_interface()) {
 807       assert(is_nonv == is_static() || is_nonv == is_private(),
 808              "nonvirtual unexpected for non-static, non-private: %s",
 809              name_and_sig_as_C_string());
 810   }
 811 #endif
 812   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 813   return vtable_index() == nonvirtual_vtable_index;
 814 }
 815 
 816 bool Method::can_be_statically_bound() const {
 817   return can_be_statically_bound(method_holder()->access_flags());
 818 }
 819 
 820 bool Method::can_be_statically_bound(InstanceKlass* context) const {
 821   return (method_holder() == context) && can_be_statically_bound();
 822 }
 823 
 824 bool Method::is_accessor() const {
 825   return is_getter() || is_setter();
 826 }
 827 
 828 bool Method::is_getter() const {
 829   if (code_size() != 5) return false;
 830   if (size_of_parameters() != 1) return false;
 831   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 832   if (java_code_at(1) != Bytecodes::_getfield) return false;
 833   switch (java_code_at(4)) {
 834     case Bytecodes::_ireturn:
 835     case Bytecodes::_lreturn:
 836     case Bytecodes::_freturn:
 837     case Bytecodes::_dreturn:
 838     case Bytecodes::_areturn:
 839       break;
 840     default:
 841       return false;
 842   }
 843   return true;
 844 }
 845 
 846 bool Method::is_setter() const {
 847   if (code_size() != 6) return false;
 848   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 849   switch (java_code_at(1)) {
 850     case Bytecodes::_iload_1:
 851     case Bytecodes::_aload_1:
 852     case Bytecodes::_fload_1:
 853       if (size_of_parameters() != 2) return false;
 854       break;
 855     case Bytecodes::_dload_1:
 856     case Bytecodes::_lload_1:
 857       if (size_of_parameters() != 3) return false;
 858       break;
 859     default:
 860       return false;
 861   }
 862   if (java_code_at(2) != Bytecodes::_putfield) return false;
 863   if (java_code_at(5) != Bytecodes::_return)   return false;
 864   return true;
 865 }
 866 
 867 bool Method::is_constant_getter() const {
 868   int last_index = code_size() - 1;
 869   // Check if the first 1-3 bytecodes are a constant push
 870   // and the last bytecode is a return.
 871   return (2 <= code_size() && code_size() <= 4 &&
 872           Bytecodes::is_const(java_code_at(0)) &&
 873           Bytecodes::length_for(java_code_at(0)) == last_index &&
 874           Bytecodes::is_return(java_code_at(last_index)));
 875 }
 876 
 877 bool Method::is_initializer() const {
 878   return is_object_initializer() || is_static_initializer();
 879 }
 880 
 881 bool Method::has_valid_initializer_flags() const {
 882   return (is_static() ||
 883           method_holder()->major_version() < 51);
 884 }
 885 
 886 bool Method::is_static_initializer() const {
 887   // For classfiles version 51 or greater, ensure that the clinit method is
 888   // static.  Non-static methods with the name "<clinit>" are not static
 889   // initializers. (older classfiles exempted for backward compatibility)
 890   return name() == vmSymbols::class_initializer_name() &&
 891          has_valid_initializer_flags();
 892 }
 893 
 894 bool Method::is_object_initializer() const {
 895    return name() == vmSymbols::object_initializer_name();
 896 }
 897 
 898 bool Method::needs_clinit_barrier() const {
 899   return is_static() && !method_holder()->is_initialized();
 900 }
 901 
 902 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 903   int length = method->checked_exceptions_length();
 904   if (length == 0) {  // common case
 905     return objArrayHandle(THREAD, Universe::the_empty_class_array());
 906   } else {
 907     methodHandle h_this(THREAD, method);
 908     objArrayOop m_oop = oopFactory::new_objArray(vmClasses::Class_klass(), length, CHECK_(objArrayHandle()));
 909     objArrayHandle mirrors (THREAD, m_oop);
 910     for (int i = 0; i < length; i++) {
 911       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 912       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 913       if (log_is_enabled(Warning, exceptions) &&
 914           !k->is_subclass_of(vmClasses::Throwable_klass())) {
 915         ResourceMark rm(THREAD);
 916         log_warning(exceptions)(
 917           "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
 918           k->external_name(), method->external_name());
 919       }
 920       mirrors->obj_at_put(i, k->java_mirror());
 921     }
 922     return mirrors;
 923   }
 924 };
 925 
 926 
 927 int Method::line_number_from_bci(int bci) const {
 928   int best_bci  =  0;
 929   int best_line = -1;
 930   if (bci == SynchronizationEntryBCI) bci = 0;
 931   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 932     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 933     // Not necessarily sorted and not necessarily one-to-one.
 934     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 935     while (stream.read_pair()) {
 936       if (stream.bci() == bci) {
 937         // perfect match
 938         return stream.line();
 939       } else {
 940         // update best_bci/line
 941         if (stream.bci() < bci && stream.bci() >= best_bci) {
 942           best_bci  = stream.bci();
 943           best_line = stream.line();
 944         }
 945       }
 946     }
 947   }
 948   return best_line;
 949 }
 950 
 951 
 952 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 953   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 954     Thread *thread = Thread::current();
 955     Symbol* klass_name = constants()->klass_name_at(klass_index);
 956     Handle loader(thread, method_holder()->class_loader());
 957     Handle prot  (thread, method_holder()->protection_domain());
 958     return SystemDictionary::find_instance_klass(klass_name, loader, prot) != NULL;
 959   } else {
 960     return true;
 961   }
 962 }
 963 
 964 
 965 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 966   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 967   if (must_be_resolved) {
 968     // Make sure klass is resolved in constantpool.
 969     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 970   }
 971   return is_klass_loaded_by_klass_index(klass_index);
 972 }
 973 
 974 
 975 void Method::set_native_function(address function, bool post_event_flag) {
 976   assert(function != NULL, "use clear_native_function to unregister natives");
 977   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 978   address* native_function = native_function_addr();
 979 
 980   // We can see racers trying to place the same native function into place. Once
 981   // is plenty.
 982   address current = *native_function;
 983   if (current == function) return;
 984   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 985       function != NULL) {
 986     // native_method_throw_unsatisfied_link_error_entry() should only
 987     // be passed when post_event_flag is false.
 988     assert(function !=
 989       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 990       "post_event_flag mis-match");
 991 
 992     // post the bind event, and possible change the bind function
 993     JvmtiExport::post_native_method_bind(this, &function);
 994   }
 995   *native_function = function;
 996   // This function can be called more than once. We must make sure that we always
 997   // use the latest registered method -> check if a stub already has been generated.
 998   // If so, we have to make it not_entrant.
 999   CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
1000   if (nm != NULL) {
1001     nm->make_not_entrant();
1002   }
1003 }
1004 
1005 
1006 bool Method::has_native_function() const {
1007   if (is_method_handle_intrinsic())
1008     return false;  // special-cased in SharedRuntime::generate_native_wrapper
1009   address func = native_function();
1010   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
1011 }
1012 
1013 
1014 void Method::clear_native_function() {
1015   // Note: is_method_handle_intrinsic() is allowed here.
1016   set_native_function(
1017     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1018     !native_bind_event_is_interesting);
1019   this->unlink_code();
1020 }
1021 
1022 
1023 void Method::set_signature_handler(address handler) {
1024   address* signature_handler =  signature_handler_addr();
1025   *signature_handler = handler;
1026 }
1027 
1028 
1029 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
1030   assert(reason != NULL, "must provide a reason");
1031   if (PrintCompilation && report) {
1032     ttyLocker ttyl;
1033     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
1034     if (comp_level == CompLevel_all) {
1035       tty->print("all levels ");
1036     } else {
1037       tty->print("level %d ", comp_level);
1038     }
1039     this->print_short_name(tty);
1040     int size = this->code_size();
1041     if (size > 0) {
1042       tty->print(" (%d bytes)", size);
1043     }
1044     if (reason != NULL) {
1045       tty->print("   %s", reason);
1046     }
1047     tty->cr();
1048   }
1049   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
1050     ttyLocker ttyl;
1051     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
1052                      os::current_thread_id(), is_osr, comp_level);
1053     if (reason != NULL) {
1054       xtty->print(" reason=\'%s\'", reason);
1055     }
1056     xtty->method(this);
1057     xtty->stamp();
1058     xtty->end_elem();
1059   }
1060 }
1061 
1062 bool Method::is_always_compilable() const {
1063   // Generated adapters must be compiled
1064   if (is_method_handle_intrinsic() && is_synthetic()) {
1065     assert(!is_not_c1_compilable(), "sanity check");
1066     assert(!is_not_c2_compilable(), "sanity check");
1067     return true;
1068   }
1069 
1070   return false;
1071 }
1072 
1073 bool Method::is_not_compilable(int comp_level) const {
1074   if (number_of_breakpoints() > 0)
1075     return true;
1076   if (is_always_compilable())
1077     return false;
1078   if (comp_level == CompLevel_any)
1079     return is_not_c1_compilable() && is_not_c2_compilable();
1080   if (is_c1_compile(comp_level))
1081     return is_not_c1_compilable();
1082   if (is_c2_compile(comp_level))
1083     return is_not_c2_compilable();
1084   return false;
1085 }
1086 
1087 // call this when compiler finds that this method is not compilable
1088 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
1089   if (is_always_compilable()) {
1090     // Don't mark a method which should be always compilable
1091     return;
1092   }
1093   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
1094   if (comp_level == CompLevel_all) {
1095     set_not_c1_compilable();
1096     set_not_c2_compilable();
1097   } else {
1098     if (is_c1_compile(comp_level))
1099       set_not_c1_compilable();
1100     if (is_c2_compile(comp_level))
1101       set_not_c2_compilable();
1102   }
1103   assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1104 }
1105 
1106 bool Method::is_not_osr_compilable(int comp_level) const {
1107   if (is_not_compilable(comp_level))
1108     return true;
1109   if (comp_level == CompLevel_any)
1110     return is_not_c1_osr_compilable() && is_not_c2_osr_compilable();
1111   if (is_c1_compile(comp_level))
1112     return is_not_c1_osr_compilable();
1113   if (is_c2_compile(comp_level))
1114     return is_not_c2_osr_compilable();
1115   return false;
1116 }
1117 
1118 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1119   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1120   if (comp_level == CompLevel_all) {
1121     set_not_c1_osr_compilable();
1122     set_not_c2_osr_compilable();
1123   } else {
1124     if (is_c1_compile(comp_level))
1125       set_not_c1_osr_compilable();
1126     if (is_c2_compile(comp_level))
1127       set_not_c2_osr_compilable();
1128   }
1129   assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1130 }
1131 
1132 // Revert to using the interpreter and clear out the nmethod
1133 void Method::clear_code() {
1134   // this may be NULL if c2i adapters have not been made yet
1135   // Only should happen at allocate time.
1136   if (adapter() == NULL) {
1137     _from_compiled_entry    = NULL;
1138   } else {
1139     _from_compiled_entry    = adapter()->get_c2i_entry();
1140   }
1141   OrderAccess::storestore();
1142   _from_interpreted_entry = _i2i_entry;
1143   OrderAccess::storestore();
1144   _code = NULL;
1145 }
1146 
1147 void Method::unlink_code(CompiledMethod *compare) {
1148   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1149   // We need to check if either the _code or _from_compiled_code_entry_point
1150   // refer to this nmethod because there is a race in setting these two fields
1151   // in Method* as seen in bugid 4947125.
1152   // If the vep() points to the zombie nmethod, the memory for the nmethod
1153   // could be flushed and the compiler and vtable stubs could still call
1154   // through it.
1155   if (code() == compare ||
1156       from_compiled_entry() == compare->verified_entry_point()) {
1157     clear_code();
1158   }
1159 }
1160 
1161 void Method::unlink_code() {
1162   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
1163   clear_code();
1164 }
1165 
1166 #if INCLUDE_CDS
1167 // Called by class data sharing to remove any entry points (which are not shared)
1168 void Method::unlink_method() {
1169   Arguments::assert_is_dumping_archive();
1170   _code = NULL;
1171   _adapter = NULL;
1172   _i2i_entry = NULL;
1173   _from_compiled_entry = NULL;
1174   _from_interpreted_entry = NULL;
1175 
1176   if (is_native()) {
1177     *native_function_addr() = NULL;
1178     set_signature_handler(NULL);
1179   }
1180   NOT_PRODUCT(set_compiled_invocation_count(0);)
1181 
1182   set_method_data(NULL);
1183   clear_method_counters();
1184 }
1185 #endif
1186 
1187 // Called when the method_holder is getting linked. Setup entrypoints so the method
1188 // is ready to be called from interpreter, compiler, and vtables.
1189 void Method::link_method(const methodHandle& h_method, TRAPS) {
1190   // If the code cache is full, we may reenter this function for the
1191   // leftover methods that weren't linked.
1192   if (_i2i_entry != NULL) {
1193     return;
1194   }
1195   assert( _code == NULL, "nothing compiled yet" );
1196 
1197   // Setup interpreter entrypoint
1198   assert(this == h_method(), "wrong h_method()" );
1199 
1200   assert(adapter() == NULL, "init'd to NULL");
1201   address entry = Interpreter::entry_for_method(h_method);
1202   assert(entry != NULL, "interpreter entry must be non-null");
1203   // Sets both _i2i_entry and _from_interpreted_entry
1204   set_interpreter_entry(entry);
1205 
1206   // Don't overwrite already registered native entries.
1207   if (is_native() && !has_native_function()) {
1208     set_native_function(
1209       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1210       !native_bind_event_is_interesting);
1211   }
1212 
1213   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1214   // special handling of vtables.  An alternative is to make adapters more
1215   // lazily by calling make_adapter() from from_compiled_entry() for the
1216   // normal calls.  For vtable calls life gets more complicated.  When a
1217   // call-site goes mega-morphic we need adapters in all methods which can be
1218   // called from the vtable.  We need adapters on such methods that get loaded
1219   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1220   // problem we'll make these lazily later.
1221   (void) make_adapters(h_method, CHECK);
1222 
1223   // ONLY USE the h_method now as make_adapter may have blocked
1224 }
1225 
1226 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1227   // Adapters for compiled code are made eagerly here.  They are fairly
1228   // small (generally < 100 bytes) and quick to make (and cached and shared)
1229   // so making them eagerly shouldn't be too expensive.
1230   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1231   if (adapter == NULL ) {
1232     if (!is_init_completed()) {
1233       // Don't throw exceptions during VM initialization because java.lang.* classes
1234       // might not have been initialized, causing problems when constructing the
1235       // Java exception object.
1236       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1237     } else {
1238       THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1239     }
1240   }
1241 
1242   mh->set_adapter_entry(adapter);
1243   mh->_from_compiled_entry = adapter->get_c2i_entry();
1244   return adapter->get_c2i_entry();
1245 }
1246 
1247 void Method::restore_unshareable_info(TRAPS) {
1248   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1249 }
1250 
1251 address Method::from_compiled_entry_no_trampoline() const {
1252   CompiledMethod *code = Atomic::load_acquire(&_code);
1253   if (code) {
1254     return code->verified_entry_point();
1255   } else {
1256     return adapter()->get_c2i_entry();
1257   }
1258 }
1259 
1260 // The verified_code_entry() must be called when a invoke is resolved
1261 // on this method.
1262 
1263 // It returns the compiled code entry point, after asserting not null.
1264 // This function is called after potential safepoints so that nmethod
1265 // or adapter that it points to is still live and valid.
1266 // This function must not hit a safepoint!
1267 address Method::verified_code_entry() {
1268   debug_only(NoSafepointVerifier nsv;)
1269   assert(_from_compiled_entry != NULL, "must be set");
1270   return _from_compiled_entry;
1271 }
1272 
1273 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1274 // (could be racing a deopt).
1275 // Not inline to avoid circular ref.
1276 bool Method::check_code() const {
1277   // cached in a register or local.  There's a race on the value of the field.
1278   CompiledMethod *code = Atomic::load_acquire(&_code);
1279   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1280 }
1281 
1282 // Install compiled code.  Instantly it can execute.
1283 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1284   assert_lock_strong(CompiledMethod_lock);
1285   assert( code, "use clear_code to remove code" );
1286   assert( mh->check_code(), "" );
1287 
1288   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1289 
1290   // These writes must happen in this order, because the interpreter will
1291   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1292   // which jumps to _from_compiled_entry.
1293   mh->_code = code;             // Assign before allowing compiled code to exec
1294 
1295   int comp_level = code->comp_level();
1296   // In theory there could be a race here. In practice it is unlikely
1297   // and not worth worrying about.
1298   if (comp_level > mh->highest_comp_level()) {
1299     mh->set_highest_comp_level(comp_level);
1300   }
1301 
1302   OrderAccess::storestore();
1303   mh->_from_compiled_entry = code->verified_entry_point();
1304   OrderAccess::storestore();
1305   // Instantly compiled code can execute.
1306   if (!mh->is_method_handle_intrinsic())
1307     mh->_from_interpreted_entry = mh->get_i2c_entry();
1308 }
1309 
1310 
1311 bool Method::is_overridden_in(Klass* k) const {
1312   InstanceKlass* ik = InstanceKlass::cast(k);
1313 
1314   if (ik->is_interface()) return false;
1315 
1316   // If method is an interface, we skip it - except if it
1317   // is a miranda method
1318   if (method_holder()->is_interface()) {
1319     // Check that method is not a miranda method
1320     if (ik->lookup_method(name(), signature()) == NULL) {
1321       // No implementation exist - so miranda method
1322       return false;
1323     }
1324     return true;
1325   }
1326 
1327   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1328   if (!has_vtable_index()) {
1329     return false;
1330   } else {
1331     Method* vt_m = ik->method_at_vtable(vtable_index());
1332     return vt_m != this;
1333   }
1334 }
1335 
1336 
1337 // give advice about whether this Method* should be cached or not
1338 bool Method::should_not_be_cached() const {
1339   if (is_old()) {
1340     // This method has been redefined. It is either EMCP or obsolete
1341     // and we don't want to cache it because that would pin the method
1342     // down and prevent it from being collectible if and when it
1343     // finishes executing.
1344     return true;
1345   }
1346 
1347   // caching this method should be just fine
1348   return false;
1349 }
1350 
1351 
1352 /**
1353  *  Returns true if this is one of the specially treated methods for
1354  *  security related stack walks (like Reflection.getCallerClass).
1355  */
1356 bool Method::is_ignored_by_security_stack_walk() const {
1357   if (intrinsic_id() == vmIntrinsics::_invoke) {
1358     // This is Method.invoke() -- ignore it
1359     return true;
1360   }
1361   if (method_holder()->is_subclass_of(vmClasses::reflect_MethodAccessorImpl_klass())) {
1362     // This is an auxilary frame -- ignore it
1363     return true;
1364   }
1365   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1366     // This is an internal adapter frame for method handles -- ignore it
1367     return true;
1368   }
1369   return false;
1370 }
1371 
1372 
1373 // Constant pool structure for invoke methods:
1374 enum {
1375   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1376   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1377   _imcp_limit
1378 };
1379 
1380 // Test if this method is an MH adapter frame generated by Java code.
1381 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1382 bool Method::is_compiled_lambda_form() const {
1383   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1384 }
1385 
1386 // Test if this method is an internal MH primitive method.
1387 bool Method::is_method_handle_intrinsic() const {
1388   vmIntrinsics::ID iid = intrinsic_id();
1389   return (MethodHandles::is_signature_polymorphic(iid) &&
1390           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1391 }
1392 
1393 bool Method::has_member_arg() const {
1394   vmIntrinsics::ID iid = intrinsic_id();
1395   return (MethodHandles::is_signature_polymorphic(iid) &&
1396           MethodHandles::has_member_arg(iid));
1397 }
1398 
1399 // Make an instance of a signature-polymorphic internal MH primitive.
1400 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1401                                                          Symbol* signature,
1402                                                          TRAPS) {
1403   ResourceMark rm(THREAD);
1404   methodHandle empty;
1405 
1406   InstanceKlass* holder = vmClasses::MethodHandle_klass();
1407   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1408   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1409 
1410   log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1411 
1412   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1413   name->increment_refcount();
1414   signature->increment_refcount();
1415 
1416   int cp_length = _imcp_limit;
1417   ClassLoaderData* loader_data = holder->class_loader_data();
1418   constantPoolHandle cp;
1419   {
1420     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1421     cp = constantPoolHandle(THREAD, cp_oop);
1422   }
1423   cp->copy_fields(holder->constants());
1424   cp->set_pool_holder(holder);
1425   cp->symbol_at_put(_imcp_invoke_name,       name);
1426   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1427   cp->set_has_preresolution();
1428 
1429   // decide on access bits:  public or not?
1430   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1431   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1432   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1433   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1434 
1435   methodHandle m;
1436   {
1437     InlineTableSizes sizes;
1438     Method* m_oop = Method::allocate(loader_data, 0,
1439                                      accessFlags_from(flags_bits), &sizes,
1440                                      ConstMethod::NORMAL, CHECK_(empty));
1441     m = methodHandle(THREAD, m_oop);
1442   }
1443   m->set_constants(cp());
1444   m->set_name_index(_imcp_invoke_name);
1445   m->set_signature_index(_imcp_invoke_signature);
1446   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1447   assert(m->signature() == signature, "");
1448   m->compute_from_signature(signature);
1449   m->init_intrinsic_id(klass_id_for_intrinsics(m->method_holder()));
1450   assert(m->is_method_handle_intrinsic(), "");
1451 #ifdef ASSERT
1452   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1453   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1454   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1455 #endif //ASSERT
1456 
1457   // Finally, set up its entry points.
1458   assert(m->can_be_statically_bound(), "");
1459   m->set_vtable_index(Method::nonvirtual_vtable_index);
1460   m->link_method(m, CHECK_(empty));
1461 
1462   if (iid == vmIntrinsics::_linkToNative) {
1463     m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1464   }
1465   if (log_is_enabled(Info, methodhandles) && (Verbose || WizardMode)) {
1466     LogTarget(Info, methodhandles) lt;
1467     LogStream ls(lt);
1468     m->print_on(&ls);
1469   }
1470 
1471   return m;
1472 }
1473 
1474 Klass* Method::check_non_bcp_klass(Klass* klass) {
1475   if (klass != NULL && klass->class_loader() != NULL) {
1476     if (klass->is_objArray_klass())
1477       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1478     return klass;
1479   }
1480   return NULL;
1481 }
1482 
1483 
1484 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1485                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1486   // Code below does not work for native methods - they should never get rewritten anyway
1487   assert(!m->is_native(), "cannot rewrite native methods");
1488   // Allocate new Method*
1489   AccessFlags flags = m->access_flags();
1490 
1491   ConstMethod* cm = m->constMethod();
1492   int checked_exceptions_len = cm->checked_exceptions_length();
1493   int localvariable_len = cm->localvariable_table_length();
1494   int exception_table_len = cm->exception_table_length();
1495   int method_parameters_len = cm->method_parameters_length();
1496   int method_annotations_len = cm->method_annotations_length();
1497   int parameter_annotations_len = cm->parameter_annotations_length();
1498   int type_annotations_len = cm->type_annotations_length();
1499   int default_annotations_len = cm->default_annotations_length();
1500 
1501   InlineTableSizes sizes(
1502       localvariable_len,
1503       new_compressed_linenumber_size,
1504       exception_table_len,
1505       checked_exceptions_len,
1506       method_parameters_len,
1507       cm->generic_signature_index(),
1508       method_annotations_len,
1509       parameter_annotations_len,
1510       type_annotations_len,
1511       default_annotations_len,
1512       0);
1513 
1514   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1515   Method* newm_oop = Method::allocate(loader_data,
1516                                       new_code_length,
1517                                       flags,
1518                                       &sizes,
1519                                       m->method_type(),
1520                                       CHECK_(methodHandle()));
1521   methodHandle newm (THREAD, newm_oop);
1522 
1523   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1524   ConstMethod* newcm = newm->constMethod();
1525   int new_const_method_size = newm->constMethod()->size();
1526 
1527   // This works because the source and target are both Methods. Some compilers
1528   // (e.g., clang) complain that the target vtable pointer will be stomped,
1529   // so cast away newm()'s and m()'s Methodness.
1530   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1531 
1532   // Create shallow copy of ConstMethod.
1533   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1534 
1535   // Reset correct method/const method, method size, and parameter info
1536   newm->set_constMethod(newcm);
1537   newm->constMethod()->set_code_size(new_code_length);
1538   newm->constMethod()->set_constMethod_size(new_const_method_size);
1539   assert(newm->code_size() == new_code_length, "check");
1540   assert(newm->method_parameters_length() == method_parameters_len, "check");
1541   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1542   assert(newm->exception_table_length() == exception_table_len, "check");
1543   assert(newm->localvariable_table_length() == localvariable_len, "check");
1544   // Copy new byte codes
1545   memcpy(newm->code_base(), new_code, new_code_length);
1546   // Copy line number table
1547   if (new_compressed_linenumber_size > 0) {
1548     memcpy(newm->compressed_linenumber_table(),
1549            new_compressed_linenumber_table,
1550            new_compressed_linenumber_size);
1551   }
1552   // Copy method_parameters
1553   if (method_parameters_len > 0) {
1554     memcpy(newm->method_parameters_start(),
1555            m->method_parameters_start(),
1556            method_parameters_len * sizeof(MethodParametersElement));
1557   }
1558   // Copy checked_exceptions
1559   if (checked_exceptions_len > 0) {
1560     memcpy(newm->checked_exceptions_start(),
1561            m->checked_exceptions_start(),
1562            checked_exceptions_len * sizeof(CheckedExceptionElement));
1563   }
1564   // Copy exception table
1565   if (exception_table_len > 0) {
1566     memcpy(newm->exception_table_start(),
1567            m->exception_table_start(),
1568            exception_table_len * sizeof(ExceptionTableElement));
1569   }
1570   // Copy local variable number table
1571   if (localvariable_len > 0) {
1572     memcpy(newm->localvariable_table_start(),
1573            m->localvariable_table_start(),
1574            localvariable_len * sizeof(LocalVariableTableElement));
1575   }
1576   // Copy stackmap table
1577   if (m->has_stackmap_table()) {
1578     int code_attribute_length = m->stackmap_data()->length();
1579     Array<u1>* stackmap_data =
1580       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1581     memcpy((void*)stackmap_data->adr_at(0),
1582            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1583     newm->set_stackmap_data(stackmap_data);
1584   }
1585 
1586   // copy annotations over to new method
1587   newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1588   return newm;
1589 }
1590 
1591 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) {
1592   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1593   // because we are not loading from core libraries
1594   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1595   // which does not use the class default class loader so we check for its loader here
1596   const InstanceKlass* ik = InstanceKlass::cast(holder);
1597   if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1598     return vmSymbolID::NO_SID;   // regardless of name, no intrinsics here
1599   }
1600 
1601   // see if the klass name is well-known:
1602   Symbol* klass_name = ik->name();
1603   vmSymbolID id = vmSymbols::find_sid(klass_name);
1604   if (id != vmSymbolID::NO_SID && vmIntrinsics::class_has_intrinsics(id)) {
1605     return id;
1606   } else {
1607     return vmSymbolID::NO_SID;
1608   }
1609 }
1610 
1611 void Method::init_intrinsic_id(vmSymbolID klass_id) {
1612   assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once");
1613   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1614   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1615   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1616 
1617   // the klass name is well-known:
1618   assert(klass_id == klass_id_for_intrinsics(method_holder()), "must be");
1619   assert(klass_id != vmSymbolID::NO_SID, "caller responsibility");
1620 
1621   // ditto for method and signature:
1622   vmSymbolID name_id = vmSymbols::find_sid(name());
1623   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1624       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1625       && name_id == vmSymbolID::NO_SID) {
1626     return;
1627   }
1628   vmSymbolID sig_id = vmSymbols::find_sid(signature());
1629   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1630       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1631       && sig_id == vmSymbolID::NO_SID) {
1632     return;
1633   }
1634   jshort flags = access_flags().as_short();
1635 
1636   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1637   if (id != vmIntrinsics::_none) {
1638     set_intrinsic_id(id);
1639     if (id == vmIntrinsics::_Class_cast) {
1640       // Even if the intrinsic is rejected, we want to inline this simple method.
1641       set_force_inline(true);
1642     }
1643     return;
1644   }
1645 
1646   // A few slightly irregular cases:
1647   switch (klass_id) {
1648   case VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1649     // Second chance: check in regular Math.
1650     switch (name_id) {
1651     case VM_SYMBOL_ENUM_NAME(min_name):
1652     case VM_SYMBOL_ENUM_NAME(max_name):
1653     case VM_SYMBOL_ENUM_NAME(sqrt_name):
1654       // pretend it is the corresponding method in the non-strict class:
1655       klass_id = VM_SYMBOL_ENUM_NAME(java_lang_Math);
1656       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1657       break;
1658     default:
1659       break;
1660     }
1661     break;
1662 
1663   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1664   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1665   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1666     if (!is_native())  break;
1667     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1668     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1669       id = vmIntrinsics::_none;
1670     break;
1671 
1672   default:
1673     break;
1674   }
1675 
1676   if (id != vmIntrinsics::_none) {
1677     // Set up its iid.  It is an alias method.
1678     set_intrinsic_id(id);
1679     return;
1680   }
1681 }
1682 
1683 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1684   if (!THREAD->can_call_java()) {
1685     // There is nothing useful this routine can do from within the Compile thread.
1686     // Hopefully, the signature contains only well-known classes.
1687     // We could scan for this and return true/false, but the caller won't care.
1688     return false;
1689   }
1690   bool sig_is_loaded = true;
1691   ResourceMark rm(THREAD);
1692   for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1693     if (ss.is_reference()) {
1694       // load everything, including arrays "[Lfoo;"
1695       Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1696       // We are loading classes eagerly. If a ClassNotFoundException or
1697       // a LinkageError was generated, be sure to ignore it.
1698       if (HAS_PENDING_EXCEPTION) {
1699         if (PENDING_EXCEPTION->is_a(vmClasses::ClassNotFoundException_klass()) ||
1700             PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass())) {
1701           CLEAR_PENDING_EXCEPTION;
1702         } else {
1703           return false;
1704         }
1705       }
1706       if( klass == NULL) { sig_is_loaded = false; }
1707     }
1708   }
1709   return sig_is_loaded;
1710 }
1711 
1712 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1713   ResourceMark rm(THREAD);
1714   for(ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1715     if (ss.type() == T_OBJECT) {
1716       // Do not use ss.is_reference() here, since we don't care about
1717       // unloaded array component types.
1718       Klass* klass = ss.as_klass_if_loaded(THREAD);
1719       assert(!HAS_PENDING_EXCEPTION, "as_klass_if_loaded contract");
1720       if (klass == NULL) return true;
1721     }
1722   }
1723   return false;
1724 }
1725 
1726 // Exposed so field engineers can debug VM
1727 void Method::print_short_name(outputStream* st) {
1728   ResourceMark rm;
1729 #ifdef PRODUCT
1730   st->print(" %s::", method_holder()->external_name());
1731 #else
1732   st->print(" %s::", method_holder()->internal_name());
1733 #endif
1734   name()->print_symbol_on(st);
1735   if (WizardMode) signature()->print_symbol_on(st);
1736   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1737     MethodHandles::print_as_basic_type_signature_on(st, signature());
1738 }
1739 
1740 // Comparer for sorting an object array containing
1741 // Method*s.
1742 static int method_comparator(Method* a, Method* b) {
1743   return a->name()->fast_compare(b->name());
1744 }
1745 
1746 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1747 // default_methods also uses this without the ordering for fast find_method
1748 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1749   int length = methods->length();
1750   if (length > 1) {
1751     if (func == NULL) {
1752       func = method_comparator;
1753     }
1754     {
1755       NoSafepointVerifier nsv;
1756       QuickSort::sort(methods->data(), length, func, /*idempotent=*/false);
1757     }
1758     // Reset method ordering
1759     if (set_idnums) {
1760       for (int i = 0; i < length; i++) {
1761         Method* m = methods->at(i);
1762         m->set_method_idnum(i);
1763         m->set_orig_method_idnum(i);
1764       }
1765     }
1766   }
1767 }
1768 
1769 //-----------------------------------------------------------------------------------
1770 // Non-product code unless JVM/TI needs it
1771 
1772 #if !defined(PRODUCT) || INCLUDE_JVMTI
1773 class SignatureTypePrinter : public SignatureTypeNames {
1774  private:
1775   outputStream* _st;
1776   bool _use_separator;
1777 
1778   void type_name(const char* name) {
1779     if (_use_separator) _st->print(", ");
1780     _st->print("%s", name);
1781     _use_separator = true;
1782   }
1783 
1784  public:
1785   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1786     _st = st;
1787     _use_separator = false;
1788   }
1789 
1790   void print_parameters()              { _use_separator = false; do_parameters_on(this); }
1791   void print_returntype()              { _use_separator = false; do_type(return_type()); }
1792 };
1793 
1794 
1795 void Method::print_name(outputStream* st) {
1796   Thread *thread = Thread::current();
1797   ResourceMark rm(thread);
1798   st->print("%s ", is_static() ? "static" : "virtual");
1799   if (WizardMode) {
1800     st->print("%s.", method_holder()->internal_name());
1801     name()->print_symbol_on(st);
1802     signature()->print_symbol_on(st);
1803   } else {
1804     SignatureTypePrinter sig(signature(), st);
1805     sig.print_returntype();
1806     st->print(" %s.", method_holder()->internal_name());
1807     name()->print_symbol_on(st);
1808     st->print("(");
1809     sig.print_parameters();
1810     st->print(")");
1811   }
1812 }
1813 #endif // !PRODUCT || INCLUDE_JVMTI
1814 
1815 
1816 void Method::print_codes_on(outputStream* st) const {
1817   print_codes_on(0, code_size(), st);
1818 }
1819 
1820 void Method::print_codes_on(int from, int to, outputStream* st) const {
1821   Thread *thread = Thread::current();
1822   ResourceMark rm(thread);
1823   methodHandle mh (thread, (Method*)this);
1824   BytecodeStream s(mh);
1825   s.set_interval(from, to);
1826   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1827   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1828 }
1829 
1830 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1831   _bci = 0;
1832   _line = 0;
1833 };
1834 
1835 bool CompressedLineNumberReadStream::read_pair() {
1836   jubyte next = read_byte();
1837   // Check for terminator
1838   if (next == 0) return false;
1839   if (next == 0xFF) {
1840     // Escape character, regular compression used
1841     _bci  += read_signed_int();
1842     _line += read_signed_int();
1843   } else {
1844     // Single byte compression used
1845     _bci  += next >> 3;
1846     _line += next & 0x7;
1847   }
1848   return true;
1849 }
1850 
1851 #if INCLUDE_JVMTI
1852 
1853 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1854   BreakpointInfo* bp = method_holder()->breakpoints();
1855   for (; bp != NULL; bp = bp->next()) {
1856     if (bp->match(this, bci)) {
1857       return bp->orig_bytecode();
1858     }
1859   }
1860   {
1861     ResourceMark rm;
1862     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1863   }
1864   return Bytecodes::_shouldnotreachhere;
1865 }
1866 
1867 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1868   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1869   BreakpointInfo* bp = method_holder()->breakpoints();
1870   for (; bp != NULL; bp = bp->next()) {
1871     if (bp->match(this, bci)) {
1872       bp->set_orig_bytecode(code);
1873       // and continue, in case there is more than one
1874     }
1875   }
1876 }
1877 
1878 void Method::set_breakpoint(int bci) {
1879   InstanceKlass* ik = method_holder();
1880   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1881   bp->set_next(ik->breakpoints());
1882   ik->set_breakpoints(bp);
1883   // do this last:
1884   bp->set(this);
1885 }
1886 
1887 static void clear_matches(Method* m, int bci) {
1888   InstanceKlass* ik = m->method_holder();
1889   BreakpointInfo* prev_bp = NULL;
1890   BreakpointInfo* next_bp;
1891   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1892     next_bp = bp->next();
1893     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1894     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1895       // do this first:
1896       bp->clear(m);
1897       // unhook it
1898       if (prev_bp != NULL)
1899         prev_bp->set_next(next_bp);
1900       else
1901         ik->set_breakpoints(next_bp);
1902       delete bp;
1903       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1904       // at same location. So we have multiple matching (method_index and bci)
1905       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1906       // breakpoint for clear_breakpoint request and keep all other method versions
1907       // BreakpointInfo for future clear_breakpoint request.
1908       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1909       // which is being called when class is unloaded. We delete all the Breakpoint
1910       // information for all versions of method. We may not correctly restore the original
1911       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1912       // so these methods won't be used anymore.
1913       if (bci >= 0) {
1914         break;
1915       }
1916     } else {
1917       // This one is a keeper.
1918       prev_bp = bp;
1919     }
1920   }
1921 }
1922 
1923 void Method::clear_breakpoint(int bci) {
1924   assert(bci >= 0, "");
1925   clear_matches(this, bci);
1926 }
1927 
1928 void Method::clear_all_breakpoints() {
1929   clear_matches(this, -1);
1930 }
1931 
1932 #endif // INCLUDE_JVMTI
1933 
1934 int Method::invocation_count() const {
1935   MethodCounters* mcs = method_counters();
1936   MethodData* mdo = method_data();
1937   if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1938       ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1939     return InvocationCounter::count_limit;
1940   } else {
1941     return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1942            ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1943   }
1944 }
1945 
1946 int Method::backedge_count() const {
1947   MethodCounters* mcs = method_counters();
1948   MethodData* mdo = method_data();
1949   if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1950       ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1951     return InvocationCounter::count_limit;
1952   } else {
1953     return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1954            ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1955   }
1956 }
1957 
1958 int Method::highest_comp_level() const {
1959   const MethodCounters* mcs = method_counters();
1960   if (mcs != NULL) {
1961     return mcs->highest_comp_level();
1962   } else {
1963     return CompLevel_none;
1964   }
1965 }
1966 
1967 int Method::highest_osr_comp_level() const {
1968   const MethodCounters* mcs = method_counters();
1969   if (mcs != NULL) {
1970     return mcs->highest_osr_comp_level();
1971   } else {
1972     return CompLevel_none;
1973   }
1974 }
1975 
1976 void Method::set_highest_comp_level(int level) {
1977   MethodCounters* mcs = method_counters();
1978   if (mcs != NULL) {
1979     mcs->set_highest_comp_level(level);
1980   }
1981 }
1982 
1983 void Method::set_highest_osr_comp_level(int level) {
1984   MethodCounters* mcs = method_counters();
1985   if (mcs != NULL) {
1986     mcs->set_highest_osr_comp_level(level);
1987   }
1988 }
1989 
1990 #if INCLUDE_JVMTI
1991 
1992 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1993   _bci = bci;
1994   _name_index = m->name_index();
1995   _signature_index = m->signature_index();
1996   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1997   if (_orig_bytecode == Bytecodes::_breakpoint)
1998     _orig_bytecode = m->orig_bytecode_at(_bci);
1999   _next = NULL;
2000 }
2001 
2002 void BreakpointInfo::set(Method* method) {
2003 #ifdef ASSERT
2004   {
2005     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2006     if (code == Bytecodes::_breakpoint)
2007       code = method->orig_bytecode_at(_bci);
2008     assert(orig_bytecode() == code, "original bytecode must be the same");
2009   }
2010 #endif
2011   Thread *thread = Thread::current();
2012   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2013   method->incr_number_of_breakpoints(thread);
2014   {
2015     // Deoptimize all dependents on this method
2016     HandleMark hm(thread);
2017     methodHandle mh(thread, method);
2018     CodeCache::flush_dependents_on_method(mh);
2019   }
2020 }
2021 
2022 void BreakpointInfo::clear(Method* method) {
2023   *method->bcp_from(_bci) = orig_bytecode();
2024   assert(method->number_of_breakpoints() > 0, "must not go negative");
2025   method->decr_number_of_breakpoints(Thread::current());
2026 }
2027 
2028 #endif // INCLUDE_JVMTI
2029 
2030 // jmethodID handling
2031 
2032 // This is a block allocating object, sort of like JNIHandleBlock, only a
2033 // lot simpler.
2034 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2035 // never get rid of it.
2036 
2037 static const int min_block_size = 8;
2038 
2039 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2040   friend class JNIMethodBlock;
2041   Method**        _methods;
2042   int             _number_of_methods;
2043   int             _top;
2044   JNIMethodBlockNode* _next;
2045 
2046  public:
2047 
2048   JNIMethodBlockNode(int num_methods = min_block_size);
2049 
2050   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2051 
2052   void ensure_methods(int num_addl_methods) {
2053     if (_top < _number_of_methods) {
2054       num_addl_methods -= _number_of_methods - _top;
2055       if (num_addl_methods <= 0) {
2056         return;
2057       }
2058     }
2059     if (_next == NULL) {
2060       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2061     } else {
2062       _next->ensure_methods(num_addl_methods);
2063     }
2064   }
2065 };
2066 
2067 class JNIMethodBlock : public CHeapObj<mtClass> {
2068   JNIMethodBlockNode _head;
2069   JNIMethodBlockNode *_last_free;
2070  public:
2071   static Method* const _free_method;
2072 
2073   JNIMethodBlock(int initial_capacity = min_block_size)
2074       : _head(initial_capacity), _last_free(&_head) {}
2075 
2076   void ensure_methods(int num_addl_methods) {
2077     _last_free->ensure_methods(num_addl_methods);
2078   }
2079 
2080   Method** add_method(Method* m) {
2081     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2082       if (b->_top < b->_number_of_methods) {
2083         // top points to the next free entry.
2084         int i = b->_top;
2085         b->_methods[i] = m;
2086         b->_top++;
2087         _last_free = b;
2088         return &(b->_methods[i]);
2089       } else if (b->_top == b->_number_of_methods) {
2090         // if the next free entry ran off the block see if there's a free entry
2091         for (int i = 0; i < b->_number_of_methods; i++) {
2092           if (b->_methods[i] == _free_method) {
2093             b->_methods[i] = m;
2094             _last_free = b;
2095             return &(b->_methods[i]);
2096           }
2097         }
2098         // Only check each block once for frees.  They're very unlikely.
2099         // Increment top past the end of the block.
2100         b->_top++;
2101       }
2102       // need to allocate a next block.
2103       if (b->_next == NULL) {
2104         b->_next = _last_free = new JNIMethodBlockNode();
2105       }
2106     }
2107     guarantee(false, "Should always allocate a free block");
2108     return NULL;
2109   }
2110 
2111   bool contains(Method** m) {
2112     if (m == NULL) return false;
2113     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2114       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2115         // This is a bit of extra checking, for two reasons.  One is
2116         // that contains() deals with pointers that are passed in by
2117         // JNI code, so making sure that the pointer is aligned
2118         // correctly is valuable.  The other is that <= and > are
2119         // technically not defined on pointers, so the if guard can
2120         // pass spuriously; no modern compiler is likely to make that
2121         // a problem, though (and if one did, the guard could also
2122         // fail spuriously, which would be bad).
2123         ptrdiff_t idx = m - b->_methods;
2124         if (b->_methods + idx == m) {
2125           return true;
2126         }
2127       }
2128     }
2129     return false;  // not found
2130   }
2131 
2132   // Doesn't really destroy it, just marks it as free so it can be reused.
2133   void destroy_method(Method** m) {
2134 #ifdef ASSERT
2135     assert(contains(m), "should be a methodID");
2136 #endif // ASSERT
2137     *m = _free_method;
2138   }
2139 
2140   // During class unloading the methods are cleared, which is different
2141   // than freed.
2142   void clear_all_methods() {
2143     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2144       for (int i = 0; i< b->_number_of_methods; i++) {
2145         b->_methods[i] = NULL;
2146       }
2147     }
2148   }
2149 #ifndef PRODUCT
2150   int count_methods() {
2151     // count all allocated methods
2152     int count = 0;
2153     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2154       for (int i = 0; i< b->_number_of_methods; i++) {
2155         if (b->_methods[i] != _free_method) count++;
2156       }
2157     }
2158     return count;
2159   }
2160 #endif // PRODUCT
2161 };
2162 
2163 // Something that can't be mistaken for an address or a markWord
2164 Method* const JNIMethodBlock::_free_method = (Method*)55;
2165 
2166 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2167   _number_of_methods = MAX2(num_methods, min_block_size);
2168   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2169   for (int i = 0; i < _number_of_methods; i++) {
2170     _methods[i] = JNIMethodBlock::_free_method;
2171   }
2172 }
2173 
2174 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2175   ClassLoaderData* cld = loader_data;
2176   if (!SafepointSynchronize::is_at_safepoint()) {
2177     // Have to add jmethod_ids() to class loader data thread-safely.
2178     // Also have to add the method to the list safely, which the lock
2179     // protects as well.
2180     MutexLocker ml(JmethodIdCreation_lock,  Mutex::_no_safepoint_check_flag);
2181     if (cld->jmethod_ids() == NULL) {
2182       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2183     } else {
2184       cld->jmethod_ids()->ensure_methods(capacity);
2185     }
2186   } else {
2187     // At safepoint, we are single threaded and can set this.
2188     if (cld->jmethod_ids() == NULL) {
2189       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2190     } else {
2191       cld->jmethod_ids()->ensure_methods(capacity);
2192     }
2193   }
2194 }
2195 
2196 // Add a method id to the jmethod_ids
2197 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2198   ClassLoaderData* cld = loader_data;
2199 
2200   if (!SafepointSynchronize::is_at_safepoint()) {
2201     // Have to add jmethod_ids() to class loader data thread-safely.
2202     // Also have to add the method to the list safely, which the lock
2203     // protects as well.
2204     MutexLocker ml(JmethodIdCreation_lock,  Mutex::_no_safepoint_check_flag);
2205     if (cld->jmethod_ids() == NULL) {
2206       cld->set_jmethod_ids(new JNIMethodBlock());
2207     }
2208     // jmethodID is a pointer to Method*
2209     return (jmethodID)cld->jmethod_ids()->add_method(m);
2210   } else {
2211     // At safepoint, we are single threaded and can set this.
2212     if (cld->jmethod_ids() == NULL) {
2213       cld->set_jmethod_ids(new JNIMethodBlock());
2214     }
2215     // jmethodID is a pointer to Method*
2216     return (jmethodID)cld->jmethod_ids()->add_method(m);
2217   }
2218 }
2219 
2220 jmethodID Method::jmethod_id() {
2221   methodHandle mh(Thread::current(), this);
2222   return method_holder()->get_jmethod_id(mh);
2223 }
2224 
2225 // Mark a jmethodID as free.  This is called when there is a data race in
2226 // InstanceKlass while creating the jmethodID cache.
2227 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2228   ClassLoaderData* cld = loader_data;
2229   Method** ptr = (Method**)m;
2230   assert(cld->jmethod_ids() != NULL, "should have method handles");
2231   cld->jmethod_ids()->destroy_method(ptr);
2232 }
2233 
2234 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2235   // Can't assert the method_holder is the same because the new method has the
2236   // scratch method holder.
2237   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2238            == new_method->method_holder()->class_loader() ||
2239            new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2240          "changing to a different class loader");
2241   // Just change the method in place, jmethodID pointer doesn't change.
2242   *((Method**)jmid) = new_method;
2243 }
2244 
2245 bool Method::is_method_id(jmethodID mid) {
2246   Method* m = resolve_jmethod_id(mid);
2247   assert(m != NULL, "should be called with non-null method");
2248   InstanceKlass* ik = m->method_holder();
2249   ClassLoaderData* cld = ik->class_loader_data();
2250   if (cld->jmethod_ids() == NULL) return false;
2251   return (cld->jmethod_ids()->contains((Method**)mid));
2252 }
2253 
2254 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2255   if (mid == NULL) return NULL;
2256   Method* o = resolve_jmethod_id(mid);
2257   if (o == NULL || o == JNIMethodBlock::_free_method) {
2258     return NULL;
2259   }
2260   // Method should otherwise be valid. Assert for testing.
2261   assert(is_valid_method(o), "should be valid jmethodid");
2262   // If the method's class holder object is unreferenced, but not yet marked as
2263   // unloaded, we need to return NULL here too because after a safepoint, its memory
2264   // will be reclaimed.
2265   return o->method_holder()->is_loader_alive() ? o : NULL;
2266 };
2267 
2268 void Method::set_on_stack(const bool value) {
2269   // Set both the method itself and its constant pool.  The constant pool
2270   // on stack means some method referring to it is also on the stack.
2271   constants()->set_on_stack(value);
2272 
2273   bool already_set = on_stack();
2274   _access_flags.set_on_stack(value);
2275   if (value && !already_set) {
2276     MetadataOnStackMark::record(this);
2277   }
2278 }
2279 
2280 // Called when the class loader is unloaded to make all methods weak.
2281 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2282   loader_data->jmethod_ids()->clear_all_methods();
2283 }
2284 
2285 bool Method::has_method_vptr(const void* ptr) {
2286   Method m;
2287   // This assumes that the vtbl pointer is the first word of a C++ object.
2288   return dereference_vptr(&m) == dereference_vptr(ptr);
2289 }
2290 
2291 // Check that this pointer is valid by checking that the vtbl pointer matches
2292 bool Method::is_valid_method(const Method* m) {
2293   if (m == NULL) {
2294     return false;
2295   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2296     // Quick sanity check on pointer.
2297     return false;
2298   } else if (m->is_shared()) {
2299     return CppVtables::is_valid_shared_method(m);
2300   } else if (Metaspace::contains_non_shared(m)) {
2301     return has_method_vptr((const void*)m);
2302   } else {
2303     return false;
2304   }
2305 }
2306 
2307 #ifndef PRODUCT
2308 void Method::print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) {
2309   out->print("%d", loader_data->jmethod_ids()->count_methods());
2310 }
2311 #endif // PRODUCT
2312 
2313 
2314 // Printing
2315 
2316 #ifndef PRODUCT
2317 
2318 void Method::print_on(outputStream* st) const {
2319   ResourceMark rm;
2320   assert(is_method(), "must be method");
2321   st->print_cr("%s", internal_name());
2322   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2323   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2324   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2325   constants()->print_value_on(st); st->cr();
2326   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2327   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2328   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2329   st->print_cr(" - max stack:         %d",   max_stack());
2330   st->print_cr(" - max locals:        %d",   max_locals());
2331   st->print_cr(" - size of params:    %d",   size_of_parameters());
2332   st->print_cr(" - method size:       %d",   method_size());
2333   if (intrinsic_id() != vmIntrinsics::_none)
2334     st->print_cr(" - intrinsic id:      %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id()));
2335   if (highest_comp_level() != CompLevel_none)
2336     st->print_cr(" - highest level:     %d", highest_comp_level());
2337   st->print_cr(" - vtable index:      %d",   _vtable_index);
2338   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2339   st->print(   " - adapters:          ");
2340   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2341   if (a == NULL)
2342     st->print_cr(INTPTR_FORMAT, p2i(a));
2343   else
2344     a->print_adapter_on(st);
2345   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2346   st->print_cr(" - code size:         %d",   code_size());
2347   if (code_size() != 0) {
2348     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2349     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2350   }
2351   if (method_data() != NULL) {
2352     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2353   }
2354   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2355   if (checked_exceptions_length() > 0) {
2356     CheckedExceptionElement* table = checked_exceptions_start();
2357     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2358     if (Verbose) {
2359       for (int i = 0; i < checked_exceptions_length(); i++) {
2360         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2361       }
2362     }
2363   }
2364   if (has_linenumber_table()) {
2365     u_char* table = compressed_linenumber_table();
2366     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2367     if (Verbose) {
2368       CompressedLineNumberReadStream stream(table);
2369       while (stream.read_pair()) {
2370         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2371       }
2372     }
2373   }
2374   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2375   if (localvariable_table_length() > 0) {
2376     LocalVariableTableElement* table = localvariable_table_start();
2377     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2378     if (Verbose) {
2379       for (int i = 0; i < localvariable_table_length(); i++) {
2380         int bci = table[i].start_bci;
2381         int len = table[i].length;
2382         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2383         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2384         int slot = table[i].slot;
2385         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2386       }
2387     }
2388   }
2389   if (code() != NULL) {
2390     st->print   (" - compiled code: ");
2391     code()->print_value_on(st);
2392   }
2393   if (is_native()) {
2394     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2395     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2396   }
2397 }
2398 
2399 void Method::print_linkage_flags(outputStream* st) {
2400   access_flags().print_on(st);
2401   if (is_default_method()) {
2402     st->print("default ");
2403   }
2404   if (is_overpass()) {
2405     st->print("overpass ");
2406   }
2407 }
2408 #endif //PRODUCT
2409 
2410 void Method::print_value_on(outputStream* st) const {
2411   assert(is_method(), "must be method");
2412   st->print("%s", internal_name());
2413   print_address_on(st);
2414   st->print(" ");
2415   name()->print_value_on(st);
2416   st->print(" ");
2417   signature()->print_value_on(st);
2418   st->print(" in ");
2419   method_holder()->print_value_on(st);
2420   if (WizardMode) st->print("#%d", _vtable_index);
2421   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2422   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2423 }
2424 
2425 // LogTouchedMethods and PrintTouchedMethods
2426 
2427 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2428 // the Method may be garbage collected. Let's roll our own hash table.
2429 class TouchedMethodRecord : CHeapObj<mtTracing> {
2430 public:
2431   // It's OK to store Symbols here because they will NOT be GC'ed if
2432   // LogTouchedMethods is enabled.
2433   TouchedMethodRecord* _next;
2434   Symbol* _class_name;
2435   Symbol* _method_name;
2436   Symbol* _method_signature;
2437 };
2438 
2439 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2440 static TouchedMethodRecord** _touched_method_table = NULL;
2441 
2442 void Method::log_touched(Thread* current) {
2443 
2444   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2445   Symbol* my_class = klass_name();
2446   Symbol* my_name  = name();
2447   Symbol* my_sig   = signature();
2448 
2449   unsigned int hash = my_class->identity_hash() +
2450                       my_name->identity_hash() +
2451                       my_sig->identity_hash();
2452   juint index = juint(hash) % table_size;
2453 
2454   MutexLocker ml(current, TouchedMethodLog_lock);
2455   if (_touched_method_table == NULL) {
2456     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2457                                               mtTracing, CURRENT_PC);
2458     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2459   }
2460 
2461   TouchedMethodRecord* ptr = _touched_method_table[index];
2462   while (ptr) {
2463     if (ptr->_class_name       == my_class &&
2464         ptr->_method_name      == my_name &&
2465         ptr->_method_signature == my_sig) {
2466       return;
2467     }
2468     if (ptr->_next == NULL) break;
2469     ptr = ptr->_next;
2470   }
2471   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2472   my_class->increment_refcount();
2473   my_name->increment_refcount();
2474   my_sig->increment_refcount();
2475   nptr->_class_name         = my_class;
2476   nptr->_method_name        = my_name;
2477   nptr->_method_signature   = my_sig;
2478   nptr->_next               = NULL;
2479 
2480   if (ptr == NULL) {
2481     // first
2482     _touched_method_table[index] = nptr;
2483   } else {
2484     ptr->_next = nptr;
2485   }
2486 }
2487 
2488 void Method::print_touched_methods(outputStream* out) {
2489   MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2490   out->print_cr("# Method::print_touched_methods version 1");
2491   if (_touched_method_table) {
2492     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2493       TouchedMethodRecord* ptr = _touched_method_table[i];
2494       while(ptr) {
2495         ptr->_class_name->print_symbol_on(out);       out->print(".");
2496         ptr->_method_name->print_symbol_on(out);      out->print(":");
2497         ptr->_method_signature->print_symbol_on(out); out->cr();
2498         ptr = ptr->_next;
2499       }
2500     }
2501   }
2502 }
2503 
2504 // Verification
2505 
2506 void Method::verify_on(outputStream* st) {
2507   guarantee(is_method(), "object must be method");
2508   guarantee(constants()->is_constantPool(), "should be constant pool");
2509   MethodData* md = method_data();
2510   guarantee(md == NULL ||
2511       md->is_methodData(), "should be method data");
2512 }