codeBuffer.cpp revision 6412:53a41e7cbe05
1/* 2 * Copyright (c) 1997, 2014, 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 "asm/codeBuffer.hpp" 27#include "compiler/disassembler.hpp" 28#include "memory/gcLocker.hpp" 29#include "oops/methodData.hpp" 30#include "oops/oop.inline.hpp" 31#include "utilities/copy.hpp" 32#include "utilities/xmlstream.hpp" 33 34// The structure of a CodeSection: 35// 36// _start -> +----------------+ 37// | machine code...| 38// _end -> |----------------| 39// | | 40// | (empty) | 41// | | 42// | | 43// +----------------+ 44// _limit -> | | 45// 46// _locs_start -> +----------------+ 47// |reloc records...| 48// |----------------| 49// _locs_end -> | | 50// | | 51// | (empty) | 52// | | 53// | | 54// +----------------+ 55// _locs_limit -> | | 56// The _end (resp. _limit) pointer refers to the first 57// unused (resp. unallocated) byte. 58 59// The structure of the CodeBuffer while code is being accumulated: 60// 61// _total_start -> \ 62// _insts._start -> +----------------+ 63// | | 64// | Code | 65// | | 66// _stubs._start -> |----------------| 67// | | 68// | Stubs | (also handlers for deopt/exception) 69// | | 70// _consts._start -> |----------------| 71// | | 72// | Constants | 73// | | 74// +----------------+ 75// + _total_size -> | | 76// 77// When the code and relocations are copied to the code cache, 78// the empty parts of each section are removed, and everything 79// is copied into contiguous locations. 80 81typedef CodeBuffer::csize_t csize_t; // file-local definition 82 83// External buffer, in a predefined CodeBlob. 84// Important: The code_start must be taken exactly, and not realigned. 85CodeBuffer::CodeBuffer(CodeBlob* blob) { 86 initialize_misc("static buffer"); 87 initialize(blob->content_begin(), blob->content_size()); 88 verify_section_allocation(); 89} 90 91void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) { 92 // Compute maximal alignment. 93 int align = _insts.alignment(); 94 // Always allow for empty slop around each section. 95 int slop = (int) CodeSection::end_slop(); 96 97 assert(blob() == NULL, "only once"); 98 set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1))); 99 if (blob() == NULL) { 100 // The assembler constructor will throw a fatal on an empty CodeBuffer. 101 return; // caller must test this 102 } 103 104 // Set up various pointers into the blob. 105 initialize(_total_start, _total_size); 106 107 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned"); 108 109 pd_initialize(); 110 111 if (locs_size != 0) { 112 _insts.initialize_locs(locs_size / sizeof(relocInfo)); 113 } 114 115 verify_section_allocation(); 116} 117 118 119CodeBuffer::~CodeBuffer() { 120 verify_section_allocation(); 121 122 // If we allocate our code buffer from the CodeCache 123 // via a BufferBlob, and it's not permanent, then 124 // free the BufferBlob. 125 // The rest of the memory will be freed when the ResourceObj 126 // is released. 127 for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) { 128 // Previous incarnations of this buffer are held live, so that internal 129 // addresses constructed before expansions will not be confused. 130 cb->free_blob(); 131 } 132 133 // free any overflow storage 134 delete _overflow_arena; 135 136#ifdef ASSERT 137 // Save allocation type to execute assert in ~ResourceObj() 138 // which is called after this destructor. 139 assert(_default_oop_recorder.allocated_on_stack(), "should be embedded object"); 140 ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type(); 141 Copy::fill_to_bytes(this, sizeof(*this), badResourceValue); 142 ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at); 143#endif 144} 145 146void CodeBuffer::initialize_oop_recorder(OopRecorder* r) { 147 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once"); 148 DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen 149 _oop_recorder = r; 150} 151 152void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) { 153 assert(cs != &_insts, "insts is the memory provider, not the consumer"); 154 csize_t slop = CodeSection::end_slop(); // margin between sections 155 int align = cs->alignment(); 156 assert(is_power_of_2(align), "sanity"); 157 address start = _insts._start; 158 address limit = _insts._limit; 159 address middle = limit - size; 160 middle -= (intptr_t)middle & (align-1); // align the division point downward 161 guarantee(middle - slop > start, "need enough space to divide up"); 162 _insts._limit = middle - slop; // subtract desired space, plus slop 163 cs->initialize(middle, limit - middle); 164 assert(cs->start() == middle, "sanity"); 165 assert(cs->limit() == limit, "sanity"); 166 // give it some relocations to start with, if the main section has them 167 if (_insts.has_locs()) cs->initialize_locs(1); 168} 169 170void CodeBuffer::freeze_section(CodeSection* cs) { 171 CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1); 172 csize_t frozen_size = cs->size(); 173 if (next_cs != NULL) { 174 frozen_size = next_cs->align_at_start(frozen_size); 175 } 176 address old_limit = cs->limit(); 177 address new_limit = cs->start() + frozen_size; 178 relocInfo* old_locs_limit = cs->locs_limit(); 179 relocInfo* new_locs_limit = cs->locs_end(); 180 // Patch the limits. 181 cs->_limit = new_limit; 182 cs->_locs_limit = new_locs_limit; 183 cs->_frozen = true; 184 if (!next_cs->is_allocated() && !next_cs->is_frozen()) { 185 // Give remaining buffer space to the following section. 186 next_cs->initialize(new_limit, old_limit - new_limit); 187 next_cs->initialize_shared_locs(new_locs_limit, 188 old_locs_limit - new_locs_limit); 189 } 190} 191 192void CodeBuffer::set_blob(BufferBlob* blob) { 193 _blob = blob; 194 if (blob != NULL) { 195 address start = blob->content_begin(); 196 address end = blob->content_end(); 197 // Round up the starting address. 198 int align = _insts.alignment(); 199 start += (-(intptr_t)start) & (align-1); 200 _total_start = start; 201 _total_size = end - start; 202 } else { 203#ifdef ASSERT 204 // Clean out dangling pointers. 205 _total_start = badAddress; 206 _consts._start = _consts._end = badAddress; 207 _insts._start = _insts._end = badAddress; 208 _stubs._start = _stubs._end = badAddress; 209#endif //ASSERT 210 } 211} 212 213void CodeBuffer::free_blob() { 214 if (_blob != NULL) { 215 BufferBlob::free(_blob); 216 set_blob(NULL); 217 } 218} 219 220const char* CodeBuffer::code_section_name(int n) { 221#ifdef PRODUCT 222 return NULL; 223#else //PRODUCT 224 switch (n) { 225 case SECT_CONSTS: return "consts"; 226 case SECT_INSTS: return "insts"; 227 case SECT_STUBS: return "stubs"; 228 default: return NULL; 229 } 230#endif //PRODUCT 231} 232 233int CodeBuffer::section_index_of(address addr) const { 234 for (int n = 0; n < (int)SECT_LIMIT; n++) { 235 const CodeSection* cs = code_section(n); 236 if (cs->allocates(addr)) return n; 237 } 238 return SECT_NONE; 239} 240 241int CodeBuffer::locator(address addr) const { 242 for (int n = 0; n < (int)SECT_LIMIT; n++) { 243 const CodeSection* cs = code_section(n); 244 if (cs->allocates(addr)) { 245 return locator(addr - cs->start(), n); 246 } 247 } 248 return -1; 249} 250 251address CodeBuffer::locator_address(int locator) const { 252 if (locator < 0) return NULL; 253 address start = code_section(locator_sect(locator))->start(); 254 return start + locator_pos(locator); 255} 256 257bool CodeBuffer::is_backward_branch(Label& L) { 258 return L.is_bound() && insts_end() <= locator_address(L.loc()); 259} 260 261address CodeBuffer::decode_begin() { 262 address begin = _insts.start(); 263 if (_decode_begin != NULL && _decode_begin > begin) 264 begin = _decode_begin; 265 return begin; 266} 267 268 269GrowableArray<int>* CodeBuffer::create_patch_overflow() { 270 if (_overflow_arena == NULL) { 271 _overflow_arena = new (mtCode) Arena(); 272 } 273 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0); 274} 275 276 277// Helper function for managing labels and their target addresses. 278// Returns a sensible address, and if it is not the label's final 279// address, notes the dependency (at 'branch_pc') on the label. 280address CodeSection::target(Label& L, address branch_pc) { 281 if (L.is_bound()) { 282 int loc = L.loc(); 283 if (index() == CodeBuffer::locator_sect(loc)) { 284 return start() + CodeBuffer::locator_pos(loc); 285 } else { 286 return outer()->locator_address(loc); 287 } 288 } else { 289 assert(allocates2(branch_pc), "sanity"); 290 address base = start(); 291 int patch_loc = CodeBuffer::locator(branch_pc - base, index()); 292 L.add_patch_at(outer(), patch_loc); 293 294 // Need to return a pc, doesn't matter what it is since it will be 295 // replaced during resolution later. 296 // Don't return NULL or badAddress, since branches shouldn't overflow. 297 // Don't return base either because that could overflow displacements 298 // for shorter branches. It will get checked when bound. 299 return branch_pc; 300 } 301} 302 303void CodeSection::relocate(address at, RelocationHolder const& spec, int format) { 304 Relocation* reloc = spec.reloc(); 305 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type(); 306 if (rtype == relocInfo::none) return; 307 308 // The assertion below has been adjusted, to also work for 309 // relocation for fixup. Sometimes we want to put relocation 310 // information for the next instruction, since it will be patched 311 // with a call. 312 assert(start() <= at && at <= end()+1, 313 "cannot relocate data outside code boundaries"); 314 315 if (!has_locs()) { 316 // no space for relocation information provided => code cannot be 317 // relocated. Make sure that relocate is only called with rtypes 318 // that can be ignored for this kind of code. 319 assert(rtype == relocInfo::none || 320 rtype == relocInfo::runtime_call_type || 321 rtype == relocInfo::internal_word_type|| 322 rtype == relocInfo::section_word_type || 323 rtype == relocInfo::external_word_type, 324 "code needs relocation information"); 325 // leave behind an indication that we attempted a relocation 326 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress); 327 return; 328 } 329 330 // Advance the point, noting the offset we'll have to record. 331 csize_t offset = at - locs_point(); 332 set_locs_point(at); 333 334 // Test for a couple of overflow conditions; maybe expand the buffer. 335 relocInfo* end = locs_end(); 336 relocInfo* req = end + relocInfo::length_limit; 337 // Check for (potential) overflow 338 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) { 339 req += (uint)offset / (uint)relocInfo::offset_limit(); 340 if (req >= locs_limit()) { 341 // Allocate or reallocate. 342 expand_locs(locs_count() + (req - end)); 343 // reload pointer 344 end = locs_end(); 345 } 346 } 347 348 // If the offset is giant, emit filler relocs, of type 'none', but 349 // each carrying the largest possible offset, to advance the locs_point. 350 while (offset >= relocInfo::offset_limit()) { 351 assert(end < locs_limit(), "adjust previous paragraph of code"); 352 *end++ = filler_relocInfo(); 353 offset -= filler_relocInfo().addr_offset(); 354 } 355 356 // If it's a simple reloc with no data, we'll just write (rtype | offset). 357 (*end) = relocInfo(rtype, offset, format); 358 359 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2. 360 end->initialize(this, reloc); 361} 362 363void CodeSection::initialize_locs(int locs_capacity) { 364 assert(_locs_start == NULL, "only one locs init step, please"); 365 // Apply a priori lower limits to relocation size: 366 csize_t min_locs = MAX2(size() / 16, (csize_t)4); 367 if (locs_capacity < min_locs) locs_capacity = min_locs; 368 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity); 369 _locs_start = locs_start; 370 _locs_end = locs_start; 371 _locs_limit = locs_start + locs_capacity; 372 _locs_own = true; 373} 374 375void CodeSection::initialize_shared_locs(relocInfo* buf, int length) { 376 assert(_locs_start == NULL, "do this before locs are allocated"); 377 // Internal invariant: locs buf must be fully aligned. 378 // See copy_relocations_to() below. 379 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) { 380 ++buf; --length; 381 } 382 if (length > 0) { 383 _locs_start = buf; 384 _locs_end = buf; 385 _locs_limit = buf + length; 386 _locs_own = false; 387 } 388} 389 390void CodeSection::initialize_locs_from(const CodeSection* source_cs) { 391 int lcount = source_cs->locs_count(); 392 if (lcount != 0) { 393 initialize_shared_locs(source_cs->locs_start(), lcount); 394 _locs_end = _locs_limit = _locs_start + lcount; 395 assert(is_allocated(), "must have copied code already"); 396 set_locs_point(start() + source_cs->locs_point_off()); 397 } 398 assert(this->locs_count() == source_cs->locs_count(), "sanity"); 399} 400 401void CodeSection::expand_locs(int new_capacity) { 402 if (_locs_start == NULL) { 403 initialize_locs(new_capacity); 404 return; 405 } else { 406 int old_count = locs_count(); 407 int old_capacity = locs_capacity(); 408 if (new_capacity < old_capacity * 2) 409 new_capacity = old_capacity * 2; 410 relocInfo* locs_start; 411 if (_locs_own) { 412 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity); 413 } else { 414 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity); 415 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo)); 416 _locs_own = true; 417 } 418 _locs_start = locs_start; 419 _locs_end = locs_start + old_count; 420 _locs_limit = locs_start + new_capacity; 421 } 422} 423 424 425/// Support for emitting the code to its final location. 426/// The pattern is the same for all functions. 427/// We iterate over all the sections, padding each to alignment. 428 429csize_t CodeBuffer::total_content_size() const { 430 csize_t size_so_far = 0; 431 for (int n = 0; n < (int)SECT_LIMIT; n++) { 432 const CodeSection* cs = code_section(n); 433 if (cs->is_empty()) continue; // skip trivial section 434 size_so_far = cs->align_at_start(size_so_far); 435 size_so_far += cs->size(); 436 } 437 return size_so_far; 438} 439 440void CodeBuffer::compute_final_layout(CodeBuffer* dest) const { 441 address buf = dest->_total_start; 442 csize_t buf_offset = 0; 443 assert(dest->_total_size >= total_content_size(), "must be big enough"); 444 445 { 446 // not sure why this is here, but why not... 447 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment); 448 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment"); 449 } 450 451 const CodeSection* prev_cs = NULL; 452 CodeSection* prev_dest_cs = NULL; 453 454 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 455 // figure compact layout of each section 456 const CodeSection* cs = code_section(n); 457 csize_t csize = cs->size(); 458 459 CodeSection* dest_cs = dest->code_section(n); 460 if (!cs->is_empty()) { 461 // Compute initial padding; assign it to the previous non-empty guy. 462 // Cf. figure_expanded_capacities. 463 csize_t padding = cs->align_at_start(buf_offset) - buf_offset; 464 if (padding != 0) { 465 buf_offset += padding; 466 assert(prev_dest_cs != NULL, "sanity"); 467 prev_dest_cs->_limit += padding; 468 } 469 #ifdef ASSERT 470 if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) { 471 // Make sure the ends still match up. 472 // This is important because a branch in a frozen section 473 // might target code in a following section, via a Label, 474 // and without a relocation record. See Label::patch_instructions. 475 address dest_start = buf+buf_offset; 476 csize_t start2start = cs->start() - prev_cs->start(); 477 csize_t dest_start2start = dest_start - prev_dest_cs->start(); 478 assert(start2start == dest_start2start, "cannot stretch frozen sect"); 479 } 480 #endif //ASSERT 481 prev_dest_cs = dest_cs; 482 prev_cs = cs; 483 } 484 485 debug_only(dest_cs->_start = NULL); // defeat double-initialization assert 486 dest_cs->initialize(buf+buf_offset, csize); 487 dest_cs->set_end(buf+buf_offset+csize); 488 assert(dest_cs->is_allocated(), "must always be allocated"); 489 assert(cs->is_empty() == dest_cs->is_empty(), "sanity"); 490 491 buf_offset += csize; 492 } 493 494 // Done calculating sections; did it come out to the right end? 495 assert(buf_offset == total_content_size(), "sanity"); 496 dest->verify_section_allocation(); 497} 498 499// Append an oop reference that keeps the class alive. 500static void append_oop_references(GrowableArray<oop>* oops, Klass* k) { 501 oop cl = k->klass_holder(); 502 if (cl != NULL && !oops->contains(cl)) { 503 oops->append(cl); 504 } 505} 506 507void CodeBuffer::finalize_oop_references(methodHandle mh) { 508 No_Safepoint_Verifier nsv; 509 510 GrowableArray<oop> oops; 511 512 // Make sure that immediate metadata records something in the OopRecorder 513 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 514 // pull code out of each section 515 CodeSection* cs = code_section(n); 516 if (cs->is_empty()) continue; // skip trivial section 517 RelocIterator iter(cs); 518 while (iter.next()) { 519 if (iter.type() == relocInfo::metadata_type) { 520 metadata_Relocation* md = iter.metadata_reloc(); 521 if (md->metadata_is_immediate()) { 522 Metadata* m = md->metadata_value(); 523 if (oop_recorder()->is_real(m)) { 524 if (m->is_methodData()) { 525 m = ((MethodData*)m)->method(); 526 } 527 if (m->is_method()) { 528 m = ((Method*)m)->method_holder(); 529 } 530 if (m->is_klass()) { 531 append_oop_references(&oops, (Klass*)m); 532 } else { 533 // XXX This will currently occur for MDO which don't 534 // have a backpointer. This has to be fixed later. 535 m->print(); 536 ShouldNotReachHere(); 537 } 538 } 539 } 540 } 541 } 542 } 543 544 if (!oop_recorder()->is_unused()) { 545 for (int i = 0; i < oop_recorder()->metadata_count(); i++) { 546 Metadata* m = oop_recorder()->metadata_at(i); 547 if (oop_recorder()->is_real(m)) { 548 if (m->is_methodData()) { 549 m = ((MethodData*)m)->method(); 550 } 551 if (m->is_method()) { 552 m = ((Method*)m)->method_holder(); 553 } 554 if (m->is_klass()) { 555 append_oop_references(&oops, (Klass*)m); 556 } else { 557 m->print(); 558 ShouldNotReachHere(); 559 } 560 } 561 } 562 563 } 564 565 // Add the class loader of Method* for the nmethod itself 566 append_oop_references(&oops, mh->method_holder()); 567 568 // Add any oops that we've found 569 Thread* thread = Thread::current(); 570 for (int i = 0; i < oops.length(); i++) { 571 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i))); 572 } 573} 574 575 576 577csize_t CodeBuffer::total_offset_of(CodeSection* cs) const { 578 csize_t size_so_far = 0; 579 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 580 const CodeSection* cur_cs = code_section(n); 581 if (!cur_cs->is_empty()) { 582 size_so_far = cur_cs->align_at_start(size_so_far); 583 } 584 if (cur_cs->index() == cs->index()) { 585 return size_so_far; 586 } 587 size_so_far += cur_cs->size(); 588 } 589 ShouldNotReachHere(); 590 return -1; 591} 592 593csize_t CodeBuffer::total_relocation_size() const { 594 csize_t lsize = copy_relocations_to(NULL); // dry run only 595 csize_t csize = total_content_size(); 596 csize_t total = RelocIterator::locs_and_index_size(csize, lsize); 597 return (csize_t) align_size_up(total, HeapWordSize); 598} 599 600csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const { 601 address buf = NULL; 602 csize_t buf_offset = 0; 603 csize_t buf_limit = 0; 604 if (dest != NULL) { 605 buf = (address)dest->relocation_begin(); 606 buf_limit = (address)dest->relocation_end() - buf; 607 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned"); 608 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized"); 609 } 610 // if dest == NULL, this is just the sizing pass 611 612 csize_t code_end_so_far = 0; 613 csize_t code_point_so_far = 0; 614 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) { 615 // pull relocs out of each section 616 const CodeSection* cs = code_section(n); 617 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity"); 618 if (cs->is_empty()) continue; // skip trivial section 619 relocInfo* lstart = cs->locs_start(); 620 relocInfo* lend = cs->locs_end(); 621 csize_t lsize = (csize_t)( (address)lend - (address)lstart ); 622 csize_t csize = cs->size(); 623 code_end_so_far = cs->align_at_start(code_end_so_far); 624 625 if (lsize > 0) { 626 // Figure out how to advance the combined relocation point 627 // first to the beginning of this section. 628 // We'll insert one or more filler relocs to span that gap. 629 // (Don't bother to improve this by editing the first reloc's offset.) 630 csize_t new_code_point = code_end_so_far; 631 for (csize_t jump; 632 code_point_so_far < new_code_point; 633 code_point_so_far += jump) { 634 jump = new_code_point - code_point_so_far; 635 relocInfo filler = filler_relocInfo(); 636 if (jump >= filler.addr_offset()) { 637 jump = filler.addr_offset(); 638 } else { // else shrink the filler to fit 639 filler = relocInfo(relocInfo::none, jump); 640 } 641 if (buf != NULL) { 642 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds"); 643 *(relocInfo*)(buf+buf_offset) = filler; 644 } 645 buf_offset += sizeof(filler); 646 } 647 648 // Update code point and end to skip past this section: 649 csize_t last_code_point = code_end_so_far + cs->locs_point_off(); 650 assert(code_point_so_far <= last_code_point, "sanity"); 651 code_point_so_far = last_code_point; // advance past this guy's relocs 652 } 653 code_end_so_far += csize; // advance past this guy's instructions too 654 655 // Done with filler; emit the real relocations: 656 if (buf != NULL && lsize != 0) { 657 assert(buf_offset + lsize <= buf_limit, "target in bounds"); 658 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start"); 659 if (buf_offset % HeapWordSize == 0) { 660 // Use wordwise copies if possible: 661 Copy::disjoint_words((HeapWord*)lstart, 662 (HeapWord*)(buf+buf_offset), 663 (lsize + HeapWordSize-1) / HeapWordSize); 664 } else { 665 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize); 666 } 667 } 668 buf_offset += lsize; 669 } 670 671 // Align end of relocation info in target. 672 while (buf_offset % HeapWordSize != 0) { 673 if (buf != NULL) { 674 relocInfo padding = relocInfo(relocInfo::none, 0); 675 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds"); 676 *(relocInfo*)(buf+buf_offset) = padding; 677 } 678 buf_offset += sizeof(relocInfo); 679 } 680 681 assert(code_end_so_far == total_content_size(), "sanity"); 682 683 // Account for index: 684 if (buf != NULL) { 685 RelocIterator::create_index(dest->relocation_begin(), 686 buf_offset / sizeof(relocInfo), 687 dest->relocation_end()); 688 } 689 690 return buf_offset; 691} 692 693void CodeBuffer::copy_code_to(CodeBlob* dest_blob) { 694#ifndef PRODUCT 695 if (PrintNMethods && (WizardMode || Verbose)) { 696 tty->print("done with CodeBuffer:"); 697 ((CodeBuffer*)this)->print(); 698 } 699#endif //PRODUCT 700 701 CodeBuffer dest(dest_blob); 702 assert(dest_blob->content_size() >= total_content_size(), "good sizing"); 703 this->compute_final_layout(&dest); 704 relocate_code_to(&dest); 705 706 // transfer strings and comments from buffer to blob 707 dest_blob->set_strings(_strings); 708 709 // Done moving code bytes; were they the right size? 710 assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity"); 711 712 // Flush generated code 713 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size()); 714} 715 716// Move all my code into another code buffer. Consult applicable 717// relocs to repair embedded addresses. The layout in the destination 718// CodeBuffer is different to the source CodeBuffer: the destination 719// CodeBuffer gets the final layout (consts, insts, stubs in order of 720// ascending address). 721void CodeBuffer::relocate_code_to(CodeBuffer* dest) const { 722 address dest_end = dest->_total_start + dest->_total_size; 723 address dest_filled = NULL; 724 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 725 // pull code out of each section 726 const CodeSection* cs = code_section(n); 727 if (cs->is_empty()) continue; // skip trivial section 728 CodeSection* dest_cs = dest->code_section(n); 729 assert(cs->size() == dest_cs->size(), "sanity"); 730 csize_t usize = dest_cs->size(); 731 csize_t wsize = align_size_up(usize, HeapWordSize); 732 assert(dest_cs->start() + wsize <= dest_end, "no overflow"); 733 // Copy the code as aligned machine words. 734 // This may also include an uninitialized partial word at the end. 735 Copy::disjoint_words((HeapWord*)cs->start(), 736 (HeapWord*)dest_cs->start(), 737 wsize / HeapWordSize); 738 739 if (dest->blob() == NULL) { 740 // Destination is a final resting place, not just another buffer. 741 // Normalize uninitialized bytes in the final padding. 742 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(), 743 Assembler::code_fill_byte()); 744 } 745 // Keep track of the highest filled address 746 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining()); 747 748 assert(cs->locs_start() != (relocInfo*)badAddress, 749 "this section carries no reloc storage, but reloc was attempted"); 750 751 // Make the new code copy use the old copy's relocations: 752 dest_cs->initialize_locs_from(cs); 753 } 754 755 // Do relocation after all sections are copied. 756 // This is necessary if the code uses constants in stubs, which are 757 // relocated when the corresponding instruction in the code (e.g., a 758 // call) is relocated. Stubs are placed behind the main code 759 // section, so that section has to be copied before relocating. 760 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) { 761 // pull code out of each section 762 const CodeSection* cs = code_section(n); 763 if (cs->is_empty()) continue; // skip trivial section 764 CodeSection* dest_cs = dest->code_section(n); 765 { // Repair the pc relative information in the code after the move 766 RelocIterator iter(dest_cs); 767 while (iter.next()) { 768 iter.reloc()->fix_relocation_after_move(this, dest); 769 } 770 } 771 } 772 773 if (dest->blob() == NULL && dest_filled != NULL) { 774 // Destination is a final resting place, not just another buffer. 775 // Normalize uninitialized bytes in the final padding. 776 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled, 777 Assembler::code_fill_byte()); 778 779 } 780} 781 782csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs, 783 csize_t amount, 784 csize_t* new_capacity) { 785 csize_t new_total_cap = 0; 786 787 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 788 const CodeSection* sect = code_section(n); 789 790 if (!sect->is_empty()) { 791 // Compute initial padding; assign it to the previous section, 792 // even if it's empty (e.g. consts section can be empty). 793 // Cf. compute_final_layout 794 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap; 795 if (padding != 0) { 796 new_total_cap += padding; 797 assert(n - 1 >= SECT_FIRST, "sanity"); 798 new_capacity[n - 1] += padding; 799 } 800 } 801 802 csize_t exp = sect->size(); // 100% increase 803 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase 804 if (sect == which_cs) { 805 if (exp < amount) exp = amount; 806 if (StressCodeBuffers) exp = amount; // expand only slightly 807 } else if (n == SECT_INSTS) { 808 // scale down inst increases to a more modest 25% 809 exp = 4*K + ((exp - 4*K) >> 2); 810 if (StressCodeBuffers) exp = amount / 2; // expand only slightly 811 } else if (sect->is_empty()) { 812 // do not grow an empty secondary section 813 exp = 0; 814 } 815 // Allow for inter-section slop: 816 exp += CodeSection::end_slop(); 817 csize_t new_cap = sect->size() + exp; 818 if (new_cap < sect->capacity()) { 819 // No need to expand after all. 820 new_cap = sect->capacity(); 821 } 822 new_capacity[n] = new_cap; 823 new_total_cap += new_cap; 824 } 825 826 return new_total_cap; 827} 828 829void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) { 830#ifndef PRODUCT 831 if (PrintNMethods && (WizardMode || Verbose)) { 832 tty->print("expanding CodeBuffer:"); 833 this->print(); 834 } 835 836 if (StressCodeBuffers && blob() != NULL) { 837 static int expand_count = 0; 838 if (expand_count >= 0) expand_count += 1; 839 if (expand_count > 100 && is_power_of_2(expand_count)) { 840 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count); 841 // simulate an occasional allocation failure: 842 free_blob(); 843 } 844 } 845#endif //PRODUCT 846 847 // Resizing must be allowed 848 { 849 if (blob() == NULL) return; // caller must check for blob == NULL 850 for (int n = 0; n < (int)SECT_LIMIT; n++) { 851 guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen"); 852 } 853 } 854 855 // Figure new capacity for each section. 856 csize_t new_capacity[SECT_LIMIT]; 857 csize_t new_total_cap 858 = figure_expanded_capacities(which_cs, amount, new_capacity); 859 860 // Create a new (temporary) code buffer to hold all the new data 861 CodeBuffer cb(name(), new_total_cap, 0); 862 if (cb.blob() == NULL) { 863 // Failed to allocate in code cache. 864 free_blob(); 865 return; 866 } 867 868 // Create an old code buffer to remember which addresses used to go where. 869 // This will be useful when we do final assembly into the code cache, 870 // because we will need to know how to warp any internal address that 871 // has been created at any time in this CodeBuffer's past. 872 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size); 873 bxp->take_over_code_from(this); // remember the old undersized blob 874 DEBUG_ONLY(this->_blob = NULL); // silence a later assert 875 bxp->_before_expand = this->_before_expand; 876 this->_before_expand = bxp; 877 878 // Give each section its required (expanded) capacity. 879 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) { 880 CodeSection* cb_sect = cb.code_section(n); 881 CodeSection* this_sect = code_section(n); 882 if (new_capacity[n] == 0) continue; // already nulled out 883 if (n != SECT_INSTS) { 884 cb.initialize_section_size(cb_sect, new_capacity[n]); 885 } 886 assert(cb_sect->capacity() >= new_capacity[n], "big enough"); 887 address cb_start = cb_sect->start(); 888 cb_sect->set_end(cb_start + this_sect->size()); 889 if (this_sect->mark() == NULL) { 890 cb_sect->clear_mark(); 891 } else { 892 cb_sect->set_mark(cb_start + this_sect->mark_off()); 893 } 894 } 895 896 // Move all the code and relocations to the new blob: 897 relocate_code_to(&cb); 898 899 // Copy the temporary code buffer into the current code buffer. 900 // Basically, do {*this = cb}, except for some control information. 901 this->take_over_code_from(&cb); 902 cb.set_blob(NULL); 903 904 // Zap the old code buffer contents, to avoid mistakenly using them. 905 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size, 906 badCodeHeapFreeVal)); 907 908 _decode_begin = NULL; // sanity 909 910 // Make certain that the new sections are all snugly inside the new blob. 911 verify_section_allocation(); 912 913#ifndef PRODUCT 914 if (PrintNMethods && (WizardMode || Verbose)) { 915 tty->print("expanded CodeBuffer:"); 916 this->print(); 917 } 918#endif //PRODUCT 919} 920 921void CodeBuffer::take_over_code_from(CodeBuffer* cb) { 922 // Must already have disposed of the old blob somehow. 923 assert(blob() == NULL, "must be empty"); 924#ifdef ASSERT 925 926#endif 927 // Take the new blob away from cb. 928 set_blob(cb->blob()); 929 // Take over all the section pointers. 930 for (int n = 0; n < (int)SECT_LIMIT; n++) { 931 CodeSection* cb_sect = cb->code_section(n); 932 CodeSection* this_sect = code_section(n); 933 this_sect->take_over_code_from(cb_sect); 934 } 935 _overflow_arena = cb->_overflow_arena; 936 // Make sure the old cb won't try to use it or free it. 937 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress); 938} 939 940void CodeBuffer::verify_section_allocation() { 941 address tstart = _total_start; 942 if (tstart == badAddress) return; // smashed by set_blob(NULL) 943 address tend = tstart + _total_size; 944 if (_blob != NULL) { 945 946 guarantee(tstart >= _blob->content_begin(), "sanity"); 947 guarantee(tend <= _blob->content_end(), "sanity"); 948 } 949 // Verify disjointness. 950 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 951 CodeSection* sect = code_section(n); 952 if (!sect->is_allocated() || sect->is_empty()) continue; 953 guarantee((intptr_t)sect->start() % sect->alignment() == 0 954 || sect->is_empty() || _blob == NULL, 955 "start is aligned"); 956 for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) { 957 CodeSection* other = code_section(m); 958 if (!other->is_allocated() || other == sect) continue; 959 guarantee(!other->contains(sect->start() ), "sanity"); 960 // limit is an exclusive address and can be the start of another 961 // section. 962 guarantee(!other->contains(sect->limit() - 1), "sanity"); 963 } 964 guarantee(sect->end() <= tend, "sanity"); 965 guarantee(sect->end() <= sect->limit(), "sanity"); 966 } 967} 968 969void CodeBuffer::log_section_sizes(const char* name) { 970 if (xtty != NULL) { 971 ttyLocker ttyl; 972 // log info about buffer usage 973 xtty->print_cr("<blob name='%s' size='%d'>", name, _total_size); 974 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) { 975 CodeSection* sect = code_section(n); 976 if (!sect->is_allocated() || sect->is_empty()) continue; 977 xtty->print_cr("<sect index='%d' size='" SIZE_FORMAT "' free='" SIZE_FORMAT "'/>", 978 n, sect->limit() - sect->start(), sect->limit() - sect->end()); 979 } 980 xtty->print_cr("</blob>"); 981 } 982} 983 984#ifndef PRODUCT 985 986void CodeSection::dump() { 987 address ptr = start(); 988 for (csize_t step; ptr < end(); ptr += step) { 989 step = end() - ptr; 990 if (step > jintSize * 4) step = jintSize * 4; 991 tty->print(INTPTR_FORMAT ": ", p2i(ptr)); 992 while (step > 0) { 993 tty->print(" " PTR32_FORMAT, *(jint*)ptr); 994 ptr += jintSize; 995 } 996 tty->cr(); 997 } 998} 999 1000 1001void CodeSection::decode() { 1002 Disassembler::decode(start(), end()); 1003} 1004 1005 1006void CodeBuffer::block_comment(intptr_t offset, const char * comment) { 1007 _strings.add_comment(offset, comment); 1008} 1009 1010const char* CodeBuffer::code_string(const char* str) { 1011 return _strings.add_string(str); 1012} 1013 1014class CodeString: public CHeapObj<mtCode> { 1015 private: 1016 friend class CodeStrings; 1017 const char * _string; 1018 CodeString* _next; 1019 intptr_t _offset; 1020 1021 ~CodeString() { 1022 assert(_next == NULL, "wrong interface for freeing list"); 1023 os::free((void*)_string, mtCode); 1024 } 1025 1026 bool is_comment() const { return _offset >= 0; } 1027 1028 public: 1029 CodeString(const char * string, intptr_t offset = -1) 1030 : _next(NULL), _offset(offset) { 1031 _string = os::strdup(string, mtCode); 1032 } 1033 1034 const char * string() const { return _string; } 1035 intptr_t offset() const { assert(_offset >= 0, "offset for non comment?"); return _offset; } 1036 CodeString* next() const { return _next; } 1037 1038 void set_next(CodeString* next) { _next = next; } 1039 1040 CodeString* first_comment() { 1041 if (is_comment()) { 1042 return this; 1043 } else { 1044 return next_comment(); 1045 } 1046 } 1047 CodeString* next_comment() const { 1048 CodeString* s = _next; 1049 while (s != NULL && !s->is_comment()) { 1050 s = s->_next; 1051 } 1052 return s; 1053 } 1054}; 1055 1056CodeString* CodeStrings::find(intptr_t offset) const { 1057 CodeString* a = _strings->first_comment(); 1058 while (a != NULL && a->offset() != offset) { 1059 a = a->next_comment(); 1060 } 1061 return a; 1062} 1063 1064// Convenience for add_comment. 1065CodeString* CodeStrings::find_last(intptr_t offset) const { 1066 CodeString* a = find(offset); 1067 if (a != NULL) { 1068 CodeString* c = NULL; 1069 while (((c = a->next_comment()) != NULL) && (c->offset() == offset)) { 1070 a = c; 1071 } 1072 } 1073 return a; 1074} 1075 1076void CodeStrings::add_comment(intptr_t offset, const char * comment) { 1077 CodeString* c = new CodeString(comment, offset); 1078 CodeString* inspos = (_strings == NULL) ? NULL : find_last(offset); 1079 1080 if (inspos) { 1081 // insert after already existing comments with same offset 1082 c->set_next(inspos->next()); 1083 inspos->set_next(c); 1084 } else { 1085 // no comments with such offset, yet. Insert before anything else. 1086 c->set_next(_strings); 1087 _strings = c; 1088 } 1089} 1090 1091void CodeStrings::assign(CodeStrings& other) { 1092 _strings = other._strings; 1093} 1094 1095void CodeStrings::print_block_comment(outputStream* stream, intptr_t offset) const { 1096 if (_strings != NULL) { 1097 CodeString* c = find(offset); 1098 while (c && c->offset() == offset) { 1099 stream->bol(); 1100 stream->print(" ;; "); 1101 stream->print_cr("%s", c->string()); 1102 c = c->next_comment(); 1103 } 1104 } 1105} 1106 1107 1108void CodeStrings::free() { 1109 CodeString* n = _strings; 1110 while (n) { 1111 // unlink the node from the list saving a pointer to the next 1112 CodeString* p = n->next(); 1113 n->set_next(NULL); 1114 delete n; 1115 n = p; 1116 } 1117 _strings = NULL; 1118} 1119 1120const char* CodeStrings::add_string(const char * string) { 1121 CodeString* s = new CodeString(string); 1122 s->set_next(_strings); 1123 _strings = s; 1124 assert(s->string() != NULL, "should have a string"); 1125 return s->string(); 1126} 1127 1128void CodeBuffer::decode() { 1129 ttyLocker ttyl; 1130 Disassembler::decode(decode_begin(), insts_end()); 1131 _decode_begin = insts_end(); 1132} 1133 1134 1135void CodeBuffer::skip_decode() { 1136 _decode_begin = insts_end(); 1137} 1138 1139 1140void CodeBuffer::decode_all() { 1141 ttyLocker ttyl; 1142 for (int n = 0; n < (int)SECT_LIMIT; n++) { 1143 // dump contents of each section 1144 CodeSection* cs = code_section(n); 1145 tty->print_cr("! %s:", code_section_name(n)); 1146 if (cs != consts()) 1147 cs->decode(); 1148 else 1149 cs->dump(); 1150 } 1151} 1152 1153 1154void CodeSection::print(const char* name) { 1155 csize_t locs_size = locs_end() - locs_start(); 1156 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s", 1157 name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity(), 1158 is_frozen()? " [frozen]": ""); 1159 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d", 1160 name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off()); 1161 if (PrintRelocations) { 1162 RelocIterator iter(this); 1163 iter.print(); 1164 } 1165} 1166 1167void CodeBuffer::print() { 1168 if (this == NULL) { 1169 tty->print_cr("NULL CodeBuffer pointer"); 1170 return; 1171 } 1172 1173 tty->print_cr("CodeBuffer:"); 1174 for (int n = 0; n < (int)SECT_LIMIT; n++) { 1175 // print each section 1176 CodeSection* cs = code_section(n); 1177 cs->print(code_section_name(n)); 1178 } 1179} 1180 1181#endif // PRODUCT 1182