1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "classfile/vmSymbols.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/compiledIC.hpp"
  30 #include "code/codeCacheExtensions.hpp"
  31 #include "code/scopeDesc.hpp"
  32 #include "code/vtableStubs.hpp"
  33 #include "compiler/abstractCompiler.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/compilerOracle.hpp"
  36 #include "compiler/disassembler.hpp"
  37 #include "gc/shared/gcLocker.inline.hpp"
  38 #include "interpreter/interpreter.hpp"
  39 #include "interpreter/interpreterRuntime.hpp"
  40 #include "memory/universe.inline.hpp"
  41 #include "oops/oop.inline.hpp"
  42 #include "prims/forte.hpp"
  43 #include "prims/jvmtiExport.hpp"
  44 #include "prims/jvmtiRedefineClassesTrace.hpp"
  45 #include "prims/methodHandles.hpp"
  46 #include "prims/nativeLookup.hpp"
  47 #include "runtime/arguments.hpp"
  48 #include "runtime/atomic.inline.hpp"
  49 #include "runtime/biasedLocking.hpp"
  50 #include "runtime/handles.inline.hpp"
  51 #include "runtime/init.hpp"
  52 #include "runtime/interfaceSupport.hpp"
  53 #include "runtime/javaCalls.hpp"
  54 #include "runtime/sharedRuntime.hpp"
  55 #include "runtime/stubRoutines.hpp"
  56 #include "runtime/vframe.hpp"
  57 #include "runtime/vframeArray.hpp"
  58 #include "utilities/copy.hpp"
  59 #include "utilities/dtrace.hpp"
  60 #include "utilities/events.hpp"
  61 #include "utilities/hashtable.inline.hpp"
  62 #include "utilities/macros.hpp"
  63 #include "utilities/xmlstream.hpp"
  64 #ifdef COMPILER1
  65 #include "c1/c1_Runtime1.hpp"
  66 #endif
  67 
  68 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  69 
  70 // Shared stub locations
  71 RuntimeStub*        SharedRuntime::_wrong_method_blob;
  72 RuntimeStub*        SharedRuntime::_wrong_method_abstract_blob;
  73 RuntimeStub*        SharedRuntime::_ic_miss_blob;
  74 RuntimeStub*        SharedRuntime::_resolve_opt_virtual_call_blob;
  75 RuntimeStub*        SharedRuntime::_resolve_virtual_call_blob;
  76 RuntimeStub*        SharedRuntime::_resolve_static_call_blob;
  77 
  78 DeoptimizationBlob* SharedRuntime::_deopt_blob;
  79 SafepointBlob*      SharedRuntime::_polling_page_vectors_safepoint_handler_blob;
  80 SafepointBlob*      SharedRuntime::_polling_page_safepoint_handler_blob;
  81 SafepointBlob*      SharedRuntime::_polling_page_return_handler_blob;
  82 
  83 #ifdef COMPILER2
  84 UncommonTrapBlob*   SharedRuntime::_uncommon_trap_blob;
  85 #endif // COMPILER2
  86 
  87 
  88 //----------------------------generate_stubs-----------------------------------
  89 void SharedRuntime::generate_stubs() {
  90   _wrong_method_blob                   = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::handle_wrong_method),          "wrong_method_stub");
  91   _wrong_method_abstract_blob          = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::handle_wrong_method_abstract), "wrong_method_abstract_stub");
  92   _ic_miss_blob                        = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::handle_wrong_method_ic_miss),  "ic_miss_stub");
  93   _resolve_opt_virtual_call_blob       = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::resolve_opt_virtual_call_C),   "resolve_opt_virtual_call");
  94   _resolve_virtual_call_blob           = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::resolve_virtual_call_C),       "resolve_virtual_call");
  95   _resolve_static_call_blob            = generate_resolve_blob(CAST_FROM_FN_PTR(address, SharedRuntime::resolve_static_call_C),        "resolve_static_call");
  96 
  97 #ifdef COMPILER2
  98   // Vectors are generated only by C2.
  99   if (is_wide_vector(MaxVectorSize)) {
 100     _polling_page_vectors_safepoint_handler_blob = generate_handler_blob(CAST_FROM_FN_PTR(address, SafepointSynchronize::handle_polling_page_exception), POLL_AT_VECTOR_LOOP);
 101   }
 102 #endif // COMPILER2
 103   _polling_page_safepoint_handler_blob = generate_handler_blob(CAST_FROM_FN_PTR(address, SafepointSynchronize::handle_polling_page_exception), POLL_AT_LOOP);
 104   _polling_page_return_handler_blob    = generate_handler_blob(CAST_FROM_FN_PTR(address, SafepointSynchronize::handle_polling_page_exception), POLL_AT_RETURN);
 105 
 106   generate_deopt_blob();
 107 
 108 #ifdef COMPILER2
 109   generate_uncommon_trap_blob();
 110 #endif // COMPILER2
 111 }
 112 
 113 #include <math.h>
 114 
 115 // Implementation of SharedRuntime
 116 
 117 #ifndef PRODUCT
 118 // For statistics
 119 int SharedRuntime::_ic_miss_ctr = 0;
 120 int SharedRuntime::_wrong_method_ctr = 0;
 121 int SharedRuntime::_resolve_static_ctr = 0;
 122 int SharedRuntime::_resolve_virtual_ctr = 0;
 123 int SharedRuntime::_resolve_opt_virtual_ctr = 0;
 124 int SharedRuntime::_implicit_null_throws = 0;
 125 int SharedRuntime::_implicit_div0_throws = 0;
 126 int SharedRuntime::_throw_null_ctr = 0;
 127 
 128 int SharedRuntime::_nof_normal_calls = 0;
 129 int SharedRuntime::_nof_optimized_calls = 0;
 130 int SharedRuntime::_nof_inlined_calls = 0;
 131 int SharedRuntime::_nof_megamorphic_calls = 0;
 132 int SharedRuntime::_nof_static_calls = 0;
 133 int SharedRuntime::_nof_inlined_static_calls = 0;
 134 int SharedRuntime::_nof_interface_calls = 0;
 135 int SharedRuntime::_nof_optimized_interface_calls = 0;
 136 int SharedRuntime::_nof_inlined_interface_calls = 0;
 137 int SharedRuntime::_nof_megamorphic_interface_calls = 0;
 138 int SharedRuntime::_nof_removable_exceptions = 0;
 139 
 140 int SharedRuntime::_new_instance_ctr=0;
 141 int SharedRuntime::_new_array_ctr=0;
 142 int SharedRuntime::_multi1_ctr=0;
 143 int SharedRuntime::_multi2_ctr=0;
 144 int SharedRuntime::_multi3_ctr=0;
 145 int SharedRuntime::_multi4_ctr=0;
 146 int SharedRuntime::_multi5_ctr=0;
 147 int SharedRuntime::_mon_enter_stub_ctr=0;
 148 int SharedRuntime::_mon_exit_stub_ctr=0;
 149 int SharedRuntime::_mon_enter_ctr=0;
 150 int SharedRuntime::_mon_exit_ctr=0;
 151 int SharedRuntime::_partial_subtype_ctr=0;
 152 int SharedRuntime::_jbyte_array_copy_ctr=0;
 153 int SharedRuntime::_jshort_array_copy_ctr=0;
 154 int SharedRuntime::_jint_array_copy_ctr=0;
 155 int SharedRuntime::_jlong_array_copy_ctr=0;
 156 int SharedRuntime::_oop_array_copy_ctr=0;
 157 int SharedRuntime::_checkcast_array_copy_ctr=0;
 158 int SharedRuntime::_unsafe_array_copy_ctr=0;
 159 int SharedRuntime::_generic_array_copy_ctr=0;
 160 int SharedRuntime::_slow_array_copy_ctr=0;
 161 int SharedRuntime::_find_handler_ctr=0;
 162 int SharedRuntime::_rethrow_ctr=0;
 163 
 164 int     SharedRuntime::_ICmiss_index                    = 0;
 165 int     SharedRuntime::_ICmiss_count[SharedRuntime::maxICmiss_count];
 166 address SharedRuntime::_ICmiss_at[SharedRuntime::maxICmiss_count];
 167 
 168 
 169 void SharedRuntime::trace_ic_miss(address at) {
 170   for (int i = 0; i < _ICmiss_index; i++) {
 171     if (_ICmiss_at[i] == at) {
 172       _ICmiss_count[i]++;
 173       return;
 174     }
 175   }
 176   int index = _ICmiss_index++;
 177   if (_ICmiss_index >= maxICmiss_count) _ICmiss_index = maxICmiss_count - 1;
 178   _ICmiss_at[index] = at;
 179   _ICmiss_count[index] = 1;
 180 }
 181 
 182 void SharedRuntime::print_ic_miss_histogram() {
 183   if (ICMissHistogram) {
 184     tty->print_cr("IC Miss Histogram:");
 185     int tot_misses = 0;
 186     for (int i = 0; i < _ICmiss_index; i++) {
 187       tty->print_cr("  at: " INTPTR_FORMAT "  nof: %d", _ICmiss_at[i], _ICmiss_count[i]);
 188       tot_misses += _ICmiss_count[i];
 189     }
 190     tty->print_cr("Total IC misses: %7d", tot_misses);
 191   }
 192 }
 193 #endif // PRODUCT
 194 
 195 #if INCLUDE_ALL_GCS
 196 
 197 // G1 write-barrier pre: executed before a pointer store.
 198 JRT_LEAF(void, SharedRuntime::g1_wb_pre(oopDesc* orig, JavaThread *thread))
 199   if (orig == NULL) {
 200     assert(false, "should be optimized out");
 201     return;
 202   }
 203   assert(orig->is_oop(true /* ignore mark word */), "Error");
 204   // store the original value that was in the field reference
 205   thread->satb_mark_queue().enqueue(orig);
 206 JRT_END
 207 
 208 // G1 write-barrier post: executed after a pointer store.
 209 JRT_LEAF(void, SharedRuntime::g1_wb_post(void* card_addr, JavaThread* thread))
 210   thread->dirty_card_queue().enqueue(card_addr);
 211 JRT_END
 212 
 213 #endif // INCLUDE_ALL_GCS
 214 
 215 
 216 JRT_LEAF(jlong, SharedRuntime::lmul(jlong y, jlong x))
 217   return x * y;
 218 JRT_END
 219 
 220 
 221 JRT_LEAF(jlong, SharedRuntime::ldiv(jlong y, jlong x))
 222   if (x == min_jlong && y == CONST64(-1)) {
 223     return x;
 224   } else {
 225     return x / y;
 226   }
 227 JRT_END
 228 
 229 
 230 JRT_LEAF(jlong, SharedRuntime::lrem(jlong y, jlong x))
 231   if (x == min_jlong && y == CONST64(-1)) {
 232     return 0;
 233   } else {
 234     return x % y;
 235   }
 236 JRT_END
 237 
 238 
 239 const juint  float_sign_mask  = 0x7FFFFFFF;
 240 const juint  float_infinity   = 0x7F800000;
 241 const julong double_sign_mask = CONST64(0x7FFFFFFFFFFFFFFF);
 242 const julong double_infinity  = CONST64(0x7FF0000000000000);
 243 
 244 JRT_LEAF(jfloat, SharedRuntime::frem(jfloat  x, jfloat  y))
 245 #ifdef _WIN64
 246   // 64-bit Windows on amd64 returns the wrong values for
 247   // infinity operands.
 248   union { jfloat f; juint i; } xbits, ybits;
 249   xbits.f = x;
 250   ybits.f = y;
 251   // x Mod Infinity == x unless x is infinity
 252   if (((xbits.i & float_sign_mask) != float_infinity) &&
 253        ((ybits.i & float_sign_mask) == float_infinity) ) {
 254     return x;
 255   }
 256 #endif
 257   return ((jfloat)fmod((double)x,(double)y));
 258 JRT_END
 259 
 260 
 261 JRT_LEAF(jdouble, SharedRuntime::drem(jdouble x, jdouble y))
 262 #ifdef _WIN64
 263   union { jdouble d; julong l; } xbits, ybits;
 264   xbits.d = x;
 265   ybits.d = y;
 266   // x Mod Infinity == x unless x is infinity
 267   if (((xbits.l & double_sign_mask) != double_infinity) &&
 268        ((ybits.l & double_sign_mask) == double_infinity) ) {
 269     return x;
 270   }
 271 #endif
 272   return ((jdouble)fmod((double)x,(double)y));
 273 JRT_END
 274 
 275 #ifdef __SOFTFP__
 276 JRT_LEAF(jfloat, SharedRuntime::fadd(jfloat x, jfloat y))
 277   return x + y;
 278 JRT_END
 279 
 280 JRT_LEAF(jfloat, SharedRuntime::fsub(jfloat x, jfloat y))
 281   return x - y;
 282 JRT_END
 283 
 284 JRT_LEAF(jfloat, SharedRuntime::fmul(jfloat x, jfloat y))
 285   return x * y;
 286 JRT_END
 287 
 288 JRT_LEAF(jfloat, SharedRuntime::fdiv(jfloat x, jfloat y))
 289   return x / y;
 290 JRT_END
 291 
 292 JRT_LEAF(jdouble, SharedRuntime::dadd(jdouble x, jdouble y))
 293   return x + y;
 294 JRT_END
 295 
 296 JRT_LEAF(jdouble, SharedRuntime::dsub(jdouble x, jdouble y))
 297   return x - y;
 298 JRT_END
 299 
 300 JRT_LEAF(jdouble, SharedRuntime::dmul(jdouble x, jdouble y))
 301   return x * y;
 302 JRT_END
 303 
 304 JRT_LEAF(jdouble, SharedRuntime::ddiv(jdouble x, jdouble y))
 305   return x / y;
 306 JRT_END
 307 
 308 JRT_LEAF(jfloat, SharedRuntime::i2f(jint x))
 309   return (jfloat)x;
 310 JRT_END
 311 
 312 JRT_LEAF(jdouble, SharedRuntime::i2d(jint x))
 313   return (jdouble)x;
 314 JRT_END
 315 
 316 JRT_LEAF(jdouble, SharedRuntime::f2d(jfloat x))
 317   return (jdouble)x;
 318 JRT_END
 319 
 320 JRT_LEAF(int,  SharedRuntime::fcmpl(float x, float y))
 321   return x>y ? 1 : (x==y ? 0 : -1);  /* x<y or is_nan*/
 322 JRT_END
 323 
 324 JRT_LEAF(int,  SharedRuntime::fcmpg(float x, float y))
 325   return x<y ? -1 : (x==y ? 0 : 1);  /* x>y or is_nan */
 326 JRT_END
 327 
 328 JRT_LEAF(int,  SharedRuntime::dcmpl(double x, double y))
 329   return x>y ? 1 : (x==y ? 0 : -1); /* x<y or is_nan */
 330 JRT_END
 331 
 332 JRT_LEAF(int,  SharedRuntime::dcmpg(double x, double y))
 333   return x<y ? -1 : (x==y ? 0 : 1);  /* x>y or is_nan */
 334 JRT_END
 335 
 336 // Functions to return the opposite of the aeabi functions for nan.
 337 JRT_LEAF(int, SharedRuntime::unordered_fcmplt(float x, float y))
 338   return (x < y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 339 JRT_END
 340 
 341 JRT_LEAF(int, SharedRuntime::unordered_dcmplt(double x, double y))
 342   return (x < y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 343 JRT_END
 344 
 345 JRT_LEAF(int, SharedRuntime::unordered_fcmple(float x, float y))
 346   return (x <= y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 347 JRT_END
 348 
 349 JRT_LEAF(int, SharedRuntime::unordered_dcmple(double x, double y))
 350   return (x <= y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 351 JRT_END
 352 
 353 JRT_LEAF(int, SharedRuntime::unordered_fcmpge(float x, float y))
 354   return (x >= y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 355 JRT_END
 356 
 357 JRT_LEAF(int, SharedRuntime::unordered_dcmpge(double x, double y))
 358   return (x >= y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 359 JRT_END
 360 
 361 JRT_LEAF(int, SharedRuntime::unordered_fcmpgt(float x, float y))
 362   return (x > y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 363 JRT_END
 364 
 365 JRT_LEAF(int, SharedRuntime::unordered_dcmpgt(double x, double y))
 366   return (x > y) ? 1 : ((g_isnan(x) || g_isnan(y)) ? 1 : 0);
 367 JRT_END
 368 
 369 // Intrinsics make gcc generate code for these.
 370 float  SharedRuntime::fneg(float f)   {
 371   return -f;
 372 }
 373 
 374 double SharedRuntime::dneg(double f)  {
 375   return -f;
 376 }
 377 
 378 #endif // __SOFTFP__
 379 
 380 #if defined(__SOFTFP__) || defined(E500V2)
 381 // Intrinsics make gcc generate code for these.
 382 double SharedRuntime::dabs(double f)  {
 383   return (f <= (double)0.0) ? (double)0.0 - f : f;
 384 }
 385 
 386 #endif
 387 
 388 #if defined(__SOFTFP__) || defined(PPC32)
 389 double SharedRuntime::dsqrt(double f) {
 390   return sqrt(f);
 391 }
 392 #endif
 393 
 394 JRT_LEAF(jint, SharedRuntime::f2i(jfloat  x))
 395   if (g_isnan(x))
 396     return 0;
 397   if (x >= (jfloat) max_jint)
 398     return max_jint;
 399   if (x <= (jfloat) min_jint)
 400     return min_jint;
 401   return (jint) x;
 402 JRT_END
 403 
 404 
 405 JRT_LEAF(jlong, SharedRuntime::f2l(jfloat  x))
 406   if (g_isnan(x))
 407     return 0;
 408   if (x >= (jfloat) max_jlong)
 409     return max_jlong;
 410   if (x <= (jfloat) min_jlong)
 411     return min_jlong;
 412   return (jlong) x;
 413 JRT_END
 414 
 415 
 416 JRT_LEAF(jint, SharedRuntime::d2i(jdouble x))
 417   if (g_isnan(x))
 418     return 0;
 419   if (x >= (jdouble) max_jint)
 420     return max_jint;
 421   if (x <= (jdouble) min_jint)
 422     return min_jint;
 423   return (jint) x;
 424 JRT_END
 425 
 426 
 427 JRT_LEAF(jlong, SharedRuntime::d2l(jdouble x))
 428   if (g_isnan(x))
 429     return 0;
 430   if (x >= (jdouble) max_jlong)
 431     return max_jlong;
 432   if (x <= (jdouble) min_jlong)
 433     return min_jlong;
 434   return (jlong) x;
 435 JRT_END
 436 
 437 
 438 JRT_LEAF(jfloat, SharedRuntime::d2f(jdouble x))
 439   return (jfloat)x;
 440 JRT_END
 441 
 442 
 443 JRT_LEAF(jfloat, SharedRuntime::l2f(jlong x))
 444   return (jfloat)x;
 445 JRT_END
 446 
 447 
 448 JRT_LEAF(jdouble, SharedRuntime::l2d(jlong x))
 449   return (jdouble)x;
 450 JRT_END
 451 
 452 // Exception handling across interpreter/compiler boundaries
 453 //
 454 // exception_handler_for_return_address(...) returns the continuation address.
 455 // The continuation address is the entry point of the exception handler of the
 456 // previous frame depending on the return address.
 457 
 458 address SharedRuntime::raw_exception_handler_for_return_address(JavaThread* thread, address return_address) {
 459   assert(frame::verify_return_pc(return_address), err_msg("must be a return address: " INTPTR_FORMAT, return_address));
 460   assert(thread->frames_to_pop_failed_realloc() == 0 || Interpreter::contains(return_address), "missed frames to pop?");
 461 
 462   // Reset method handle flag.
 463   thread->set_is_method_handle_return(false);
 464 
 465   // The fastest case first
 466   CodeBlob* blob = CodeCache::find_blob(return_address);
 467   nmethod* nm = (blob != NULL) ? blob->as_nmethod_or_null() : NULL;
 468   if (nm != NULL) {
 469     // Set flag if return address is a method handle call site.
 470     thread->set_is_method_handle_return(nm->is_method_handle_return(return_address));
 471     // native nmethods don't have exception handlers
 472     assert(!nm->is_native_method(), "no exception handler");
 473     assert(nm->header_begin() != nm->exception_begin(), "no exception handler");
 474     if (nm->is_deopt_pc(return_address)) {
 475       // If we come here because of a stack overflow, the stack may be
 476       // unguarded. Reguard the stack otherwise if we return to the
 477       // deopt blob and the stack bang causes a stack overflow we
 478       // crash.
 479       bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
 480       if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
 481       assert(guard_pages_enabled, "stack banging in deopt blob may cause crash");
 482       return SharedRuntime::deopt_blob()->unpack_with_exception();
 483     } else {
 484       return nm->exception_begin();
 485     }
 486   }
 487 
 488   // Entry code
 489   if (StubRoutines::returns_to_call_stub(return_address)) {
 490     return StubRoutines::catch_exception_entry();
 491   }
 492   // Interpreted code
 493   if (Interpreter::contains(return_address)) {
 494     return Interpreter::rethrow_exception_entry();
 495   }
 496 
 497   guarantee(blob == NULL || !blob->is_runtime_stub(), "caller should have skipped stub");
 498   guarantee(!VtableStubs::contains(return_address), "NULL exceptions in vtables should have been handled already!");
 499 
 500 #ifndef PRODUCT
 501   { ResourceMark rm;
 502     tty->print_cr("No exception handler found for exception at " INTPTR_FORMAT " - potential problems:", return_address);
 503     tty->print_cr("a) exception happened in (new?) code stubs/buffers that is not handled here");
 504     tty->print_cr("b) other problem");
 505   }
 506 #endif // PRODUCT
 507 
 508   ShouldNotReachHere();
 509   return NULL;
 510 }
 511 
 512 
 513 JRT_LEAF(address, SharedRuntime::exception_handler_for_return_address(JavaThread* thread, address return_address))
 514   return raw_exception_handler_for_return_address(thread, return_address);
 515 JRT_END
 516 
 517 
 518 address SharedRuntime::get_poll_stub(address pc) {
 519   address stub;
 520   // Look up the code blob
 521   CodeBlob *cb = CodeCache::find_blob(pc);
 522 
 523   // Should be an nmethod
 524   assert(cb && cb->is_nmethod(), "safepoint polling: pc must refer to an nmethod");
 525 
 526   // Look up the relocation information
 527   assert(((nmethod*)cb)->is_at_poll_or_poll_return(pc),
 528     "safepoint polling: type must be poll");
 529 
 530   assert(((NativeInstruction*)pc)->is_safepoint_poll(),
 531     "Only polling locations are used for safepoint");
 532 
 533   bool at_poll_return = ((nmethod*)cb)->is_at_poll_return(pc);
 534   bool has_wide_vectors = ((nmethod*)cb)->has_wide_vectors();
 535   if (at_poll_return) {
 536     assert(SharedRuntime::polling_page_return_handler_blob() != NULL,
 537            "polling page return stub not created yet");
 538     stub = SharedRuntime::polling_page_return_handler_blob()->entry_point();
 539   } else if (has_wide_vectors) {
 540     assert(SharedRuntime::polling_page_vectors_safepoint_handler_blob() != NULL,
 541            "polling page vectors safepoint stub not created yet");
 542     stub = SharedRuntime::polling_page_vectors_safepoint_handler_blob()->entry_point();
 543   } else {
 544     assert(SharedRuntime::polling_page_safepoint_handler_blob() != NULL,
 545            "polling page safepoint stub not created yet");
 546     stub = SharedRuntime::polling_page_safepoint_handler_blob()->entry_point();
 547   }
 548 #ifndef PRODUCT
 549   if (TraceSafepoint) {
 550     char buf[256];
 551     jio_snprintf(buf, sizeof(buf),
 552                  "... found polling page %s exception at pc = "
 553                  INTPTR_FORMAT ", stub =" INTPTR_FORMAT,
 554                  at_poll_return ? "return" : "loop",
 555                  (intptr_t)pc, (intptr_t)stub);
 556     tty->print_raw_cr(buf);
 557   }
 558 #endif // PRODUCT
 559   return stub;
 560 }
 561 
 562 
 563 oop SharedRuntime::retrieve_receiver( Symbol* sig, frame caller ) {
 564   assert(caller.is_interpreted_frame(), "");
 565   int args_size = ArgumentSizeComputer(sig).size() + 1;
 566   assert(args_size <= caller.interpreter_frame_expression_stack_size(), "receiver must be on interpreter stack");
 567   oop result = cast_to_oop(*caller.interpreter_frame_tos_at(args_size - 1));
 568   assert(Universe::heap()->is_in(result) && result->is_oop(), "receiver must be an oop");
 569   return result;
 570 }
 571 
 572 
 573 void SharedRuntime::throw_and_post_jvmti_exception(JavaThread *thread, Handle h_exception) {
 574   if (JvmtiExport::can_post_on_exceptions()) {
 575     vframeStream vfst(thread, true);
 576     methodHandle method = methodHandle(thread, vfst.method());
 577     address bcp = method()->bcp_from(vfst.bci());
 578     JvmtiExport::post_exception_throw(thread, method(), bcp, h_exception());
 579   }
 580   Exceptions::_throw(thread, __FILE__, __LINE__, h_exception);
 581 }
 582 
 583 void SharedRuntime::throw_and_post_jvmti_exception(JavaThread *thread, Symbol* name, const char *message) {
 584   Handle h_exception = Exceptions::new_exception(thread, name, message);
 585   throw_and_post_jvmti_exception(thread, h_exception);
 586 }
 587 
 588 // The interpreter code to call this tracing function is only
 589 // called/generated when TraceRedefineClasses has the right bits
 590 // set. Since obsolete methods are never compiled, we don't have
 591 // to modify the compilers to generate calls to this function.
 592 //
 593 JRT_LEAF(int, SharedRuntime::rc_trace_method_entry(
 594     JavaThread* thread, Method* method))
 595   assert(RC_TRACE_IN_RANGE(0x00001000, 0x00002000), "wrong call");
 596 
 597   if (method->is_obsolete()) {
 598     // We are calling an obsolete method, but this is not necessarily
 599     // an error. Our method could have been redefined just after we
 600     // fetched the Method* from the constant pool.
 601 
 602     // RC_TRACE macro has an embedded ResourceMark
 603     RC_TRACE_WITH_THREAD(0x00001000, thread,
 604                          ("calling obsolete method '%s'",
 605                           method->name_and_sig_as_C_string()));
 606     if (RC_TRACE_ENABLED(0x00002000)) {
 607       // this option is provided to debug calls to obsolete methods
 608       guarantee(false, "faulting at call to an obsolete method.");
 609     }
 610   }
 611   return 0;
 612 JRT_END
 613 
 614 // ret_pc points into caller; we are returning caller's exception handler
 615 // for given exception
 616 address SharedRuntime::compute_compiled_exc_handler(nmethod* nm, address ret_pc, Handle& exception,
 617                                                     bool force_unwind, bool top_frame_only) {
 618   assert(nm != NULL, "must exist");
 619   ResourceMark rm;
 620 
 621   ScopeDesc* sd = nm->scope_desc_at(ret_pc);
 622   // determine handler bci, if any
 623   EXCEPTION_MARK;
 624 
 625   int handler_bci = -1;
 626   int scope_depth = 0;
 627   if (!force_unwind) {
 628     int bci = sd->bci();
 629     bool recursive_exception = false;
 630     do {
 631       bool skip_scope_increment = false;
 632       // exception handler lookup
 633       KlassHandle ek (THREAD, exception->klass());
 634       methodHandle mh(THREAD, sd->method());
 635       handler_bci = Method::fast_exception_handler_bci_for(mh, ek, bci, THREAD);
 636       if (HAS_PENDING_EXCEPTION) {
 637         recursive_exception = true;
 638         // We threw an exception while trying to find the exception handler.
 639         // Transfer the new exception to the exception handle which will
 640         // be set into thread local storage, and do another lookup for an
 641         // exception handler for this exception, this time starting at the
 642         // BCI of the exception handler which caused the exception to be
 643         // thrown (bugs 4307310 and 4546590). Set "exception" reference
 644         // argument to ensure that the correct exception is thrown (4870175).
 645         exception = Handle(THREAD, PENDING_EXCEPTION);
 646         CLEAR_PENDING_EXCEPTION;
 647         if (handler_bci >= 0) {
 648           bci = handler_bci;
 649           handler_bci = -1;
 650           skip_scope_increment = true;
 651         }
 652       }
 653       else {
 654         recursive_exception = false;
 655       }
 656       if (!top_frame_only && handler_bci < 0 && !skip_scope_increment) {
 657         sd = sd->sender();
 658         if (sd != NULL) {
 659           bci = sd->bci();
 660         }
 661         ++scope_depth;
 662       }
 663     } while (recursive_exception || (!top_frame_only && handler_bci < 0 && sd != NULL));
 664   }
 665 
 666   // found handling method => lookup exception handler
 667   int catch_pco = ret_pc - nm->code_begin();
 668 
 669   ExceptionHandlerTable table(nm);
 670   HandlerTableEntry *t = table.entry_for(catch_pco, handler_bci, scope_depth);
 671   if (t == NULL && (nm->is_compiled_by_c1() || handler_bci != -1)) {
 672     // Allow abbreviated catch tables.  The idea is to allow a method
 673     // to materialize its exceptions without committing to the exact
 674     // routing of exceptions.  In particular this is needed for adding
 675     // a synthetic handler to unlock monitors when inlining
 676     // synchronized methods since the unlock path isn't represented in
 677     // the bytecodes.
 678     t = table.entry_for(catch_pco, -1, 0);
 679   }
 680 
 681 #ifdef COMPILER1
 682   if (t == NULL && nm->is_compiled_by_c1()) {
 683     assert(nm->unwind_handler_begin() != NULL, "");
 684     return nm->unwind_handler_begin();
 685   }
 686 #endif
 687 
 688   if (t == NULL) {
 689     tty->print_cr("MISSING EXCEPTION HANDLER for pc " INTPTR_FORMAT " and handler bci %d", ret_pc, handler_bci);
 690     tty->print_cr("   Exception:");
 691     exception->print();
 692     tty->cr();
 693     tty->print_cr(" Compiled exception table :");
 694     table.print();
 695     nm->print_code();
 696     guarantee(false, "missing exception handler");
 697     return NULL;
 698   }
 699 
 700   return nm->code_begin() + t->pco();
 701 }
 702 
 703 JRT_ENTRY(void, SharedRuntime::throw_AbstractMethodError(JavaThread* thread))
 704   // These errors occur only at call sites
 705   throw_and_post_jvmti_exception(thread, vmSymbols::java_lang_AbstractMethodError());
 706 JRT_END
 707 
 708 JRT_ENTRY(void, SharedRuntime::throw_IncompatibleClassChangeError(JavaThread* thread))
 709   // These errors occur only at call sites
 710   throw_and_post_jvmti_exception(thread, vmSymbols::java_lang_IncompatibleClassChangeError(), "vtable stub");
 711 JRT_END
 712 
 713 JRT_ENTRY(void, SharedRuntime::throw_ArithmeticException(JavaThread* thread))
 714   throw_and_post_jvmti_exception(thread, vmSymbols::java_lang_ArithmeticException(), "/ by zero");
 715 JRT_END
 716 
 717 JRT_ENTRY(void, SharedRuntime::throw_NullPointerException(JavaThread* thread))
 718   throw_and_post_jvmti_exception(thread, vmSymbols::java_lang_NullPointerException());
 719 JRT_END
 720 
 721 JRT_ENTRY(void, SharedRuntime::throw_NullPointerException_at_call(JavaThread* thread))
 722   // This entry point is effectively only used for NullPointerExceptions which occur at inline
 723   // cache sites (when the callee activation is not yet set up) so we are at a call site
 724   throw_and_post_jvmti_exception(thread, vmSymbols::java_lang_NullPointerException());
 725 JRT_END
 726 
 727 JRT_ENTRY(void, SharedRuntime::throw_StackOverflowError(JavaThread* thread))
 728   // We avoid using the normal exception construction in this case because
 729   // it performs an upcall to Java, and we're already out of stack space.
 730   Klass* k = SystemDictionary::StackOverflowError_klass();
 731   oop exception_oop = InstanceKlass::cast(k)->allocate_instance(CHECK);
 732   Handle exception (thread, exception_oop);
 733   if (StackTraceInThrowable) {
 734     java_lang_Throwable::fill_in_stack_trace(exception);
 735   }
 736   // Increment counter for hs_err file reporting
 737   Atomic::inc(&Exceptions::_stack_overflow_errors);
 738   throw_and_post_jvmti_exception(thread, exception);
 739 JRT_END
 740 
 741 address SharedRuntime::continuation_for_implicit_exception(JavaThread* thread,
 742                                                            address pc,
 743                                                            SharedRuntime::ImplicitExceptionKind exception_kind)
 744 {
 745   address target_pc = NULL;
 746 
 747   if (Interpreter::contains(pc)) {
 748 #ifdef CC_INTERP
 749     // C++ interpreter doesn't throw implicit exceptions
 750     ShouldNotReachHere();
 751 #else
 752     switch (exception_kind) {
 753       case IMPLICIT_NULL:           return Interpreter::throw_NullPointerException_entry();
 754       case IMPLICIT_DIVIDE_BY_ZERO: return Interpreter::throw_ArithmeticException_entry();
 755       case STACK_OVERFLOW:          return Interpreter::throw_StackOverflowError_entry();
 756       default:                      ShouldNotReachHere();
 757     }
 758 #endif // !CC_INTERP
 759   } else {
 760     switch (exception_kind) {
 761       case STACK_OVERFLOW: {
 762         // Stack overflow only occurs upon frame setup; the callee is
 763         // going to be unwound. Dispatch to a shared runtime stub
 764         // which will cause the StackOverflowError to be fabricated
 765         // and processed.
 766         // Stack overflow should never occur during deoptimization:
 767         // the compiled method bangs the stack by as much as the
 768         // interpreter would need in case of a deoptimization. The
 769         // deoptimization blob and uncommon trap blob bang the stack
 770         // in a debug VM to verify the correctness of the compiled
 771         // method stack banging.
 772         assert(thread->deopt_mark() == NULL, "no stack overflow from deopt blob/uncommon trap");
 773         Events::log_exception(thread, "StackOverflowError at " INTPTR_FORMAT, pc);
 774         return StubRoutines::throw_StackOverflowError_entry();
 775       }
 776 
 777       case IMPLICIT_NULL: {
 778         if (VtableStubs::contains(pc)) {
 779           // We haven't yet entered the callee frame. Fabricate an
 780           // exception and begin dispatching it in the caller. Since
 781           // the caller was at a call site, it's safe to destroy all
 782           // caller-saved registers, as these entry points do.
 783           VtableStub* vt_stub = VtableStubs::stub_containing(pc);
 784 
 785           // If vt_stub is NULL, then return NULL to signal handler to report the SEGV error.
 786           if (vt_stub == NULL) return NULL;
 787 
 788           if (vt_stub->is_abstract_method_error(pc)) {
 789             assert(!vt_stub->is_vtable_stub(), "should never see AbstractMethodErrors from vtable-type VtableStubs");
 790             Events::log_exception(thread, "AbstractMethodError at " INTPTR_FORMAT, pc);
 791             return StubRoutines::throw_AbstractMethodError_entry();
 792           } else {
 793             Events::log_exception(thread, "NullPointerException at vtable entry " INTPTR_FORMAT, pc);
 794             return StubRoutines::throw_NullPointerException_at_call_entry();
 795           }
 796         } else {
 797           CodeBlob* cb = CodeCache::find_blob(pc);
 798 
 799           // If code blob is NULL, then return NULL to signal handler to report the SEGV error.
 800           if (cb == NULL) return NULL;
 801 
 802           // Exception happened in CodeCache. Must be either:
 803           // 1. Inline-cache check in C2I handler blob,
 804           // 2. Inline-cache check in nmethod, or
 805           // 3. Implicit null exception in nmethod
 806 
 807           if (!cb->is_nmethod()) {
 808             bool is_in_blob = cb->is_adapter_blob() || cb->is_method_handles_adapter_blob();
 809             if (!is_in_blob) {
 810               cb->print();
 811               fatal(err_msg("exception happened outside interpreter, nmethods and vtable stubs at pc " INTPTR_FORMAT, pc));
 812             }
 813             Events::log_exception(thread, "NullPointerException in code blob at " INTPTR_FORMAT, pc);
 814             // There is no handler here, so we will simply unwind.
 815             return StubRoutines::throw_NullPointerException_at_call_entry();
 816           }
 817 
 818           // Otherwise, it's an nmethod.  Consult its exception handlers.
 819           nmethod* nm = (nmethod*)cb;
 820           if (nm->inlinecache_check_contains(pc)) {
 821             // exception happened inside inline-cache check code
 822             // => the nmethod is not yet active (i.e., the frame
 823             // is not set up yet) => use return address pushed by
 824             // caller => don't push another return address
 825             Events::log_exception(thread, "NullPointerException in IC check " INTPTR_FORMAT, pc);
 826             return StubRoutines::throw_NullPointerException_at_call_entry();
 827           }
 828 
 829           if (nm->method()->is_method_handle_intrinsic()) {
 830             // exception happened inside MH dispatch code, similar to a vtable stub
 831             Events::log_exception(thread, "NullPointerException in MH adapter " INTPTR_FORMAT, pc);
 832             return StubRoutines::throw_NullPointerException_at_call_entry();
 833           }
 834 
 835 #ifndef PRODUCT
 836           _implicit_null_throws++;
 837 #endif
 838           target_pc = nm->continuation_for_implicit_exception(pc);
 839           // If there's an unexpected fault, target_pc might be NULL,
 840           // in which case we want to fall through into the normal
 841           // error handling code.
 842         }
 843 
 844         break; // fall through
 845       }
 846 
 847 
 848       case IMPLICIT_DIVIDE_BY_ZERO: {
 849         nmethod* nm = CodeCache::find_nmethod(pc);
 850         guarantee(nm != NULL, "must have containing nmethod for implicit division-by-zero exceptions");
 851 #ifndef PRODUCT
 852         _implicit_div0_throws++;
 853 #endif
 854         target_pc = nm->continuation_for_implicit_exception(pc);
 855         // If there's an unexpected fault, target_pc might be NULL,
 856         // in which case we want to fall through into the normal
 857         // error handling code.
 858         break; // fall through
 859       }
 860 
 861       default: ShouldNotReachHere();
 862     }
 863 
 864     assert(exception_kind == IMPLICIT_NULL || exception_kind == IMPLICIT_DIVIDE_BY_ZERO, "wrong implicit exception kind");
 865 
 866     // for AbortVMOnException flag
 867     NOT_PRODUCT(Exceptions::debug_check_abort("java.lang.NullPointerException"));
 868     if (exception_kind == IMPLICIT_NULL) {
 869       Events::log_exception(thread, "Implicit null exception at " INTPTR_FORMAT " to " INTPTR_FORMAT, pc, target_pc);
 870     } else {
 871       Events::log_exception(thread, "Implicit division by zero exception at " INTPTR_FORMAT " to " INTPTR_FORMAT, pc, target_pc);
 872     }
 873     return target_pc;
 874   }
 875 
 876   ShouldNotReachHere();
 877   return NULL;
 878 }
 879 
 880 
 881 /**
 882  * Throws an java/lang/UnsatisfiedLinkError.  The address of this method is
 883  * installed in the native function entry of all native Java methods before
 884  * they get linked to their actual native methods.
 885  *
 886  * \note
 887  * This method actually never gets called!  The reason is because
 888  * the interpreter's native entries call NativeLookup::lookup() which
 889  * throws the exception when the lookup fails.  The exception is then
 890  * caught and forwarded on the return from NativeLookup::lookup() call
 891  * before the call to the native function.  This might change in the future.
 892  */
 893 JNI_ENTRY(void*, throw_unsatisfied_link_error(JNIEnv* env, ...))
 894 {
 895   // We return a bad value here to make sure that the exception is
 896   // forwarded before we look at the return value.
 897   THROW_(vmSymbols::java_lang_UnsatisfiedLinkError(), (void*)badJNIHandle);
 898 }
 899 JNI_END
 900 
 901 address SharedRuntime::native_method_throw_unsatisfied_link_error_entry() {
 902   return CAST_FROM_FN_PTR(address, &throw_unsatisfied_link_error);
 903 }
 904 
 905 
 906 #ifndef PRODUCT
 907 JRT_ENTRY(intptr_t, SharedRuntime::trace_bytecode(JavaThread* thread, intptr_t preserve_this_value, intptr_t tos, intptr_t tos2))
 908   const frame f = thread->last_frame();
 909   assert(f.is_interpreted_frame(), "must be an interpreted frame");
 910 #ifndef PRODUCT
 911   methodHandle mh(THREAD, f.interpreter_frame_method());
 912   BytecodeTracer::trace(mh, f.interpreter_frame_bcp(), tos, tos2);
 913 #endif // !PRODUCT
 914   return preserve_this_value;
 915 JRT_END
 916 #endif // !PRODUCT
 917 
 918 JRT_ENTRY_NO_ASYNC(void, SharedRuntime::register_finalizer(JavaThread* thread, oopDesc* obj))
 919   assert(obj->is_oop(), "must be a valid oop");
 920   assert(obj->klass()->has_finalizer(), "shouldn't be here otherwise");
 921   InstanceKlass::register_finalizer(instanceOop(obj), CHECK);
 922 JRT_END
 923 
 924 
 925 jlong SharedRuntime::get_java_tid(Thread* thread) {
 926   if (thread != NULL) {
 927     if (thread->is_Java_thread()) {
 928       oop obj = ((JavaThread*)thread)->threadObj();
 929       return (obj == NULL) ? 0 : java_lang_Thread::thread_id(obj);
 930     }
 931   }
 932   return 0;
 933 }
 934 
 935 /**
 936  * This function ought to be a void function, but cannot be because
 937  * it gets turned into a tail-call on sparc, which runs into dtrace bug
 938  * 6254741.  Once that is fixed we can remove the dummy return value.
 939  */
 940 int SharedRuntime::dtrace_object_alloc(oopDesc* o, int size) {
 941   return dtrace_object_alloc_base(Thread::current(), o, size);
 942 }
 943 
 944 int SharedRuntime::dtrace_object_alloc_base(Thread* thread, oopDesc* o, int size) {
 945   assert(DTraceAllocProbes, "wrong call");
 946   Klass* klass = o->klass();
 947   Symbol* name = klass->name();
 948   HOTSPOT_OBJECT_ALLOC(
 949                    get_java_tid(thread),
 950                    (char *) name->bytes(), name->utf8_length(), size * HeapWordSize);
 951   return 0;
 952 }
 953 
 954 JRT_LEAF(int, SharedRuntime::dtrace_method_entry(
 955     JavaThread* thread, Method* method))
 956   assert(DTraceMethodProbes, "wrong call");
 957   Symbol* kname = method->klass_name();
 958   Symbol* name = method->name();
 959   Symbol* sig = method->signature();
 960   HOTSPOT_METHOD_ENTRY(
 961       get_java_tid(thread),
 962       (char *) kname->bytes(), kname->utf8_length(),
 963       (char *) name->bytes(), name->utf8_length(),
 964       (char *) sig->bytes(), sig->utf8_length());
 965   return 0;
 966 JRT_END
 967 
 968 JRT_LEAF(int, SharedRuntime::dtrace_method_exit(
 969     JavaThread* thread, Method* method))
 970   assert(DTraceMethodProbes, "wrong call");
 971   Symbol* kname = method->klass_name();
 972   Symbol* name = method->name();
 973   Symbol* sig = method->signature();
 974   HOTSPOT_METHOD_RETURN(
 975       get_java_tid(thread),
 976       (char *) kname->bytes(), kname->utf8_length(),
 977       (char *) name->bytes(), name->utf8_length(),
 978       (char *) sig->bytes(), sig->utf8_length());
 979   return 0;
 980 JRT_END
 981 
 982 
 983 // Finds receiver, CallInfo (i.e. receiver method), and calling bytecode)
 984 // for a call current in progress, i.e., arguments has been pushed on stack
 985 // put callee has not been invoked yet.  Used by: resolve virtual/static,
 986 // vtable updates, etc.  Caller frame must be compiled.
 987 Handle SharedRuntime::find_callee_info(JavaThread* thread, Bytecodes::Code& bc, CallInfo& callinfo, TRAPS) {
 988   ResourceMark rm(THREAD);
 989 
 990   // last java frame on stack (which includes native call frames)
 991   vframeStream vfst(thread, true);  // Do not skip and javaCalls
 992 
 993   return find_callee_info_helper(thread, vfst, bc, callinfo, THREAD);
 994 }
 995 
 996 
 997 // Finds receiver, CallInfo (i.e. receiver method), and calling bytecode
 998 // for a call current in progress, i.e., arguments has been pushed on stack
 999 // but callee has not been invoked yet.  Caller frame must be compiled.
1000 Handle SharedRuntime::find_callee_info_helper(JavaThread* thread,
1001                                               vframeStream& vfst,
1002                                               Bytecodes::Code& bc,
1003                                               CallInfo& callinfo, TRAPS) {
1004   Handle receiver;
1005   Handle nullHandle;  //create a handy null handle for exception returns
1006 
1007   assert(!vfst.at_end(), "Java frame must exist");
1008 
1009   // Find caller and bci from vframe
1010   methodHandle caller(THREAD, vfst.method());
1011   int          bci   = vfst.bci();
1012 
1013   // Find bytecode
1014   Bytecode_invoke bytecode(caller, bci);
1015   bc = bytecode.invoke_code();
1016   int bytecode_index = bytecode.index();
1017 
1018   // Find receiver for non-static call
1019   if (bc != Bytecodes::_invokestatic &&
1020       bc != Bytecodes::_invokedynamic &&
1021       bc != Bytecodes::_invokehandle) {
1022     // This register map must be update since we need to find the receiver for
1023     // compiled frames. The receiver might be in a register.
1024     RegisterMap reg_map2(thread);
1025     frame stubFrame   = thread->last_frame();
1026     // Caller-frame is a compiled frame
1027     frame callerFrame = stubFrame.sender(&reg_map2);
1028 
1029     methodHandle callee = bytecode.static_target(CHECK_(nullHandle));
1030     if (callee.is_null()) {
1031       THROW_(vmSymbols::java_lang_NoSuchMethodException(), nullHandle);
1032     }
1033     // Retrieve from a compiled argument list
1034     receiver = Handle(THREAD, callerFrame.retrieve_receiver(&reg_map2));
1035 
1036     if (receiver.is_null()) {
1037       THROW_(vmSymbols::java_lang_NullPointerException(), nullHandle);
1038     }
1039   }
1040 
1041   // Resolve method. This is parameterized by bytecode.
1042   constantPoolHandle constants(THREAD, caller->constants());
1043   assert(receiver.is_null() || receiver->is_oop(), "wrong receiver");
1044   LinkResolver::resolve_invoke(callinfo, receiver, constants, bytecode_index, bc, CHECK_(nullHandle));
1045 
1046 #ifdef ASSERT
1047   // Check that the receiver klass is of the right subtype and that it is initialized for virtual calls
1048   if (bc != Bytecodes::_invokestatic && bc != Bytecodes::_invokedynamic && bc != Bytecodes::_invokehandle) {
1049     assert(receiver.not_null(), "should have thrown exception");
1050     KlassHandle receiver_klass(THREAD, receiver->klass());
1051     Klass* rk = constants->klass_ref_at(bytecode_index, CHECK_(nullHandle));
1052                             // klass is already loaded
1053     KlassHandle static_receiver_klass(THREAD, rk);
1054     // Method handle invokes might have been optimized to a direct call
1055     // so don't check for the receiver class.
1056     // FIXME this weakens the assert too much
1057     methodHandle callee = callinfo.selected_method();
1058     assert(receiver_klass->is_subtype_of(static_receiver_klass()) ||
1059            callee->is_method_handle_intrinsic() ||
1060            callee->is_compiled_lambda_form(),
1061            "actual receiver must be subclass of static receiver klass");
1062     if (receiver_klass->oop_is_instance()) {
1063       if (InstanceKlass::cast(receiver_klass())->is_not_initialized()) {
1064         tty->print_cr("ERROR: Klass not yet initialized!!");
1065         receiver_klass()->print();
1066       }
1067       assert(!InstanceKlass::cast(receiver_klass())->is_not_initialized(), "receiver_klass must be initialized");
1068     }
1069   }
1070 #endif
1071 
1072   return receiver;
1073 }
1074 
1075 methodHandle SharedRuntime::find_callee_method(JavaThread* thread, TRAPS) {
1076   ResourceMark rm(THREAD);
1077   // We need first to check if any Java activations (compiled, interpreted)
1078   // exist on the stack since last JavaCall.  If not, we need
1079   // to get the target method from the JavaCall wrapper.
1080   vframeStream vfst(thread, true);  // Do not skip any javaCalls
1081   methodHandle callee_method;
1082   if (vfst.at_end()) {
1083     // No Java frames were found on stack since we did the JavaCall.
1084     // Hence the stack can only contain an entry_frame.  We need to
1085     // find the target method from the stub frame.
1086     RegisterMap reg_map(thread, false);
1087     frame fr = thread->last_frame();
1088     assert(fr.is_runtime_frame(), "must be a runtimeStub");
1089     fr = fr.sender(&reg_map);
1090     assert(fr.is_entry_frame(), "must be");
1091     // fr is now pointing to the entry frame.
1092     callee_method = methodHandle(THREAD, fr.entry_frame_call_wrapper()->callee_method());
1093     assert(fr.entry_frame_call_wrapper()->receiver() == NULL || !callee_method->is_static(), "non-null receiver for static call??");
1094   } else {
1095     Bytecodes::Code bc;
1096     CallInfo callinfo;
1097     find_callee_info_helper(thread, vfst, bc, callinfo, CHECK_(methodHandle()));
1098     callee_method = callinfo.selected_method();
1099   }
1100   assert(callee_method()->is_method(), "must be");
1101   return callee_method;
1102 }
1103 
1104 // Resolves a call.
1105 methodHandle SharedRuntime::resolve_helper(JavaThread *thread,
1106                                            bool is_virtual,
1107                                            bool is_optimized, TRAPS) {
1108   methodHandle callee_method;
1109   callee_method = resolve_sub_helper(thread, is_virtual, is_optimized, THREAD);
1110   if (JvmtiExport::can_hotswap_or_post_breakpoint()) {
1111     int retry_count = 0;
1112     while (!HAS_PENDING_EXCEPTION && callee_method->is_old() &&
1113            callee_method->method_holder() != SystemDictionary::Object_klass()) {
1114       // If has a pending exception then there is no need to re-try to
1115       // resolve this method.
1116       // If the method has been redefined, we need to try again.
1117       // Hack: we have no way to update the vtables of arrays, so don't
1118       // require that java.lang.Object has been updated.
1119 
1120       // It is very unlikely that method is redefined more than 100 times
1121       // in the middle of resolve. If it is looping here more than 100 times
1122       // means then there could be a bug here.
1123       guarantee((retry_count++ < 100),
1124                 "Could not resolve to latest version of redefined method");
1125       // method is redefined in the middle of resolve so re-try.
1126       callee_method = resolve_sub_helper(thread, is_virtual, is_optimized, THREAD);
1127     }
1128   }
1129   return callee_method;
1130 }
1131 
1132 // Resolves a call.  The compilers generate code for calls that go here
1133 // and are patched with the real destination of the call.
1134 methodHandle SharedRuntime::resolve_sub_helper(JavaThread *thread,
1135                                            bool is_virtual,
1136                                            bool is_optimized, TRAPS) {
1137 
1138   ResourceMark rm(thread);
1139   RegisterMap cbl_map(thread, false);
1140   frame caller_frame = thread->last_frame().sender(&cbl_map);
1141 
1142   CodeBlob* caller_cb = caller_frame.cb();
1143   guarantee(caller_cb != NULL && caller_cb->is_nmethod(), "must be called from nmethod");
1144   nmethod* caller_nm = caller_cb->as_nmethod_or_null();
1145 
1146   // make sure caller is not getting deoptimized
1147   // and removed before we are done with it.
1148   // CLEANUP - with lazy deopt shouldn't need this lock
1149   nmethodLocker caller_lock(caller_nm);
1150 
1151   // determine call info & receiver
1152   // note: a) receiver is NULL for static calls
1153   //       b) an exception is thrown if receiver is NULL for non-static calls
1154   CallInfo call_info;
1155   Bytecodes::Code invoke_code = Bytecodes::_illegal;
1156   Handle receiver = find_callee_info(thread, invoke_code,
1157                                      call_info, CHECK_(methodHandle()));
1158   methodHandle callee_method = call_info.selected_method();
1159 
1160   assert((!is_virtual && invoke_code == Bytecodes::_invokestatic ) ||
1161          (!is_virtual && invoke_code == Bytecodes::_invokehandle ) ||
1162          (!is_virtual && invoke_code == Bytecodes::_invokedynamic) ||
1163          ( is_virtual && invoke_code != Bytecodes::_invokestatic ), "inconsistent bytecode");
1164 
1165   assert(caller_nm->is_alive(), "It should be alive");
1166 
1167 #ifndef PRODUCT
1168   // tracing/debugging/statistics
1169   int *addr = (is_optimized) ? (&_resolve_opt_virtual_ctr) :
1170                 (is_virtual) ? (&_resolve_virtual_ctr) :
1171                                (&_resolve_static_ctr);
1172   Atomic::inc(addr);
1173 
1174   if (TraceCallFixup) {
1175     ResourceMark rm(thread);
1176     tty->print("resolving %s%s (%s) call to",
1177       (is_optimized) ? "optimized " : "", (is_virtual) ? "virtual" : "static",
1178       Bytecodes::name(invoke_code));
1179     callee_method->print_short_name(tty);
1180     tty->print_cr(" at pc: " INTPTR_FORMAT " to code: " INTPTR_FORMAT, caller_frame.pc(), callee_method->code());
1181   }
1182 #endif
1183 
1184   // JSR 292 key invariant:
1185   // If the resolved method is a MethodHandle invoke target, the call
1186   // site must be a MethodHandle call site, because the lambda form might tail-call
1187   // leaving the stack in a state unknown to either caller or callee
1188   // TODO detune for now but we might need it again
1189 //  assert(!callee_method->is_compiled_lambda_form() ||
1190 //         caller_nm->is_method_handle_return(caller_frame.pc()), "must be MH call site");
1191 
1192   // Compute entry points. This might require generation of C2I converter
1193   // frames, so we cannot be holding any locks here. Furthermore, the
1194   // computation of the entry points is independent of patching the call.  We
1195   // always return the entry-point, but we only patch the stub if the call has
1196   // not been deoptimized.  Return values: For a virtual call this is an
1197   // (cached_oop, destination address) pair. For a static call/optimized
1198   // virtual this is just a destination address.
1199 
1200   StaticCallInfo static_call_info;
1201   CompiledICInfo virtual_call_info;
1202 
1203   // Make sure the callee nmethod does not get deoptimized and removed before
1204   // we are done patching the code.
1205   nmethod* callee_nm = callee_method->code();
1206   if (callee_nm != NULL && !callee_nm->is_in_use()) {
1207     // Patch call site to C2I adapter if callee nmethod is deoptimized or unloaded.
1208     callee_nm = NULL;
1209   }
1210   nmethodLocker nl_callee(callee_nm);
1211 #ifdef ASSERT
1212   address dest_entry_point = callee_nm == NULL ? 0 : callee_nm->entry_point(); // used below
1213 #endif
1214 
1215   if (is_virtual) {
1216     assert(receiver.not_null() || invoke_code == Bytecodes::_invokehandle, "sanity check");
1217     bool static_bound = call_info.resolved_method()->can_be_statically_bound();
1218     KlassHandle h_klass(THREAD, invoke_code == Bytecodes::_invokehandle ? NULL : receiver->klass());
1219     CompiledIC::compute_monomorphic_entry(callee_method, h_klass,
1220                      is_optimized, static_bound, virtual_call_info,
1221                      CHECK_(methodHandle()));
1222   } else {
1223     // static call
1224     CompiledStaticCall::compute_entry(callee_method, static_call_info);
1225   }
1226 
1227   // grab lock, check for deoptimization and potentially patch caller
1228   {
1229     MutexLocker ml_patch(CompiledIC_lock);
1230 
1231     // Lock blocks for safepoint during which both nmethods can change state.
1232 
1233     // Now that we are ready to patch if the Method* was redefined then
1234     // don't update call site and let the caller retry.
1235     // Don't update call site if callee nmethod was unloaded or deoptimized.
1236     // Don't update call site if callee nmethod was replaced by an other nmethod
1237     // which may happen when multiply alive nmethod (tiered compilation)
1238     // will be supported.
1239     if (!callee_method->is_old() &&
1240         (callee_nm == NULL || callee_nm->is_in_use() && (callee_method->code() == callee_nm))) {
1241 #ifdef ASSERT
1242       // We must not try to patch to jump to an already unloaded method.
1243       if (dest_entry_point != 0) {
1244         CodeBlob* cb = CodeCache::find_blob(dest_entry_point);
1245         assert((cb != NULL) && cb->is_nmethod() && (((nmethod*)cb) == callee_nm),
1246                "should not call unloaded nmethod");
1247       }
1248 #endif
1249       if (is_virtual) {
1250         CompiledIC* inline_cache = CompiledIC_before(caller_nm, caller_frame.pc());
1251         if (inline_cache->is_clean()) {
1252           inline_cache->set_to_monomorphic(virtual_call_info);
1253         }
1254       } else {
1255         CompiledStaticCall* ssc = compiledStaticCall_before(caller_frame.pc());
1256         if (ssc->is_clean()) ssc->set(static_call_info);
1257       }
1258     }
1259 
1260   } // unlock CompiledIC_lock
1261 
1262   return callee_method;
1263 }
1264 
1265 
1266 // Inline caches exist only in compiled code
1267 JRT_BLOCK_ENTRY(address, SharedRuntime::handle_wrong_method_ic_miss(JavaThread* thread))
1268 #ifdef ASSERT
1269   RegisterMap reg_map(thread, false);
1270   frame stub_frame = thread->last_frame();
1271   assert(stub_frame.is_runtime_frame(), "sanity check");
1272   frame caller_frame = stub_frame.sender(&reg_map);
1273   assert(!caller_frame.is_interpreted_frame() && !caller_frame.is_entry_frame(), "unexpected frame");
1274 #endif /* ASSERT */
1275 
1276   methodHandle callee_method;
1277   JRT_BLOCK
1278     callee_method = SharedRuntime::handle_ic_miss_helper(thread, CHECK_NULL);
1279     // Return Method* through TLS
1280     thread->set_vm_result_2(callee_method());
1281   JRT_BLOCK_END
1282   // return compiled code entry point after potential safepoints
1283   assert(callee_method->verified_code_entry() != NULL, " Jump to zero!");
1284   return callee_method->verified_code_entry();
1285 JRT_END
1286 
1287 
1288 // Handle call site that has been made non-entrant
1289 JRT_BLOCK_ENTRY(address, SharedRuntime::handle_wrong_method(JavaThread* thread))
1290   // 6243940 We might end up in here if the callee is deoptimized
1291   // as we race to call it.  We don't want to take a safepoint if
1292   // the caller was interpreted because the caller frame will look
1293   // interpreted to the stack walkers and arguments are now
1294   // "compiled" so it is much better to make this transition
1295   // invisible to the stack walking code. The i2c path will
1296   // place the callee method in the callee_target. It is stashed
1297   // there because if we try and find the callee by normal means a
1298   // safepoint is possible and have trouble gc'ing the compiled args.
1299   RegisterMap reg_map(thread, false);
1300   frame stub_frame = thread->last_frame();
1301   assert(stub_frame.is_runtime_frame(), "sanity check");
1302   frame caller_frame = stub_frame.sender(&reg_map);
1303 
1304   if (caller_frame.is_interpreted_frame() ||
1305       caller_frame.is_entry_frame()) {
1306     Method* callee = thread->callee_target();
1307     guarantee(callee != NULL && callee->is_method(), "bad handshake");
1308     thread->set_vm_result_2(callee);
1309     thread->set_callee_target(NULL);
1310     return callee->get_c2i_entry();
1311   }
1312 
1313   // Must be compiled to compiled path which is safe to stackwalk
1314   methodHandle callee_method;
1315   JRT_BLOCK
1316     // Force resolving of caller (if we called from compiled frame)
1317     callee_method = SharedRuntime::reresolve_call_site(thread, CHECK_NULL);
1318     thread->set_vm_result_2(callee_method());
1319   JRT_BLOCK_END
1320   // return compiled code entry point after potential safepoints
1321   assert(callee_method->verified_code_entry() != NULL, " Jump to zero!");
1322   return callee_method->verified_code_entry();
1323 JRT_END
1324 
1325 // Handle abstract method call
1326 JRT_BLOCK_ENTRY(address, SharedRuntime::handle_wrong_method_abstract(JavaThread* thread))
1327   return StubRoutines::throw_AbstractMethodError_entry();
1328 JRT_END
1329 
1330 
1331 // resolve a static call and patch code
1332 JRT_BLOCK_ENTRY(address, SharedRuntime::resolve_static_call_C(JavaThread *thread ))
1333   methodHandle callee_method;
1334   JRT_BLOCK
1335     callee_method = SharedRuntime::resolve_helper(thread, false, false, CHECK_NULL);
1336     thread->set_vm_result_2(callee_method());
1337   JRT_BLOCK_END
1338   // return compiled code entry point after potential safepoints
1339   assert(callee_method->verified_code_entry() != NULL, " Jump to zero!");
1340   return callee_method->verified_code_entry();
1341 JRT_END
1342 
1343 
1344 // resolve virtual call and update inline cache to monomorphic
1345 JRT_BLOCK_ENTRY(address, SharedRuntime::resolve_virtual_call_C(JavaThread *thread ))
1346   methodHandle callee_method;
1347   JRT_BLOCK
1348     callee_method = SharedRuntime::resolve_helper(thread, true, false, CHECK_NULL);
1349     thread->set_vm_result_2(callee_method());
1350   JRT_BLOCK_END
1351   // return compiled code entry point after potential safepoints
1352   assert(callee_method->verified_code_entry() != NULL, " Jump to zero!");
1353   return callee_method->verified_code_entry();
1354 JRT_END
1355 
1356 
1357 // Resolve a virtual call that can be statically bound (e.g., always
1358 // monomorphic, so it has no inline cache).  Patch code to resolved target.
1359 JRT_BLOCK_ENTRY(address, SharedRuntime::resolve_opt_virtual_call_C(JavaThread *thread))
1360   methodHandle callee_method;
1361   JRT_BLOCK
1362     callee_method = SharedRuntime::resolve_helper(thread, true, true, CHECK_NULL);
1363     thread->set_vm_result_2(callee_method());
1364   JRT_BLOCK_END
1365   // return compiled code entry point after potential safepoints
1366   assert(callee_method->verified_code_entry() != NULL, " Jump to zero!");
1367   return callee_method->verified_code_entry();
1368 JRT_END
1369 
1370 
1371 
1372 
1373 
1374 methodHandle SharedRuntime::handle_ic_miss_helper(JavaThread *thread, TRAPS) {
1375   ResourceMark rm(thread);
1376   CallInfo call_info;
1377   Bytecodes::Code bc;
1378 
1379   // receiver is NULL for static calls. An exception is thrown for NULL
1380   // receivers for non-static calls
1381   Handle receiver = find_callee_info(thread, bc, call_info,
1382                                      CHECK_(methodHandle()));
1383   // Compiler1 can produce virtual call sites that can actually be statically bound
1384   // If we fell thru to below we would think that the site was going megamorphic
1385   // when in fact the site can never miss. Worse because we'd think it was megamorphic
1386   // we'd try and do a vtable dispatch however methods that can be statically bound
1387   // don't have vtable entries (vtable_index < 0) and we'd blow up. So we force a
1388   // reresolution of the  call site (as if we did a handle_wrong_method and not an
1389   // plain ic_miss) and the site will be converted to an optimized virtual call site
1390   // never to miss again. I don't believe C2 will produce code like this but if it
1391   // did this would still be the correct thing to do for it too, hence no ifdef.
1392   //
1393   if (call_info.resolved_method()->can_be_statically_bound()) {
1394     methodHandle callee_method = SharedRuntime::reresolve_call_site(thread, CHECK_(methodHandle()));
1395     if (TraceCallFixup) {
1396       RegisterMap reg_map(thread, false);
1397       frame caller_frame = thread->last_frame().sender(&reg_map);
1398       ResourceMark rm(thread);
1399       tty->print("converting IC miss to reresolve (%s) call to", Bytecodes::name(bc));
1400       callee_method->print_short_name(tty);
1401       tty->print_cr(" from pc: " INTPTR_FORMAT, caller_frame.pc());
1402       tty->print_cr(" code: " INTPTR_FORMAT, callee_method->code());
1403     }
1404     return callee_method;
1405   }
1406 
1407   methodHandle callee_method = call_info.selected_method();
1408 
1409   bool should_be_mono = false;
1410 
1411 #ifndef PRODUCT
1412   Atomic::inc(&_ic_miss_ctr);
1413 
1414   // Statistics & Tracing
1415   if (TraceCallFixup) {
1416     ResourceMark rm(thread);
1417     tty->print("IC miss (%s) call to", Bytecodes::name(bc));
1418     callee_method->print_short_name(tty);
1419     tty->print_cr(" code: " INTPTR_FORMAT, callee_method->code());
1420   }
1421 
1422   if (ICMissHistogram) {
1423     MutexLocker m(VMStatistic_lock);
1424     RegisterMap reg_map(thread, false);
1425     frame f = thread->last_frame().real_sender(&reg_map);// skip runtime stub
1426     // produce statistics under the lock
1427     trace_ic_miss(f.pc());
1428   }
1429 #endif
1430 
1431   // install an event collector so that when a vtable stub is created the
1432   // profiler can be notified via a DYNAMIC_CODE_GENERATED event. The
1433   // event can't be posted when the stub is created as locks are held
1434   // - instead the event will be deferred until the event collector goes
1435   // out of scope.
1436   JvmtiDynamicCodeEventCollector event_collector;
1437 
1438   // Update inline cache to megamorphic. Skip update if we are called from interpreted.
1439   { MutexLocker ml_patch (CompiledIC_lock);
1440     RegisterMap reg_map(thread, false);
1441     frame caller_frame = thread->last_frame().sender(&reg_map);
1442     CodeBlob* cb = caller_frame.cb();
1443     if (cb->is_nmethod()) {
1444       CompiledIC* inline_cache = CompiledIC_before(((nmethod*)cb), caller_frame.pc());
1445       bool should_be_mono = false;
1446       if (inline_cache->is_optimized()) {
1447         if (TraceCallFixup) {
1448           ResourceMark rm(thread);
1449           tty->print("OPTIMIZED IC miss (%s) call to", Bytecodes::name(bc));
1450           callee_method->print_short_name(tty);
1451           tty->print_cr(" code: " INTPTR_FORMAT, callee_method->code());
1452         }
1453         should_be_mono = true;
1454       } else if (inline_cache->is_icholder_call()) {
1455         CompiledICHolder* ic_oop = inline_cache->cached_icholder();
1456         if (ic_oop != NULL) {
1457 
1458           if (receiver()->klass() == ic_oop->holder_klass()) {
1459             // This isn't a real miss. We must have seen that compiled code
1460             // is now available and we want the call site converted to a
1461             // monomorphic compiled call site.
1462             // We can't assert for callee_method->code() != NULL because it
1463             // could have been deoptimized in the meantime
1464             if (TraceCallFixup) {
1465               ResourceMark rm(thread);
1466               tty->print("FALSE IC miss (%s) converting to compiled call to", Bytecodes::name(bc));
1467               callee_method->print_short_name(tty);
1468               tty->print_cr(" code: " INTPTR_FORMAT, callee_method->code());
1469             }
1470             should_be_mono = true;
1471           }
1472         }
1473       }
1474 
1475       if (should_be_mono) {
1476 
1477         // We have a path that was monomorphic but was going interpreted
1478         // and now we have (or had) a compiled entry. We correct the IC
1479         // by using a new icBuffer.
1480         CompiledICInfo info;
1481         KlassHandle receiver_klass(THREAD, receiver()->klass());
1482         inline_cache->compute_monomorphic_entry(callee_method,
1483                                                 receiver_klass,
1484                                                 inline_cache->is_optimized(),
1485                                                 false,
1486                                                 info, CHECK_(methodHandle()));
1487         inline_cache->set_to_monomorphic(info);
1488       } else if (!inline_cache->is_megamorphic() && !inline_cache->is_clean()) {
1489         // Potential change to megamorphic
1490         bool successful = inline_cache->set_to_megamorphic(&call_info, bc, CHECK_(methodHandle()));
1491         if (!successful) {
1492           inline_cache->set_to_clean();
1493         }
1494       } else {
1495         // Either clean or megamorphic
1496       }
1497     }
1498   } // Release CompiledIC_lock
1499 
1500   return callee_method;
1501 }
1502 
1503 //
1504 // Resets a call-site in compiled code so it will get resolved again.
1505 // This routines handles both virtual call sites, optimized virtual call
1506 // sites, and static call sites. Typically used to change a call sites
1507 // destination from compiled to interpreted.
1508 //
1509 methodHandle SharedRuntime::reresolve_call_site(JavaThread *thread, TRAPS) {
1510   ResourceMark rm(thread);
1511   RegisterMap reg_map(thread, false);
1512   frame stub_frame = thread->last_frame();
1513   assert(stub_frame.is_runtime_frame(), "must be a runtimeStub");
1514   frame caller = stub_frame.sender(&reg_map);
1515 
1516   // Do nothing if the frame isn't a live compiled frame.
1517   // nmethod could be deoptimized by the time we get here
1518   // so no update to the caller is needed.
1519 
1520   if (caller.is_compiled_frame() && !caller.is_deoptimized_frame()) {
1521 
1522     address pc = caller.pc();
1523 
1524     // Default call_addr is the location of the "basic" call.
1525     // Determine the address of the call we a reresolving. With
1526     // Inline Caches we will always find a recognizable call.
1527     // With Inline Caches disabled we may or may not find a
1528     // recognizable call. We will always find a call for static
1529     // calls and for optimized virtual calls. For vanilla virtual
1530     // calls it depends on the state of the UseInlineCaches switch.
1531     //
1532     // With Inline Caches disabled we can get here for a virtual call
1533     // for two reasons:
1534     //   1 - calling an abstract method. The vtable for abstract methods
1535     //       will run us thru handle_wrong_method and we will eventually
1536     //       end up in the interpreter to throw the ame.
1537     //   2 - a racing deoptimization. We could be doing a vanilla vtable
1538     //       call and between the time we fetch the entry address and
1539     //       we jump to it the target gets deoptimized. Similar to 1
1540     //       we will wind up in the interprter (thru a c2i with c2).
1541     //
1542     address call_addr = NULL;
1543     {
1544       // Get call instruction under lock because another thread may be
1545       // busy patching it.
1546       MutexLockerEx ml_patch(Patching_lock, Mutex::_no_safepoint_check_flag);
1547       // Location of call instruction
1548       if (NativeCall::is_call_before(pc)) {
1549         NativeCall *ncall = nativeCall_before(pc);
1550         call_addr = ncall->instruction_address();
1551       }
1552     }
1553 
1554     // Check for static or virtual call
1555     bool is_static_call = false;
1556     nmethod* caller_nm = CodeCache::find_nmethod(pc);
1557     // Make sure nmethod doesn't get deoptimized and removed until
1558     // this is done with it.
1559     // CLEANUP - with lazy deopt shouldn't need this lock
1560     nmethodLocker nmlock(caller_nm);
1561 
1562     if (call_addr != NULL) {
1563       RelocIterator iter(caller_nm, call_addr, call_addr+1);
1564       int ret = iter.next(); // Get item
1565       if (ret) {
1566         assert(iter.addr() == call_addr, "must find call");
1567         if (iter.type() == relocInfo::static_call_type) {
1568           is_static_call = true;
1569         } else {
1570           assert(iter.type() == relocInfo::virtual_call_type ||
1571                  iter.type() == relocInfo::opt_virtual_call_type
1572                 , "unexpected relocInfo. type");
1573         }
1574       } else {
1575         assert(!UseInlineCaches, "relocation info. must exist for this address");
1576       }
1577 
1578       // Cleaning the inline cache will force a new resolve. This is more robust
1579       // than directly setting it to the new destination, since resolving of calls
1580       // is always done through the same code path. (experience shows that it
1581       // leads to very hard to track down bugs, if an inline cache gets updated
1582       // to a wrong method). It should not be performance critical, since the
1583       // resolve is only done once.
1584 
1585       MutexLocker ml(CompiledIC_lock);
1586       if (is_static_call) {
1587         CompiledStaticCall* ssc= compiledStaticCall_at(call_addr);
1588         ssc->set_to_clean();
1589       } else {
1590         // compiled, dispatched call (which used to call an interpreted method)
1591         CompiledIC* inline_cache = CompiledIC_at(caller_nm, call_addr);
1592         inline_cache->set_to_clean();
1593       }
1594     }
1595 
1596   }
1597 
1598   methodHandle callee_method = find_callee_method(thread, CHECK_(methodHandle()));
1599 
1600 
1601 #ifndef PRODUCT
1602   Atomic::inc(&_wrong_method_ctr);
1603 
1604   if (TraceCallFixup) {
1605     ResourceMark rm(thread);
1606     tty->print("handle_wrong_method reresolving call to");
1607     callee_method->print_short_name(tty);
1608     tty->print_cr(" code: " INTPTR_FORMAT, callee_method->code());
1609   }
1610 #endif
1611 
1612   return callee_method;
1613 }
1614 
1615 #ifdef ASSERT
1616 void SharedRuntime::check_member_name_argument_is_last_argument(methodHandle method,
1617                                                                 const BasicType* sig_bt,
1618                                                                 const VMRegPair* regs) {
1619   ResourceMark rm;
1620   const int total_args_passed = method->size_of_parameters();
1621   const VMRegPair*    regs_with_member_name = regs;
1622         VMRegPair* regs_without_member_name = NEW_RESOURCE_ARRAY(VMRegPair, total_args_passed - 1);
1623 
1624   const int member_arg_pos = total_args_passed - 1;
1625   assert(member_arg_pos >= 0 && member_arg_pos < total_args_passed, "oob");
1626   assert(sig_bt[member_arg_pos] == T_OBJECT, "dispatch argument must be an object");
1627 
1628   const bool is_outgoing = method->is_method_handle_intrinsic();
1629   int comp_args_on_stack = java_calling_convention(sig_bt, regs_without_member_name, total_args_passed - 1, is_outgoing);
1630 
1631   for (int i = 0; i < member_arg_pos; i++) {
1632     VMReg a =    regs_with_member_name[i].first();
1633     VMReg b = regs_without_member_name[i].first();
1634     assert(a->value() == b->value(), err_msg_res("register allocation mismatch: a=%d, b=%d", a->value(), b->value()));
1635   }
1636   assert(regs_with_member_name[member_arg_pos].first()->is_valid(), "bad member arg");
1637 }
1638 #endif
1639 
1640 // ---------------------------------------------------------------------------
1641 // We are calling the interpreter via a c2i. Normally this would mean that
1642 // we were called by a compiled method. However we could have lost a race
1643 // where we went int -> i2c -> c2i and so the caller could in fact be
1644 // interpreted. If the caller is compiled we attempt to patch the caller
1645 // so he no longer calls into the interpreter.
1646 IRT_LEAF(void, SharedRuntime::fixup_callers_callsite(Method* method, address caller_pc))
1647   Method* moop(method);
1648 
1649   address entry_point = moop->from_compiled_entry();
1650 
1651   // It's possible that deoptimization can occur at a call site which hasn't
1652   // been resolved yet, in which case this function will be called from
1653   // an nmethod that has been patched for deopt and we can ignore the
1654   // request for a fixup.
1655   // Also it is possible that we lost a race in that from_compiled_entry
1656   // is now back to the i2c in that case we don't need to patch and if
1657   // we did we'd leap into space because the callsite needs to use
1658   // "to interpreter" stub in order to load up the Method*. Don't
1659   // ask me how I know this...
1660 
1661   CodeBlob* cb = CodeCache::find_blob(caller_pc);
1662   if (!cb->is_nmethod() || entry_point == moop->get_c2i_entry()) {
1663     return;
1664   }
1665 
1666   // The check above makes sure this is a nmethod.
1667   nmethod* nm = cb->as_nmethod_or_null();
1668   assert(nm, "must be");
1669 
1670   // Get the return PC for the passed caller PC.
1671   address return_pc = caller_pc + frame::pc_return_offset;
1672 
1673   // There is a benign race here. We could be attempting to patch to a compiled
1674   // entry point at the same time the callee is being deoptimized. If that is
1675   // the case then entry_point may in fact point to a c2i and we'd patch the
1676   // call site with the same old data. clear_code will set code() to NULL
1677   // at the end of it. If we happen to see that NULL then we can skip trying
1678   // to patch. If we hit the window where the callee has a c2i in the
1679   // from_compiled_entry and the NULL isn't present yet then we lose the race
1680   // and patch the code with the same old data. Asi es la vida.
1681 
1682   if (moop->code() == NULL) return;
1683 
1684   if (nm->is_in_use()) {
1685 
1686     // Expect to find a native call there (unless it was no-inline cache vtable dispatch)
1687     MutexLockerEx ml_patch(Patching_lock, Mutex::_no_safepoint_check_flag);
1688     if (NativeCall::is_call_before(return_pc)) {
1689       NativeCall *call = nativeCall_before(return_pc);
1690       //
1691       // bug 6281185. We might get here after resolving a call site to a vanilla
1692       // virtual call. Because the resolvee uses the verified entry it may then
1693       // see compiled code and attempt to patch the site by calling us. This would
1694       // then incorrectly convert the call site to optimized and its downhill from
1695       // there. If you're lucky you'll get the assert in the bugid, if not you've
1696       // just made a call site that could be megamorphic into a monomorphic site
1697       // for the rest of its life! Just another racing bug in the life of
1698       // fixup_callers_callsite ...
1699       //
1700       RelocIterator iter(nm, call->instruction_address(), call->next_instruction_address());
1701       iter.next();
1702       assert(iter.has_current(), "must have a reloc at java call site");
1703       relocInfo::relocType typ = iter.reloc()->type();
1704       if (typ != relocInfo::static_call_type &&
1705            typ != relocInfo::opt_virtual_call_type &&
1706            typ != relocInfo::static_stub_type) {
1707         return;
1708       }
1709       address destination = call->destination();
1710       if (destination != entry_point) {
1711         CodeBlob* callee = CodeCache::find_blob(destination);
1712         // callee == cb seems weird. It means calling interpreter thru stub.
1713         if (callee == cb || callee->is_adapter_blob()) {
1714           // static call or optimized virtual
1715           if (TraceCallFixup) {
1716             tty->print("fixup callsite           at " INTPTR_FORMAT " to compiled code for", caller_pc);
1717             moop->print_short_name(tty);
1718             tty->print_cr(" to " INTPTR_FORMAT, entry_point);
1719           }
1720           call->set_destination_mt_safe(entry_point);
1721         } else {
1722           if (TraceCallFixup) {
1723             tty->print("failed to fixup callsite at " INTPTR_FORMAT " to compiled code for", caller_pc);
1724             moop->print_short_name(tty);
1725             tty->print_cr(" to " INTPTR_FORMAT, entry_point);
1726           }
1727           // assert is too strong could also be resolve destinations.
1728           // assert(InlineCacheBuffer::contains(destination) || VtableStubs::contains(destination), "must be");
1729         }
1730       } else {
1731           if (TraceCallFixup) {
1732             tty->print("already patched callsite at " INTPTR_FORMAT " to compiled code for", caller_pc);
1733             moop->print_short_name(tty);
1734             tty->print_cr(" to " INTPTR_FORMAT, entry_point);
1735           }
1736       }
1737     }
1738   }
1739 IRT_END
1740 
1741 
1742 // same as JVM_Arraycopy, but called directly from compiled code
1743 JRT_ENTRY(void, SharedRuntime::slow_arraycopy_C(oopDesc* src,  jint src_pos,
1744                                                 oopDesc* dest, jint dest_pos,
1745                                                 jint length,
1746                                                 JavaThread* thread)) {
1747 #ifndef PRODUCT
1748   _slow_array_copy_ctr++;
1749 #endif
1750   // Check if we have null pointers
1751   if (src == NULL || dest == NULL) {
1752     THROW(vmSymbols::java_lang_NullPointerException());
1753   }
1754   // Do the copy.  The casts to arrayOop are necessary to the copy_array API,
1755   // even though the copy_array API also performs dynamic checks to ensure
1756   // that src and dest are truly arrays (and are conformable).
1757   // The copy_array mechanism is awkward and could be removed, but
1758   // the compilers don't call this function except as a last resort,
1759   // so it probably doesn't matter.
1760   src->klass()->copy_array((arrayOopDesc*)src, src_pos,
1761                                         (arrayOopDesc*)dest, dest_pos,
1762                                         length, thread);
1763 }
1764 JRT_END
1765 
1766 char* SharedRuntime::generate_class_cast_message(
1767     JavaThread* thread, const char* objName) {
1768 
1769   // Get target class name from the checkcast instruction
1770   vframeStream vfst(thread, true);
1771   assert(!vfst.at_end(), "Java frame must exist");
1772   Bytecode_checkcast cc(vfst.method(), vfst.method()->bcp_from(vfst.bci()));
1773   Klass* targetKlass = vfst.method()->constants()->klass_at(
1774     cc.index(), thread);
1775   return generate_class_cast_message(objName, targetKlass->external_name());
1776 }
1777 
1778 char* SharedRuntime::generate_class_cast_message(
1779     const char* objName, const char* targetKlassName, const char* desc) {
1780   size_t msglen = strlen(objName) + strlen(desc) + strlen(targetKlassName) + 1;
1781 
1782   char* message = NEW_RESOURCE_ARRAY(char, msglen);
1783   if (NULL == message) {
1784     // Shouldn't happen, but don't cause even more problems if it does
1785     message = const_cast<char*>(objName);
1786   } else {
1787     jio_snprintf(message, msglen, "%s%s%s", objName, desc, targetKlassName);
1788   }
1789   return message;
1790 }
1791 
1792 JRT_LEAF(void, SharedRuntime::reguard_yellow_pages())
1793   (void) JavaThread::current()->reguard_stack();
1794 JRT_END
1795 
1796 
1797 // Handles the uncommon case in locking, i.e., contention or an inflated lock.
1798 JRT_BLOCK_ENTRY(void, SharedRuntime::complete_monitor_locking_C(oopDesc* _obj, BasicLock* lock, JavaThread* thread))
1799   if (!SafepointSynchronize::is_synchronizing()) {
1800     // Only try quick_enter() if we're not trying to reach a safepoint
1801     // so that the calling thread reaches the safepoint more quickly.
1802     if (ObjectSynchronizer::quick_enter(_obj, thread, lock)) return;
1803   }
1804   // NO_ASYNC required because an async exception on the state transition destructor
1805   // would leave you with the lock held and it would never be released.
1806   // The normal monitorenter NullPointerException is thrown without acquiring a lock
1807   // and the model is that an exception implies the method failed.
1808   JRT_BLOCK_NO_ASYNC
1809   oop obj(_obj);
1810   if (PrintBiasedLockingStatistics) {
1811     Atomic::inc(BiasedLocking::slow_path_entry_count_addr());
1812   }
1813   Handle h_obj(THREAD, obj);
1814   if (UseBiasedLocking) {
1815     // Retry fast entry if bias is revoked to avoid unnecessary inflation
1816     ObjectSynchronizer::fast_enter(h_obj, lock, true, CHECK);
1817   } else {
1818     ObjectSynchronizer::slow_enter(h_obj, lock, CHECK);
1819   }
1820   assert(!HAS_PENDING_EXCEPTION, "Should have no exception here");
1821   JRT_BLOCK_END
1822 JRT_END
1823 
1824 // Handles the uncommon cases of monitor unlocking in compiled code
1825 JRT_LEAF(void, SharedRuntime::complete_monitor_unlocking_C(oopDesc* _obj, BasicLock* lock, JavaThread * THREAD))
1826    oop obj(_obj);
1827   assert(JavaThread::current() == THREAD, "invariant");
1828   // I'm not convinced we need the code contained by MIGHT_HAVE_PENDING anymore
1829   // testing was unable to ever fire the assert that guarded it so I have removed it.
1830   assert(!HAS_PENDING_EXCEPTION, "Do we need code below anymore?");
1831 #undef MIGHT_HAVE_PENDING
1832 #ifdef MIGHT_HAVE_PENDING
1833   // Save and restore any pending_exception around the exception mark.
1834   // While the slow_exit must not throw an exception, we could come into
1835   // this routine with one set.
1836   oop pending_excep = NULL;
1837   const char* pending_file;
1838   int pending_line;
1839   if (HAS_PENDING_EXCEPTION) {
1840     pending_excep = PENDING_EXCEPTION;
1841     pending_file  = THREAD->exception_file();
1842     pending_line  = THREAD->exception_line();
1843     CLEAR_PENDING_EXCEPTION;
1844   }
1845 #endif /* MIGHT_HAVE_PENDING */
1846 
1847   {
1848     // Exit must be non-blocking, and therefore no exceptions can be thrown.
1849     EXCEPTION_MARK;
1850     ObjectSynchronizer::slow_exit(obj, lock, THREAD);
1851   }
1852 
1853 #ifdef MIGHT_HAVE_PENDING
1854   if (pending_excep != NULL) {
1855     THREAD->set_pending_exception(pending_excep, pending_file, pending_line);
1856   }
1857 #endif /* MIGHT_HAVE_PENDING */
1858 JRT_END
1859 
1860 #ifndef PRODUCT
1861 
1862 void SharedRuntime::print_statistics() {
1863   ttyLocker ttyl;
1864   if (xtty != NULL)  xtty->head("statistics type='SharedRuntime'");
1865 
1866   if (_throw_null_ctr) tty->print_cr("%5d implicit null throw", _throw_null_ctr);
1867 
1868   SharedRuntime::print_ic_miss_histogram();
1869 
1870   if (CountRemovableExceptions) {
1871     if (_nof_removable_exceptions > 0) {
1872       Unimplemented(); // this counter is not yet incremented
1873       tty->print_cr("Removable exceptions: %d", _nof_removable_exceptions);
1874     }
1875   }
1876 
1877   // Dump the JRT_ENTRY counters
1878   if (_new_instance_ctr) tty->print_cr("%5d new instance requires GC", _new_instance_ctr);
1879   if (_new_array_ctr) tty->print_cr("%5d new array requires GC", _new_array_ctr);
1880   if (_multi1_ctr) tty->print_cr("%5d multianewarray 1 dim", _multi1_ctr);
1881   if (_multi2_ctr) tty->print_cr("%5d multianewarray 2 dim", _multi2_ctr);
1882   if (_multi3_ctr) tty->print_cr("%5d multianewarray 3 dim", _multi3_ctr);
1883   if (_multi4_ctr) tty->print_cr("%5d multianewarray 4 dim", _multi4_ctr);
1884   if (_multi5_ctr) tty->print_cr("%5d multianewarray 5 dim", _multi5_ctr);
1885 
1886   tty->print_cr("%5d inline cache miss in compiled", _ic_miss_ctr);
1887   tty->print_cr("%5d wrong method", _wrong_method_ctr);
1888   tty->print_cr("%5d unresolved static call site", _resolve_static_ctr);
1889   tty->print_cr("%5d unresolved virtual call site", _resolve_virtual_ctr);
1890   tty->print_cr("%5d unresolved opt virtual call site", _resolve_opt_virtual_ctr);
1891 
1892   if (_mon_enter_stub_ctr) tty->print_cr("%5d monitor enter stub", _mon_enter_stub_ctr);
1893   if (_mon_exit_stub_ctr) tty->print_cr("%5d monitor exit stub", _mon_exit_stub_ctr);
1894   if (_mon_enter_ctr) tty->print_cr("%5d monitor enter slow", _mon_enter_ctr);
1895   if (_mon_exit_ctr) tty->print_cr("%5d monitor exit slow", _mon_exit_ctr);
1896   if (_partial_subtype_ctr) tty->print_cr("%5d slow partial subtype", _partial_subtype_ctr);
1897   if (_jbyte_array_copy_ctr) tty->print_cr("%5d byte array copies", _jbyte_array_copy_ctr);
1898   if (_jshort_array_copy_ctr) tty->print_cr("%5d short array copies", _jshort_array_copy_ctr);
1899   if (_jint_array_copy_ctr) tty->print_cr("%5d int array copies", _jint_array_copy_ctr);
1900   if (_jlong_array_copy_ctr) tty->print_cr("%5d long array copies", _jlong_array_copy_ctr);
1901   if (_oop_array_copy_ctr) tty->print_cr("%5d oop array copies", _oop_array_copy_ctr);
1902   if (_checkcast_array_copy_ctr) tty->print_cr("%5d checkcast array copies", _checkcast_array_copy_ctr);
1903   if (_unsafe_array_copy_ctr) tty->print_cr("%5d unsafe array copies", _unsafe_array_copy_ctr);
1904   if (_generic_array_copy_ctr) tty->print_cr("%5d generic array copies", _generic_array_copy_ctr);
1905   if (_slow_array_copy_ctr) tty->print_cr("%5d slow array copies", _slow_array_copy_ctr);
1906   if (_find_handler_ctr) tty->print_cr("%5d find exception handler", _find_handler_ctr);
1907   if (_rethrow_ctr) tty->print_cr("%5d rethrow handler", _rethrow_ctr);
1908 
1909   AdapterHandlerLibrary::print_statistics();
1910 
1911   if (xtty != NULL)  xtty->tail("statistics");
1912 }
1913 
1914 inline double percent(int x, int y) {
1915   return 100.0 * x / MAX2(y, 1);
1916 }
1917 
1918 class MethodArityHistogram {
1919  public:
1920   enum { MAX_ARITY = 256 };
1921  private:
1922   static int _arity_histogram[MAX_ARITY];     // histogram of #args
1923   static int _size_histogram[MAX_ARITY];      // histogram of arg size in words
1924   static int _max_arity;                      // max. arity seen
1925   static int _max_size;                       // max. arg size seen
1926 
1927   static void add_method_to_histogram(nmethod* nm) {
1928     Method* m = nm->method();
1929     ArgumentCount args(m->signature());
1930     int arity   = args.size() + (m->is_static() ? 0 : 1);
1931     int argsize = m->size_of_parameters();
1932     arity   = MIN2(arity, MAX_ARITY-1);
1933     argsize = MIN2(argsize, MAX_ARITY-1);
1934     int count = nm->method()->compiled_invocation_count();
1935     _arity_histogram[arity]  += count;
1936     _size_histogram[argsize] += count;
1937     _max_arity = MAX2(_max_arity, arity);
1938     _max_size  = MAX2(_max_size, argsize);
1939   }
1940 
1941   void print_histogram_helper(int n, int* histo, const char* name) {
1942     const int N = MIN2(5, n);
1943     tty->print_cr("\nHistogram of call arity (incl. rcvr, calls to compiled methods only):");
1944     double sum = 0;
1945     double weighted_sum = 0;
1946     int i;
1947     for (i = 0; i <= n; i++) { sum += histo[i]; weighted_sum += i*histo[i]; }
1948     double rest = sum;
1949     double percent = sum / 100;
1950     for (i = 0; i <= N; i++) {
1951       rest -= histo[i];
1952       tty->print_cr("%4d: %7d (%5.1f%%)", i, histo[i], histo[i] / percent);
1953     }
1954     tty->print_cr("rest: %7d (%5.1f%%))", (int)rest, rest / percent);
1955     tty->print_cr("(avg. %s = %3.1f, max = %d)", name, weighted_sum / sum, n);
1956   }
1957 
1958   void print_histogram() {
1959     tty->print_cr("\nHistogram of call arity (incl. rcvr, calls to compiled methods only):");
1960     print_histogram_helper(_max_arity, _arity_histogram, "arity");
1961     tty->print_cr("\nSame for parameter size (in words):");
1962     print_histogram_helper(_max_size, _size_histogram, "size");
1963     tty->cr();
1964   }
1965 
1966  public:
1967   MethodArityHistogram() {
1968     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1969     _max_arity = _max_size = 0;
1970     for (int i = 0; i < MAX_ARITY; i++) _arity_histogram[i] = _size_histogram[i] = 0;
1971     CodeCache::nmethods_do(add_method_to_histogram);
1972     print_histogram();
1973   }
1974 };
1975 
1976 int MethodArityHistogram::_arity_histogram[MethodArityHistogram::MAX_ARITY];
1977 int MethodArityHistogram::_size_histogram[MethodArityHistogram::MAX_ARITY];
1978 int MethodArityHistogram::_max_arity;
1979 int MethodArityHistogram::_max_size;
1980 
1981 void SharedRuntime::print_call_statistics(int comp_total) {
1982   tty->print_cr("Calls from compiled code:");
1983   int total  = _nof_normal_calls + _nof_interface_calls + _nof_static_calls;
1984   int mono_c = _nof_normal_calls - _nof_optimized_calls - _nof_megamorphic_calls;
1985   int mono_i = _nof_interface_calls - _nof_optimized_interface_calls - _nof_megamorphic_interface_calls;
1986   tty->print_cr("\t%9d   (%4.1f%%) total non-inlined   ", total, percent(total, total));
1987   tty->print_cr("\t%9d   (%4.1f%%) virtual calls       ", _nof_normal_calls, percent(_nof_normal_calls, total));
1988   tty->print_cr("\t  %9d  (%3.0f%%)   inlined          ", _nof_inlined_calls, percent(_nof_inlined_calls, _nof_normal_calls));
1989   tty->print_cr("\t  %9d  (%3.0f%%)   optimized        ", _nof_optimized_calls, percent(_nof_optimized_calls, _nof_normal_calls));
1990   tty->print_cr("\t  %9d  (%3.0f%%)   monomorphic      ", mono_c, percent(mono_c, _nof_normal_calls));
1991   tty->print_cr("\t  %9d  (%3.0f%%)   megamorphic      ", _nof_megamorphic_calls, percent(_nof_megamorphic_calls, _nof_normal_calls));
1992   tty->print_cr("\t%9d   (%4.1f%%) interface calls     ", _nof_interface_calls, percent(_nof_interface_calls, total));
1993   tty->print_cr("\t  %9d  (%3.0f%%)   inlined          ", _nof_inlined_interface_calls, percent(_nof_inlined_interface_calls, _nof_interface_calls));
1994   tty->print_cr("\t  %9d  (%3.0f%%)   optimized        ", _nof_optimized_interface_calls, percent(_nof_optimized_interface_calls, _nof_interface_calls));
1995   tty->print_cr("\t  %9d  (%3.0f%%)   monomorphic      ", mono_i, percent(mono_i, _nof_interface_calls));
1996   tty->print_cr("\t  %9d  (%3.0f%%)   megamorphic      ", _nof_megamorphic_interface_calls, percent(_nof_megamorphic_interface_calls, _nof_interface_calls));
1997   tty->print_cr("\t%9d   (%4.1f%%) static/special calls", _nof_static_calls, percent(_nof_static_calls, total));
1998   tty->print_cr("\t  %9d  (%3.0f%%)   inlined          ", _nof_inlined_static_calls, percent(_nof_inlined_static_calls, _nof_static_calls));
1999   tty->cr();
2000   tty->print_cr("Note 1: counter updates are not MT-safe.");
2001   tty->print_cr("Note 2: %% in major categories are relative to total non-inlined calls;");
2002   tty->print_cr("        %% in nested categories are relative to their category");
2003   tty->print_cr("        (and thus add up to more than 100%% with inlining)");
2004   tty->cr();
2005 
2006   MethodArityHistogram h;
2007 }
2008 #endif
2009 
2010 
2011 // A simple wrapper class around the calling convention information
2012 // that allows sharing of adapters for the same calling convention.
2013 class AdapterFingerPrint : public CHeapObj<mtCode> {
2014  private:
2015   enum {
2016     _basic_type_bits = 4,
2017     _basic_type_mask = right_n_bits(_basic_type_bits),
2018     _basic_types_per_int = BitsPerInt / _basic_type_bits,
2019     _compact_int_count = 3
2020   };
2021   // TO DO:  Consider integrating this with a more global scheme for compressing signatures.
2022   // For now, 4 bits per components (plus T_VOID gaps after double/long) is not excessive.
2023 
2024   union {
2025     int  _compact[_compact_int_count];
2026     int* _fingerprint;
2027   } _value;
2028   int _length; // A negative length indicates the fingerprint is in the compact form,
2029                // Otherwise _value._fingerprint is the array.
2030 
2031   // Remap BasicTypes that are handled equivalently by the adapters.
2032   // These are correct for the current system but someday it might be
2033   // necessary to make this mapping platform dependent.
2034   static int adapter_encoding(BasicType in) {
2035     switch (in) {
2036       case T_BOOLEAN:
2037       case T_BYTE:
2038       case T_SHORT:
2039       case T_CHAR:
2040         // There are all promoted to T_INT in the calling convention
2041         return T_INT;
2042 
2043       case T_OBJECT:
2044       case T_ARRAY:
2045         // In other words, we assume that any register good enough for
2046         // an int or long is good enough for a managed pointer.
2047 #ifdef _LP64
2048         return T_LONG;
2049 #else
2050         return T_INT;
2051 #endif
2052 
2053       case T_INT:
2054       case T_LONG:
2055       case T_FLOAT:
2056       case T_DOUBLE:
2057       case T_VOID:
2058         return in;
2059 
2060       default:
2061         ShouldNotReachHere();
2062         return T_CONFLICT;
2063     }
2064   }
2065 
2066  public:
2067   AdapterFingerPrint(int total_args_passed, BasicType* sig_bt) {
2068     // The fingerprint is based on the BasicType signature encoded
2069     // into an array of ints with eight entries per int.
2070     int* ptr;
2071     int len = (total_args_passed + (_basic_types_per_int-1)) / _basic_types_per_int;
2072     if (len <= _compact_int_count) {
2073       assert(_compact_int_count == 3, "else change next line");
2074       _value._compact[0] = _value._compact[1] = _value._compact[2] = 0;
2075       // Storing the signature encoded as signed chars hits about 98%
2076       // of the time.
2077       _length = -len;
2078       ptr = _value._compact;
2079     } else {
2080       _length = len;
2081       _value._fingerprint = NEW_C_HEAP_ARRAY(int, _length, mtCode);
2082       ptr = _value._fingerprint;
2083     }
2084 
2085     // Now pack the BasicTypes with 8 per int
2086     int sig_index = 0;
2087     for (int index = 0; index < len; index++) {
2088       int value = 0;
2089       for (int byte = 0; byte < _basic_types_per_int; byte++) {
2090         int bt = ((sig_index < total_args_passed)
2091                   ? adapter_encoding(sig_bt[sig_index++])
2092                   : 0);
2093         assert((bt & _basic_type_mask) == bt, "must fit in 4 bits");
2094         value = (value << _basic_type_bits) | bt;
2095       }
2096       ptr[index] = value;
2097     }
2098   }
2099 
2100   ~AdapterFingerPrint() {
2101     if (_length > 0) {
2102       FREE_C_HEAP_ARRAY(int, _value._fingerprint);
2103     }
2104   }
2105 
2106   int value(int index) {
2107     if (_length < 0) {
2108       return _value._compact[index];
2109     }
2110     return _value._fingerprint[index];
2111   }
2112   int length() {
2113     if (_length < 0) return -_length;
2114     return _length;
2115   }
2116 
2117   bool is_compact() {
2118     return _length <= 0;
2119   }
2120 
2121   unsigned int compute_hash() {
2122     int hash = 0;
2123     for (int i = 0; i < length(); i++) {
2124       int v = value(i);
2125       hash = (hash << 8) ^ v ^ (hash >> 5);
2126     }
2127     return (unsigned int)hash;
2128   }
2129 
2130   const char* as_string() {
2131     stringStream st;
2132     st.print("0x");
2133     for (int i = 0; i < length(); i++) {
2134       st.print("%08x", value(i));
2135     }
2136     return st.as_string();
2137   }
2138 
2139   bool equals(AdapterFingerPrint* other) {
2140     if (other->_length != _length) {
2141       return false;
2142     }
2143     if (_length < 0) {
2144       assert(_compact_int_count == 3, "else change next line");
2145       return _value._compact[0] == other->_value._compact[0] &&
2146              _value._compact[1] == other->_value._compact[1] &&
2147              _value._compact[2] == other->_value._compact[2];
2148     } else {
2149       for (int i = 0; i < _length; i++) {
2150         if (_value._fingerprint[i] != other->_value._fingerprint[i]) {
2151           return false;
2152         }
2153       }
2154     }
2155     return true;
2156   }
2157 };
2158 
2159 
2160 // A hashtable mapping from AdapterFingerPrints to AdapterHandlerEntries
2161 class AdapterHandlerTable : public BasicHashtable<mtCode> {
2162   friend class AdapterHandlerTableIterator;
2163 
2164  private:
2165 
2166 #ifndef PRODUCT
2167   static int _lookups; // number of calls to lookup
2168   static int _buckets; // number of buckets checked
2169   static int _equals;  // number of buckets checked with matching hash
2170   static int _hits;    // number of successful lookups
2171   static int _compact; // number of equals calls with compact signature
2172 #endif
2173 
2174   AdapterHandlerEntry* bucket(int i) {
2175     return (AdapterHandlerEntry*)BasicHashtable<mtCode>::bucket(i);
2176   }
2177 
2178  public:
2179   AdapterHandlerTable()
2180     : BasicHashtable<mtCode>(293, sizeof(AdapterHandlerEntry)) { }
2181 
2182   // Create a new entry suitable for insertion in the table
2183   AdapterHandlerEntry* new_entry(AdapterFingerPrint* fingerprint, address i2c_entry, address c2i_entry, address c2i_unverified_entry) {
2184     AdapterHandlerEntry* entry = (AdapterHandlerEntry*)BasicHashtable<mtCode>::new_entry(fingerprint->compute_hash());
2185     entry->init(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry);
2186     return entry;
2187   }
2188 
2189   // Insert an entry into the table
2190   void add(AdapterHandlerEntry* entry) {
2191     int index = hash_to_index(entry->hash());
2192     add_entry(index, entry);
2193   }
2194 
2195   void free_entry(AdapterHandlerEntry* entry) {
2196     entry->deallocate();
2197     BasicHashtable<mtCode>::free_entry(entry);
2198   }
2199 
2200   // Find a entry with the same fingerprint if it exists
2201   AdapterHandlerEntry* lookup(int total_args_passed, BasicType* sig_bt) {
2202     NOT_PRODUCT(_lookups++);
2203     AdapterFingerPrint fp(total_args_passed, sig_bt);
2204     unsigned int hash = fp.compute_hash();
2205     int index = hash_to_index(hash);
2206     for (AdapterHandlerEntry* e = bucket(index); e != NULL; e = e->next()) {
2207       NOT_PRODUCT(_buckets++);
2208       if (e->hash() == hash) {
2209         NOT_PRODUCT(_equals++);
2210         if (fp.equals(e->fingerprint())) {
2211 #ifndef PRODUCT
2212           if (fp.is_compact()) _compact++;
2213           _hits++;
2214 #endif
2215           return e;
2216         }
2217       }
2218     }
2219     return NULL;
2220   }
2221 
2222 #ifndef PRODUCT
2223   void print_statistics() {
2224     ResourceMark rm;
2225     int longest = 0;
2226     int empty = 0;
2227     int total = 0;
2228     int nonempty = 0;
2229     for (int index = 0; index < table_size(); index++) {
2230       int count = 0;
2231       for (AdapterHandlerEntry* e = bucket(index); e != NULL; e = e->next()) {
2232         count++;
2233       }
2234       if (count != 0) nonempty++;
2235       if (count == 0) empty++;
2236       if (count > longest) longest = count;
2237       total += count;
2238     }
2239     tty->print_cr("AdapterHandlerTable: empty %d longest %d total %d average %f",
2240                   empty, longest, total, total / (double)nonempty);
2241     tty->print_cr("AdapterHandlerTable: lookups %d buckets %d equals %d hits %d compact %d",
2242                   _lookups, _buckets, _equals, _hits, _compact);
2243   }
2244 #endif
2245 };
2246 
2247 
2248 #ifndef PRODUCT
2249 
2250 int AdapterHandlerTable::_lookups;
2251 int AdapterHandlerTable::_buckets;
2252 int AdapterHandlerTable::_equals;
2253 int AdapterHandlerTable::_hits;
2254 int AdapterHandlerTable::_compact;
2255 
2256 #endif
2257 
2258 class AdapterHandlerTableIterator : public StackObj {
2259  private:
2260   AdapterHandlerTable* _table;
2261   int _index;
2262   AdapterHandlerEntry* _current;
2263 
2264   void scan() {
2265     while (_index < _table->table_size()) {
2266       AdapterHandlerEntry* a = _table->bucket(_index);
2267       _index++;
2268       if (a != NULL) {
2269         _current = a;
2270         return;
2271       }
2272     }
2273   }
2274 
2275  public:
2276   AdapterHandlerTableIterator(AdapterHandlerTable* table): _table(table), _index(0), _current(NULL) {
2277     scan();
2278   }
2279   bool has_next() {
2280     return _current != NULL;
2281   }
2282   AdapterHandlerEntry* next() {
2283     if (_current != NULL) {
2284       AdapterHandlerEntry* result = _current;
2285       _current = _current->next();
2286       if (_current == NULL) scan();
2287       return result;
2288     } else {
2289       return NULL;
2290     }
2291   }
2292 };
2293 
2294 
2295 // ---------------------------------------------------------------------------
2296 // Implementation of AdapterHandlerLibrary
2297 AdapterHandlerTable* AdapterHandlerLibrary::_adapters = NULL;
2298 AdapterHandlerEntry* AdapterHandlerLibrary::_abstract_method_handler = NULL;
2299 const int AdapterHandlerLibrary_size = 16*K;
2300 BufferBlob* AdapterHandlerLibrary::_buffer = NULL;
2301 
2302 BufferBlob* AdapterHandlerLibrary::buffer_blob() {
2303   // Should be called only when AdapterHandlerLibrary_lock is active.
2304   if (_buffer == NULL) // Initialize lazily
2305       _buffer = BufferBlob::create("adapters", AdapterHandlerLibrary_size);
2306   return _buffer;
2307 }
2308 
2309 extern "C" void unexpected_adapter_call() {
2310   ShouldNotCallThis();
2311 }
2312 
2313 void AdapterHandlerLibrary::initialize() {
2314   if (_adapters != NULL) return;
2315   _adapters = new AdapterHandlerTable();
2316 
2317   if (!CodeCacheExtensions::skip_compiler_support()) {
2318     // Create a special handler for abstract methods.  Abstract methods
2319     // are never compiled so an i2c entry is somewhat meaningless, but
2320     // throw AbstractMethodError just in case.
2321     // Pass wrong_method_abstract for the c2i transitions to return
2322     // AbstractMethodError for invalid invocations.
2323     address wrong_method_abstract = SharedRuntime::get_handle_wrong_method_abstract_stub();
2324     _abstract_method_handler = AdapterHandlerLibrary::new_entry(new AdapterFingerPrint(0, NULL),
2325                                                                 StubRoutines::throw_AbstractMethodError_entry(),
2326                                                                 wrong_method_abstract, wrong_method_abstract);
2327   } else {
2328     // Adapters are not supposed to be used.
2329     // Generate a special one to cause an error if used (and store this
2330     // singleton in place of the useless _abstract_method_error adapter).
2331     address entry = (address) &unexpected_adapter_call;
2332     _abstract_method_handler = AdapterHandlerLibrary::new_entry(new AdapterFingerPrint(0, NULL),
2333                                                                 entry,
2334                                                                 entry,
2335                                                                 entry);
2336 
2337   }
2338 }
2339 
2340 AdapterHandlerEntry* AdapterHandlerLibrary::new_entry(AdapterFingerPrint* fingerprint,
2341                                                       address i2c_entry,
2342                                                       address c2i_entry,
2343                                                       address c2i_unverified_entry) {
2344   return _adapters->new_entry(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry);
2345 }
2346 
2347 AdapterHandlerEntry* AdapterHandlerLibrary::get_adapter(methodHandle method) {
2348   // Use customized signature handler.  Need to lock around updates to
2349   // the AdapterHandlerTable (it is not safe for concurrent readers
2350   // and a single writer: this could be fixed if it becomes a
2351   // problem).
2352 
2353   ResourceMark rm;
2354 
2355   NOT_PRODUCT(int insts_size);
2356   AdapterBlob* new_adapter = NULL;
2357   AdapterHandlerEntry* entry = NULL;
2358   AdapterFingerPrint* fingerprint = NULL;
2359   {
2360     MutexLocker mu(AdapterHandlerLibrary_lock);
2361     // make sure data structure is initialized
2362     initialize();
2363 
2364     if (CodeCacheExtensions::skip_compiler_support()) {
2365       // adapters are useless and should not be used, including the
2366       // abstract_method_handler. However, some callers check that
2367       // an adapter was installed.
2368       // Return the singleton adapter, stored into _abstract_method_handler
2369       // and modified to cause an error if we ever call it.
2370       return _abstract_method_handler;
2371     }
2372 
2373     if (method->is_abstract()) {
2374       return _abstract_method_handler;
2375     }
2376 
2377     // Fill in the signature array, for the calling-convention call.
2378     int total_args_passed = method->size_of_parameters(); // All args on stack
2379 
2380     BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_args_passed);
2381     VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_args_passed);
2382     int i = 0;
2383     if (!method->is_static())  // Pass in receiver first
2384       sig_bt[i++] = T_OBJECT;
2385     for (SignatureStream ss(method->signature()); !ss.at_return_type(); ss.next()) {
2386       sig_bt[i++] = ss.type();  // Collect remaining bits of signature
2387       if (ss.type() == T_LONG || ss.type() == T_DOUBLE)
2388         sig_bt[i++] = T_VOID;   // Longs & doubles take 2 Java slots
2389     }
2390     assert(i == total_args_passed, "");
2391 
2392     // Lookup method signature's fingerprint
2393     entry = _adapters->lookup(total_args_passed, sig_bt);
2394 
2395 #ifdef ASSERT
2396     AdapterHandlerEntry* shared_entry = NULL;
2397     // Start adapter sharing verification only after the VM is booted.
2398     if (VerifyAdapterSharing && (entry != NULL)) {
2399       shared_entry = entry;
2400       entry = NULL;
2401     }
2402 #endif
2403 
2404     if (entry != NULL) {
2405       return entry;
2406     }
2407 
2408     // Get a description of the compiled java calling convention and the largest used (VMReg) stack slot usage
2409     int comp_args_on_stack = SharedRuntime::java_calling_convention(sig_bt, regs, total_args_passed, false);
2410 
2411     // Make a C heap allocated version of the fingerprint to store in the adapter
2412     fingerprint = new AdapterFingerPrint(total_args_passed, sig_bt);
2413 
2414     // StubRoutines::code2() is initialized after this function can be called. As a result,
2415     // VerifyAdapterCalls and VerifyAdapterSharing can fail if we re-use code that generated
2416     // prior to StubRoutines::code2() being set. Checks refer to checks generated in an I2C
2417     // stub that ensure that an I2C stub is called from an interpreter frame.
2418     bool contains_all_checks = StubRoutines::code2() != NULL;
2419 
2420     // Create I2C & C2I handlers
2421     BufferBlob* buf = buffer_blob(); // the temporary code buffer in CodeCache
2422     if (buf != NULL) {
2423       CodeBuffer buffer(buf);
2424       short buffer_locs[20];
2425       buffer.insts()->initialize_shared_locs((relocInfo*)buffer_locs,
2426                                              sizeof(buffer_locs)/sizeof(relocInfo));
2427 
2428       MacroAssembler _masm(&buffer);
2429       entry = SharedRuntime::generate_i2c2i_adapters(&_masm,
2430                                                      total_args_passed,
2431                                                      comp_args_on_stack,
2432                                                      sig_bt,
2433                                                      regs,
2434                                                      fingerprint);
2435 #ifdef ASSERT
2436       if (VerifyAdapterSharing) {
2437         if (shared_entry != NULL) {
2438           assert(shared_entry->compare_code(buf->code_begin(), buffer.insts_size()), "code must match");
2439           // Release the one just created and return the original
2440           _adapters->free_entry(entry);
2441           return shared_entry;
2442         } else  {
2443           entry->save_code(buf->code_begin(), buffer.insts_size());
2444         }
2445       }
2446 #endif
2447 
2448       new_adapter = AdapterBlob::create(&buffer);
2449       NOT_PRODUCT(insts_size = buffer.insts_size());
2450     }
2451     if (new_adapter == NULL) {
2452       // CodeCache is full, disable compilation
2453       // Ought to log this but compile log is only per compile thread
2454       // and we're some non descript Java thread.
2455       return NULL; // Out of CodeCache space
2456     }
2457     entry->relocate(new_adapter->content_begin());
2458 #ifndef PRODUCT
2459     // debugging suppport
2460     if (PrintAdapterHandlers || PrintStubCode) {
2461       ttyLocker ttyl;
2462       entry->print_adapter_on(tty);
2463       tty->print_cr("i2c argument handler #%d for: %s %s %s (%d bytes generated)",
2464                     _adapters->number_of_entries(), (method->is_static() ? "static" : "receiver"),
2465                     method->signature()->as_C_string(), fingerprint->as_string(), insts_size);
2466       tty->print_cr("c2i argument handler starts at %p", entry->get_c2i_entry());
2467       if (Verbose || PrintStubCode) {
2468         address first_pc = entry->base_address();
2469         if (first_pc != NULL) {
2470           Disassembler::decode(first_pc, first_pc + insts_size);
2471           tty->cr();
2472         }
2473       }
2474     }
2475 #endif
2476     // Add the entry only if the entry contains all required checks (see sharedRuntime_xxx.cpp)
2477     // The checks are inserted only if -XX:+VerifyAdapterCalls is specified.
2478     if (contains_all_checks || !VerifyAdapterCalls) {
2479       _adapters->add(entry);
2480     }
2481   }
2482   // Outside of the lock
2483   if (new_adapter != NULL) {
2484     char blob_id[256];
2485     jio_snprintf(blob_id,
2486                  sizeof(blob_id),
2487                  "%s(%s)@" PTR_FORMAT,
2488                  new_adapter->name(),
2489                  fingerprint->as_string(),
2490                  new_adapter->content_begin());
2491     Forte::register_stub(blob_id, new_adapter->content_begin(), new_adapter->content_end());
2492 
2493     if (JvmtiExport::should_post_dynamic_code_generated()) {
2494       JvmtiExport::post_dynamic_code_generated(blob_id, new_adapter->content_begin(), new_adapter->content_end());
2495     }
2496   }
2497   return entry;
2498 }
2499 
2500 address AdapterHandlerEntry::base_address() {
2501   address base = _i2c_entry;
2502   if (base == NULL)  base = _c2i_entry;
2503   assert(base <= _c2i_entry || _c2i_entry == NULL, "");
2504   assert(base <= _c2i_unverified_entry || _c2i_unverified_entry == NULL, "");
2505   return base;
2506 }
2507 
2508 void AdapterHandlerEntry::relocate(address new_base) {
2509   address old_base = base_address();
2510   assert(old_base != NULL, "");
2511   ptrdiff_t delta = new_base - old_base;
2512   if (_i2c_entry != NULL)
2513     _i2c_entry += delta;
2514   if (_c2i_entry != NULL)
2515     _c2i_entry += delta;
2516   if (_c2i_unverified_entry != NULL)
2517     _c2i_unverified_entry += delta;
2518   assert(base_address() == new_base, "");
2519 }
2520 
2521 
2522 void AdapterHandlerEntry::deallocate() {
2523   delete _fingerprint;
2524 #ifdef ASSERT
2525   if (_saved_code) FREE_C_HEAP_ARRAY(unsigned char, _saved_code);
2526 #endif
2527 }
2528 
2529 
2530 #ifdef ASSERT
2531 // Capture the code before relocation so that it can be compared
2532 // against other versions.  If the code is captured after relocation
2533 // then relative instructions won't be equivalent.
2534 void AdapterHandlerEntry::save_code(unsigned char* buffer, int length) {
2535   _saved_code = NEW_C_HEAP_ARRAY(unsigned char, length, mtCode);
2536   _saved_code_length = length;
2537   memcpy(_saved_code, buffer, length);
2538 }
2539 
2540 
2541 bool AdapterHandlerEntry::compare_code(unsigned char* buffer, int length) {
2542   if (length != _saved_code_length) {
2543     return false;
2544   }
2545 
2546   return (memcmp(buffer, _saved_code, length) == 0) ? true : false;
2547 }
2548 #endif
2549 
2550 
2551 /**
2552  * Create a native wrapper for this native method.  The wrapper converts the
2553  * Java-compiled calling convention to the native convention, handles
2554  * arguments, and transitions to native.  On return from the native we transition
2555  * back to java blocking if a safepoint is in progress.
2556  */
2557 void AdapterHandlerLibrary::create_native_wrapper(methodHandle method) {
2558   ResourceMark rm;
2559   nmethod* nm = NULL;
2560 
2561   assert(method->is_native(), "must be native");
2562   assert(method->is_method_handle_intrinsic() ||
2563          method->has_native_function(), "must have something valid to call!");
2564 
2565   {
2566     // Perform the work while holding the lock, but perform any printing outside the lock
2567     MutexLocker mu(AdapterHandlerLibrary_lock);
2568     // See if somebody beat us to it
2569     nm = method->code();
2570     if (nm != NULL) {
2571       return;
2572     }
2573 
2574     const int compile_id = CompileBroker::assign_compile_id(method, CompileBroker::standard_entry_bci);
2575     assert(compile_id > 0, "Must generate native wrapper");
2576 
2577 
2578     ResourceMark rm;
2579     BufferBlob*  buf = buffer_blob(); // the temporary code buffer in CodeCache
2580     if (buf != NULL) {
2581       CodeBuffer buffer(buf);
2582       double locs_buf[20];
2583       buffer.insts()->initialize_shared_locs((relocInfo*)locs_buf, sizeof(locs_buf) / sizeof(relocInfo));
2584       MacroAssembler _masm(&buffer);
2585 
2586       // Fill in the signature array, for the calling-convention call.
2587       const int total_args_passed = method->size_of_parameters();
2588 
2589       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_args_passed);
2590       VMRegPair*   regs = NEW_RESOURCE_ARRAY(VMRegPair, total_args_passed);
2591       int i=0;
2592       if (!method->is_static())  // Pass in receiver first
2593         sig_bt[i++] = T_OBJECT;
2594       SignatureStream ss(method->signature());
2595       for (; !ss.at_return_type(); ss.next()) {
2596         sig_bt[i++] = ss.type();  // Collect remaining bits of signature
2597         if (ss.type() == T_LONG || ss.type() == T_DOUBLE)
2598           sig_bt[i++] = T_VOID;   // Longs & doubles take 2 Java slots
2599       }
2600       assert(i == total_args_passed, "");
2601       BasicType ret_type = ss.type();
2602 
2603       // Now get the compiled-Java layout as input (or output) arguments.
2604       // NOTE: Stubs for compiled entry points of method handle intrinsics
2605       // are just trampolines so the argument registers must be outgoing ones.
2606       const bool is_outgoing = method->is_method_handle_intrinsic();
2607       int comp_args_on_stack = SharedRuntime::java_calling_convention(sig_bt, regs, total_args_passed, is_outgoing);
2608 
2609       // Generate the compiled-to-native wrapper code
2610       nm = SharedRuntime::generate_native_wrapper(&_masm, method, compile_id, sig_bt, regs, ret_type);
2611 
2612       if (nm != NULL) {
2613         method->set_code(method, nm);
2614       }
2615     }
2616   } // Unlock AdapterHandlerLibrary_lock
2617 
2618 
2619   // Install the generated code.
2620   if (nm != NULL) {
2621     if (PrintCompilation) {
2622       ttyLocker ttyl;
2623       CompileTask::print_compilation(tty, nm, method->is_static() ? "(static)" : "");
2624     }
2625     nm->post_compiled_method_load_event();
2626   }
2627 }
2628 
2629 JRT_ENTRY_NO_ASYNC(void, SharedRuntime::block_for_jni_critical(JavaThread* thread))
2630   assert(thread == JavaThread::current(), "must be");
2631   // The code is about to enter a JNI lazy critical native method and
2632   // _needs_gc is true, so if this thread is already in a critical
2633   // section then just return, otherwise this thread should block
2634   // until needs_gc has been cleared.
2635   if (thread->in_critical()) {
2636     return;
2637   }
2638   // Lock and unlock a critical section to give the system a chance to block
2639   GC_locker::lock_critical(thread);
2640   GC_locker::unlock_critical(thread);
2641 JRT_END
2642 
2643 int SharedRuntime::convert_ints_to_longints_argcnt(int in_args_count, BasicType* in_sig_bt) {
2644   int argcnt = in_args_count;
2645   if (CCallingConventionRequiresIntsAsLongs) {
2646     for (int in = 0; in < in_args_count; in++) {
2647       BasicType bt = in_sig_bt[in];
2648       switch (bt) {
2649         case T_BOOLEAN:
2650         case T_CHAR:
2651         case T_BYTE:
2652         case T_SHORT:
2653         case T_INT:
2654           argcnt++;
2655           break;
2656         default:
2657           break;
2658       }
2659     }
2660   } else {
2661     assert(0, "This should not be needed on this platform");
2662   }
2663 
2664   return argcnt;
2665 }
2666 
2667 void SharedRuntime::convert_ints_to_longints(int i2l_argcnt, int& in_args_count,
2668                                              BasicType*& in_sig_bt, VMRegPair*& in_regs) {
2669   if (CCallingConventionRequiresIntsAsLongs) {
2670     VMRegPair *new_in_regs   = NEW_RESOURCE_ARRAY(VMRegPair, i2l_argcnt);
2671     BasicType *new_in_sig_bt = NEW_RESOURCE_ARRAY(BasicType, i2l_argcnt);
2672 
2673     int argcnt = 0;
2674     for (int in = 0; in < in_args_count; in++, argcnt++) {
2675       BasicType bt  = in_sig_bt[in];
2676       VMRegPair reg = in_regs[in];
2677       switch (bt) {
2678         case T_BOOLEAN:
2679         case T_CHAR:
2680         case T_BYTE:
2681         case T_SHORT:
2682         case T_INT:
2683           // Convert (bt) to (T_LONG,bt).
2684           new_in_sig_bt[argcnt] = T_LONG;
2685           new_in_sig_bt[argcnt+1] = bt;
2686           assert(reg.first()->is_valid() && !reg.second()->is_valid(), "");
2687           new_in_regs[argcnt].set2(reg.first());
2688           new_in_regs[argcnt+1].set_bad();
2689           argcnt++;
2690           break;
2691         default:
2692           // No conversion needed.
2693           new_in_sig_bt[argcnt] = bt;
2694           new_in_regs[argcnt]   = reg;
2695           break;
2696       }
2697     }
2698     assert(argcnt == i2l_argcnt, "must match");
2699 
2700     in_regs = new_in_regs;
2701     in_sig_bt = new_in_sig_bt;
2702     in_args_count = i2l_argcnt;
2703   } else {
2704     assert(0, "This should not be needed on this platform");
2705   }
2706 }
2707 
2708 // -------------------------------------------------------------------------
2709 // Java-Java calling convention
2710 // (what you use when Java calls Java)
2711 
2712 //------------------------------name_for_receiver----------------------------------
2713 // For a given signature, return the VMReg for parameter 0.
2714 VMReg SharedRuntime::name_for_receiver() {
2715   VMRegPair regs;
2716   BasicType sig_bt = T_OBJECT;
2717   (void) java_calling_convention(&sig_bt, &regs, 1, true);
2718   // Return argument 0 register.  In the LP64 build pointers
2719   // take 2 registers, but the VM wants only the 'main' name.
2720   return regs.first();
2721 }
2722 
2723 VMRegPair *SharedRuntime::find_callee_arguments(Symbol* sig, bool has_receiver, bool has_appendix, int* arg_size) {
2724   // This method is returning a data structure allocating as a
2725   // ResourceObject, so do not put any ResourceMarks in here.
2726   char *s = sig->as_C_string();
2727   int len = (int)strlen(s);
2728   s++; len--;                   // Skip opening paren
2729   char *t = s+len;
2730   while (*(--t) != ')');      // Find close paren
2731 
2732   BasicType *sig_bt = NEW_RESOURCE_ARRAY(BasicType, 256);
2733   VMRegPair *regs = NEW_RESOURCE_ARRAY(VMRegPair, 256);
2734   int cnt = 0;
2735   if (has_receiver) {
2736     sig_bt[cnt++] = T_OBJECT; // Receiver is argument 0; not in signature
2737   }
2738 
2739   while (s < t) {
2740     switch (*s++) {            // Switch on signature character
2741     case 'B': sig_bt[cnt++] = T_BYTE;    break;
2742     case 'C': sig_bt[cnt++] = T_CHAR;    break;
2743     case 'D': sig_bt[cnt++] = T_DOUBLE;  sig_bt[cnt++] = T_VOID; break;
2744     case 'F': sig_bt[cnt++] = T_FLOAT;   break;
2745     case 'I': sig_bt[cnt++] = T_INT;     break;
2746     case 'J': sig_bt[cnt++] = T_LONG;    sig_bt[cnt++] = T_VOID; break;
2747     case 'S': sig_bt[cnt++] = T_SHORT;   break;
2748     case 'Z': sig_bt[cnt++] = T_BOOLEAN; break;
2749     case 'V': sig_bt[cnt++] = T_VOID;    break;
2750     case 'L':                   // Oop
2751       while (*s++ != ';');   // Skip signature
2752       sig_bt[cnt++] = T_OBJECT;
2753       break;
2754     case '[': {                 // Array
2755       do {                      // Skip optional size
2756         while (*s >= '0' && *s <= '9') s++;
2757       } while (*s++ == '[');   // Nested arrays?
2758       // Skip element type
2759       if (s[-1] == 'L')
2760         while (*s++ != ';'); // Skip signature
2761       sig_bt[cnt++] = T_ARRAY;
2762       break;
2763     }
2764     default : ShouldNotReachHere();
2765     }
2766   }
2767 
2768   if (has_appendix) {
2769     sig_bt[cnt++] = T_OBJECT;
2770   }
2771 
2772   assert(cnt < 256, "grow table size");
2773 
2774   int comp_args_on_stack;
2775   comp_args_on_stack = java_calling_convention(sig_bt, regs, cnt, true);
2776 
2777   // the calling convention doesn't count out_preserve_stack_slots so
2778   // we must add that in to get "true" stack offsets.
2779 
2780   if (comp_args_on_stack) {
2781     for (int i = 0; i < cnt; i++) {
2782       VMReg reg1 = regs[i].first();
2783       if (reg1->is_stack()) {
2784         // Yuck
2785         reg1 = reg1->bias(out_preserve_stack_slots());
2786       }
2787       VMReg reg2 = regs[i].second();
2788       if (reg2->is_stack()) {
2789         // Yuck
2790         reg2 = reg2->bias(out_preserve_stack_slots());
2791       }
2792       regs[i].set_pair(reg2, reg1);
2793     }
2794   }
2795 
2796   // results
2797   *arg_size = cnt;
2798   return regs;
2799 }
2800 
2801 // OSR Migration Code
2802 //
2803 // This code is used convert interpreter frames into compiled frames.  It is
2804 // called from very start of a compiled OSR nmethod.  A temp array is
2805 // allocated to hold the interesting bits of the interpreter frame.  All
2806 // active locks are inflated to allow them to move.  The displaced headers and
2807 // active interpreter locals are copied into the temp buffer.  Then we return
2808 // back to the compiled code.  The compiled code then pops the current
2809 // interpreter frame off the stack and pushes a new compiled frame.  Then it
2810 // copies the interpreter locals and displaced headers where it wants.
2811 // Finally it calls back to free the temp buffer.
2812 //
2813 // All of this is done NOT at any Safepoint, nor is any safepoint or GC allowed.
2814 
2815 JRT_LEAF(intptr_t*, SharedRuntime::OSR_migration_begin( JavaThread *thread) )
2816 
2817   //
2818   // This code is dependent on the memory layout of the interpreter local
2819   // array and the monitors. On all of our platforms the layout is identical
2820   // so this code is shared. If some platform lays the their arrays out
2821   // differently then this code could move to platform specific code or
2822   // the code here could be modified to copy items one at a time using
2823   // frame accessor methods and be platform independent.
2824 
2825   frame fr = thread->last_frame();
2826   assert(fr.is_interpreted_frame(), "");
2827   assert(fr.interpreter_frame_expression_stack_size()==0, "only handle empty stacks");
2828 
2829   // Figure out how many monitors are active.
2830   int active_monitor_count = 0;
2831   for (BasicObjectLock *kptr = fr.interpreter_frame_monitor_end();
2832        kptr < fr.interpreter_frame_monitor_begin();
2833        kptr = fr.next_monitor_in_interpreter_frame(kptr) ) {
2834     if (kptr->obj() != NULL) active_monitor_count++;
2835   }
2836 
2837   // QQQ we could place number of active monitors in the array so that compiled code
2838   // could double check it.
2839 
2840   Method* moop = fr.interpreter_frame_method();
2841   int max_locals = moop->max_locals();
2842   // Allocate temp buffer, 1 word per local & 2 per active monitor
2843   int buf_size_words = max_locals + active_monitor_count*2;
2844   intptr_t *buf = NEW_C_HEAP_ARRAY(intptr_t,buf_size_words, mtCode);
2845 
2846   // Copy the locals.  Order is preserved so that loading of longs works.
2847   // Since there's no GC I can copy the oops blindly.
2848   assert(sizeof(HeapWord)==sizeof(intptr_t), "fix this code");
2849   Copy::disjoint_words((HeapWord*)fr.interpreter_frame_local_at(max_locals-1),
2850                        (HeapWord*)&buf[0],
2851                        max_locals);
2852 
2853   // Inflate locks.  Copy the displaced headers.  Be careful, there can be holes.
2854   int i = max_locals;
2855   for (BasicObjectLock *kptr2 = fr.interpreter_frame_monitor_end();
2856        kptr2 < fr.interpreter_frame_monitor_begin();
2857        kptr2 = fr.next_monitor_in_interpreter_frame(kptr2) ) {
2858     if (kptr2->obj() != NULL) {         // Avoid 'holes' in the monitor array
2859       BasicLock *lock = kptr2->lock();
2860       // Inflate so the displaced header becomes position-independent
2861       if (lock->displaced_header()->is_unlocked())
2862         ObjectSynchronizer::inflate_helper(kptr2->obj());
2863       // Now the displaced header is free to move
2864       buf[i++] = (intptr_t)lock->displaced_header();
2865       buf[i++] = cast_from_oop<intptr_t>(kptr2->obj());
2866     }
2867   }
2868   assert(i - max_locals == active_monitor_count*2, "found the expected number of monitors");
2869 
2870   return buf;
2871 JRT_END
2872 
2873 JRT_LEAF(void, SharedRuntime::OSR_migration_end( intptr_t* buf) )
2874   FREE_C_HEAP_ARRAY(intptr_t, buf);
2875 JRT_END
2876 
2877 bool AdapterHandlerLibrary::contains(CodeBlob* b) {
2878   AdapterHandlerTableIterator iter(_adapters);
2879   while (iter.has_next()) {
2880     AdapterHandlerEntry* a = iter.next();
2881     if (b == CodeCache::find_blob(a->get_i2c_entry())) return true;
2882   }
2883   return false;
2884 }
2885 
2886 void AdapterHandlerLibrary::print_handler_on(outputStream* st, CodeBlob* b) {
2887   AdapterHandlerTableIterator iter(_adapters);
2888   while (iter.has_next()) {
2889     AdapterHandlerEntry* a = iter.next();
2890     if (b == CodeCache::find_blob(a->get_i2c_entry())) {
2891       st->print("Adapter for signature: ");
2892       a->print_adapter_on(tty);
2893       return;
2894     }
2895   }
2896   assert(false, "Should have found handler");
2897 }
2898 
2899 void AdapterHandlerEntry::print_adapter_on(outputStream* st) const {
2900   st->print_cr("AHE@" INTPTR_FORMAT ": %s i2c: " INTPTR_FORMAT " c2i: " INTPTR_FORMAT " c2iUV: " INTPTR_FORMAT,
2901                (intptr_t) this, fingerprint()->as_string(),
2902                get_i2c_entry(), get_c2i_entry(), get_c2i_unverified_entry());
2903 
2904 }
2905 
2906 #ifndef PRODUCT
2907 
2908 void AdapterHandlerLibrary::print_statistics() {
2909   _adapters->print_statistics();
2910 }
2911 
2912 #endif /* PRODUCT */