1 /*
2 * Copyright (c) 1997, 2010, 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 "utilities/copy.hpp"
29
30 // The structure of a CodeSection:
31 //
32 // _start -> +----------------+
33 // | machine code...|
34 // _end -> |----------------|
35 // | |
36 // | (empty) |
37 // | |
38 // | |
39 // +----------------+
40 // _limit -> | |
41 //
42 // _locs_start -> +----------------+
43 // |reloc records...|
44 // |----------------|
45 // _locs_end -> | |
46 // | |
47 // | (empty) |
48 // | |
49 // | |
50 // +----------------+
51 // _locs_limit -> | |
52 // The _end (resp. _limit) pointer refers to the first
53 // unused (resp. unallocated) byte.
54
55 // The structure of the CodeBuffer while code is being accumulated:
56 //
57 // _total_start -> \
58 // _insts._start -> +----------------+
59 // | |
60 // | Code |
61 // | |
62 // _stubs._start -> |----------------|
63 // | |
64 // | Stubs | (also handlers for deopt/exception)
65 // | |
66 // _consts._start -> |----------------|
67 // | |
68 // | Constants |
69 // | |
70 // +----------------+
71 // + _total_size -> | |
72 //
73 // When the code and relocations are copied to the code cache,
74 // the empty parts of each section are removed, and everything
75 // is copied into contiguous locations.
76
77 typedef CodeBuffer::csize_t csize_t; // file-local definition
78
79 // External buffer, in a predefined CodeBlob.
80 // Important: The code_start must be taken exactly, and not realigned.
81 CodeBuffer::CodeBuffer(CodeBlob* blob) {
82 initialize_misc("static buffer");
83 initialize(blob->content_begin(), blob->content_size());
84 assert(verify_section_allocation(), "initial use of buffer OK");
85 }
86
87 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
88 // Compute maximal alignment.
89 int align = _insts.alignment();
90 // Always allow for empty slop around each section.
91 int slop = (int) CodeSection::end_slop();
92
93 assert(blob() == NULL, "only once");
94 set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1)));
95 if (blob() == NULL) {
96 // The assembler constructor will throw a fatal on an empty CodeBuffer.
97 return; // caller must test this
98 }
99
100 // Set up various pointers into the blob.
101 initialize(_total_start, _total_size);
102
103 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
104
105 pd_initialize();
106
107 if (locs_size != 0) {
108 _insts.initialize_locs(locs_size / sizeof(relocInfo));
109 }
110
111 assert(verify_section_allocation(), "initial use of blob is OK");
112 }
113
114
115 CodeBuffer::~CodeBuffer() {
116 // If we allocate our code buffer from the CodeCache
117 // via a BufferBlob, and it's not permanent, then
118 // free the BufferBlob.
119 // The rest of the memory will be freed when the ResourceObj
120 // is released.
121 assert(verify_section_allocation(), "final storage configuration still OK");
122 for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) {
123 // Previous incarnations of this buffer are held live, so that internal
124 // addresses constructed before expansions will not be confused.
125 cb->free_blob();
126 }
127
128 // free any overflow storage
129 delete _overflow_arena;
130
131 #ifdef ASSERT
132 // Save allocation type to execute assert in ~ResourceObj()
133 // which is called after this destructor.
134 ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type();
135 Copy::fill_to_bytes(this, sizeof(*this), badResourceValue);
136 ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at);
137 #endif
138 }
139
140 void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
141 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
142 DEBUG_ONLY(_default_oop_recorder.oop_size()); // force unused OR to be frozen
143 _oop_recorder = r;
144 }
145
146 void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
147 assert(cs != &_insts, "insts is the memory provider, not the consumer");
148 csize_t slop = CodeSection::end_slop(); // margin between sections
149 int align = cs->alignment();
150 assert(is_power_of_2(align), "sanity");
151 address start = _insts._start;
152 address limit = _insts._limit;
153 address middle = limit - size;
154 middle -= (intptr_t)middle & (align-1); // align the division point downward
155 guarantee(middle - slop > start, "need enough space to divide up");
156 _insts._limit = middle - slop; // subtract desired space, plus slop
157 cs->initialize(middle, limit - middle);
158 assert(cs->start() == middle, "sanity");
159 assert(cs->limit() == limit, "sanity");
160 // give it some relocations to start with, if the main section has them
161 if (_insts.has_locs()) cs->initialize_locs(1);
162 }
163
164 void CodeBuffer::freeze_section(CodeSection* cs) {
165 CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1);
166 csize_t frozen_size = cs->size();
167 if (next_cs != NULL) {
168 frozen_size = next_cs->align_at_start(frozen_size);
169 }
170 address old_limit = cs->limit();
171 address new_limit = cs->start() + frozen_size;
172 relocInfo* old_locs_limit = cs->locs_limit();
173 relocInfo* new_locs_limit = cs->locs_end();
174 // Patch the limits.
175 cs->_limit = new_limit;
176 cs->_locs_limit = new_locs_limit;
177 cs->_frozen = true;
178 if (!next_cs->is_allocated() && !next_cs->is_frozen()) {
179 // Give remaining buffer space to the following section.
180 next_cs->initialize(new_limit, old_limit - new_limit);
181 next_cs->initialize_shared_locs(new_locs_limit,
182 old_locs_limit - new_locs_limit);
183 }
184 }
185
186 void CodeBuffer::set_blob(BufferBlob* blob) {
187 _blob = blob;
188 if (blob != NULL) {
189 address start = blob->content_begin();
190 address end = blob->content_end();
191 // Round up the starting address.
192 int align = _insts.alignment();
193 start += (-(intptr_t)start) & (align-1);
194 _total_start = start;
195 _total_size = end - start;
196 } else {
197 #ifdef ASSERT
198 // Clean out dangling pointers.
199 _total_start = badAddress;
200 _consts._start = _consts._end = badAddress;
201 _insts._start = _insts._end = badAddress;
202 _stubs._start = _stubs._end = badAddress;
203 #endif //ASSERT
204 }
205 }
206
207 void CodeBuffer::free_blob() {
208 if (_blob != NULL) {
209 BufferBlob::free(_blob);
210 set_blob(NULL);
211 }
212 }
213
214 const char* CodeBuffer::code_section_name(int n) {
215 #ifdef PRODUCT
216 return NULL;
217 #else //PRODUCT
218 switch (n) {
219 case SECT_CONSTS: return "consts";
220 case SECT_INSTS: return "insts";
221 case SECT_STUBS: return "stubs";
222 default: return NULL;
223 }
224 #endif //PRODUCT
225 }
226
227 int CodeBuffer::section_index_of(address addr) const {
228 for (int n = 0; n < (int)SECT_LIMIT; n++) {
229 const CodeSection* cs = code_section(n);
230 if (cs->allocates(addr)) return n;
231 }
232 return SECT_NONE;
233 }
234
235 int CodeBuffer::locator(address addr) const {
236 for (int n = 0; n < (int)SECT_LIMIT; n++) {
237 const CodeSection* cs = code_section(n);
238 if (cs->allocates(addr)) {
239 return locator(addr - cs->start(), n);
240 }
241 }
242 return -1;
243 }
244
245 address CodeBuffer::locator_address(int locator) const {
246 if (locator < 0) return NULL;
247 address start = code_section(locator_sect(locator))->start();
248 return start + locator_pos(locator);
249 }
250
251 address CodeBuffer::decode_begin() {
252 address begin = _insts.start();
253 if (_decode_begin != NULL && _decode_begin > begin)
254 begin = _decode_begin;
255 return begin;
256 }
257
258
259 GrowableArray<int>* CodeBuffer::create_patch_overflow() {
260 if (_overflow_arena == NULL) {
261 _overflow_arena = new Arena();
262 }
263 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
264 }
265
266
267 // Helper function for managing labels and their target addresses.
268 // Returns a sensible address, and if it is not the label's final
269 // address, notes the dependency (at 'branch_pc') on the label.
270 address CodeSection::target(Label& L, address branch_pc) {
271 if (L.is_bound()) {
272 int loc = L.loc();
273 if (index() == CodeBuffer::locator_sect(loc)) {
274 return start() + CodeBuffer::locator_pos(loc);
275 } else {
276 return outer()->locator_address(loc);
277 }
278 } else {
279 assert(allocates2(branch_pc), "sanity");
280 address base = start();
281 int patch_loc = CodeBuffer::locator(branch_pc - base, index());
282 L.add_patch_at(outer(), patch_loc);
283
284 // Need to return a pc, doesn't matter what it is since it will be
285 // replaced during resolution later.
286 // Don't return NULL or badAddress, since branches shouldn't overflow.
287 // Don't return base either because that could overflow displacements
288 // for shorter branches. It will get checked when bound.
289 return branch_pc;
290 }
291 }
292
293 void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
294 Relocation* reloc = spec.reloc();
295 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
296 if (rtype == relocInfo::none) return;
297
298 // The assertion below has been adjusted, to also work for
299 // relocation for fixup. Sometimes we want to put relocation
300 // information for the next instruction, since it will be patched
301 // with a call.
302 assert(start() <= at && at <= end()+1,
303 "cannot relocate data outside code boundaries");
304
305 if (!has_locs()) {
306 // no space for relocation information provided => code cannot be
307 // relocated. Make sure that relocate is only called with rtypes
308 // that can be ignored for this kind of code.
309 assert(rtype == relocInfo::none ||
310 rtype == relocInfo::runtime_call_type ||
311 rtype == relocInfo::internal_word_type||
312 rtype == relocInfo::section_word_type ||
313 rtype == relocInfo::external_word_type,
314 "code needs relocation information");
315 // leave behind an indication that we attempted a relocation
316 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
317 return;
318 }
319
320 // Advance the point, noting the offset we'll have to record.
321 csize_t offset = at - locs_point();
322 set_locs_point(at);
323
324 // Test for a couple of overflow conditions; maybe expand the buffer.
325 relocInfo* end = locs_end();
326 relocInfo* req = end + relocInfo::length_limit;
327 // Check for (potential) overflow
328 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
329 req += (uint)offset / (uint)relocInfo::offset_limit();
330 if (req >= locs_limit()) {
331 // Allocate or reallocate.
332 expand_locs(locs_count() + (req - end));
333 // reload pointer
334 end = locs_end();
335 }
336 }
337
338 // If the offset is giant, emit filler relocs, of type 'none', but
339 // each carrying the largest possible offset, to advance the locs_point.
340 while (offset >= relocInfo::offset_limit()) {
341 assert(end < locs_limit(), "adjust previous paragraph of code");
342 *end++ = filler_relocInfo();
343 offset -= filler_relocInfo().addr_offset();
344 }
345
346 // 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
353 void 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
365 void 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
380 void 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
391 void 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
419 csize_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
430 void 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
489 csize_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
505 csize_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
512 csize_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
605 void 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).
633 void 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
672 csize_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
719 void 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
811 void 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
831 bool 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
862 void 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
877 void CodeSection::decode() {
878 Disassembler::decode(start(), end());
879 }
880
881
882 void CodeBuffer::block_comment(intptr_t offset, const char * comment) {
883 _comments.add_comment(offset, comment);
884 }
885
886
887 class 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
922 void 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
944 void CodeComments::assign(CodeComments& other) {
945 assert(_comments == NULL, "don't overwrite old value");
946 _comments = other._comments;
947 }
948
949
950 void 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
963 void 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
977 void CodeBuffer::decode() {
978 Disassembler::decode(decode_begin(), insts_end());
979 _decode_begin = insts_end();
980 }
981
982
983 void CodeBuffer::skip_decode() {
984 _decode_begin = insts_end();
985 }
986
987
988 void 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
1001 void 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
1014 void 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