1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/codeBuffer.hpp"
27 #include "compiler/disassembler.hpp"
28 #include "memory/gcLocker.hpp"
29 #include "oops/methodData.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/icache.hpp"
32 #include "utilities/copy.hpp"
33 #include "utilities/xmlstream.hpp"
34
35 // The structure of a CodeSection:
36 //
37 // _start -> +----------------+
38 // | machine code...|
39 // _end -> |----------------|
40 // | |
41 // | (empty) |
42 // | |
43 // | |
44 // +----------------+
45 // _limit -> | |
46 //
47 // _locs_start -> +----------------+
48 // |reloc records...|
49 // |----------------|
50 // _locs_end -> | |
51 // | |
52 // | (empty) |
53 // | |
54 // | |
55 // +----------------+
56 // _locs_limit -> | |
57 // The _end (resp. _limit) pointer refers to the first
58 // unused (resp. unallocated) byte.
59
60 // The structure of the CodeBuffer while code is being accumulated:
61 //
62 // _total_start -> \
63 // _insts._start -> +----------------+
64 // | |
65 // | Code |
66 // | |
67 // _stubs._start -> |----------------|
68 // | |
69 // | Stubs | (also handlers for deopt/exception)
70 // | |
71 // _consts._start -> |----------------|
72 // | |
73 // | Constants |
74 // | |
75 // +----------------+
76 // + _total_size -> | |
77 //
78 // When the code and relocations are copied to the code cache,
79 // the empty parts of each section are removed, and everything
80 // is copied into contiguous locations.
81
82 typedef CodeBuffer::csize_t csize_t; // file-local definition
83
84 // External buffer, in a predefined CodeBlob.
85 // Important: The code_start must be taken exactly, and not realigned.
86 CodeBuffer::CodeBuffer(CodeBlob* blob) {
87 initialize_misc("static buffer");
88 initialize(blob->content_begin(), blob->content_size());
89 verify_section_allocation();
90 }
91
92 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
93 // Compute maximal alignment.
94 int align = _insts.alignment();
95 // Always allow for empty slop around each section.
96 int slop = (int) CodeSection::end_slop();
97
98 assert(blob() == NULL, "only once");
99 set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1)));
100 if (blob() == NULL) {
101 // The assembler constructor will throw a fatal on an empty CodeBuffer.
102 return; // caller must test this
103 }
104
105 // Set up various pointers into the blob.
106 initialize(_total_start, _total_size);
107
108 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
109
110 pd_initialize();
111
112 if (locs_size != 0) {
113 _insts.initialize_locs(locs_size / sizeof(relocInfo));
114 }
115
116 verify_section_allocation();
117 }
118
119
120 CodeBuffer::~CodeBuffer() {
121 verify_section_allocation();
122
123 // If we allocate our code buffer from the CodeCache
124 // via a BufferBlob, and it's not permanent, then
125 // free the BufferBlob.
126 // The rest of the memory will be freed when the ResourceObj
127 // is released.
128 for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) {
129 // Previous incarnations of this buffer are held live, so that internal
130 // addresses constructed before expansions will not be confused.
131 cb->free_blob();
132 }
133
134 // free any overflow storage
135 delete _overflow_arena;
136
137 #ifdef ASSERT
138 // Save allocation type to execute assert in ~ResourceObj()
139 // which is called after this destructor.
140 assert(_default_oop_recorder.allocated_on_stack(), "should be embedded object");
141 ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type();
142 Copy::fill_to_bytes(this, sizeof(*this), badResourceValue);
143 ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at);
144 #endif
145 }
146
147 void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
148 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
149 DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen
150 _oop_recorder = r;
151 }
152
153 void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
154 assert(cs != &_insts, "insts is the memory provider, not the consumer");
155 csize_t slop = CodeSection::end_slop(); // margin between sections
156 int align = cs->alignment();
157 assert(is_power_of_2(align), "sanity");
158 address start = _insts._start;
159 address limit = _insts._limit;
160 address middle = limit - size;
161 middle -= (intptr_t)middle & (align-1); // align the division point downward
162 guarantee(middle - slop > start, "need enough space to divide up");
163 _insts._limit = middle - slop; // subtract desired space, plus slop
164 cs->initialize(middle, limit - middle);
165 assert(cs->start() == middle, "sanity");
166 assert(cs->limit() == limit, "sanity");
167 // give it some relocations to start with, if the main section has them
168 if (_insts.has_locs()) cs->initialize_locs(1);
169 }
170
171 void CodeBuffer::freeze_section(CodeSection* cs) {
172 CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1);
173 csize_t frozen_size = cs->size();
174 if (next_cs != NULL) {
175 frozen_size = next_cs->align_at_start(frozen_size);
176 }
177 address old_limit = cs->limit();
178 address new_limit = cs->start() + frozen_size;
179 relocInfo* old_locs_limit = cs->locs_limit();
180 relocInfo* new_locs_limit = cs->locs_end();
181 // Patch the limits.
182 cs->_limit = new_limit;
183 cs->_locs_limit = new_locs_limit;
184 cs->_frozen = true;
185 if (!next_cs->is_allocated() && !next_cs->is_frozen()) {
186 // Give remaining buffer space to the following section.
187 next_cs->initialize(new_limit, old_limit - new_limit);
188 next_cs->initialize_shared_locs(new_locs_limit,
189 old_locs_limit - new_locs_limit);
190 }
191 }
192
193 void CodeBuffer::set_blob(BufferBlob* blob) {
194 _blob = blob;
195 if (blob != NULL) {
196 address start = blob->content_begin();
197 address end = blob->content_end();
198 // Round up the starting address.
199 int align = _insts.alignment();
200 start += (-(intptr_t)start) & (align-1);
201 _total_start = start;
202 _total_size = end - start;
203 } else {
204 #ifdef ASSERT
205 // Clean out dangling pointers.
206 _total_start = badAddress;
207 _consts._start = _consts._end = badAddress;
208 _insts._start = _insts._end = badAddress;
209 _stubs._start = _stubs._end = badAddress;
210 #endif //ASSERT
211 }
212 }
213
214 void CodeBuffer::free_blob() {
215 if (_blob != NULL) {
216 BufferBlob::free(_blob);
217 set_blob(NULL);
218 }
219 }
220
221 const char* CodeBuffer::code_section_name(int n) {
222 #ifdef PRODUCT
223 return NULL;
224 #else //PRODUCT
225 switch (n) {
226 case SECT_CONSTS: return "consts";
227 case SECT_INSTS: return "insts";
228 case SECT_STUBS: return "stubs";
229 default: return NULL;
230 }
231 #endif //PRODUCT
232 }
233
234 int CodeBuffer::section_index_of(address addr) const {
235 for (int n = 0; n < (int)SECT_LIMIT; n++) {
236 const CodeSection* cs = code_section(n);
237 if (cs->allocates(addr)) return n;
238 }
239 return SECT_NONE;
240 }
241
242 int CodeBuffer::locator(address addr) const {
243 for (int n = 0; n < (int)SECT_LIMIT; n++) {
244 const CodeSection* cs = code_section(n);
245 if (cs->allocates(addr)) {
246 return locator(addr - cs->start(), n);
247 }
248 }
249 return -1;
250 }
251
252 address CodeBuffer::locator_address(int locator) const {
253 if (locator < 0) return NULL;
254 address start = code_section(locator_sect(locator))->start();
255 return start + locator_pos(locator);
256 }
257
258 bool CodeBuffer::is_backward_branch(Label& L) {
259 return L.is_bound() && insts_end() <= locator_address(L.loc());
260 }
261
262 address CodeBuffer::decode_begin() {
263 address begin = _insts.start();
264 if (_decode_begin != NULL && _decode_begin > begin)
265 begin = _decode_begin;
266 return begin;
267 }
268
269
270 GrowableArray<int>* CodeBuffer::create_patch_overflow() {
271 if (_overflow_arena == NULL) {
272 _overflow_arena = new (mtCode) Arena(mtCode);
273 }
274 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
275 }
276
277
278 // Helper function for managing labels and their target addresses.
279 // Returns a sensible address, and if it is not the label's final
280 // address, notes the dependency (at 'branch_pc') on the label.
281 address CodeSection::target(Label& L, address branch_pc) {
282 if (L.is_bound()) {
283 int loc = L.loc();
284 if (index() == CodeBuffer::locator_sect(loc)) {
285 return start() + CodeBuffer::locator_pos(loc);
286 } else {
287 return outer()->locator_address(loc);
288 }
289 } else {
290 assert(allocates2(branch_pc), "sanity");
291 address base = start();
292 int patch_loc = CodeBuffer::locator(branch_pc - base, index());
293 L.add_patch_at(outer(), patch_loc);
294
295 // Need to return a pc, doesn't matter what it is since it will be
296 // replaced during resolution later.
297 // Don't return NULL or badAddress, since branches shouldn't overflow.
298 // Don't return base either because that could overflow displacements
299 // for shorter branches. It will get checked when bound.
300 return branch_pc;
301 }
302 }
303
304 void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
305 Relocation* reloc = spec.reloc();
306 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
307 if (rtype == relocInfo::none) return;
308
309 // The assertion below has been adjusted, to also work for
310 // relocation for fixup. Sometimes we want to put relocation
311 // information for the next instruction, since it will be patched
312 // with a call.
313 assert(start() <= at && at <= end()+1,
314 "cannot relocate data outside code boundaries");
315
316 if (!has_locs()) {
317 // no space for relocation information provided => code cannot be
318 // relocated. Make sure that relocate is only called with rtypes
319 // that can be ignored for this kind of code.
320 assert(rtype == relocInfo::none ||
321 rtype == relocInfo::runtime_call_type ||
322 rtype == relocInfo::internal_word_type||
323 rtype == relocInfo::section_word_type ||
324 rtype == relocInfo::external_word_type,
325 "code needs relocation information");
326 // leave behind an indication that we attempted a relocation
327 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
328 return;
329 }
330
331 // Advance the point, noting the offset we'll have to record.
332 csize_t offset = at - locs_point();
333 set_locs_point(at);
334
335 // Test for a couple of overflow conditions; maybe expand the buffer.
336 relocInfo* end = locs_end();
337 relocInfo* req = end + relocInfo::length_limit;
338 // Check for (potential) overflow
339 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
340 req += (uint)offset / (uint)relocInfo::offset_limit();
341 if (req >= locs_limit()) {
342 // Allocate or reallocate.
343 expand_locs(locs_count() + (req - end));
344 // reload pointer
345 end = locs_end();
346 }
347 }
348
349 // If the offset is giant, emit filler relocs, of type 'none', but
350 // each carrying the largest possible offset, to advance the locs_point.
351 while (offset >= relocInfo::offset_limit()) {
352 assert(end < locs_limit(), "adjust previous paragraph of code");
353 *end++ = filler_relocInfo();
354 offset -= filler_relocInfo().addr_offset();
355 }
356
357 // If it's a simple reloc with no data, we'll just write (rtype | offset).
358 (*end) = relocInfo(rtype, offset, format);
359
360 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
361 end->initialize(this, reloc);
362 }
363
364 void CodeSection::initialize_locs(int locs_capacity) {
365 assert(_locs_start == NULL, "only one locs init step, please");
366 // Apply a priori lower limits to relocation size:
367 csize_t min_locs = MAX2(size() / 16, (csize_t)4);
368 if (locs_capacity < min_locs) locs_capacity = min_locs;
369 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
370 _locs_start = locs_start;
371 _locs_end = locs_start;
372 _locs_limit = locs_start + locs_capacity;
373 _locs_own = true;
374 }
375
376 void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
377 assert(_locs_start == NULL, "do this before locs are allocated");
378 // Internal invariant: locs buf must be fully aligned.
379 // See copy_relocations_to() below.
380 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
381 ++buf; --length;
382 }
383 if (length > 0) {
384 _locs_start = buf;
385 _locs_end = buf;
386 _locs_limit = buf + length;
387 _locs_own = false;
388 }
389 }
390
391 void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
392 int lcount = source_cs->locs_count();
393 if (lcount != 0) {
394 initialize_shared_locs(source_cs->locs_start(), lcount);
395 _locs_end = _locs_limit = _locs_start + lcount;
396 assert(is_allocated(), "must have copied code already");
397 set_locs_point(start() + source_cs->locs_point_off());
398 }
399 assert(this->locs_count() == source_cs->locs_count(), "sanity");
400 }
401
402 void CodeSection::expand_locs(int new_capacity) {
403 if (_locs_start == NULL) {
404 initialize_locs(new_capacity);
405 return;
406 } else {
407 int old_count = locs_count();
408 int old_capacity = locs_capacity();
409 if (new_capacity < old_capacity * 2)
410 new_capacity = old_capacity * 2;
411 relocInfo* locs_start;
412 if (_locs_own) {
413 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
414 } else {
415 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
416 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
417 _locs_own = true;
418 }
419 _locs_start = locs_start;
420 _locs_end = locs_start + old_count;
421 _locs_limit = locs_start + new_capacity;
422 }
423 }
424
425
426 /// Support for emitting the code to its final location.
427 /// The pattern is the same for all functions.
428 /// We iterate over all the sections, padding each to alignment.
429
430 csize_t CodeBuffer::total_content_size() const {
431 csize_t size_so_far = 0;
432 for (int n = 0; n < (int)SECT_LIMIT; n++) {
433 const CodeSection* cs = code_section(n);
434 if (cs->is_empty()) continue; // skip trivial section
435 size_so_far = cs->align_at_start(size_so_far);
436 size_so_far += cs->size();
437 }
438 return size_so_far;
439 }
440
441 void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
442 address buf = dest->_total_start;
443 csize_t buf_offset = 0;
444 assert(dest->_total_size >= total_content_size(), "must be big enough");
445
446 {
447 // not sure why this is here, but why not...
448 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
449 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
450 }
451
452 const CodeSection* prev_cs = NULL;
453 CodeSection* prev_dest_cs = NULL;
454
455 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
456 // figure compact layout of each section
457 const CodeSection* cs = code_section(n);
458 csize_t csize = cs->size();
459
460 CodeSection* dest_cs = dest->code_section(n);
461 if (!cs->is_empty()) {
462 // Compute initial padding; assign it to the previous non-empty guy.
463 // Cf. figure_expanded_capacities.
464 csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
465 if (padding != 0) {
466 buf_offset += padding;
467 assert(prev_dest_cs != NULL, "sanity");
468 prev_dest_cs->_limit += padding;
469 }
470 #ifdef ASSERT
471 if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) {
472 // Make sure the ends still match up.
473 // This is important because a branch in a frozen section
474 // might target code in a following section, via a Label,
475 // and without a relocation record. See Label::patch_instructions.
476 address dest_start = buf+buf_offset;
477 csize_t start2start = cs->start() - prev_cs->start();
478 csize_t dest_start2start = dest_start - prev_dest_cs->start();
479 assert(start2start == dest_start2start, "cannot stretch frozen sect");
480 }
481 #endif //ASSERT
482 prev_dest_cs = dest_cs;
483 prev_cs = cs;
484 }
485
486 debug_only(dest_cs->_start = NULL); // defeat double-initialization assert
487 dest_cs->initialize(buf+buf_offset, csize);
488 dest_cs->set_end(buf+buf_offset+csize);
489 assert(dest_cs->is_allocated(), "must always be allocated");
490 assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
491
492 buf_offset += csize;
493 }
494
495 // Done calculating sections; did it come out to the right end?
496 assert(buf_offset == total_content_size(), "sanity");
497 dest->verify_section_allocation();
498 }
499
500 // Append an oop reference that keeps the class alive.
501 static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
502 oop cl = k->klass_holder();
503 if (cl != NULL && !oops->contains(cl)) {
504 oops->append(cl);
505 }
506 }
507
508 void CodeBuffer::finalize_oop_references(methodHandle mh) {
509 No_Safepoint_Verifier nsv;
510
511 GrowableArray<oop> oops;
512
513 // Make sure that immediate metadata records something in the OopRecorder
514 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
515 // pull code out of each section
516 CodeSection* cs = code_section(n);
517 if (cs->is_empty()) continue; // skip trivial section
518 RelocIterator iter(cs);
519 while (iter.next()) {
520 if (iter.type() == relocInfo::metadata_type) {
521 metadata_Relocation* md = iter.metadata_reloc();
522 if (md->metadata_is_immediate()) {
523 Metadata* m = md->metadata_value();
524 if (oop_recorder()->is_real(m)) {
525 if (m->is_methodData()) {
526 m = ((MethodData*)m)->method();
527 }
528 if (m->is_method()) {
529 m = ((Method*)m)->method_holder();
530 }
531 if (m->is_klass()) {
532 append_oop_references(&oops, (Klass*)m);
533 } else {
534 // XXX This will currently occur for MDO which don't
535 // have a backpointer. This has to be fixed later.
536 m->print();
537 ShouldNotReachHere();
538 }
539 }
540 }
541 }
542 }
543 }
544
545 if (!oop_recorder()->is_unused()) {
546 for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
547 Metadata* m = oop_recorder()->metadata_at(i);
548 if (oop_recorder()->is_real(m)) {
549 if (m->is_methodData()) {
550 m = ((MethodData*)m)->method();
551 }
552 if (m->is_method()) {
553 m = ((Method*)m)->method_holder();
554 }
555 if (m->is_klass()) {
556 append_oop_references(&oops, (Klass*)m);
557 } else {
558 m->print();
559 ShouldNotReachHere();
560 }
561 }
562 }
563
564 }
565
566 // Add the class loader of Method* for the nmethod itself
567 append_oop_references(&oops, mh->method_holder());
568
569 // Add any oops that we've found
570 Thread* thread = Thread::current();
571 for (int i = 0; i < oops.length(); i++) {
572 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
573 }
574 }
575
576
577
578 csize_t CodeBuffer::total_offset_of(CodeSection* cs) const {
579 csize_t size_so_far = 0;
580 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
581 const CodeSection* cur_cs = code_section(n);
582 if (!cur_cs->is_empty()) {
583 size_so_far = cur_cs->align_at_start(size_so_far);
584 }
585 if (cur_cs->index() == cs->index()) {
586 return size_so_far;
587 }
588 size_so_far += cur_cs->size();
589 }
590 ShouldNotReachHere();
591 return -1;
592 }
593
594 csize_t CodeBuffer::total_relocation_size() const {
595 csize_t lsize = copy_relocations_to(NULL); // dry run only
596 csize_t csize = total_content_size();
597 csize_t total = RelocIterator::locs_and_index_size(csize, lsize);
598 return (csize_t) align_size_up(total, HeapWordSize);
599 }
600
601 csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
602 address buf = NULL;
603 csize_t buf_offset = 0;
604 csize_t buf_limit = 0;
605 if (dest != NULL) {
606 buf = (address)dest->relocation_begin();
607 buf_limit = (address)dest->relocation_end() - buf;
608 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
609 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
610 }
611 // if dest == NULL, this is just the sizing pass
612
613 csize_t code_end_so_far = 0;
614 csize_t code_point_so_far = 0;
615 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
616 // pull relocs out of each section
617 const CodeSection* cs = code_section(n);
618 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
619 if (cs->is_empty()) continue; // skip trivial section
620 relocInfo* lstart = cs->locs_start();
621 relocInfo* lend = cs->locs_end();
622 csize_t lsize = (csize_t)( (address)lend - (address)lstart );
623 csize_t csize = cs->size();
624 code_end_so_far = cs->align_at_start(code_end_so_far);
625
626 if (lsize > 0) {
627 // Figure out how to advance the combined relocation point
628 // first to the beginning of this section.
629 // We'll insert one or more filler relocs to span that gap.
630 // (Don't bother to improve this by editing the first reloc's offset.)
631 csize_t new_code_point = code_end_so_far;
632 for (csize_t jump;
633 code_point_so_far < new_code_point;
634 code_point_so_far += jump) {
635 jump = new_code_point - code_point_so_far;
636 relocInfo filler = filler_relocInfo();
637 if (jump >= filler.addr_offset()) {
638 jump = filler.addr_offset();
639 } else { // else shrink the filler to fit
640 filler = relocInfo(relocInfo::none, jump);
641 }
642 if (buf != NULL) {
643 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
644 *(relocInfo*)(buf+buf_offset) = filler;
645 }
646 buf_offset += sizeof(filler);
647 }
648
649 // Update code point and end to skip past this section:
650 csize_t last_code_point = code_end_so_far + cs->locs_point_off();
651 assert(code_point_so_far <= last_code_point, "sanity");
652 code_point_so_far = last_code_point; // advance past this guy's relocs
653 }
654 code_end_so_far += csize; // advance past this guy's instructions too
655
656 // Done with filler; emit the real relocations:
657 if (buf != NULL && lsize != 0) {
658 assert(buf_offset + lsize <= buf_limit, "target in bounds");
659 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
660 if (buf_offset % HeapWordSize == 0) {
661 // Use wordwise copies if possible:
662 Copy::disjoint_words((HeapWord*)lstart,
663 (HeapWord*)(buf+buf_offset),
664 (lsize + HeapWordSize-1) / HeapWordSize);
665 } else {
666 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
667 }
668 }
669 buf_offset += lsize;
670 }
671
672 // Align end of relocation info in target.
673 while (buf_offset % HeapWordSize != 0) {
674 if (buf != NULL) {
675 relocInfo padding = relocInfo(relocInfo::none, 0);
676 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
677 *(relocInfo*)(buf+buf_offset) = padding;
678 }
679 buf_offset += sizeof(relocInfo);
680 }
681
682 assert(code_end_so_far == total_content_size(), "sanity");
683
684 // Account for index:
685 if (buf != NULL) {
686 RelocIterator::create_index(dest->relocation_begin(),
687 buf_offset / sizeof(relocInfo),
688 dest->relocation_end());
689 }
690
691 return buf_offset;
692 }
693
694 void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
695 #ifndef PRODUCT
696 if (PrintNMethods && (WizardMode || Verbose)) {
697 tty->print("done with CodeBuffer:");
698 ((CodeBuffer*)this)->print();
699 }
700 #endif //PRODUCT
701
702 CodeBuffer dest(dest_blob);
703 assert(dest_blob->content_size() >= total_content_size(), "good sizing");
704 this->compute_final_layout(&dest);
705 relocate_code_to(&dest);
706
707 // transfer strings and comments from buffer to blob
708 dest_blob->set_strings(_strings);
709
710 // Done moving code bytes; were they the right size?
711 assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
712
713 // Flush generated code
714 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
715 }
716
717 // Move all my code into another code buffer. Consult applicable
718 // relocs to repair embedded addresses. The layout in the destination
719 // CodeBuffer is different to the source CodeBuffer: the destination
720 // CodeBuffer gets the final layout (consts, insts, stubs in order of
721 // ascending address).
722 void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
723 address dest_end = dest->_total_start + dest->_total_size;
724 address dest_filled = NULL;
725 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
726 // pull code out of each section
727 const CodeSection* cs = code_section(n);
728 if (cs->is_empty()) continue; // skip trivial section
729 CodeSection* dest_cs = dest->code_section(n);
730 assert(cs->size() == dest_cs->size(), "sanity");
731 csize_t usize = dest_cs->size();
732 csize_t wsize = align_size_up(usize, HeapWordSize);
733 assert(dest_cs->start() + wsize <= dest_end, "no overflow");
734 // Copy the code as aligned machine words.
735 // This may also include an uninitialized partial word at the end.
736 Copy::disjoint_words((HeapWord*)cs->start(),
737 (HeapWord*)dest_cs->start(),
738 wsize / HeapWordSize);
739
740 if (dest->blob() == NULL) {
741 // Destination is a final resting place, not just another buffer.
742 // Normalize uninitialized bytes in the final padding.
743 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
744 Assembler::code_fill_byte());
745 }
746 // Keep track of the highest filled address
747 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
748
749 assert(cs->locs_start() != (relocInfo*)badAddress,
750 "this section carries no reloc storage, but reloc was attempted");
751
752 // Make the new code copy use the old copy's relocations:
753 dest_cs->initialize_locs_from(cs);
754 }
755
756 // Do relocation after all sections are copied.
757 // This is necessary if the code uses constants in stubs, which are
758 // relocated when the corresponding instruction in the code (e.g., a
759 // call) is relocated. Stubs are placed behind the main code
760 // section, so that section has to be copied before relocating.
761 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
762 // pull code out of each section
763 const CodeSection* cs = code_section(n);
764 if (cs->is_empty()) continue; // skip trivial section
765 CodeSection* dest_cs = dest->code_section(n);
766 { // Repair the pc relative information in the code after the move
767 RelocIterator iter(dest_cs);
768 while (iter.next()) {
769 iter.reloc()->fix_relocation_after_move(this, dest);
770 }
771 }
772 }
773
774 if (dest->blob() == NULL && dest_filled != NULL) {
775 // Destination is a final resting place, not just another buffer.
776 // Normalize uninitialized bytes in the final padding.
777 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
778 Assembler::code_fill_byte());
779
780 }
781 }
782
783 csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
784 csize_t amount,
785 csize_t* new_capacity) {
786 csize_t new_total_cap = 0;
787
788 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
789 const CodeSection* sect = code_section(n);
790
791 if (!sect->is_empty()) {
792 // Compute initial padding; assign it to the previous section,
793 // even if it's empty (e.g. consts section can be empty).
794 // Cf. compute_final_layout
795 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
796 if (padding != 0) {
797 new_total_cap += padding;
798 assert(n - 1 >= SECT_FIRST, "sanity");
799 new_capacity[n - 1] += padding;
800 }
801 }
802
803 csize_t exp = sect->size(); // 100% increase
804 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
805 if (sect == which_cs) {
806 if (exp < amount) exp = amount;
807 if (StressCodeBuffers) exp = amount; // expand only slightly
808 } else if (n == SECT_INSTS) {
809 // scale down inst increases to a more modest 25%
810 exp = 4*K + ((exp - 4*K) >> 2);
811 if (StressCodeBuffers) exp = amount / 2; // expand only slightly
812 } else if (sect->is_empty()) {
813 // do not grow an empty secondary section
814 exp = 0;
815 }
816 // Allow for inter-section slop:
817 exp += CodeSection::end_slop();
818 csize_t new_cap = sect->size() + exp;
819 if (new_cap < sect->capacity()) {
820 // No need to expand after all.
821 new_cap = sect->capacity();
822 }
823 new_capacity[n] = new_cap;
824 new_total_cap += new_cap;
825 }
826
827 return new_total_cap;
828 }
829
830 void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
831 #ifndef PRODUCT
832 if (PrintNMethods && (WizardMode || Verbose)) {
833 tty->print("expanding CodeBuffer:");
834 this->print();
835 }
836
837 if (StressCodeBuffers && blob() != NULL) {
838 static int expand_count = 0;
839 if (expand_count >= 0) expand_count += 1;
840 if (expand_count > 100 && is_power_of_2(expand_count)) {
841 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
842 // simulate an occasional allocation failure:
843 free_blob();
844 }
845 }
846 #endif //PRODUCT
847
848 // Resizing must be allowed
849 {
850 if (blob() == NULL) return; // caller must check for blob == NULL
851 for (int n = 0; n < (int)SECT_LIMIT; n++) {
852 guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen");
853 }
854 }
855
856 // Figure new capacity for each section.
857 csize_t new_capacity[SECT_LIMIT];
858 csize_t new_total_cap
859 = figure_expanded_capacities(which_cs, amount, new_capacity);
860
861 // Create a new (temporary) code buffer to hold all the new data
862 CodeBuffer cb(name(), new_total_cap, 0);
863 if (cb.blob() == NULL) {
864 // Failed to allocate in code cache.
865 free_blob();
866 return;
867 }
868
869 // Create an old code buffer to remember which addresses used to go where.
870 // This will be useful when we do final assembly into the code cache,
871 // because we will need to know how to warp any internal address that
872 // has been created at any time in this CodeBuffer's past.
873 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
874 bxp->take_over_code_from(this); // remember the old undersized blob
875 DEBUG_ONLY(this->_blob = NULL); // silence a later assert
876 bxp->_before_expand = this->_before_expand;
877 this->_before_expand = bxp;
878
879 // Give each section its required (expanded) capacity.
880 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
881 CodeSection* cb_sect = cb.code_section(n);
882 CodeSection* this_sect = code_section(n);
883 if (new_capacity[n] == 0) continue; // already nulled out
884 if (n != SECT_INSTS) {
885 cb.initialize_section_size(cb_sect, new_capacity[n]);
886 }
887 assert(cb_sect->capacity() >= new_capacity[n], "big enough");
888 address cb_start = cb_sect->start();
889 cb_sect->set_end(cb_start + this_sect->size());
890 if (this_sect->mark() == NULL) {
891 cb_sect->clear_mark();
892 } else {
893 cb_sect->set_mark(cb_start + this_sect->mark_off());
894 }
895 }
896
897 // Move all the code and relocations to the new blob:
898 relocate_code_to(&cb);
899
900 // Copy the temporary code buffer into the current code buffer.
901 // Basically, do {*this = cb}, except for some control information.
902 this->take_over_code_from(&cb);
903 cb.set_blob(NULL);
904
905 // Zap the old code buffer contents, to avoid mistakenly using them.
906 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
907 badCodeHeapFreeVal));
908
909 _decode_begin = NULL; // sanity
910
911 // Make certain that the new sections are all snugly inside the new blob.
912 verify_section_allocation();
913
914 #ifndef PRODUCT
915 if (PrintNMethods && (WizardMode || Verbose)) {
916 tty->print("expanded CodeBuffer:");
917 this->print();
918 }
919 #endif //PRODUCT
920 }
921
922 void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
923 // Must already have disposed of the old blob somehow.
924 assert(blob() == NULL, "must be empty");
925 #ifdef ASSERT
926
927 #endif
928 // Take the new blob away from cb.
929 set_blob(cb->blob());
930 // Take over all the section pointers.
931 for (int n = 0; n < (int)SECT_LIMIT; n++) {
932 CodeSection* cb_sect = cb->code_section(n);
933 CodeSection* this_sect = code_section(n);
934 this_sect->take_over_code_from(cb_sect);
935 }
936 _overflow_arena = cb->_overflow_arena;
937 // Make sure the old cb won't try to use it or free it.
938 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
939 }
940
941 void CodeBuffer::verify_section_allocation() {
942 address tstart = _total_start;
943 if (tstart == badAddress) return; // smashed by set_blob(NULL)
944 address tend = tstart + _total_size;
945 if (_blob != NULL) {
946
947 guarantee(tstart >= _blob->content_begin(), "sanity");
948 guarantee(tend <= _blob->content_end(), "sanity");
949 }
950 // Verify disjointness.
951 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
952 CodeSection* sect = code_section(n);
953 if (!sect->is_allocated() || sect->is_empty()) continue;
954 guarantee((intptr_t)sect->start() % sect->alignment() == 0
955 || sect->is_empty() || _blob == NULL,
956 "start is aligned");
957 for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) {
958 CodeSection* other = code_section(m);
959 if (!other->is_allocated() || other == sect) continue;
960 guarantee(!other->contains(sect->start() ), "sanity");
961 // limit is an exclusive address and can be the start of another
962 // section.
963 guarantee(!other->contains(sect->limit() - 1), "sanity");
964 }
965 guarantee(sect->end() <= tend, "sanity");
966 guarantee(sect->end() <= sect->limit(), "sanity");
967 }
968 }
969
970 void CodeBuffer::log_section_sizes(const char* name) {
971 if (xtty != NULL) {
972 ttyLocker ttyl;
973 // log info about buffer usage
974 xtty->print_cr("<blob name='%s' size='%d'>", name, _total_size);
975 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
976 CodeSection* sect = code_section(n);
977 if (!sect->is_allocated() || sect->is_empty()) continue;
978 xtty->print_cr("<sect index='%d' size='" SIZE_FORMAT "' free='" SIZE_FORMAT "'/>",
979 n, sect->limit() - sect->start(), sect->limit() - sect->end());
980 }
981 xtty->print_cr("</blob>");
982 }
983 }
984
985 #ifndef PRODUCT
986
987 void CodeSection::dump() {
988 address ptr = start();
989 for (csize_t step; ptr < end(); ptr += step) {
990 step = end() - ptr;
991 if (step > jintSize * 4) step = jintSize * 4;
992 tty->print(INTPTR_FORMAT ": ", p2i(ptr));
993 while (step > 0) {
994 tty->print(" " PTR32_FORMAT, *(jint*)ptr);
995 ptr += jintSize;
996 }
997 tty->cr();
998 }
999 }
1000
1001
1002 void CodeSection::decode() {
1003 Disassembler::decode(start(), end());
1004 }
1005
1006
1007 void CodeBuffer::block_comment(intptr_t offset, const char * comment) {
1008 _strings.add_comment(offset, comment);
1009 }
1010
1011 const char* CodeBuffer::code_string(const char* str) {
1012 return _strings.add_string(str);
1013 }
1014
1015 class CodeString: public CHeapObj<mtCode> {
1016 private:
1017 friend class CodeStrings;
1018 const char * _string;
1019 CodeString* _next;
1020 intptr_t _offset;
1021
1022 ~CodeString() {
1023 assert(_next == NULL, "wrong interface for freeing list");
1024 os::free((void*)_string, mtCode);
1025 }
1026
1027 bool is_comment() const { return _offset >= 0; }
1028
1029 public:
1030 CodeString(const char * string, intptr_t offset = -1)
1031 : _next(NULL), _offset(offset) {
1032 _string = os::strdup(string, mtCode);
1033 }
1034
1035 const char * string() const { return _string; }
1036 intptr_t offset() const { assert(_offset >= 0, "offset for non comment?"); return _offset; }
1037 CodeString* next() const { return _next; }
1038
1039 void set_next(CodeString* next) { _next = next; }
1040
1041 CodeString* first_comment() {
1042 if (is_comment()) {
1043 return this;
1044 } else {
1045 return next_comment();
1046 }
1047 }
1048 CodeString* next_comment() const {
1049 CodeString* s = _next;
1050 while (s != NULL && !s->is_comment()) {
1051 s = s->_next;
1052 }
1053 return s;
1054 }
1055 };
1056
1057 CodeString* CodeStrings::find(intptr_t offset) const {
1058 CodeString* a = _strings->first_comment();
1059 while (a != NULL && a->offset() != offset) {
1060 a = a->next_comment();
1061 }
1062 return a;
1063 }
1064
1065 // Convenience for add_comment.
1066 CodeString* CodeStrings::find_last(intptr_t offset) const {
1067 CodeString* a = find(offset);
1068 if (a != NULL) {
1069 CodeString* c = NULL;
1070 while (((c = a->next_comment()) != NULL) && (c->offset() == offset)) {
1071 a = c;
1072 }
1073 }
1074 return a;
1075 }
1076
1077 void CodeStrings::add_comment(intptr_t offset, const char * comment) {
1078 CodeString* c = new CodeString(comment, offset);
1079 CodeString* inspos = (_strings == NULL) ? NULL : find_last(offset);
1080
1081 if (inspos) {
1082 // insert after already existing comments with same offset
1083 c->set_next(inspos->next());
1084 inspos->set_next(c);
1085 } else {
1086 // no comments with such offset, yet. Insert before anything else.
1087 c->set_next(_strings);
1088 _strings = c;
1089 }
1090 }
1091
1092 void CodeStrings::assign(CodeStrings& other) {
1093 _strings = other._strings;
1094 }
1095
1096 void CodeStrings::print_block_comment(outputStream* stream, intptr_t offset) const {
1097 if (_strings != NULL) {
1098 CodeString* c = find(offset);
1099 while (c && c->offset() == offset) {
1100 stream->bol();
1101 stream->print(" ;; ");
1102 stream->print_cr("%s", c->string());
1103 c = c->next_comment();
1104 }
1105 }
1106 }
1107
1108
1109 void CodeStrings::free() {
1110 CodeString* n = _strings;
1111 while (n) {
1112 // unlink the node from the list saving a pointer to the next
1113 CodeString* p = n->next();
1114 n->set_next(NULL);
1115 delete n;
1116 n = p;
1117 }
1118 _strings = NULL;
1119 }
1120
1121 const char* CodeStrings::add_string(const char * string) {
1122 CodeString* s = new CodeString(string);
1123 s->set_next(_strings);
1124 _strings = s;
1125 assert(s->string() != NULL, "should have a string");
1126 return s->string();
1127 }
1128
1129 void CodeBuffer::decode() {
1130 ttyLocker ttyl;
1131 Disassembler::decode(decode_begin(), insts_end());
1132 _decode_begin = insts_end();
1133 }
1134
1135
1136 void CodeBuffer::skip_decode() {
1137 _decode_begin = insts_end();
1138 }
1139
1140
1141 void CodeBuffer::decode_all() {
1142 ttyLocker ttyl;
1143 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1144 // dump contents of each section
1145 CodeSection* cs = code_section(n);
1146 tty->print_cr("! %s:", code_section_name(n));
1147 if (cs != consts())
1148 cs->decode();
1149 else
1150 cs->dump();
1151 }
1152 }
1153
1154
1155 void CodeSection::print(const char* name) {
1156 csize_t locs_size = locs_end() - locs_start();
1157 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s",
1158 name, p2i(start()), p2i(end()), p2i(limit()), size(), capacity(),
1159 is_frozen()? " [frozen]": "");
1160 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1161 name, p2i(locs_start()), p2i(locs_end()), p2i(locs_limit()), locs_size, locs_capacity(), locs_point_off());
1162 if (PrintRelocations) {
1163 RelocIterator iter(this);
1164 iter.print();
1165 }
1166 }
1167
1168 void CodeBuffer::print() {
1169 if (this == NULL) {
1170 tty->print_cr("NULL CodeBuffer pointer");
1171 return;
1172 }
1173
1174 tty->print_cr("CodeBuffer:");
1175 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1176 // print each section
1177 CodeSection* cs = code_section(n);
1178 cs->print(code_section_name(n));
1179 }
1180 }
1181
1182 #endif // PRODUCT