codeBuffer.cpp revision 1879:f95d63e2154a
1262266Sbapt/* 2289123Sbapt * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. 3262266Sbapt * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4262266Sbapt * 5262266Sbapt * This code is free software; you can redistribute it and/or modify it 6289123Sbapt * under the terms of the GNU General Public License version 2 only, as 7262266Sbapt * published by the Free Software Foundation. 8262266Sbapt * 9262266Sbapt * This code is distributed in the hope that it will be useful, but WITHOUT 10262266Sbapt * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11262266Sbapt * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12262266Sbapt * version 2 for more details (a copy is included in the LICENSE file that 13262266Sbapt * accompanied this code). 14262266Sbapt * 15262266Sbapt * You should have received a copy of the GNU General Public License version 16262266Sbapt * 2 along with this work; if not, write to the Free Software Foundation, 17262266Sbapt * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18262266Sbapt * 19262266Sbapt * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20262266Sbapt * or visit www.oracle.com if you need additional information or have any 21262266Sbapt * questions. 22262266Sbapt * 23262266Sbapt */ 24262266Sbapt 25262266Sbapt#include "precompiled.hpp" 26262266Sbapt#include "asm/codeBuffer.hpp" 27262266Sbapt#include "compiler/disassembler.hpp" 28262266Sbapt#include "utilities/copy.hpp" 29262266Sbapt 30262266Sbapt// The structure of a CodeSection: 31262266Sbapt// 32262266Sbapt// _start -> +----------------+ 33262266Sbapt// | machine code...| 34262266Sbapt// _end -> |----------------| 35262266Sbapt// | | 36262266Sbapt// | (empty) | 37262266Sbapt// | | 38262266Sbapt// | | 39262266Sbapt// +----------------+ 40262266Sbapt// _limit -> | | 41262266Sbapt// 42262266Sbapt// _locs_start -> +----------------+ 43262266Sbapt// |reloc records...| 44262266Sbapt// |----------------| 45262266Sbapt// _locs_end -> | | 46262266Sbapt// | | 47262266Sbapt// | (empty) | 48262266Sbapt// | | 49262266Sbapt// | | 50262266Sbapt// +----------------+ 51262266Sbapt// _locs_limit -> | | 52262266Sbapt// The _end (resp. _limit) pointer refers to the first 53262266Sbapt// unused (resp. unallocated) byte. 54262266Sbapt 55262266Sbapt// The structure of the CodeBuffer while code is being accumulated: 56262266Sbapt// 57262266Sbapt// _total_start -> \ 58262266Sbapt// _insts._start -> +----------------+ 59262266Sbapt// | | 60262266Sbapt// | Code | 61262266Sbapt// | | 62262266Sbapt// _stubs._start -> |----------------| 63262266Sbapt// | | 64262266Sbapt// | Stubs | (also handlers for deopt/exception) 65262266Sbapt// | | 66262266Sbapt// _consts._start -> |----------------| 67262266Sbapt// | | 68262266Sbapt// | Constants | 69262266Sbapt// | | 70262266Sbapt// +----------------+ 71262266Sbapt// + _total_size -> | | 72262266Sbapt// 73262266Sbapt// When the code and relocations are copied to the code cache, 74262266Sbapt// the empty parts of each section are removed, and everything 75262266Sbapt// is copied into contiguous locations. 76262266Sbapt 77262266Sbapttypedef CodeBuffer::csize_t csize_t; // file-local definition 78262266Sbapt 79262266Sbapt// External buffer, in a predefined CodeBlob. 80262266Sbapt// Important: The code_start must be taken exactly, and not realigned. 81262266SbaptCodeBuffer::CodeBuffer(CodeBlob* blob) { 82262266Sbapt initialize_misc("static buffer"); 83262266Sbapt initialize(blob->content_begin(), blob->content_size()); 84262266Sbapt assert(verify_section_allocation(), "initial use of buffer OK"); 85262266Sbapt} 86262266Sbapt 87262266Sbaptvoid CodeBuffer::initialize(csize_t code_size, csize_t locs_size) { 88262266Sbapt // Compute maximal alignment. 89262266Sbapt int align = _insts.alignment(); 90262266Sbapt // Always allow for empty slop around each section. 91262266Sbapt int slop = (int) CodeSection::end_slop(); 92262266Sbapt 93262266Sbapt assert(blob() == NULL, "only once"); 94262266Sbapt set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1))); 95262266Sbapt if (blob() == NULL) { 96262266Sbapt // The assembler constructor will throw a fatal on an empty CodeBuffer. 97262266Sbapt return; // caller must test this 98262266Sbapt } 99262266Sbapt 100262266Sbapt // Set up various pointers into the blob. 101262266Sbapt initialize(_total_start, _total_size); 102262266Sbapt 103262266Sbapt assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned"); 104262266Sbapt 105262266Sbapt pd_initialize(); 106262266Sbapt 107262266Sbapt if (locs_size != 0) { 108262266Sbapt _insts.initialize_locs(locs_size / sizeof(relocInfo)); 109262266Sbapt } 110262266Sbapt 111262266Sbapt assert(verify_section_allocation(), "initial use of blob is OK"); 112262266Sbapt} 113262266Sbapt 114262266Sbapt 115262266SbaptCodeBuffer::~CodeBuffer() { 116262266Sbapt // If we allocate our code buffer from the CodeCache 117262266Sbapt // via a BufferBlob, and it's not permanent, then 118262266Sbapt // free the BufferBlob. 119262266Sbapt // The rest of the memory will be freed when the ResourceObj 120262266Sbapt // is released. 121262266Sbapt assert(verify_section_allocation(), "final storage configuration still OK"); 122262266Sbapt for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) { 123262266Sbapt // Previous incarnations of this buffer are held live, so that internal 124262266Sbapt // addresses constructed before expansions will not be confused. 125262266Sbapt cb->free_blob(); 126262266Sbapt } 127262266Sbapt 128262266Sbapt // free any overflow storage 129262266Sbapt delete _overflow_arena; 130262266Sbapt 131262266Sbapt#ifdef ASSERT 132262266Sbapt // Save allocation type to execute assert in ~ResourceObj() 133262266Sbapt // which is called after this destructor. 134262266Sbapt ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type(); 135262266Sbapt Copy::fill_to_bytes(this, sizeof(*this), badResourceValue); 136262266Sbapt ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at); 137262266Sbapt#endif 138262266Sbapt} 139262266Sbapt 140262266Sbaptvoid CodeBuffer::initialize_oop_recorder(OopRecorder* r) { 141262266Sbapt assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once"); 142262266Sbapt DEBUG_ONLY(_default_oop_recorder.oop_size()); // force unused OR to be frozen 143262266Sbapt _oop_recorder = r; 144262266Sbapt} 145262266Sbapt 146262266Sbaptvoid CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) { 147262266Sbapt assert(cs != &_insts, "insts is the memory provider, not the consumer"); 148262266Sbapt csize_t slop = CodeSection::end_slop(); // margin between sections 149262266Sbapt int align = cs->alignment(); 150262266Sbapt assert(is_power_of_2(align), "sanity"); 151262266Sbapt address start = _insts._start; 152262266Sbapt address limit = _insts._limit; 153262266Sbapt address middle = limit - size; 154262266Sbapt middle -= (intptr_t)middle & (align-1); // align the division point downward 155262266Sbapt guarantee(middle - slop > start, "need enough space to divide up"); 156262266Sbapt _insts._limit = middle - slop; // subtract desired space, plus slop 157262266Sbapt cs->initialize(middle, limit - middle); 158262266Sbapt assert(cs->start() == middle, "sanity"); 159262266Sbapt assert(cs->limit() == limit, "sanity"); 160262266Sbapt // give it some relocations to start with, if the main section has them 161262266Sbapt if (_insts.has_locs()) cs->initialize_locs(1); 162262266Sbapt} 163262266Sbapt 164262266Sbaptvoid CodeBuffer::freeze_section(CodeSection* cs) { 165262266Sbapt CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1); 166262266Sbapt csize_t frozen_size = cs->size(); 167262266Sbapt if (next_cs != NULL) { 168262266Sbapt frozen_size = next_cs->align_at_start(frozen_size); 169262266Sbapt } 170262266Sbapt address old_limit = cs->limit(); 171262266Sbapt address new_limit = cs->start() + frozen_size; 172262266Sbapt relocInfo* old_locs_limit = cs->locs_limit(); 173262266Sbapt relocInfo* new_locs_limit = cs->locs_end(); 174262266Sbapt // Patch the limits. 175262266Sbapt cs->_limit = new_limit; 176262266Sbapt cs->_locs_limit = new_locs_limit; 177262266Sbapt cs->_frozen = true; 178262266Sbapt if (!next_cs->is_allocated() && !next_cs->is_frozen()) { 179262266Sbapt // Give remaining buffer space to the following section. 180262266Sbapt next_cs->initialize(new_limit, old_limit - new_limit); 181262266Sbapt next_cs->initialize_shared_locs(new_locs_limit, 182262266Sbapt old_locs_limit - new_locs_limit); 183262266Sbapt } 184262266Sbapt} 185262266Sbapt 186262266Sbaptvoid CodeBuffer::set_blob(BufferBlob* blob) { 187262266Sbapt _blob = blob; 188262266Sbapt if (blob != NULL) { 189262266Sbapt address start = blob->content_begin(); 190262266Sbapt address end = blob->content_end(); 191262266Sbapt // Round up the starting address. 192262266Sbapt int align = _insts.alignment(); 193262266Sbapt start += (-(intptr_t)start) & (align-1); 194262266Sbapt _total_start = start; 195262266Sbapt _total_size = end - start; 196262266Sbapt } else { 197262266Sbapt#ifdef ASSERT 198262266Sbapt // Clean out dangling pointers. 199262266Sbapt _total_start = badAddress; 200262266Sbapt _consts._start = _consts._end = badAddress; 201262266Sbapt _insts._start = _insts._end = badAddress; 202262266Sbapt _stubs._start = _stubs._end = badAddress; 203262266Sbapt#endif //ASSERT 204262266Sbapt } 205262266Sbapt} 206262266Sbapt 207262266Sbaptvoid CodeBuffer::free_blob() { 208262266Sbapt if (_blob != NULL) { 209262266Sbapt BufferBlob::free(_blob); 210262266Sbapt set_blob(NULL); 211262266Sbapt } 212262266Sbapt} 213262266Sbapt 214262266Sbaptconst char* CodeBuffer::code_section_name(int n) { 215262266Sbapt#ifdef PRODUCT 216262266Sbapt return NULL; 217262266Sbapt#else //PRODUCT 218262266Sbapt switch (n) { 219262266Sbapt case SECT_CONSTS: return "consts"; 220262266Sbapt case SECT_INSTS: return "insts"; 221262266Sbapt case SECT_STUBS: return "stubs"; 222262266Sbapt default: return NULL; 223262266Sbapt } 224262266Sbapt#endif //PRODUCT 225262266Sbapt} 226262266Sbapt 227262266Sbaptint CodeBuffer::section_index_of(address addr) const { 228262266Sbapt for (int n = 0; n < (int)SECT_LIMIT; n++) { 229262266Sbapt const CodeSection* cs = code_section(n); 230262266Sbapt if (cs->allocates(addr)) return n; 231262266Sbapt } 232262266Sbapt return SECT_NONE; 233262266Sbapt} 234262266Sbapt 235262266Sbaptint CodeBuffer::locator(address addr) const { 236262266Sbapt for (int n = 0; n < (int)SECT_LIMIT; n++) { 237262266Sbapt const CodeSection* cs = code_section(n); 238262266Sbapt if (cs->allocates(addr)) { 239262266Sbapt return locator(addr - cs->start(), n); 240262266Sbapt } 241262266Sbapt } 242262266Sbapt return -1; 243262266Sbapt} 244262266Sbapt 245262266Sbaptaddress CodeBuffer::locator_address(int locator) const { 246262266Sbapt if (locator < 0) return NULL; 247262266Sbapt address start = code_section(locator_sect(locator))->start(); 248262266Sbapt return start + locator_pos(locator); 249262266Sbapt} 250262266Sbapt 251262266Sbaptaddress CodeBuffer::decode_begin() { 252262266Sbapt address begin = _insts.start(); 253262266Sbapt if (_decode_begin != NULL && _decode_begin > begin) 254262266Sbapt begin = _decode_begin; 255262266Sbapt return begin; 256262266Sbapt} 257262266Sbapt 258262266Sbapt 259262266SbaptGrowableArray<int>* CodeBuffer::create_patch_overflow() { 260262266Sbapt if (_overflow_arena == NULL) { 261262266Sbapt _overflow_arena = new Arena(); 262262266Sbapt } 263262266Sbapt return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0); 264262266Sbapt} 265262266Sbapt 266262266Sbapt 267262266Sbapt// Helper function for managing labels and their target addresses. 268262266Sbapt// Returns a sensible address, and if it is not the label's final 269262266Sbapt// address, notes the dependency (at 'branch_pc') on the label. 270262266Sbaptaddress CodeSection::target(Label& L, address branch_pc) { 271262266Sbapt if (L.is_bound()) { 272262266Sbapt int loc = L.loc(); 273262266Sbapt if (index() == CodeBuffer::locator_sect(loc)) { 274262266Sbapt return start() + CodeBuffer::locator_pos(loc); 275262266Sbapt } else { 276262266Sbapt return outer()->locator_address(loc); 277262266Sbapt } 278262266Sbapt } else { 279262266Sbapt assert(allocates2(branch_pc), "sanity"); 280262266Sbapt address base = start(); 281262266Sbapt int patch_loc = CodeBuffer::locator(branch_pc - base, index()); 282262266Sbapt L.add_patch_at(outer(), patch_loc); 283262266Sbapt 284262266Sbapt // Need to return a pc, doesn't matter what it is since it will be 285262266Sbapt // replaced during resolution later. 286262266Sbapt // Don't return NULL or badAddress, since branches shouldn't overflow. 287262266Sbapt // Don't return base either because that could overflow displacements 288262266Sbapt // for shorter branches. It will get checked when bound. 289262266Sbapt return branch_pc; 290262266Sbapt } 291262266Sbapt} 292262266Sbapt 293262266Sbaptvoid CodeSection::relocate(address at, RelocationHolder const& spec, int format) { 294262266Sbapt Relocation* reloc = spec.reloc(); 295262266Sbapt relocInfo::relocType rtype = (relocInfo::relocType) reloc->type(); 296262266Sbapt if (rtype == relocInfo::none) return; 297262266Sbapt 298262266Sbapt // The assertion below has been adjusted, to also work for 299262266Sbapt // relocation for fixup. Sometimes we want to put relocation 300262266Sbapt // information for the next instruction, since it will be patched 301262266Sbapt // with a call. 302262266Sbapt assert(start() <= at && at <= end()+1, 303262266Sbapt "cannot relocate data outside code boundaries"); 304262266Sbapt 305262266Sbapt if (!has_locs()) { 306262266Sbapt // no space for relocation information provided => code cannot be 307262266Sbapt // relocated. Make sure that relocate is only called with rtypes 308262266Sbapt // that can be ignored for this kind of code. 309262266Sbapt assert(rtype == relocInfo::none || 310262266Sbapt rtype == relocInfo::runtime_call_type || 311262266Sbapt rtype == relocInfo::internal_word_type|| 312262266Sbapt rtype == relocInfo::section_word_type || 313262266Sbapt rtype == relocInfo::external_word_type, 314262266Sbapt "code needs relocation information"); 315262266Sbapt // leave behind an indication that we attempted a relocation 316262266Sbapt DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress); 317262266Sbapt return; 318262266Sbapt } 319262266Sbapt 320262266Sbapt // Advance the point, noting the offset we'll have to record. 321262266Sbapt csize_t offset = at - locs_point(); 322262266Sbapt set_locs_point(at); 323262266Sbapt 324262266Sbapt // Test for a couple of overflow conditions; maybe expand the buffer. 325262266Sbapt relocInfo* end = locs_end(); 326262266Sbapt relocInfo* req = end + relocInfo::length_limit; 327262266Sbapt // Check for (potential) overflow 328262266Sbapt if (req >= locs_limit() || offset >= relocInfo::offset_limit()) { 329262266Sbapt req += (uint)offset / (uint)relocInfo::offset_limit(); 330262266Sbapt if (req >= locs_limit()) { 331262266Sbapt // Allocate or reallocate. 332262266Sbapt expand_locs(locs_count() + (req - end)); 333262266Sbapt // reload pointer 334262266Sbapt end = locs_end(); 335262266Sbapt } 336262266Sbapt } 337262266Sbapt 338262266Sbapt // If the offset is giant, emit filler relocs, of type 'none', but 339262266Sbapt // each carrying the largest possible offset, to advance the locs_point. 340262266Sbapt while (offset >= relocInfo::offset_limit()) { 341262266Sbapt assert(end < locs_limit(), "adjust previous paragraph of code"); 342262266Sbapt *end++ = filler_relocInfo(); 343262266Sbapt offset -= filler_relocInfo().addr_offset(); 344262266Sbapt } 345262266Sbapt 346262266Sbapt // If it's a simple reloc with no data, we'll just write (rtype | offset). 347 (*end) = relocInfo(rtype, offset, format); 348 349 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2. 350 end->initialize(this, reloc); 351} 352 353void CodeSection::initialize_locs(int locs_capacity) { 354 assert(_locs_start == NULL, "only one locs init step, please"); 355 // Apply a priori lower limits to relocation size: 356 csize_t min_locs = MAX2(size() / 16, (csize_t)4); 357 if (locs_capacity < min_locs) locs_capacity = min_locs; 358 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity); 359 _locs_start = locs_start; 360 _locs_end = locs_start; 361 _locs_limit = locs_start + locs_capacity; 362 _locs_own = true; 363} 364 365void CodeSection::initialize_shared_locs(relocInfo* buf, int length) { 366 assert(_locs_start == NULL, "do this before locs are allocated"); 367 // Internal invariant: locs buf must be fully aligned. 368 // See copy_relocations_to() below. 369 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) { 370 ++buf; --length; 371 } 372 if (length > 0) { 373 _locs_start = buf; 374 _locs_end = buf; 375 _locs_limit = buf + length; 376 _locs_own = false; 377 } 378} 379 380void CodeSection::initialize_locs_from(const CodeSection* source_cs) { 381 int lcount = source_cs->locs_count(); 382 if (lcount != 0) { 383 initialize_shared_locs(source_cs->locs_start(), lcount); 384 _locs_end = _locs_limit = _locs_start + lcount; 385 assert(is_allocated(), "must have copied code already"); 386 set_locs_point(start() + source_cs->locs_point_off()); 387 } 388 assert(this->locs_count() == source_cs->locs_count(), "sanity"); 389} 390 391void CodeSection::expand_locs(int new_capacity) { 392 if (_locs_start == NULL) { 393 initialize_locs(new_capacity); 394 return; 395 } else { 396 int old_count = locs_count(); 397 int old_capacity = locs_capacity(); 398 if (new_capacity < old_capacity * 2) 399 new_capacity = old_capacity * 2; 400 relocInfo* locs_start; 401 if (_locs_own) { 402 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity); 403 } else { 404 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity); 405 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo)); 406 _locs_own = true; 407 } 408 _locs_start = locs_start; 409 _locs_end = locs_start + old_count; 410 _locs_limit = locs_start + new_capacity; 411 } 412} 413 414 415/// Support for emitting the code to its final location. 416/// The pattern is the same for all functions. 417/// We iterate over all the sections, padding each to alignment. 418 419csize_t CodeBuffer::total_content_size() const { 420 csize_t size_so_far = 0; 421 for (int n = 0; n < (int)SECT_LIMIT; n++) { 422 const CodeSection* cs = code_section(n); 423 if (cs->is_empty()) continue; // skip trivial section 424 size_so_far = cs->align_at_start(size_so_far); 425 size_so_far += cs->size(); 426 } 427 return size_so_far; 428} 429 430void CodeBuffer::compute_final_layout(CodeBuffer* dest) const { 431 address buf = dest->_total_start; 432 csize_t buf_offset = 0; 433 assert(dest->_total_size >= total_content_size(), "must be big enough"); 434 435 { 436 // not sure why this is here, but why not... 437 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment); 438 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment"); 439 } 440 441 const CodeSection* prev_cs = NULL; 442 CodeSection* prev_dest_cs = NULL; 443 444 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 445 // figure compact layout of each section 446 const CodeSection* cs = code_section(n); 447 csize_t csize = cs->size(); 448 449 CodeSection* dest_cs = dest->code_section(n); 450 if (!cs->is_empty()) { 451 // Compute initial padding; assign it to the previous non-empty guy. 452 // Cf. figure_expanded_capacities. 453 csize_t padding = cs->align_at_start(buf_offset) - buf_offset; 454 if (padding != 0) { 455 buf_offset += padding; 456 assert(prev_dest_cs != NULL, "sanity"); 457 prev_dest_cs->_limit += padding; 458 } 459 #ifdef ASSERT 460 if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) { 461 // Make sure the ends still match up. 462 // This is important because a branch in a frozen section 463 // might target code in a following section, via a Label, 464 // and without a relocation record. See Label::patch_instructions. 465 address dest_start = buf+buf_offset; 466 csize_t start2start = cs->start() - prev_cs->start(); 467 csize_t dest_start2start = dest_start - prev_dest_cs->start(); 468 assert(start2start == dest_start2start, "cannot stretch frozen sect"); 469 } 470 #endif //ASSERT 471 prev_dest_cs = dest_cs; 472 prev_cs = cs; 473 } 474 475 debug_only(dest_cs->_start = NULL); // defeat double-initialization assert 476 dest_cs->initialize(buf+buf_offset, csize); 477 dest_cs->set_end(buf+buf_offset+csize); 478 assert(dest_cs->is_allocated(), "must always be allocated"); 479 assert(cs->is_empty() == dest_cs->is_empty(), "sanity"); 480 481 buf_offset += csize; 482 } 483 484 // Done calculating sections; did it come out to the right end? 485 assert(buf_offset == total_content_size(), "sanity"); 486 assert(dest->verify_section_allocation(), "final configuration works"); 487} 488 489csize_t CodeBuffer::total_offset_of(CodeSection* cs) const { 490 csize_t size_so_far = 0; 491 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 492 const CodeSection* cur_cs = code_section(n); 493 if (!cur_cs->is_empty()) { 494 size_so_far = cur_cs->align_at_start(size_so_far); 495 } 496 if (cur_cs->index() == cs->index()) { 497 return size_so_far; 498 } 499 size_so_far += cur_cs->size(); 500 } 501 ShouldNotReachHere(); 502 return -1; 503} 504 505csize_t CodeBuffer::total_relocation_size() const { 506 csize_t lsize = copy_relocations_to(NULL); // dry run only 507 csize_t csize = total_content_size(); 508 csize_t total = RelocIterator::locs_and_index_size(csize, lsize); 509 return (csize_t) align_size_up(total, HeapWordSize); 510} 511 512csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const { 513 address buf = NULL; 514 csize_t buf_offset = 0; 515 csize_t buf_limit = 0; 516 if (dest != NULL) { 517 buf = (address)dest->relocation_begin(); 518 buf_limit = (address)dest->relocation_end() - buf; 519 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned"); 520 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized"); 521 } 522 // if dest == NULL, this is just the sizing pass 523 524 csize_t code_end_so_far = 0; 525 csize_t code_point_so_far = 0; 526 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) { 527 // pull relocs out of each section 528 const CodeSection* cs = code_section(n); 529 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity"); 530 if (cs->is_empty()) continue; // skip trivial section 531 relocInfo* lstart = cs->locs_start(); 532 relocInfo* lend = cs->locs_end(); 533 csize_t lsize = (csize_t)( (address)lend - (address)lstart ); 534 csize_t csize = cs->size(); 535 code_end_so_far = cs->align_at_start(code_end_so_far); 536 537 if (lsize > 0) { 538 // Figure out how to advance the combined relocation point 539 // first to the beginning of this section. 540 // We'll insert one or more filler relocs to span that gap. 541 // (Don't bother to improve this by editing the first reloc's offset.) 542 csize_t new_code_point = code_end_so_far; 543 for (csize_t jump; 544 code_point_so_far < new_code_point; 545 code_point_so_far += jump) { 546 jump = new_code_point - code_point_so_far; 547 relocInfo filler = filler_relocInfo(); 548 if (jump >= filler.addr_offset()) { 549 jump = filler.addr_offset(); 550 } else { // else shrink the filler to fit 551 filler = relocInfo(relocInfo::none, jump); 552 } 553 if (buf != NULL) { 554 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds"); 555 *(relocInfo*)(buf+buf_offset) = filler; 556 } 557 buf_offset += sizeof(filler); 558 } 559 560 // Update code point and end to skip past this section: 561 csize_t last_code_point = code_end_so_far + cs->locs_point_off(); 562 assert(code_point_so_far <= last_code_point, "sanity"); 563 code_point_so_far = last_code_point; // advance past this guy's relocs 564 } 565 code_end_so_far += csize; // advance past this guy's instructions too 566 567 // Done with filler; emit the real relocations: 568 if (buf != NULL && lsize != 0) { 569 assert(buf_offset + lsize <= buf_limit, "target in bounds"); 570 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start"); 571 if (buf_offset % HeapWordSize == 0) { 572 // Use wordwise copies if possible: 573 Copy::disjoint_words((HeapWord*)lstart, 574 (HeapWord*)(buf+buf_offset), 575 (lsize + HeapWordSize-1) / HeapWordSize); 576 } else { 577 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize); 578 } 579 } 580 buf_offset += lsize; 581 } 582 583 // Align end of relocation info in target. 584 while (buf_offset % HeapWordSize != 0) { 585 if (buf != NULL) { 586 relocInfo padding = relocInfo(relocInfo::none, 0); 587 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds"); 588 *(relocInfo*)(buf+buf_offset) = padding; 589 } 590 buf_offset += sizeof(relocInfo); 591 } 592 593 assert(code_end_so_far == total_content_size(), "sanity"); 594 595 // Account for index: 596 if (buf != NULL) { 597 RelocIterator::create_index(dest->relocation_begin(), 598 buf_offset / sizeof(relocInfo), 599 dest->relocation_end()); 600 } 601 602 return buf_offset; 603} 604 605void CodeBuffer::copy_code_to(CodeBlob* dest_blob) { 606#ifndef PRODUCT 607 if (PrintNMethods && (WizardMode || Verbose)) { 608 tty->print("done with CodeBuffer:"); 609 ((CodeBuffer*)this)->print(); 610 } 611#endif //PRODUCT 612 613 CodeBuffer dest(dest_blob); 614 assert(dest_blob->content_size() >= total_content_size(), "good sizing"); 615 this->compute_final_layout(&dest); 616 relocate_code_to(&dest); 617 618 // transfer comments from buffer to blob 619 dest_blob->set_comments(_comments); 620 621 // Done moving code bytes; were they the right size? 622 assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity"); 623 624 // Flush generated code 625 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size()); 626} 627 628// Move all my code into another code buffer. Consult applicable 629// relocs to repair embedded addresses. The layout in the destination 630// CodeBuffer is different to the source CodeBuffer: the destination 631// CodeBuffer gets the final layout (consts, insts, stubs in order of 632// ascending address). 633void CodeBuffer::relocate_code_to(CodeBuffer* dest) const { 634 DEBUG_ONLY(address dest_end = dest->_total_start + dest->_total_size); 635 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 636 // pull code out of each section 637 const CodeSection* cs = code_section(n); 638 if (cs->is_empty()) continue; // skip trivial section 639 CodeSection* dest_cs = dest->code_section(n); 640 assert(cs->size() == dest_cs->size(), "sanity"); 641 csize_t usize = dest_cs->size(); 642 csize_t wsize = align_size_up(usize, HeapWordSize); 643 assert(dest_cs->start() + wsize <= dest_end, "no overflow"); 644 // Copy the code as aligned machine words. 645 // This may also include an uninitialized partial word at the end. 646 Copy::disjoint_words((HeapWord*)cs->start(), 647 (HeapWord*)dest_cs->start(), 648 wsize / HeapWordSize); 649 650 if (dest->blob() == NULL) { 651 // Destination is a final resting place, not just another buffer. 652 // Normalize uninitialized bytes in the final padding. 653 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(), 654 Assembler::code_fill_byte()); 655 } 656 657 assert(cs->locs_start() != (relocInfo*)badAddress, 658 "this section carries no reloc storage, but reloc was attempted"); 659 660 // Make the new code copy use the old copy's relocations: 661 dest_cs->initialize_locs_from(cs); 662 663 { // Repair the pc relative information in the code after the move 664 RelocIterator iter(dest_cs); 665 while (iter.next()) { 666 iter.reloc()->fix_relocation_after_move(this, dest); 667 } 668 } 669 } 670} 671 672csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs, 673 csize_t amount, 674 csize_t* new_capacity) { 675 csize_t new_total_cap = 0; 676 677 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 678 const CodeSection* sect = code_section(n); 679 680 if (!sect->is_empty()) { 681 // Compute initial padding; assign it to the previous section, 682 // even if it's empty (e.g. consts section can be empty). 683 // Cf. compute_final_layout 684 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap; 685 if (padding != 0) { 686 new_total_cap += padding; 687 assert(n - 1 >= SECT_FIRST, "sanity"); 688 new_capacity[n - 1] += padding; 689 } 690 } 691 692 csize_t exp = sect->size(); // 100% increase 693 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase 694 if (sect == which_cs) { 695 if (exp < amount) exp = amount; 696 if (StressCodeBuffers) exp = amount; // expand only slightly 697 } else if (n == SECT_INSTS) { 698 // scale down inst increases to a more modest 25% 699 exp = 4*K + ((exp - 4*K) >> 2); 700 if (StressCodeBuffers) exp = amount / 2; // expand only slightly 701 } else if (sect->is_empty()) { 702 // do not grow an empty secondary section 703 exp = 0; 704 } 705 // Allow for inter-section slop: 706 exp += CodeSection::end_slop(); 707 csize_t new_cap = sect->size() + exp; 708 if (new_cap < sect->capacity()) { 709 // No need to expand after all. 710 new_cap = sect->capacity(); 711 } 712 new_capacity[n] = new_cap; 713 new_total_cap += new_cap; 714 } 715 716 return new_total_cap; 717} 718 719void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) { 720#ifndef PRODUCT 721 if (PrintNMethods && (WizardMode || Verbose)) { 722 tty->print("expanding CodeBuffer:"); 723 this->print(); 724 } 725 726 if (StressCodeBuffers && blob() != NULL) { 727 static int expand_count = 0; 728 if (expand_count >= 0) expand_count += 1; 729 if (expand_count > 100 && is_power_of_2(expand_count)) { 730 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count); 731 // simulate an occasional allocation failure: 732 free_blob(); 733 } 734 } 735#endif //PRODUCT 736 737 // Resizing must be allowed 738 { 739 if (blob() == NULL) return; // caller must check for blob == NULL 740 for (int n = 0; n < (int)SECT_LIMIT; n++) { 741 guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen"); 742 } 743 } 744 745 // Figure new capacity for each section. 746 csize_t new_capacity[SECT_LIMIT]; 747 csize_t new_total_cap 748 = figure_expanded_capacities(which_cs, amount, new_capacity); 749 750 // Create a new (temporary) code buffer to hold all the new data 751 CodeBuffer cb(name(), new_total_cap, 0); 752 if (cb.blob() == NULL) { 753 // Failed to allocate in code cache. 754 free_blob(); 755 return; 756 } 757 758 // Create an old code buffer to remember which addresses used to go where. 759 // This will be useful when we do final assembly into the code cache, 760 // because we will need to know how to warp any internal address that 761 // has been created at any time in this CodeBuffer's past. 762 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size); 763 bxp->take_over_code_from(this); // remember the old undersized blob 764 DEBUG_ONLY(this->_blob = NULL); // silence a later assert 765 bxp->_before_expand = this->_before_expand; 766 this->_before_expand = bxp; 767 768 // Give each section its required (expanded) capacity. 769 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) { 770 CodeSection* cb_sect = cb.code_section(n); 771 CodeSection* this_sect = code_section(n); 772 if (new_capacity[n] == 0) continue; // already nulled out 773 if (n != SECT_INSTS) { 774 cb.initialize_section_size(cb_sect, new_capacity[n]); 775 } 776 assert(cb_sect->capacity() >= new_capacity[n], "big enough"); 777 address cb_start = cb_sect->start(); 778 cb_sect->set_end(cb_start + this_sect->size()); 779 if (this_sect->mark() == NULL) { 780 cb_sect->clear_mark(); 781 } else { 782 cb_sect->set_mark(cb_start + this_sect->mark_off()); 783 } 784 } 785 786 // Move all the code and relocations to the new blob: 787 relocate_code_to(&cb); 788 789 // Copy the temporary code buffer into the current code buffer. 790 // Basically, do {*this = cb}, except for some control information. 791 this->take_over_code_from(&cb); 792 cb.set_blob(NULL); 793 794 // Zap the old code buffer contents, to avoid mistakenly using them. 795 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size, 796 badCodeHeapFreeVal)); 797 798 _decode_begin = NULL; // sanity 799 800 // Make certain that the new sections are all snugly inside the new blob. 801 assert(verify_section_allocation(), "expanded allocation is ship-shape"); 802 803#ifndef PRODUCT 804 if (PrintNMethods && (WizardMode || Verbose)) { 805 tty->print("expanded CodeBuffer:"); 806 this->print(); 807 } 808#endif //PRODUCT 809} 810 811void CodeBuffer::take_over_code_from(CodeBuffer* cb) { 812 // Must already have disposed of the old blob somehow. 813 assert(blob() == NULL, "must be empty"); 814#ifdef ASSERT 815 816#endif 817 // Take the new blob away from cb. 818 set_blob(cb->blob()); 819 // Take over all the section pointers. 820 for (int n = 0; n < (int)SECT_LIMIT; n++) { 821 CodeSection* cb_sect = cb->code_section(n); 822 CodeSection* this_sect = code_section(n); 823 this_sect->take_over_code_from(cb_sect); 824 } 825 _overflow_arena = cb->_overflow_arena; 826 // Make sure the old cb won't try to use it or free it. 827 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress); 828} 829 830#ifdef ASSERT 831bool CodeBuffer::verify_section_allocation() { 832 address tstart = _total_start; 833 if (tstart == badAddress) return true; // smashed by set_blob(NULL) 834 address tend = tstart + _total_size; 835 if (_blob != NULL) { 836 assert(tstart >= _blob->content_begin(), "sanity"); 837 assert(tend <= _blob->content_end(), "sanity"); 838 } 839 // Verify disjointness. 840 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { 841 CodeSection* sect = code_section(n); 842 if (!sect->is_allocated() || sect->is_empty()) continue; 843 assert((intptr_t)sect->start() % sect->alignment() == 0 844 || sect->is_empty() || _blob == NULL, 845 "start is aligned"); 846 for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) { 847 CodeSection* other = code_section(m); 848 if (!other->is_allocated() || other == sect) continue; 849 assert(!other->contains(sect->start() ), "sanity"); 850 // limit is an exclusive address and can be the start of another 851 // section. 852 assert(!other->contains(sect->limit() - 1), "sanity"); 853 } 854 assert(sect->end() <= tend, "sanity"); 855 } 856 return true; 857} 858#endif //ASSERT 859 860#ifndef PRODUCT 861 862void CodeSection::dump() { 863 address ptr = start(); 864 for (csize_t step; ptr < end(); ptr += step) { 865 step = end() - ptr; 866 if (step > jintSize * 4) step = jintSize * 4; 867 tty->print(PTR_FORMAT ": ", ptr); 868 while (step > 0) { 869 tty->print(" " PTR32_FORMAT, *(jint*)ptr); 870 ptr += jintSize; 871 } 872 tty->cr(); 873 } 874} 875 876 877void CodeSection::decode() { 878 Disassembler::decode(start(), end()); 879} 880 881 882void CodeBuffer::block_comment(intptr_t offset, const char * comment) { 883 _comments.add_comment(offset, comment); 884} 885 886 887class CodeComment: public CHeapObj { 888 private: 889 friend class CodeComments; 890 intptr_t _offset; 891 const char * _comment; 892 CodeComment* _next; 893 894 ~CodeComment() { 895 assert(_next == NULL, "wrong interface for freeing list"); 896 os::free((void*)_comment); 897 } 898 899 public: 900 CodeComment(intptr_t offset, const char * comment) { 901 _offset = offset; 902 _comment = os::strdup(comment); 903 _next = NULL; 904 } 905 906 intptr_t offset() const { return _offset; } 907 const char * comment() const { return _comment; } 908 CodeComment* next() { return _next; } 909 910 void set_next(CodeComment* next) { _next = next; } 911 912 CodeComment* find(intptr_t offset) { 913 CodeComment* a = this; 914 while (a != NULL && a->_offset != offset) { 915 a = a->_next; 916 } 917 return a; 918 } 919}; 920 921 922void CodeComments::add_comment(intptr_t offset, const char * comment) { 923 CodeComment* c = new CodeComment(offset, comment); 924 CodeComment* insert = NULL; 925 if (_comments != NULL) { 926 CodeComment* c = _comments->find(offset); 927 insert = c; 928 while (c && c->offset() == offset) { 929 insert = c; 930 c = c->next(); 931 } 932 } 933 if (insert) { 934 // insert after comments with same offset 935 c->set_next(insert->next()); 936 insert->set_next(c); 937 } else { 938 c->set_next(_comments); 939 _comments = c; 940 } 941} 942 943 944void CodeComments::assign(CodeComments& other) { 945 assert(_comments == NULL, "don't overwrite old value"); 946 _comments = other._comments; 947} 948 949 950void CodeComments::print_block_comment(outputStream* stream, intptr_t offset) { 951 if (_comments != NULL) { 952 CodeComment* c = _comments->find(offset); 953 while (c && c->offset() == offset) { 954 stream->bol(); 955 stream->print(" ;; "); 956 stream->print_cr(c->comment()); 957 c = c->next(); 958 } 959 } 960} 961 962 963void CodeComments::free() { 964 CodeComment* n = _comments; 965 while (n) { 966 // unlink the node from the list saving a pointer to the next 967 CodeComment* p = n->_next; 968 n->_next = NULL; 969 delete n; 970 n = p; 971 } 972 _comments = NULL; 973} 974 975 976 977void CodeBuffer::decode() { 978 Disassembler::decode(decode_begin(), insts_end()); 979 _decode_begin = insts_end(); 980} 981 982 983void CodeBuffer::skip_decode() { 984 _decode_begin = insts_end(); 985} 986 987 988void CodeBuffer::decode_all() { 989 for (int n = 0; n < (int)SECT_LIMIT; n++) { 990 // dump contents of each section 991 CodeSection* cs = code_section(n); 992 tty->print_cr("! %s:", code_section_name(n)); 993 if (cs != consts()) 994 cs->decode(); 995 else 996 cs->dump(); 997 } 998} 999 1000 1001void CodeSection::print(const char* name) { 1002 csize_t locs_size = locs_end() - locs_start(); 1003 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s", 1004 name, start(), end(), limit(), size(), capacity(), 1005 is_frozen()? " [frozen]": ""); 1006 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d", 1007 name, locs_start(), locs_end(), locs_limit(), locs_size, locs_capacity(), locs_point_off()); 1008 if (PrintRelocations) { 1009 RelocIterator iter(this); 1010 iter.print(); 1011 } 1012} 1013 1014void CodeBuffer::print() { 1015 if (this == NULL) { 1016 tty->print_cr("NULL CodeBuffer pointer"); 1017 return; 1018 } 1019 1020 tty->print_cr("CodeBuffer:"); 1021 for (int n = 0; n < (int)SECT_LIMIT; n++) { 1022 // print each section 1023 CodeSection* cs = code_section(n); 1024 cs->print(code_section_name(n)); 1025 } 1026} 1027 1028#endif // PRODUCT 1029