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