deoptimization.cpp revision 1472:c18cbe5936b8
1829SN/A/* 27424SN/A * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. 3829SN/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4829SN/A * 5829SN/A * This code is free software; you can redistribute it and/or modify it 6829SN/A * under the terms of the GNU General Public License version 2 only, as 72362SN/A * published by the Free Software Foundation. 8829SN/A * 92362SN/A * This code is distributed in the hope that it will be useful, but WITHOUT 10829SN/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11829SN/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12829SN/A * version 2 for more details (a copy is included in the LICENSE file that 13829SN/A * accompanied this code). 14829SN/A * 15829SN/A * You should have received a copy of the GNU General Public License version 16829SN/A * 2 along with this work; if not, write to the Free Software Foundation, 17829SN/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18829SN/A * 19829SN/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20829SN/A * or visit www.oracle.com if you need additional information or have any 212362SN/A * questions. 222362SN/A * 232362SN/A */ 24829SN/A 2515409Sserb#include "incls/_precompiled.incl" 26829SN/A#include "incls/_deoptimization.cpp.incl" 27829SN/A 28829SN/Abool DeoptimizationMarker::_is_active = false; 293957SN/A 3015409SserbDeoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame, 31829SN/A int caller_adjustment, 32829SN/A int number_of_frames, 33829SN/A intptr_t* frame_sizes, 34829SN/A address* frame_pcs, 35829SN/A BasicType return_type) { 36829SN/A _size_of_deoptimized_frame = size_of_deoptimized_frame; 37829SN/A _caller_adjustment = caller_adjustment; 38829SN/A _number_of_frames = number_of_frames; 39829SN/A _frame_sizes = frame_sizes; 40829SN/A _frame_pcs = frame_pcs; 41829SN/A _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2); 42829SN/A _return_type = return_type; 43829SN/A // PD (x86 only) 44829SN/A _counter_temp = 0; 457424SN/A _initial_fp = 0; 46829SN/A _unpack_kind = 0; 477424SN/A _sender_sp_temp = 0; 487424SN/A 497424SN/A _total_frame_sizes = size_of_frames(); 507424SN/A} 517424SN/A 52829SN/A 53829SN/ADeoptimization::UnrollBlock::~UnrollBlock() { 54829SN/A FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes); 55829SN/A FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs); 56829SN/A FREE_C_HEAP_ARRAY(intptr_t, _register_block); 57829SN/A} 58829SN/A 59829SN/A 60829SN/Aintptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const { 61829SN/A assert(register_number < RegisterMap::reg_count, "checking register number"); 62829SN/A return &_register_block[register_number * 2]; 63829SN/A} 64829SN/A 6515409Sserb 66829SN/A 67829SN/Aint Deoptimization::UnrollBlock::size_of_frames() const { 68829SN/A // Acount first for the adjustment of the initial frame 69829SN/A int result = _caller_adjustment; 70829SN/A for (int index = 0; index < number_of_frames(); index++) { 71829SN/A result += frame_sizes()[index]; 72829SN/A } 73829SN/A return result; 74829SN/A} 75829SN/A 76829SN/A 77829SN/Avoid Deoptimization::UnrollBlock::print() { 78829SN/A ttyLocker ttyl; 79829SN/A tty->print_cr("UnrollBlock"); 80829SN/A tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame); 81829SN/A tty->print( " frame_sizes: "); 82829SN/A for (int index = 0; index < number_of_frames(); index++) { 83829SN/A tty->print("%d ", frame_sizes()[index]); 84829SN/A } 85829SN/A tty->cr(); 86829SN/A} 87829SN/A 88829SN/A 89829SN/A// In order to make fetch_unroll_info work properly with escape 90829SN/A// analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and 91829SN/A// ResetNoHandleMark and HandleMark were removed from it. The actual reallocation 92829SN/A// of previously eliminated objects occurs in realloc_objects, which is 93829SN/A// called from the method fetch_unroll_info_helper below. 94829SN/AJRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread)) 95829SN/A // It is actually ok to allocate handles in a leaf method. It causes no safepoints, 96829SN/A // but makes the entry a little slower. There is however a little dance we have to 97829SN/A // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro 98829SN/A 9915409Sserb // fetch_unroll_info() is called at the beginning of the deoptimization 100829SN/A // handler. Note this fact before we start generating temporary frames 101829SN/A // that can confuse an asynchronous stack walker. This counter is 102829SN/A // decremented at the end of unpack_frames(). 103829SN/A thread->inc_in_deopt_handler(); 104829SN/A 105829SN/A return fetch_unroll_info_helper(thread); 106829SN/AJRT_END 107829SN/A 108829SN/A 109829SN/A// This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap) 110829SN/ADeoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) { 111829SN/A 112829SN/A // Note: there is a safepoint safety issue here. No matter whether we enter 113829SN/A // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once 114829SN/A // the vframeArray is created. 115829SN/A // 11615409Sserb 117829SN/A // Allocate our special deoptimization ResourceMark 118829SN/A DeoptResourceMark* dmark = new DeoptResourceMark(thread); 119829SN/A assert(thread->deopt_mark() == NULL, "Pending deopt!"); 120829SN/A thread->set_deopt_mark(dmark); 121829SN/A 1223957SN/A frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect 123829SN/A RegisterMap map(thread, true); 124829SN/A RegisterMap dummy_map(thread, false); 125829SN/A // Now get the deoptee with a valid map 1263957SN/A frame deoptee = stub_frame.sender(&map); 127829SN/A 128829SN/A // Create a growable array of VFrames where each VFrame represents an inlined 129 // Java frame. This storage is allocated with the usual system arena. 130 assert(deoptee.is_compiled_frame(), "Wrong frame type"); 131 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10); 132 vframe* vf = vframe::new_vframe(&deoptee, &map, thread); 133 while (!vf->is_top()) { 134 assert(vf->is_compiled_frame(), "Wrong frame type"); 135 chunk->push(compiledVFrame::cast(vf)); 136 vf = vf->sender(); 137 } 138 assert(vf->is_compiled_frame(), "Wrong frame type"); 139 chunk->push(compiledVFrame::cast(vf)); 140 141#ifdef COMPILER2 142 // Reallocate the non-escaping objects and restore their fields. Then 143 // relock objects if synchronization on them was eliminated. 144 if (DoEscapeAnalysis) { 145 if (EliminateAllocations) { 146 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames"); 147 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects(); 148 149 // The flag return_oop() indicates call sites which return oop 150 // in compiled code. Such sites include java method calls, 151 // runtime calls (for example, used to allocate new objects/arrays 152 // on slow code path) and any other calls generated in compiled code. 153 // It is not guaranteed that we can get such information here only 154 // by analyzing bytecode in deoptimized frames. This is why this flag 155 // is set during method compilation (see Compile::Process_OopMap_Node()). 156 bool save_oop_result = chunk->at(0)->scope()->return_oop(); 157 Handle return_value; 158 if (save_oop_result) { 159 // Reallocation may trigger GC. If deoptimization happened on return from 160 // call which returns oop we need to save it since it is not in oopmap. 161 oop result = deoptee.saved_oop_result(&map); 162 assert(result == NULL || result->is_oop(), "must be oop"); 163 return_value = Handle(thread, result); 164 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer"); 165 if (TraceDeoptimization) { 166 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread); 167 } 168 } 169 bool reallocated = false; 170 if (objects != NULL) { 171 JRT_BLOCK 172 reallocated = realloc_objects(thread, &deoptee, objects, THREAD); 173 JRT_END 174 } 175 if (reallocated) { 176 reassign_fields(&deoptee, &map, objects); 177#ifndef PRODUCT 178 if (TraceDeoptimization) { 179 ttyLocker ttyl; 180 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread); 181 print_objects(objects); 182 } 183#endif 184 } 185 if (save_oop_result) { 186 // Restore result. 187 deoptee.set_saved_oop_result(&map, return_value()); 188 } 189 } 190 if (EliminateLocks) { 191#ifndef PRODUCT 192 bool first = true; 193#endif 194 for (int i = 0; i < chunk->length(); i++) { 195 compiledVFrame* cvf = chunk->at(i); 196 assert (cvf->scope() != NULL,"expect only compiled java frames"); 197 GrowableArray<MonitorInfo*>* monitors = cvf->monitors(); 198 if (monitors->is_nonempty()) { 199 relock_objects(monitors, thread); 200#ifndef PRODUCT 201 if (TraceDeoptimization) { 202 ttyLocker ttyl; 203 for (int j = 0; j < monitors->length(); j++) { 204 MonitorInfo* mi = monitors->at(j); 205 if (mi->eliminated()) { 206 if (first) { 207 first = false; 208 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread); 209 } 210 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner()); 211 } 212 } 213 } 214#endif 215 } 216 } 217 } 218 } 219#endif // COMPILER2 220 // Ensure that no safepoint is taken after pointers have been stored 221 // in fields of rematerialized objects. If a safepoint occurs from here on 222 // out the java state residing in the vframeArray will be missed. 223 No_Safepoint_Verifier no_safepoint; 224 225 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk); 226 227 assert(thread->vframe_array_head() == NULL, "Pending deopt!");; 228 thread->set_vframe_array_head(array); 229 230 // Now that the vframeArray has been created if we have any deferred local writes 231 // added by jvmti then we can free up that structure as the data is now in the 232 // vframeArray 233 234 if (thread->deferred_locals() != NULL) { 235 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals(); 236 int i = 0; 237 do { 238 // Because of inlining we could have multiple vframes for a single frame 239 // and several of the vframes could have deferred writes. Find them all. 240 if (list->at(i)->id() == array->original().id()) { 241 jvmtiDeferredLocalVariableSet* dlv = list->at(i); 242 list->remove_at(i); 243 // individual jvmtiDeferredLocalVariableSet are CHeapObj's 244 delete dlv; 245 } else { 246 i++; 247 } 248 } while ( i < list->length() ); 249 if (list->length() == 0) { 250 thread->set_deferred_locals(NULL); 251 // free the list and elements back to C heap. 252 delete list; 253 } 254 255 } 256 257 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info. 258 CodeBlob* cb = stub_frame.cb(); 259 // Verify we have the right vframeArray 260 assert(cb->frame_size() >= 0, "Unexpected frame size"); 261 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size(); 262 263 // If the deopt call site is a MethodHandle invoke call site we have 264 // to adjust the unpack_sp. 265 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null(); 266 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc())) 267 unpack_sp = deoptee.unextended_sp(); 268 269#ifdef ASSERT 270 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking"); 271 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp); 272#endif 273 // This is a guarantee instead of an assert because if vframe doesn't match 274 // we will unpack the wrong deoptimized frame and wind up in strange places 275 // where it will be very difficult to figure out what went wrong. Better 276 // to die an early death here than some very obscure death later when the 277 // trail is cold. 278 // Note: on ia64 this guarantee can be fooled by frames with no memory stack 279 // in that it will fail to detect a problem when there is one. This needs 280 // more work in tiger timeframe. 281 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack"); 282 283 int number_of_frames = array->frames(); 284 285 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost 286 // virtual activation, which is the reverse of the elements in the vframes array. 287 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames); 288 // +1 because we always have an interpreter return address for the final slot. 289 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1); 290 int callee_parameters = 0; 291 int callee_locals = 0; 292 int popframe_extra_args = 0; 293 // Create an interpreter return address for the stub to use as its return 294 // address so the skeletal frames are perfectly walkable 295 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0); 296 297 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost 298 // activation be put back on the expression stack of the caller for reexecution 299 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) { 300 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words()); 301 } 302 303 // 304 // frame_sizes/frame_pcs[0] oldest frame (int or c2i) 305 // frame_sizes/frame_pcs[1] next oldest frame (int) 306 // frame_sizes/frame_pcs[n] youngest frame (int) 307 // 308 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame 309 // owns the space for the return address to it's caller). Confusing ain't it. 310 // 311 // The vframe array can address vframes with indices running from 312 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame. 313 // When we create the skeletal frames we need the oldest frame to be in the zero slot 314 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk. 315 // so things look a little strange in this loop. 316 // 317 for (int index = 0; index < array->frames(); index++ ) { 318 // frame[number_of_frames - 1 ] = on_stack_size(youngest) 319 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest)) 320 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest))) 321 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters, 322 callee_locals, 323 index == 0, 324 popframe_extra_args); 325 // This pc doesn't have to be perfect just good enough to identify the frame 326 // as interpreted so the skeleton frame will be walkable 327 // The correct pc will be set when the skeleton frame is completely filled out 328 // The final pc we store in the loop is wrong and will be overwritten below 329 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset; 330 331 callee_parameters = array->element(index)->method()->size_of_parameters(); 332 callee_locals = array->element(index)->method()->max_locals(); 333 popframe_extra_args = 0; 334 } 335 336 // Compute whether the root vframe returns a float or double value. 337 BasicType return_type; 338 { 339 HandleMark hm; 340 methodHandle method(thread, array->element(0)->method()); 341 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci()); 342 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL; 343 } 344 345 // Compute information for handling adapters and adjusting the frame size of the caller. 346 int caller_adjustment = 0; 347 348 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized 349 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather 350 // than simply use array->sender.pc(). This requires us to walk the current set of frames 351 // 352 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame 353 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller 354 355 // Compute the amount the oldest interpreter frame will have to adjust 356 // its caller's stack by. If the caller is a compiled frame then 357 // we pretend that the callee has no parameters so that the 358 // extension counts for the full amount of locals and not just 359 // locals-parms. This is because without a c2i adapter the parm 360 // area as created by the compiled frame will not be usable by 361 // the interpreter. (Depending on the calling convention there 362 // may not even be enough space). 363 364 // QQQ I'd rather see this pushed down into last_frame_adjust 365 // and have it take the sender (aka caller). 366 367 if (deopt_sender.is_compiled_frame()) { 368 caller_adjustment = last_frame_adjust(0, callee_locals); 369 } else if (callee_locals > callee_parameters) { 370 // The caller frame may need extending to accommodate 371 // non-parameter locals of the first unpacked interpreted frame. 372 // Compute that adjustment. 373 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals); 374 } 375 376 377 // If the sender is deoptimized the we must retrieve the address of the handler 378 // since the frame will "magically" show the original pc before the deopt 379 // and we'd undo the deopt. 380 381 frame_pcs[0] = deopt_sender.raw_pc(); 382 383 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc"); 384 385 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord, 386 caller_adjustment * BytesPerWord, 387 number_of_frames, 388 frame_sizes, 389 frame_pcs, 390 return_type); 391#if defined(IA32) || defined(AMD64) 392 // We need a way to pass fp to the unpacking code so the skeletal frames 393 // come out correct. This is only needed for x86 because of c2 using ebp 394 // as an allocatable register. So this update is useless (and harmless) 395 // on the other platforms. It would be nice to do this in a different 396 // way but even the old style deoptimization had a problem with deriving 397 // this value. NEEDS_CLEANUP 398 // Note: now that c1 is using c2's deopt blob we must do this on all 399 // x86 based platforms 400 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes()); 401 *fp_addr = array->sender().fp(); // was adapter_caller 402#endif /* IA32 || AMD64 */ 403 404 if (array->frames() > 1) { 405 if (VerifyStack && TraceDeoptimization) { 406 tty->print_cr("Deoptimizing method containing inlining"); 407 } 408 } 409 410 array->set_unroll_block(info); 411 return info; 412} 413 414// Called to cleanup deoptimization data structures in normal case 415// after unpacking to stack and when stack overflow error occurs 416void Deoptimization::cleanup_deopt_info(JavaThread *thread, 417 vframeArray *array) { 418 419 // Get array if coming from exception 420 if (array == NULL) { 421 array = thread->vframe_array_head(); 422 } 423 thread->set_vframe_array_head(NULL); 424 425 // Free the previous UnrollBlock 426 vframeArray* old_array = thread->vframe_array_last(); 427 thread->set_vframe_array_last(array); 428 429 if (old_array != NULL) { 430 UnrollBlock* old_info = old_array->unroll_block(); 431 old_array->set_unroll_block(NULL); 432 delete old_info; 433 delete old_array; 434 } 435 436 // Deallocate any resource creating in this routine and any ResourceObjs allocated 437 // inside the vframeArray (StackValueCollections) 438 439 delete thread->deopt_mark(); 440 thread->set_deopt_mark(NULL); 441 442 443 if (JvmtiExport::can_pop_frame()) { 444#ifndef CC_INTERP 445 // Regardless of whether we entered this routine with the pending 446 // popframe condition bit set, we should always clear it now 447 thread->clear_popframe_condition(); 448#else 449 // C++ interpeter will clear has_pending_popframe when it enters 450 // with method_resume. For deopt_resume2 we clear it now. 451 if (thread->popframe_forcing_deopt_reexecution()) 452 thread->clear_popframe_condition(); 453#endif /* CC_INTERP */ 454 } 455 456 // unpack_frames() is called at the end of the deoptimization handler 457 // and (in C2) at the end of the uncommon trap handler. Note this fact 458 // so that an asynchronous stack walker can work again. This counter is 459 // incremented at the beginning of fetch_unroll_info() and (in C2) at 460 // the beginning of uncommon_trap(). 461 thread->dec_in_deopt_handler(); 462} 463 464 465// Return BasicType of value being returned 466JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode)) 467 468 // We are already active int he special DeoptResourceMark any ResourceObj's we 469 // allocate will be freed at the end of the routine. 470 471 // It is actually ok to allocate handles in a leaf method. It causes no safepoints, 472 // but makes the entry a little slower. There is however a little dance we have to 473 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro 474 ResetNoHandleMark rnhm; // No-op in release/product versions 475 HandleMark hm; 476 477 frame stub_frame = thread->last_frame(); 478 479 // Since the frame to unpack is the top frame of this thread, the vframe_array_head 480 // must point to the vframeArray for the unpack frame. 481 vframeArray* array = thread->vframe_array_head(); 482 483#ifndef PRODUCT 484 if (TraceDeoptimization) { 485 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode); 486 } 487#endif 488 489 UnrollBlock* info = array->unroll_block(); 490 491 // Unpack the interpreter frames and any adapter frame (c2 only) we might create. 492 array->unpack_to_stack(stub_frame, exec_mode); 493 494 BasicType bt = info->return_type(); 495 496 // If we have an exception pending, claim that the return type is an oop 497 // so the deopt_blob does not overwrite the exception_oop. 498 499 if (exec_mode == Unpack_exception) 500 bt = T_OBJECT; 501 502 // Cleanup thread deopt data 503 cleanup_deopt_info(thread, array); 504 505#ifndef PRODUCT 506 if (VerifyStack) { 507 ResourceMark res_mark; 508 509 // Verify that the just-unpacked frames match the interpreter's 510 // notions of expression stack and locals 511 vframeArray* cur_array = thread->vframe_array_last(); 512 RegisterMap rm(thread, false); 513 rm.set_include_argument_oops(false); 514 bool is_top_frame = true; 515 int callee_size_of_parameters = 0; 516 int callee_max_locals = 0; 517 for (int i = 0; i < cur_array->frames(); i++) { 518 vframeArrayElement* el = cur_array->element(i); 519 frame* iframe = el->iframe(); 520 guarantee(iframe->is_interpreted_frame(), "Wrong frame type"); 521 522 // Get the oop map for this bci 523 InterpreterOopMap mask; 524 int cur_invoke_parameter_size = 0; 525 bool try_next_mask = false; 526 int next_mask_expression_stack_size = -1; 527 int top_frame_expression_stack_adjustment = 0; 528 methodHandle mh(thread, iframe->interpreter_frame_method()); 529 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask); 530 BytecodeStream str(mh); 531 str.set_start(iframe->interpreter_frame_bci()); 532 int max_bci = mh->code_size(); 533 // Get to the next bytecode if possible 534 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds"); 535 // Check to see if we can grab the number of outgoing arguments 536 // at an uncommon trap for an invoke (where the compiler 537 // generates debug info before the invoke has executed) 538 Bytecodes::Code cur_code = str.next(); 539 if (cur_code == Bytecodes::_invokevirtual || 540 cur_code == Bytecodes::_invokespecial || 541 cur_code == Bytecodes::_invokestatic || 542 cur_code == Bytecodes::_invokeinterface) { 543 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci()); 544 symbolHandle signature(thread, invoke->signature()); 545 ArgumentSizeComputer asc(signature); 546 cur_invoke_parameter_size = asc.size(); 547 if (cur_code != Bytecodes::_invokestatic) { 548 // Add in receiver 549 ++cur_invoke_parameter_size; 550 } 551 } 552 if (str.bci() < max_bci) { 553 Bytecodes::Code bc = str.next(); 554 if (bc >= 0) { 555 // The interpreter oop map generator reports results before 556 // the current bytecode has executed except in the case of 557 // calls. It seems to be hard to tell whether the compiler 558 // has emitted debug information matching the "state before" 559 // a given bytecode or the state after, so we try both 560 switch (cur_code) { 561 case Bytecodes::_invokevirtual: 562 case Bytecodes::_invokespecial: 563 case Bytecodes::_invokestatic: 564 case Bytecodes::_invokeinterface: 565 case Bytecodes::_athrow: 566 break; 567 default: { 568 InterpreterOopMap next_mask; 569 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask); 570 next_mask_expression_stack_size = next_mask.expression_stack_size(); 571 // Need to subtract off the size of the result type of 572 // the bytecode because this is not described in the 573 // debug info but returned to the interpreter in the TOS 574 // caching register 575 BasicType bytecode_result_type = Bytecodes::result_type(cur_code); 576 if (bytecode_result_type != T_ILLEGAL) { 577 top_frame_expression_stack_adjustment = type2size[bytecode_result_type]; 578 } 579 assert(top_frame_expression_stack_adjustment >= 0, ""); 580 try_next_mask = true; 581 break; 582 } 583 } 584 } 585 } 586 587 // Verify stack depth and oops in frame 588 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc) 589 if (!( 590 /* SPARC */ 591 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) || 592 /* x86 */ 593 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) || 594 (try_next_mask && 595 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size - 596 top_frame_expression_stack_adjustment))) || 597 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) || 598 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) && 599 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size)) 600 )) { 601 ttyLocker ttyl; 602 603 // Print out some information that will help us debug the problem 604 tty->print_cr("Wrong number of expression stack elements during deoptimization"); 605 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1); 606 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements", 607 iframe->interpreter_frame_expression_stack_size()); 608 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size()); 609 tty->print_cr(" try_next_mask = %d", try_next_mask); 610 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size); 611 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters); 612 tty->print_cr(" callee_max_locals = %d", callee_max_locals); 613 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment); 614 tty->print_cr(" exec_mode = %d", exec_mode); 615 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size); 616 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id()); 617 tty->print_cr(" Interpreted frames:"); 618 for (int k = 0; k < cur_array->frames(); k++) { 619 vframeArrayElement* el = cur_array->element(k); 620 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci()); 621 } 622 cur_array->print_on_2(tty); 623 guarantee(false, "wrong number of expression stack elements during deopt"); 624 } 625 VerifyOopClosure verify; 626 iframe->oops_interpreted_do(&verify, &rm, false); 627 callee_size_of_parameters = mh->size_of_parameters(); 628 callee_max_locals = mh->max_locals(); 629 is_top_frame = false; 630 } 631 } 632#endif /* !PRODUCT */ 633 634 635 return bt; 636JRT_END 637 638 639int Deoptimization::deoptimize_dependents() { 640 Threads::deoptimized_wrt_marked_nmethods(); 641 return 0; 642} 643 644 645#ifdef COMPILER2 646bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) { 647 Handle pending_exception(thread->pending_exception()); 648 const char* exception_file = thread->exception_file(); 649 int exception_line = thread->exception_line(); 650 thread->clear_pending_exception(); 651 652 for (int i = 0; i < objects->length(); i++) { 653 assert(objects->at(i)->is_object(), "invalid debug information"); 654 ObjectValue* sv = (ObjectValue*) objects->at(i); 655 656 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); 657 oop obj = NULL; 658 659 if (k->oop_is_instance()) { 660 instanceKlass* ik = instanceKlass::cast(k()); 661 obj = ik->allocate_instance(CHECK_(false)); 662 } else if (k->oop_is_typeArray()) { 663 typeArrayKlass* ak = typeArrayKlass::cast(k()); 664 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length"); 665 int len = sv->field_size() / type2size[ak->element_type()]; 666 obj = ak->allocate(len, CHECK_(false)); 667 } else if (k->oop_is_objArray()) { 668 objArrayKlass* ak = objArrayKlass::cast(k()); 669 obj = ak->allocate(sv->field_size(), CHECK_(false)); 670 } 671 672 assert(obj != NULL, "allocation failed"); 673 assert(sv->value().is_null(), "redundant reallocation"); 674 sv->set_value(obj); 675 } 676 677 if (pending_exception.not_null()) { 678 thread->set_pending_exception(pending_exception(), exception_file, exception_line); 679 } 680 681 return true; 682} 683 684// This assumes that the fields are stored in ObjectValue in the same order 685// they are yielded by do_nonstatic_fields. 686class FieldReassigner: public FieldClosure { 687 frame* _fr; 688 RegisterMap* _reg_map; 689 ObjectValue* _sv; 690 instanceKlass* _ik; 691 oop _obj; 692 693 int _i; 694public: 695 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) : 696 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {} 697 698 int i() const { return _i; } 699 700 701 void do_field(fieldDescriptor* fd) { 702 intptr_t val; 703 StackValue* value = 704 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i())); 705 int offset = fd->offset(); 706 switch (fd->field_type()) { 707 case T_OBJECT: case T_ARRAY: 708 assert(value->type() == T_OBJECT, "Agreement."); 709 _obj->obj_field_put(offset, value->get_obj()()); 710 break; 711 712 case T_LONG: case T_DOUBLE: { 713 assert(value->type() == T_INT, "Agreement."); 714 StackValue* low = 715 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i)); 716#ifdef _LP64 717 jlong res = (jlong)low->get_int(); 718#else 719#ifdef SPARC 720 // For SPARC we have to swap high and low words. 721 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int()); 722#else 723 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int()); 724#endif //SPARC 725#endif 726 _obj->long_field_put(offset, res); 727 break; 728 } 729 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem. 730 case T_INT: case T_FLOAT: // 4 bytes. 731 assert(value->type() == T_INT, "Agreement."); 732 val = value->get_int(); 733 _obj->int_field_put(offset, (jint)*((jint*)&val)); 734 break; 735 736 case T_SHORT: case T_CHAR: // 2 bytes 737 assert(value->type() == T_INT, "Agreement."); 738 val = value->get_int(); 739 _obj->short_field_put(offset, (jshort)*((jint*)&val)); 740 break; 741 742 case T_BOOLEAN: case T_BYTE: // 1 byte 743 assert(value->type() == T_INT, "Agreement."); 744 val = value->get_int(); 745 _obj->bool_field_put(offset, (jboolean)*((jint*)&val)); 746 break; 747 748 default: 749 ShouldNotReachHere(); 750 } 751 _i++; 752 } 753}; 754 755// restore elements of an eliminated type array 756void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) { 757 int index = 0; 758 intptr_t val; 759 760 for (int i = 0; i < sv->field_size(); i++) { 761 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i)); 762 switch(type) { 763 case T_LONG: case T_DOUBLE: { 764 assert(value->type() == T_INT, "Agreement."); 765 StackValue* low = 766 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i)); 767#ifdef _LP64 768 jlong res = (jlong)low->get_int(); 769#else 770#ifdef SPARC 771 // For SPARC we have to swap high and low words. 772 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int()); 773#else 774 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int()); 775#endif //SPARC 776#endif 777 obj->long_at_put(index, res); 778 break; 779 } 780 781 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem. 782 case T_INT: case T_FLOAT: // 4 bytes. 783 assert(value->type() == T_INT, "Agreement."); 784 val = value->get_int(); 785 obj->int_at_put(index, (jint)*((jint*)&val)); 786 break; 787 788 case T_SHORT: case T_CHAR: // 2 bytes 789 assert(value->type() == T_INT, "Agreement."); 790 val = value->get_int(); 791 obj->short_at_put(index, (jshort)*((jint*)&val)); 792 break; 793 794 case T_BOOLEAN: case T_BYTE: // 1 byte 795 assert(value->type() == T_INT, "Agreement."); 796 val = value->get_int(); 797 obj->bool_at_put(index, (jboolean)*((jint*)&val)); 798 break; 799 800 default: 801 ShouldNotReachHere(); 802 } 803 index++; 804 } 805} 806 807 808// restore fields of an eliminated object array 809void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) { 810 for (int i = 0; i < sv->field_size(); i++) { 811 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i)); 812 assert(value->type() == T_OBJECT, "object element expected"); 813 obj->obj_at_put(i, value->get_obj()()); 814 } 815} 816 817 818// restore fields of all eliminated objects and arrays 819void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) { 820 for (int i = 0; i < objects->length(); i++) { 821 ObjectValue* sv = (ObjectValue*) objects->at(i); 822 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); 823 Handle obj = sv->value(); 824 assert(obj.not_null(), "reallocation was missed"); 825 826 if (k->oop_is_instance()) { 827 instanceKlass* ik = instanceKlass::cast(k()); 828 FieldReassigner reassign(fr, reg_map, sv, obj()); 829 ik->do_nonstatic_fields(&reassign); 830 } else if (k->oop_is_typeArray()) { 831 typeArrayKlass* ak = typeArrayKlass::cast(k()); 832 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type()); 833 } else if (k->oop_is_objArray()) { 834 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj()); 835 } 836 } 837} 838 839 840// relock objects for which synchronization was eliminated 841void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) { 842 for (int i = 0; i < monitors->length(); i++) { 843 MonitorInfo* mon_info = monitors->at(i); 844 if (mon_info->eliminated()) { 845 assert(mon_info->owner() != NULL, "reallocation was missed"); 846 Handle obj = Handle(mon_info->owner()); 847 markOop mark = obj->mark(); 848 if (UseBiasedLocking && mark->has_bias_pattern()) { 849 // New allocated objects may have the mark set to anonymously biased. 850 // Also the deoptimized method may called methods with synchronization 851 // where the thread-local object is bias locked to the current thread. 852 assert(mark->is_biased_anonymously() || 853 mark->biased_locker() == thread, "should be locked to current thread"); 854 // Reset mark word to unbiased prototype. 855 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age()); 856 obj->set_mark(unbiased_prototype); 857 } 858 BasicLock* lock = mon_info->lock(); 859 ObjectSynchronizer::slow_enter(obj, lock, thread); 860 } 861 assert(mon_info->owner()->is_locked(), "object must be locked now"); 862 } 863} 864 865 866#ifndef PRODUCT 867// print information about reallocated objects 868void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) { 869 fieldDescriptor fd; 870 871 for (int i = 0; i < objects->length(); i++) { 872 ObjectValue* sv = (ObjectValue*) objects->at(i); 873 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()()); 874 Handle obj = sv->value(); 875 876 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()()); 877 k->as_klassOop()->print_value(); 878 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize); 879 tty->cr(); 880 881 if (Verbose) { 882 k->oop_print_on(obj(), tty); 883 } 884 } 885} 886#endif 887#endif // COMPILER2 888 889vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) { 890 891#ifndef PRODUCT 892 if (TraceDeoptimization) { 893 ttyLocker ttyl; 894 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread); 895 fr.print_on(tty); 896 tty->print_cr(" Virtual frames (innermost first):"); 897 for (int index = 0; index < chunk->length(); index++) { 898 compiledVFrame* vf = chunk->at(index); 899 tty->print(" %2d - ", index); 900 vf->print_value(); 901 int bci = chunk->at(index)->raw_bci(); 902 const char* code_name; 903 if (bci == SynchronizationEntryBCI) { 904 code_name = "sync entry"; 905 } else { 906 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci); 907 code_name = Bytecodes::name(code); 908 } 909 tty->print(" - %s", code_name); 910 tty->print_cr(" @ bci %d ", bci); 911 if (Verbose) { 912 vf->print(); 913 tty->cr(); 914 } 915 } 916 } 917#endif 918 919 // Register map for next frame (used for stack crawl). We capture 920 // the state of the deopt'ing frame's caller. Thus if we need to 921 // stuff a C2I adapter we can properly fill in the callee-save 922 // register locations. 923 frame caller = fr.sender(reg_map); 924 int frame_size = caller.sp() - fr.sp(); 925 926 frame sender = caller; 927 928 // Since the Java thread being deoptimized will eventually adjust it's own stack, 929 // the vframeArray containing the unpacking information is allocated in the C heap. 930 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames(). 931 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr); 932 933 // Compare the vframeArray to the collected vframes 934 assert(array->structural_compare(thread, chunk), "just checking"); 935 Events::log("# vframes = %d", (intptr_t)chunk->length()); 936 937#ifndef PRODUCT 938 if (TraceDeoptimization) { 939 ttyLocker ttyl; 940 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array); 941 } 942#endif // PRODUCT 943 944 return array; 945} 946 947 948static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) { 949 GrowableArray<MonitorInfo*>* monitors = cvf->monitors(); 950 for (int i = 0; i < monitors->length(); i++) { 951 MonitorInfo* mon_info = monitors->at(i); 952 if (!mon_info->eliminated() && mon_info->owner() != NULL) { 953 objects_to_revoke->append(Handle(mon_info->owner())); 954 } 955 } 956} 957 958 959void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) { 960 if (!UseBiasedLocking) { 961 return; 962 } 963 964 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>(); 965 966 // Unfortunately we don't have a RegisterMap available in most of 967 // the places we want to call this routine so we need to walk the 968 // stack again to update the register map. 969 if (map == NULL || !map->update_map()) { 970 StackFrameStream sfs(thread, true); 971 bool found = false; 972 while (!found && !sfs.is_done()) { 973 frame* cur = sfs.current(); 974 sfs.next(); 975 found = cur->id() == fr.id(); 976 } 977 assert(found, "frame to be deoptimized not found on target thread's stack"); 978 map = sfs.register_map(); 979 } 980 981 vframe* vf = vframe::new_vframe(&fr, map, thread); 982 compiledVFrame* cvf = compiledVFrame::cast(vf); 983 // Revoke monitors' biases in all scopes 984 while (!cvf->is_top()) { 985 collect_monitors(cvf, objects_to_revoke); 986 cvf = compiledVFrame::cast(cvf->sender()); 987 } 988 collect_monitors(cvf, objects_to_revoke); 989 990 if (SafepointSynchronize::is_at_safepoint()) { 991 BiasedLocking::revoke_at_safepoint(objects_to_revoke); 992 } else { 993 BiasedLocking::revoke(objects_to_revoke); 994 } 995} 996 997 998void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) { 999 if (!UseBiasedLocking) { 1000 return; 1001 } 1002 1003 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint"); 1004 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>(); 1005 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) { 1006 if (jt->has_last_Java_frame()) { 1007 StackFrameStream sfs(jt, true); 1008 while (!sfs.is_done()) { 1009 frame* cur = sfs.current(); 1010 if (cb->contains(cur->pc())) { 1011 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt); 1012 compiledVFrame* cvf = compiledVFrame::cast(vf); 1013 // Revoke monitors' biases in all scopes 1014 while (!cvf->is_top()) { 1015 collect_monitors(cvf, objects_to_revoke); 1016 cvf = compiledVFrame::cast(cvf->sender()); 1017 } 1018 collect_monitors(cvf, objects_to_revoke); 1019 } 1020 sfs.next(); 1021 } 1022 } 1023 } 1024 BiasedLocking::revoke_at_safepoint(objects_to_revoke); 1025} 1026 1027 1028void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) { 1029 assert(fr.can_be_deoptimized(), "checking frame type"); 1030 1031 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal); 1032 1033 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id()); 1034 1035 // Patch the nmethod so that when execution returns to it we will 1036 // deopt the execution state and return to the interpreter. 1037 fr.deoptimize(thread); 1038} 1039 1040void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) { 1041 // Deoptimize only if the frame comes from compile code. 1042 // Do not deoptimize the frame which is already patched 1043 // during the execution of the loops below. 1044 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) { 1045 return; 1046 } 1047 ResourceMark rm; 1048 DeoptimizationMarker dm; 1049 if (UseBiasedLocking) { 1050 revoke_biases_of_monitors(thread, fr, map); 1051 } 1052 deoptimize_single_frame(thread, fr); 1053 1054} 1055 1056 1057void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) { 1058 // Compute frame and register map based on thread and sp. 1059 RegisterMap reg_map(thread, UseBiasedLocking); 1060 frame fr = thread->last_frame(); 1061 while (fr.id() != id) { 1062 fr = fr.sender(®_map); 1063 } 1064 deoptimize(thread, fr, ®_map); 1065} 1066 1067 1068// JVMTI PopFrame support 1069JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address)) 1070{ 1071 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address); 1072} 1073JRT_END 1074 1075 1076#ifdef COMPILER2 1077void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) { 1078 // in case of an unresolved klass entry, load the class. 1079 if (constant_pool->tag_at(index).is_unresolved_klass()) { 1080 klassOop tk = constant_pool->klass_at(index, CHECK); 1081 return; 1082 } 1083 1084 if (!constant_pool->tag_at(index).is_symbol()) return; 1085 1086 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader()); 1087 symbolHandle symbol (THREAD, constant_pool->symbol_at(index)); 1088 1089 // class name? 1090 if (symbol->byte_at(0) != '(') { 1091 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain()); 1092 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK); 1093 return; 1094 } 1095 1096 // then it must be a signature! 1097 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) { 1098 if (ss.is_object()) { 1099 symbolOop s = ss.as_symbol(CHECK); 1100 symbolHandle class_name (THREAD, s); 1101 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain()); 1102 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK); 1103 } 1104 } 1105} 1106 1107 1108void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) { 1109 EXCEPTION_MARK; 1110 load_class_by_index(constant_pool, index, THREAD); 1111 if (HAS_PENDING_EXCEPTION) { 1112 // Exception happened during classloading. We ignore the exception here, since it 1113 // is going to be rethrown since the current activation is going to be deoptimzied and 1114 // the interpreter will re-execute the bytecode. 1115 CLEAR_PENDING_EXCEPTION; 1116 } 1117} 1118 1119JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) { 1120 HandleMark hm; 1121 1122 // uncommon_trap() is called at the beginning of the uncommon trap 1123 // handler. Note this fact before we start generating temporary frames 1124 // that can confuse an asynchronous stack walker. This counter is 1125 // decremented at the end of unpack_frames(). 1126 thread->inc_in_deopt_handler(); 1127 1128 // We need to update the map if we have biased locking. 1129 RegisterMap reg_map(thread, UseBiasedLocking); 1130 frame stub_frame = thread->last_frame(); 1131 frame fr = stub_frame.sender(®_map); 1132 // Make sure the calling nmethod is not getting deoptimized and removed 1133 // before we are done with it. 1134 nmethodLocker nl(fr.pc()); 1135 1136 { 1137 ResourceMark rm; 1138 1139 // Revoke biases of any monitors in the frame to ensure we can migrate them 1140 revoke_biases_of_monitors(thread, fr, ®_map); 1141 1142 DeoptReason reason = trap_request_reason(trap_request); 1143 DeoptAction action = trap_request_action(trap_request); 1144 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1 1145 1146 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request); 1147 vframe* vf = vframe::new_vframe(&fr, ®_map, thread); 1148 compiledVFrame* cvf = compiledVFrame::cast(vf); 1149 1150 nmethod* nm = cvf->code(); 1151 1152 ScopeDesc* trap_scope = cvf->scope(); 1153 methodHandle trap_method = trap_scope->method(); 1154 int trap_bci = trap_scope->bci(); 1155 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code(); 1156 1157 // Record this event in the histogram. 1158 gather_statistics(reason, action, trap_bc); 1159 1160 // Ensure that we can record deopt. history: 1161 bool create_if_missing = ProfileTraps; 1162 1163 methodDataHandle trap_mdo 1164 (THREAD, get_method_data(thread, trap_method, create_if_missing)); 1165 1166 // Print a bunch of diagnostics, if requested. 1167 if (TraceDeoptimization || LogCompilation) { 1168 ResourceMark rm; 1169 ttyLocker ttyl; 1170 char buf[100]; 1171 if (xtty != NULL) { 1172 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s", 1173 os::current_thread_id(), 1174 format_trap_request(buf, sizeof(buf), trap_request)); 1175 nm->log_identity(xtty); 1176 } 1177 symbolHandle class_name; 1178 bool unresolved = false; 1179 if (unloaded_class_index >= 0) { 1180 constantPoolHandle constants (THREAD, trap_method->constants()); 1181 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) { 1182 class_name = symbolHandle(THREAD, 1183 constants->klass_name_at(unloaded_class_index)); 1184 unresolved = true; 1185 if (xtty != NULL) 1186 xtty->print(" unresolved='1'"); 1187 } else if (constants->tag_at(unloaded_class_index).is_symbol()) { 1188 class_name = symbolHandle(THREAD, 1189 constants->symbol_at(unloaded_class_index)); 1190 } 1191 if (xtty != NULL) 1192 xtty->name(class_name); 1193 } 1194 if (xtty != NULL && trap_mdo.not_null()) { 1195 // Dump the relevant MDO state. 1196 // This is the deopt count for the current reason, any previous 1197 // reasons or recompiles seen at this point. 1198 int dcnt = trap_mdo->trap_count(reason); 1199 if (dcnt != 0) 1200 xtty->print(" count='%d'", dcnt); 1201 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci); 1202 int dos = (pdata == NULL)? 0: pdata->trap_state(); 1203 if (dos != 0) { 1204 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos)); 1205 if (trap_state_is_recompiled(dos)) { 1206 int recnt2 = trap_mdo->overflow_recompile_count(); 1207 if (recnt2 != 0) 1208 xtty->print(" recompiles2='%d'", recnt2); 1209 } 1210 } 1211 } 1212 if (xtty != NULL) { 1213 xtty->stamp(); 1214 xtty->end_head(); 1215 } 1216 if (TraceDeoptimization) { // make noise on the tty 1217 tty->print("Uncommon trap occurred in"); 1218 nm->method()->print_short_name(tty); 1219 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d", 1220 fr.pc(), 1221 (int) os::current_thread_id(), 1222 trap_reason_name(reason), 1223 trap_action_name(action), 1224 unloaded_class_index); 1225 if (class_name.not_null()) { 1226 tty->print(unresolved ? " unresolved class: " : " symbol: "); 1227 class_name->print_symbol_on(tty); 1228 } 1229 tty->cr(); 1230 } 1231 if (xtty != NULL) { 1232 // Log the precise location of the trap. 1233 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) { 1234 xtty->begin_elem("jvms bci='%d'", sd->bci()); 1235 xtty->method(sd->method()); 1236 xtty->end_elem(); 1237 if (sd->is_top()) break; 1238 } 1239 xtty->tail("uncommon_trap"); 1240 } 1241 } 1242 // (End diagnostic printout.) 1243 1244 // Load class if necessary 1245 if (unloaded_class_index >= 0) { 1246 constantPoolHandle constants(THREAD, trap_method->constants()); 1247 load_class_by_index(constants, unloaded_class_index); 1248 } 1249 1250 // Flush the nmethod if necessary and desirable. 1251 // 1252 // We need to avoid situations where we are re-flushing the nmethod 1253 // because of a hot deoptimization site. Repeated flushes at the same 1254 // point need to be detected by the compiler and avoided. If the compiler 1255 // cannot avoid them (or has a bug and "refuses" to avoid them), this 1256 // module must take measures to avoid an infinite cycle of recompilation 1257 // and deoptimization. There are several such measures: 1258 // 1259 // 1. If a recompilation is ordered a second time at some site X 1260 // and for the same reason R, the action is adjusted to 'reinterpret', 1261 // to give the interpreter time to exercise the method more thoroughly. 1262 // If this happens, the method's overflow_recompile_count is incremented. 1263 // 1264 // 2. If the compiler fails to reduce the deoptimization rate, then 1265 // the method's overflow_recompile_count will begin to exceed the set 1266 // limit PerBytecodeRecompilationCutoff. If this happens, the action 1267 // is adjusted to 'make_not_compilable', and the method is abandoned 1268 // to the interpreter. This is a performance hit for hot methods, 1269 // but is better than a disastrous infinite cycle of recompilations. 1270 // (Actually, only the method containing the site X is abandoned.) 1271 // 1272 // 3. In parallel with the previous measures, if the total number of 1273 // recompilations of a method exceeds the much larger set limit 1274 // PerMethodRecompilationCutoff, the method is abandoned. 1275 // This should only happen if the method is very large and has 1276 // many "lukewarm" deoptimizations. The code which enforces this 1277 // limit is elsewhere (class nmethod, class methodOopDesc). 1278 // 1279 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance 1280 // to recompile at each bytecode independently of the per-BCI cutoff. 1281 // 1282 // The decision to update code is up to the compiler, and is encoded 1283 // in the Action_xxx code. If the compiler requests Action_none 1284 // no trap state is changed, no compiled code is changed, and the 1285 // computation suffers along in the interpreter. 1286 // 1287 // The other action codes specify various tactics for decompilation 1288 // and recompilation. Action_maybe_recompile is the loosest, and 1289 // allows the compiled code to stay around until enough traps are seen, 1290 // and until the compiler gets around to recompiling the trapping method. 1291 // 1292 // The other actions cause immediate removal of the present code. 1293 1294 bool update_trap_state = true; 1295 bool make_not_entrant = false; 1296 bool make_not_compilable = false; 1297 bool reset_counters = false; 1298 switch (action) { 1299 case Action_none: 1300 // Keep the old code. 1301 update_trap_state = false; 1302 break; 1303 case Action_maybe_recompile: 1304 // Do not need to invalidate the present code, but we can 1305 // initiate another 1306 // Start compiler without (necessarily) invalidating the nmethod. 1307 // The system will tolerate the old code, but new code should be 1308 // generated when possible. 1309 break; 1310 case Action_reinterpret: 1311 // Go back into the interpreter for a while, and then consider 1312 // recompiling form scratch. 1313 make_not_entrant = true; 1314 // Reset invocation counter for outer most method. 1315 // This will allow the interpreter to exercise the bytecodes 1316 // for a while before recompiling. 1317 // By contrast, Action_make_not_entrant is immediate. 1318 // 1319 // Note that the compiler will track null_check, null_assert, 1320 // range_check, and class_check events and log them as if they 1321 // had been traps taken from compiled code. This will update 1322 // the MDO trap history so that the next compilation will 1323 // properly detect hot trap sites. 1324 reset_counters = true; 1325 break; 1326 case Action_make_not_entrant: 1327 // Request immediate recompilation, and get rid of the old code. 1328 // Make them not entrant, so next time they are called they get 1329 // recompiled. Unloaded classes are loaded now so recompile before next 1330 // time they are called. Same for uninitialized. The interpreter will 1331 // link the missing class, if any. 1332 make_not_entrant = true; 1333 break; 1334 case Action_make_not_compilable: 1335 // Give up on compiling this method at all. 1336 make_not_entrant = true; 1337 make_not_compilable = true; 1338 break; 1339 default: 1340 ShouldNotReachHere(); 1341 } 1342 1343 // Setting +ProfileTraps fixes the following, on all platforms: 1344 // 4852688: ProfileInterpreter is off by default for ia64. The result is 1345 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the 1346 // recompile relies on a methodDataOop to record heroic opt failures. 1347 1348 // Whether the interpreter is producing MDO data or not, we also need 1349 // to use the MDO to detect hot deoptimization points and control 1350 // aggressive optimization. 1351 bool inc_recompile_count = false; 1352 ProfileData* pdata = NULL; 1353 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) { 1354 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity"); 1355 uint this_trap_count = 0; 1356 bool maybe_prior_trap = false; 1357 bool maybe_prior_recompile = false; 1358 pdata = query_update_method_data(trap_mdo, trap_bci, reason, 1359 //outputs: 1360 this_trap_count, 1361 maybe_prior_trap, 1362 maybe_prior_recompile); 1363 // Because the interpreter also counts null, div0, range, and class 1364 // checks, these traps from compiled code are double-counted. 1365 // This is harmless; it just means that the PerXTrapLimit values 1366 // are in effect a little smaller than they look. 1367 1368 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason); 1369 if (per_bc_reason != Reason_none) { 1370 // Now take action based on the partially known per-BCI history. 1371 if (maybe_prior_trap 1372 && this_trap_count >= (uint)PerBytecodeTrapLimit) { 1373 // If there are too many traps at this BCI, force a recompile. 1374 // This will allow the compiler to see the limit overflow, and 1375 // take corrective action, if possible. The compiler generally 1376 // does not use the exact PerBytecodeTrapLimit value, but instead 1377 // changes its tactics if it sees any traps at all. This provides 1378 // a little hysteresis, delaying a recompile until a trap happens 1379 // several times. 1380 // 1381 // Actually, since there is only one bit of counter per BCI, 1382 // the possible per-BCI counts are {0,1,(per-method count)}. 1383 // This produces accurate results if in fact there is only 1384 // one hot trap site, but begins to get fuzzy if there are 1385 // many sites. For example, if there are ten sites each 1386 // trapping two or more times, they each get the blame for 1387 // all of their traps. 1388 make_not_entrant = true; 1389 } 1390 1391 // Detect repeated recompilation at the same BCI, and enforce a limit. 1392 if (make_not_entrant && maybe_prior_recompile) { 1393 // More than one recompile at this point. 1394 inc_recompile_count = maybe_prior_trap; 1395 } 1396 } else { 1397 // For reasons which are not recorded per-bytecode, we simply 1398 // force recompiles unconditionally. 1399 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.) 1400 make_not_entrant = true; 1401 } 1402 1403 // Go back to the compiler if there are too many traps in this method. 1404 if (this_trap_count >= (uint)PerMethodTrapLimit) { 1405 // If there are too many traps in this method, force a recompile. 1406 // This will allow the compiler to see the limit overflow, and 1407 // take corrective action, if possible. 1408 // (This condition is an unlikely backstop only, because the 1409 // PerBytecodeTrapLimit is more likely to take effect first, 1410 // if it is applicable.) 1411 make_not_entrant = true; 1412 } 1413 1414 // Here's more hysteresis: If there has been a recompile at 1415 // this trap point already, run the method in the interpreter 1416 // for a while to exercise it more thoroughly. 1417 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) { 1418 reset_counters = true; 1419 } 1420 1421 } 1422 1423 // Take requested actions on the method: 1424 1425 // Recompile 1426 if (make_not_entrant) { 1427 if (!nm->make_not_entrant()) { 1428 return; // the call did not change nmethod's state 1429 } 1430 1431 if (pdata != NULL) { 1432 // Record the recompilation event, if any. 1433 int tstate0 = pdata->trap_state(); 1434 int tstate1 = trap_state_set_recompiled(tstate0, true); 1435 if (tstate1 != tstate0) 1436 pdata->set_trap_state(tstate1); 1437 } 1438 } 1439 1440 if (inc_recompile_count) { 1441 trap_mdo->inc_overflow_recompile_count(); 1442 if ((uint)trap_mdo->overflow_recompile_count() > 1443 (uint)PerBytecodeRecompilationCutoff) { 1444 // Give up on the method containing the bad BCI. 1445 if (trap_method() == nm->method()) { 1446 make_not_compilable = true; 1447 } else { 1448 trap_method->set_not_compilable(); 1449 // But give grace to the enclosing nm->method(). 1450 } 1451 } 1452 } 1453 1454 // Reset invocation counters 1455 if (reset_counters) { 1456 if (nm->is_osr_method()) 1457 reset_invocation_counter(trap_scope, CompileThreshold); 1458 else 1459 reset_invocation_counter(trap_scope); 1460 } 1461 1462 // Give up compiling 1463 if (make_not_compilable && !nm->method()->is_not_compilable()) { 1464 assert(make_not_entrant, "consistent"); 1465 nm->method()->set_not_compilable(); 1466 } 1467 1468 } // Free marked resources 1469 1470} 1471JRT_END 1472 1473methodDataOop 1474Deoptimization::get_method_data(JavaThread* thread, methodHandle m, 1475 bool create_if_missing) { 1476 Thread* THREAD = thread; 1477 methodDataOop mdo = m()->method_data(); 1478 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) { 1479 // Build an MDO. Ignore errors like OutOfMemory; 1480 // that simply means we won't have an MDO to update. 1481 methodOopDesc::build_interpreter_method_data(m, THREAD); 1482 if (HAS_PENDING_EXCEPTION) { 1483 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here"); 1484 CLEAR_PENDING_EXCEPTION; 1485 } 1486 mdo = m()->method_data(); 1487 } 1488 return mdo; 1489} 1490 1491ProfileData* 1492Deoptimization::query_update_method_data(methodDataHandle trap_mdo, 1493 int trap_bci, 1494 Deoptimization::DeoptReason reason, 1495 //outputs: 1496 uint& ret_this_trap_count, 1497 bool& ret_maybe_prior_trap, 1498 bool& ret_maybe_prior_recompile) { 1499 uint prior_trap_count = trap_mdo->trap_count(reason); 1500 uint this_trap_count = trap_mdo->inc_trap_count(reason); 1501 1502 // If the runtime cannot find a place to store trap history, 1503 // it is estimated based on the general condition of the method. 1504 // If the method has ever been recompiled, or has ever incurred 1505 // a trap with the present reason , then this BCI is assumed 1506 // (pessimistically) to be the culprit. 1507 bool maybe_prior_trap = (prior_trap_count != 0); 1508 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0); 1509 ProfileData* pdata = NULL; 1510 1511 1512 // For reasons which are recorded per bytecode, we check per-BCI data. 1513 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason); 1514 if (per_bc_reason != Reason_none) { 1515 // Find the profile data for this BCI. If there isn't one, 1516 // try to allocate one from the MDO's set of spares. 1517 // This will let us detect a repeated trap at this point. 1518 pdata = trap_mdo->allocate_bci_to_data(trap_bci); 1519 1520 if (pdata != NULL) { 1521 // Query the trap state of this profile datum. 1522 int tstate0 = pdata->trap_state(); 1523 if (!trap_state_has_reason(tstate0, per_bc_reason)) 1524 maybe_prior_trap = false; 1525 if (!trap_state_is_recompiled(tstate0)) 1526 maybe_prior_recompile = false; 1527 1528 // Update the trap state of this profile datum. 1529 int tstate1 = tstate0; 1530 // Record the reason. 1531 tstate1 = trap_state_add_reason(tstate1, per_bc_reason); 1532 // Store the updated state on the MDO, for next time. 1533 if (tstate1 != tstate0) 1534 pdata->set_trap_state(tstate1); 1535 } else { 1536 if (LogCompilation && xtty != NULL) { 1537 ttyLocker ttyl; 1538 // Missing MDP? Leave a small complaint in the log. 1539 xtty->elem("missing_mdp bci='%d'", trap_bci); 1540 } 1541 } 1542 } 1543 1544 // Return results: 1545 ret_this_trap_count = this_trap_count; 1546 ret_maybe_prior_trap = maybe_prior_trap; 1547 ret_maybe_prior_recompile = maybe_prior_recompile; 1548 return pdata; 1549} 1550 1551void 1552Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) { 1553 ResourceMark rm; 1554 // Ignored outputs: 1555 uint ignore_this_trap_count; 1556 bool ignore_maybe_prior_trap; 1557 bool ignore_maybe_prior_recompile; 1558 query_update_method_data(trap_mdo, trap_bci, 1559 (DeoptReason)reason, 1560 ignore_this_trap_count, 1561 ignore_maybe_prior_trap, 1562 ignore_maybe_prior_recompile); 1563} 1564 1565void Deoptimization::reset_invocation_counter(ScopeDesc* trap_scope, jint top_count) { 1566 ScopeDesc* sd = trap_scope; 1567 for (; !sd->is_top(); sd = sd->sender()) { 1568 // Reset ICs of inlined methods, since they can trigger compilations also. 1569 sd->method()->invocation_counter()->reset(); 1570 } 1571 InvocationCounter* c = sd->method()->invocation_counter(); 1572 if (top_count != _no_count) { 1573 // It was an OSR method, so bump the count higher. 1574 c->set(c->state(), top_count); 1575 } else { 1576 c->reset(); 1577 } 1578 sd->method()->backedge_counter()->reset(); 1579} 1580 1581Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) { 1582 1583 // Still in Java no safepoints 1584 { 1585 // This enters VM and may safepoint 1586 uncommon_trap_inner(thread, trap_request); 1587 } 1588 return fetch_unroll_info_helper(thread); 1589} 1590 1591// Local derived constants. 1592// Further breakdown of DataLayout::trap_state, as promised by DataLayout. 1593const int DS_REASON_MASK = DataLayout::trap_mask >> 1; 1594const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK; 1595 1596//---------------------------trap_state_reason--------------------------------- 1597Deoptimization::DeoptReason 1598Deoptimization::trap_state_reason(int trap_state) { 1599 // This assert provides the link between the width of DataLayout::trap_bits 1600 // and the encoding of "recorded" reasons. It ensures there are enough 1601 // bits to store all needed reasons in the per-BCI MDO profile. 1602 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits"); 1603 int recompile_bit = (trap_state & DS_RECOMPILE_BIT); 1604 trap_state -= recompile_bit; 1605 if (trap_state == DS_REASON_MASK) { 1606 return Reason_many; 1607 } else { 1608 assert((int)Reason_none == 0, "state=0 => Reason_none"); 1609 return (DeoptReason)trap_state; 1610 } 1611} 1612//-------------------------trap_state_has_reason------------------------------- 1613int Deoptimization::trap_state_has_reason(int trap_state, int reason) { 1614 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason"); 1615 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits"); 1616 int recompile_bit = (trap_state & DS_RECOMPILE_BIT); 1617 trap_state -= recompile_bit; 1618 if (trap_state == DS_REASON_MASK) { 1619 return -1; // true, unspecifically (bottom of state lattice) 1620 } else if (trap_state == reason) { 1621 return 1; // true, definitely 1622 } else if (trap_state == 0) { 1623 return 0; // false, definitely (top of state lattice) 1624 } else { 1625 return 0; // false, definitely 1626 } 1627} 1628//-------------------------trap_state_add_reason------------------------------- 1629int Deoptimization::trap_state_add_reason(int trap_state, int reason) { 1630 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason"); 1631 int recompile_bit = (trap_state & DS_RECOMPILE_BIT); 1632 trap_state -= recompile_bit; 1633 if (trap_state == DS_REASON_MASK) { 1634 return trap_state + recompile_bit; // already at state lattice bottom 1635 } else if (trap_state == reason) { 1636 return trap_state + recompile_bit; // the condition is already true 1637 } else if (trap_state == 0) { 1638 return reason + recompile_bit; // no condition has yet been true 1639 } else { 1640 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom 1641 } 1642} 1643//-----------------------trap_state_is_recompiled------------------------------ 1644bool Deoptimization::trap_state_is_recompiled(int trap_state) { 1645 return (trap_state & DS_RECOMPILE_BIT) != 0; 1646} 1647//-----------------------trap_state_set_recompiled----------------------------- 1648int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) { 1649 if (z) return trap_state | DS_RECOMPILE_BIT; 1650 else return trap_state & ~DS_RECOMPILE_BIT; 1651} 1652//---------------------------format_trap_state--------------------------------- 1653// This is used for debugging and diagnostics, including hotspot.log output. 1654const char* Deoptimization::format_trap_state(char* buf, size_t buflen, 1655 int trap_state) { 1656 DeoptReason reason = trap_state_reason(trap_state); 1657 bool recomp_flag = trap_state_is_recompiled(trap_state); 1658 // Re-encode the state from its decoded components. 1659 int decoded_state = 0; 1660 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many) 1661 decoded_state = trap_state_add_reason(decoded_state, reason); 1662 if (recomp_flag) 1663 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag); 1664 // If the state re-encodes properly, format it symbolically. 1665 // Because this routine is used for debugging and diagnostics, 1666 // be robust even if the state is a strange value. 1667 size_t len; 1668 if (decoded_state != trap_state) { 1669 // Random buggy state that doesn't decode?? 1670 len = jio_snprintf(buf, buflen, "#%d", trap_state); 1671 } else { 1672 len = jio_snprintf(buf, buflen, "%s%s", 1673 trap_reason_name(reason), 1674 recomp_flag ? " recompiled" : ""); 1675 } 1676 if (len >= buflen) 1677 buf[buflen-1] = '\0'; 1678 return buf; 1679} 1680 1681 1682//--------------------------------statics-------------------------------------- 1683Deoptimization::DeoptAction Deoptimization::_unloaded_action 1684 = Deoptimization::Action_reinterpret; 1685const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = { 1686 // Note: Keep this in sync. with enum DeoptReason. 1687 "none", 1688 "null_check", 1689 "null_assert", 1690 "range_check", 1691 "class_check", 1692 "array_check", 1693 "intrinsic", 1694 "bimorphic", 1695 "unloaded", 1696 "uninitialized", 1697 "unreached", 1698 "unhandled", 1699 "constraint", 1700 "div0_check", 1701 "age", 1702 "predicate" 1703}; 1704const char* Deoptimization::_trap_action_name[Action_LIMIT] = { 1705 // Note: Keep this in sync. with enum DeoptAction. 1706 "none", 1707 "maybe_recompile", 1708 "reinterpret", 1709 "make_not_entrant", 1710 "make_not_compilable" 1711}; 1712 1713const char* Deoptimization::trap_reason_name(int reason) { 1714 if (reason == Reason_many) return "many"; 1715 if ((uint)reason < Reason_LIMIT) 1716 return _trap_reason_name[reason]; 1717 static char buf[20]; 1718 sprintf(buf, "reason%d", reason); 1719 return buf; 1720} 1721const char* Deoptimization::trap_action_name(int action) { 1722 if ((uint)action < Action_LIMIT) 1723 return _trap_action_name[action]; 1724 static char buf[20]; 1725 sprintf(buf, "action%d", action); 1726 return buf; 1727} 1728 1729// This is used for debugging and diagnostics, including hotspot.log output. 1730const char* Deoptimization::format_trap_request(char* buf, size_t buflen, 1731 int trap_request) { 1732 jint unloaded_class_index = trap_request_index(trap_request); 1733 const char* reason = trap_reason_name(trap_request_reason(trap_request)); 1734 const char* action = trap_action_name(trap_request_action(trap_request)); 1735 size_t len; 1736 if (unloaded_class_index < 0) { 1737 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'", 1738 reason, action); 1739 } else { 1740 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'", 1741 reason, action, unloaded_class_index); 1742 } 1743 if (len >= buflen) 1744 buf[buflen-1] = '\0'; 1745 return buf; 1746} 1747 1748juint Deoptimization::_deoptimization_hist 1749 [Deoptimization::Reason_LIMIT] 1750 [1 + Deoptimization::Action_LIMIT] 1751 [Deoptimization::BC_CASE_LIMIT] 1752 = {0}; 1753 1754enum { 1755 LSB_BITS = 8, 1756 LSB_MASK = right_n_bits(LSB_BITS) 1757}; 1758 1759void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action, 1760 Bytecodes::Code bc) { 1761 assert(reason >= 0 && reason < Reason_LIMIT, "oob"); 1762 assert(action >= 0 && action < Action_LIMIT, "oob"); 1763 _deoptimization_hist[Reason_none][0][0] += 1; // total 1764 _deoptimization_hist[reason][0][0] += 1; // per-reason total 1765 juint* cases = _deoptimization_hist[reason][1+action]; 1766 juint* bc_counter_addr = NULL; 1767 juint bc_counter = 0; 1768 // Look for an unused counter, or an exact match to this BC. 1769 if (bc != Bytecodes::_illegal) { 1770 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) { 1771 juint* counter_addr = &cases[bc_case]; 1772 juint counter = *counter_addr; 1773 if ((counter == 0 && bc_counter_addr == NULL) 1774 || (Bytecodes::Code)(counter & LSB_MASK) == bc) { 1775 // this counter is either free or is already devoted to this BC 1776 bc_counter_addr = counter_addr; 1777 bc_counter = counter | bc; 1778 } 1779 } 1780 } 1781 if (bc_counter_addr == NULL) { 1782 // Overflow, or no given bytecode. 1783 bc_counter_addr = &cases[BC_CASE_LIMIT-1]; 1784 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB 1785 } 1786 *bc_counter_addr = bc_counter + (1 << LSB_BITS); 1787} 1788 1789jint Deoptimization::total_deoptimization_count() { 1790 return _deoptimization_hist[Reason_none][0][0]; 1791} 1792 1793jint Deoptimization::deoptimization_count(DeoptReason reason) { 1794 assert(reason >= 0 && reason < Reason_LIMIT, "oob"); 1795 return _deoptimization_hist[reason][0][0]; 1796} 1797 1798void Deoptimization::print_statistics() { 1799 juint total = total_deoptimization_count(); 1800 juint account = total; 1801 if (total != 0) { 1802 ttyLocker ttyl; 1803 if (xtty != NULL) xtty->head("statistics type='deoptimization'"); 1804 tty->print_cr("Deoptimization traps recorded:"); 1805 #define PRINT_STAT_LINE(name, r) \ 1806 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name); 1807 PRINT_STAT_LINE("total", total); 1808 // For each non-zero entry in the histogram, print the reason, 1809 // the action, and (if specifically known) the type of bytecode. 1810 for (int reason = 0; reason < Reason_LIMIT; reason++) { 1811 for (int action = 0; action < Action_LIMIT; action++) { 1812 juint* cases = _deoptimization_hist[reason][1+action]; 1813 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) { 1814 juint counter = cases[bc_case]; 1815 if (counter != 0) { 1816 char name[1*K]; 1817 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK); 1818 if (bc_case == BC_CASE_LIMIT && (int)bc == 0) 1819 bc = Bytecodes::_illegal; 1820 sprintf(name, "%s/%s/%s", 1821 trap_reason_name(reason), 1822 trap_action_name(action), 1823 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other"); 1824 juint r = counter >> LSB_BITS; 1825 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total); 1826 account -= r; 1827 } 1828 } 1829 } 1830 } 1831 if (account != 0) { 1832 PRINT_STAT_LINE("unaccounted", account); 1833 } 1834 #undef PRINT_STAT_LINE 1835 if (xtty != NULL) xtty->tail("statistics"); 1836 } 1837} 1838#else // COMPILER2 1839 1840 1841// Stubs for C1 only system. 1842bool Deoptimization::trap_state_is_recompiled(int trap_state) { 1843 return false; 1844} 1845 1846const char* Deoptimization::trap_reason_name(int reason) { 1847 return "unknown"; 1848} 1849 1850void Deoptimization::print_statistics() { 1851 // no output 1852} 1853 1854void 1855Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) { 1856 // no udpate 1857} 1858 1859int Deoptimization::trap_state_has_reason(int trap_state, int reason) { 1860 return 0; 1861} 1862 1863void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action, 1864 Bytecodes::Code bc) { 1865 // no update 1866} 1867 1868const char* Deoptimization::format_trap_state(char* buf, size_t buflen, 1869 int trap_state) { 1870 jio_snprintf(buf, buflen, "#%d", trap_state); 1871 return buf; 1872} 1873 1874#endif // COMPILER2 1875