1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/codeBuffer.hpp"
27 #include "compiler/disassembler.hpp"
28 #include "memory/gcLocker.hpp"
29 #include "oops/methodData.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "utilities/copy.hpp"
32 #include "utilities/xmlstream.hpp"
33
34 // The structure of a CodeSection:
35 //
36 // _start -> +----------------+
37 // | machine code...|
38 // _end -> |----------------|
39 // | |
40 // | (empty) |
41 // | |
42 // | |
43 // +----------------+
44 // _limit -> | |
45 //
46 // _locs_start -> +----------------+
47 // |reloc records...|
48 // |----------------|
49 // _locs_end -> | |
50 // | |
51 // | (empty) |
52 // | |
53 // | |
54 // +----------------+
55 // _locs_limit -> | |
56 // The _end (resp. _limit) pointer refers to the first
57 // unused (resp. unallocated) byte.
58
59 // The structure of the CodeBuffer while code is being accumulated:
60 //
61 // _total_start -> \
62 // _insts._start -> +----------------+
63 // | |
64 // | Code |
65 // | |
66 // _stubs._start -> |----------------|
67 // | |
68 // | Stubs | (also handlers for deopt/exception)
69 // | |
70 // _consts._start -> |----------------|
71 // | |
72 // | Constants |
73 // | |
74 // +----------------+
75 // + _total_size -> | |
76 //
77 // When the code and relocations are copied to the code cache,
78 // the empty parts of each section are removed, and everything
79 // is copied into contiguous locations.
80
81 typedef CodeBuffer::csize_t csize_t; // file-local definition
82
83 // External buffer, in a predefined CodeBlob.
84 // Important: The code_start must be taken exactly, and not realigned.
85 CodeBuffer::CodeBuffer(CodeBlob* blob) {
86 initialize_misc("static buffer");
87 initialize(blob->content_begin(), blob->content_size());
88 verify_section_allocation();
89 }
90
91 void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) {
92 // Compute maximal alignment.
93 int align = _insts.alignment();
94 // Always allow for empty slop around each section.
95 int slop = (int) CodeSection::end_slop();
96
97 assert(blob() == NULL, "only once");
98 set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1)));
99 if (blob() == NULL) {
100 // The assembler constructor will throw a fatal on an empty CodeBuffer.
101 return; // caller must test this
102 }
103
104 // Set up various pointers into the blob.
105 initialize(_total_start, _total_size);
106
107 assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
108
109 pd_initialize();
110
111 if (locs_size != 0) {
112 _insts.initialize_locs(locs_size / sizeof(relocInfo));
113 }
114
115 verify_section_allocation();
116 }
117
118
119 CodeBuffer::~CodeBuffer() {
120 verify_section_allocation();
121
122 // If we allocate our code buffer from the CodeCache
123 // via a BufferBlob, and it's not permanent, then
124 // free the BufferBlob.
125 // The rest of the memory will be freed when the ResourceObj
126 // is released.
127 for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) {
128 // Previous incarnations of this buffer are held live, so that internal
129 // addresses constructed before expansions will not be confused.
130 cb->free_blob();
131 }
132
133 // free any overflow storage
134 delete _overflow_arena;
135
136 #ifdef ASSERT
137 // Save allocation type to execute assert in ~ResourceObj()
138 // which is called after this destructor.
139 assert(_default_oop_recorder.allocated_on_stack(), "should be embedded object");
140 ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type();
141 Copy::fill_to_bytes(this, sizeof(*this), badResourceValue);
142 ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at);
143 #endif
144 }
145
146 void CodeBuffer::initialize_oop_recorder(OopRecorder* r) {
147 assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once");
148 DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen
149 _oop_recorder = r;
150 }
151
152 void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) {
153 assert(cs != &_insts, "insts is the memory provider, not the consumer");
154 csize_t slop = CodeSection::end_slop(); // margin between sections
155 int align = cs->alignment();
156 assert(is_power_of_2(align), "sanity");
157 address start = _insts._start;
158 address limit = _insts._limit;
159 address middle = limit - size;
160 middle -= (intptr_t)middle & (align-1); // align the division point downward
161 guarantee(middle - slop > start, "need enough space to divide up");
162 _insts._limit = middle - slop; // subtract desired space, plus slop
163 cs->initialize(middle, limit - middle);
164 assert(cs->start() == middle, "sanity");
165 assert(cs->limit() == limit, "sanity");
166 // give it some relocations to start with, if the main section has them
167 if (_insts.has_locs()) cs->initialize_locs(1);
168 }
169
170 void CodeBuffer::freeze_section(CodeSection* cs) {
171 CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1);
172 csize_t frozen_size = cs->size();
173 if (next_cs != NULL) {
174 frozen_size = next_cs->align_at_start(frozen_size);
175 }
176 address old_limit = cs->limit();
177 address new_limit = cs->start() + frozen_size;
178 relocInfo* old_locs_limit = cs->locs_limit();
179 relocInfo* new_locs_limit = cs->locs_end();
180 // Patch the limits.
181 cs->_limit = new_limit;
182 cs->_locs_limit = new_locs_limit;
183 cs->_frozen = true;
184 if (!next_cs->is_allocated() && !next_cs->is_frozen()) {
185 // Give remaining buffer space to the following section.
186 next_cs->initialize(new_limit, old_limit - new_limit);
187 next_cs->initialize_shared_locs(new_locs_limit,
188 old_locs_limit - new_locs_limit);
189 }
190 }
191
192 void CodeBuffer::set_blob(BufferBlob* blob) {
193 _blob = blob;
194 if (blob != NULL) {
195 address start = blob->content_begin();
196 address end = blob->content_end();
197 // Round up the starting address.
198 int align = _insts.alignment();
199 start += (-(intptr_t)start) & (align-1);
200 _total_start = start;
201 _total_size = end - start;
202 } else {
203 #ifdef ASSERT
204 // Clean out dangling pointers.
205 _total_start = badAddress;
206 _consts._start = _consts._end = badAddress;
207 _insts._start = _insts._end = badAddress;
208 _stubs._start = _stubs._end = badAddress;
209 #endif //ASSERT
210 }
211 }
212
213 void CodeBuffer::free_blob() {
214 if (_blob != NULL) {
215 BufferBlob::free(_blob);
216 set_blob(NULL);
217 }
218 }
219
220 const char* CodeBuffer::code_section_name(int n) {
221 #ifdef PRODUCT
222 return NULL;
223 #else //PRODUCT
224 switch (n) {
225 case SECT_CONSTS: return "consts";
226 case SECT_INSTS: return "insts";
227 case SECT_STUBS: return "stubs";
228 default: return NULL;
229 }
230 #endif //PRODUCT
231 }
232
233 int CodeBuffer::section_index_of(address addr) const {
234 for (int n = 0; n < (int)SECT_LIMIT; n++) {
235 const CodeSection* cs = code_section(n);
236 if (cs->allocates(addr)) return n;
237 }
238 return SECT_NONE;
239 }
240
241 int CodeBuffer::locator(address addr) const {
242 for (int n = 0; n < (int)SECT_LIMIT; n++) {
243 const CodeSection* cs = code_section(n);
244 if (cs->allocates(addr)) {
245 return locator(addr - cs->start(), n);
246 }
247 }
248 return -1;
249 }
250
251 address CodeBuffer::locator_address(int locator) const {
252 if (locator < 0) return NULL;
253 address start = code_section(locator_sect(locator))->start();
254 return start + locator_pos(locator);
255 }
256
257 bool CodeBuffer::is_backward_branch(Label& L) {
258 return L.is_bound() && insts_end() <= locator_address(L.loc());
259 }
260
261 address CodeBuffer::decode_begin() {
262 address begin = _insts.start();
263 if (_decode_begin != NULL && _decode_begin > begin)
264 begin = _decode_begin;
265 return begin;
266 }
267
268
269 GrowableArray<int>* CodeBuffer::create_patch_overflow() {
270 if (_overflow_arena == NULL) {
271 _overflow_arena = new (mtCode) Arena();
272 }
273 return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0);
274 }
275
276
277 // Helper function for managing labels and their target addresses.
278 // Returns a sensible address, and if it is not the label's final
279 // address, notes the dependency (at 'branch_pc') on the label.
280 address CodeSection::target(Label& L, address branch_pc) {
281 if (L.is_bound()) {
282 int loc = L.loc();
283 if (index() == CodeBuffer::locator_sect(loc)) {
284 return start() + CodeBuffer::locator_pos(loc);
285 } else {
286 return outer()->locator_address(loc);
287 }
288 } else {
289 assert(allocates2(branch_pc), "sanity");
290 address base = start();
291 int patch_loc = CodeBuffer::locator(branch_pc - base, index());
292 L.add_patch_at(outer(), patch_loc);
293
294 // Need to return a pc, doesn't matter what it is since it will be
295 // replaced during resolution later.
296 // Don't return NULL or badAddress, since branches shouldn't overflow.
297 // Don't return base either because that could overflow displacements
298 // for shorter branches. It will get checked when bound.
299 return branch_pc;
300 }
301 }
302
303 void CodeSection::relocate(address at, RelocationHolder const& spec, int format) {
304 Relocation* reloc = spec.reloc();
305 relocInfo::relocType rtype = (relocInfo::relocType) reloc->type();
306 if (rtype == relocInfo::none) return;
307
308 // The assertion below has been adjusted, to also work for
309 // relocation for fixup. Sometimes we want to put relocation
310 // information for the next instruction, since it will be patched
311 // with a call.
312 assert(start() <= at && at <= end()+1,
313 "cannot relocate data outside code boundaries");
314
315 if (!has_locs()) {
316 // no space for relocation information provided => code cannot be
317 // relocated. Make sure that relocate is only called with rtypes
318 // that can be ignored for this kind of code.
319 assert(rtype == relocInfo::none ||
320 rtype == relocInfo::runtime_call_type ||
321 rtype == relocInfo::internal_word_type||
322 rtype == relocInfo::section_word_type ||
323 rtype == relocInfo::external_word_type,
324 "code needs relocation information");
325 // leave behind an indication that we attempted a relocation
326 DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress);
327 return;
328 }
329
330 // Advance the point, noting the offset we'll have to record.
331 csize_t offset = at - locs_point();
332 set_locs_point(at);
333
334 // Test for a couple of overflow conditions; maybe expand the buffer.
335 relocInfo* end = locs_end();
336 relocInfo* req = end + relocInfo::length_limit;
337 // Check for (potential) overflow
338 if (req >= locs_limit() || offset >= relocInfo::offset_limit()) {
339 req += (uint)offset / (uint)relocInfo::offset_limit();
340 if (req >= locs_limit()) {
341 // Allocate or reallocate.
342 expand_locs(locs_count() + (req - end));
343 // reload pointer
344 end = locs_end();
345 }
346 }
347
348 // If the offset is giant, emit filler relocs, of type 'none', but
349 // each carrying the largest possible offset, to advance the locs_point.
350 while (offset >= relocInfo::offset_limit()) {
351 assert(end < locs_limit(), "adjust previous paragraph of code");
352 *end++ = filler_relocInfo();
353 offset -= filler_relocInfo().addr_offset();
354 }
355
356 // If it's a simple reloc with no data, we'll just write (rtype | offset).
357 (*end) = relocInfo(rtype, offset, format);
358
359 // If it has data, insert the prefix, as (data_prefix_tag | data1), data2.
360 end->initialize(this, reloc);
361 }
362
363 void CodeSection::initialize_locs(int locs_capacity) {
364 assert(_locs_start == NULL, "only one locs init step, please");
365 // Apply a priori lower limits to relocation size:
366 csize_t min_locs = MAX2(size() / 16, (csize_t)4);
367 if (locs_capacity < min_locs) locs_capacity = min_locs;
368 relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity);
369 _locs_start = locs_start;
370 _locs_end = locs_start;
371 _locs_limit = locs_start + locs_capacity;
372 _locs_own = true;
373 }
374
375 void CodeSection::initialize_shared_locs(relocInfo* buf, int length) {
376 assert(_locs_start == NULL, "do this before locs are allocated");
377 // Internal invariant: locs buf must be fully aligned.
378 // See copy_relocations_to() below.
379 while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) {
380 ++buf; --length;
381 }
382 if (length > 0) {
383 _locs_start = buf;
384 _locs_end = buf;
385 _locs_limit = buf + length;
386 _locs_own = false;
387 }
388 }
389
390 void CodeSection::initialize_locs_from(const CodeSection* source_cs) {
391 int lcount = source_cs->locs_count();
392 if (lcount != 0) {
393 initialize_shared_locs(source_cs->locs_start(), lcount);
394 _locs_end = _locs_limit = _locs_start + lcount;
395 assert(is_allocated(), "must have copied code already");
396 set_locs_point(start() + source_cs->locs_point_off());
397 }
398 assert(this->locs_count() == source_cs->locs_count(), "sanity");
399 }
400
401 void CodeSection::expand_locs(int new_capacity) {
402 if (_locs_start == NULL) {
403 initialize_locs(new_capacity);
404 return;
405 } else {
406 int old_count = locs_count();
407 int old_capacity = locs_capacity();
408 if (new_capacity < old_capacity * 2)
409 new_capacity = old_capacity * 2;
410 relocInfo* locs_start;
411 if (_locs_own) {
412 locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity);
413 } else {
414 locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity);
415 Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo));
416 _locs_own = true;
417 }
418 _locs_start = locs_start;
419 _locs_end = locs_start + old_count;
420 _locs_limit = locs_start + new_capacity;
421 }
422 }
423
424
425 /// Support for emitting the code to its final location.
426 /// The pattern is the same for all functions.
427 /// We iterate over all the sections, padding each to alignment.
428
429 csize_t CodeBuffer::total_content_size() const {
430 csize_t size_so_far = 0;
431 for (int n = 0; n < (int)SECT_LIMIT; n++) {
432 const CodeSection* cs = code_section(n);
433 if (cs->is_empty()) continue; // skip trivial section
434 size_so_far = cs->align_at_start(size_so_far);
435 size_so_far += cs->size();
436 }
437 return size_so_far;
438 }
439
440 void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
441 address buf = dest->_total_start;
442 csize_t buf_offset = 0;
443 assert(dest->_total_size >= total_content_size(), "must be big enough");
444
445 {
446 // not sure why this is here, but why not...
447 int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment);
448 assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment");
449 }
450
451 const CodeSection* prev_cs = NULL;
452 CodeSection* prev_dest_cs = NULL;
453
454 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
455 // figure compact layout of each section
456 const CodeSection* cs = code_section(n);
457 csize_t csize = cs->size();
458
459 CodeSection* dest_cs = dest->code_section(n);
460 if (!cs->is_empty()) {
461 // Compute initial padding; assign it to the previous non-empty guy.
462 // Cf. figure_expanded_capacities.
463 csize_t padding = cs->align_at_start(buf_offset) - buf_offset;
464 if (padding != 0) {
465 buf_offset += padding;
466 assert(prev_dest_cs != NULL, "sanity");
467 prev_dest_cs->_limit += padding;
468 }
469 #ifdef ASSERT
470 if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) {
471 // Make sure the ends still match up.
472 // This is important because a branch in a frozen section
473 // might target code in a following section, via a Label,
474 // and without a relocation record. See Label::patch_instructions.
475 address dest_start = buf+buf_offset;
476 csize_t start2start = cs->start() - prev_cs->start();
477 csize_t dest_start2start = dest_start - prev_dest_cs->start();
478 assert(start2start == dest_start2start, "cannot stretch frozen sect");
479 }
480 #endif //ASSERT
481 prev_dest_cs = dest_cs;
482 prev_cs = cs;
483 }
484
485 debug_only(dest_cs->_start = NULL); // defeat double-initialization assert
486 dest_cs->initialize(buf+buf_offset, csize);
487 dest_cs->set_end(buf+buf_offset+csize);
488 assert(dest_cs->is_allocated(), "must always be allocated");
489 assert(cs->is_empty() == dest_cs->is_empty(), "sanity");
490
491 buf_offset += csize;
492 }
493
494 // Done calculating sections; did it come out to the right end?
495 assert(buf_offset == total_content_size(), "sanity");
496 dest->verify_section_allocation();
497 }
498
499 // Append an oop reference that keeps the class alive.
500 static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
501 oop cl = k->klass_holder();
502 if (cl != NULL && !oops->contains(cl)) {
503 oops->append(cl);
504 }
505 }
506
507 void CodeBuffer::finalize_oop_references(methodHandle mh) {
508 No_Safepoint_Verifier nsv;
509
510 GrowableArray<oop> oops;
511
512 // Make sure that immediate metadata records something in the OopRecorder
513 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
514 // pull code out of each section
515 CodeSection* cs = code_section(n);
516 if (cs->is_empty()) continue; // skip trivial section
517 RelocIterator iter(cs);
518 while (iter.next()) {
519 if (iter.type() == relocInfo::metadata_type) {
520 metadata_Relocation* md = iter.metadata_reloc();
521 if (md->metadata_is_immediate()) {
522 Metadata* m = md->metadata_value();
523 if (oop_recorder()->is_real(m)) {
524 if (m->is_methodData()) {
525 m = ((MethodData*)m)->method();
526 }
527 if (m->is_method()) {
528 m = ((Method*)m)->method_holder();
529 }
530 if (m->is_klass()) {
531 append_oop_references(&oops, (Klass*)m);
532 } else {
533 // XXX This will currently occur for MDO which don't
534 // have a backpointer. This has to be fixed later.
535 m->print();
536 ShouldNotReachHere();
537 }
538 }
539 }
540 }
541 }
542 }
543
544 if (!oop_recorder()->is_unused()) {
545 for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
546 Metadata* m = oop_recorder()->metadata_at(i);
547 if (oop_recorder()->is_real(m)) {
548 if (m->is_methodData()) {
549 m = ((MethodData*)m)->method();
550 }
551 if (m->is_method()) {
552 m = ((Method*)m)->method_holder();
553 }
554 if (m->is_klass()) {
555 append_oop_references(&oops, (Klass*)m);
556 } else {
557 m->print();
558 ShouldNotReachHere();
559 }
560 }
561 }
562
563 }
564
565 // Add the class loader of Method* for the nmethod itself
566 append_oop_references(&oops, mh->method_holder());
567
568 // Add any oops that we've found
569 Thread* thread = Thread::current();
570 for (int i = 0; i < oops.length(); i++) {
571 oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
572 }
573 }
574
575
576
577 csize_t CodeBuffer::total_offset_of(CodeSection* cs) const {
578 csize_t size_so_far = 0;
579 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
580 const CodeSection* cur_cs = code_section(n);
581 if (!cur_cs->is_empty()) {
582 size_so_far = cur_cs->align_at_start(size_so_far);
583 }
584 if (cur_cs->index() == cs->index()) {
585 return size_so_far;
586 }
587 size_so_far += cur_cs->size();
588 }
589 ShouldNotReachHere();
590 return -1;
591 }
592
593 csize_t CodeBuffer::total_relocation_size() const {
594 csize_t lsize = copy_relocations_to(NULL); // dry run only
595 csize_t csize = total_content_size();
596 csize_t total = RelocIterator::locs_and_index_size(csize, lsize);
597 return (csize_t) align_size_up(total, HeapWordSize);
598 }
599
600 csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const {
601 address buf = NULL;
602 csize_t buf_offset = 0;
603 csize_t buf_limit = 0;
604 if (dest != NULL) {
605 buf = (address)dest->relocation_begin();
606 buf_limit = (address)dest->relocation_end() - buf;
607 assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned");
608 assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized");
609 }
610 // if dest == NULL, this is just the sizing pass
611
612 csize_t code_end_so_far = 0;
613 csize_t code_point_so_far = 0;
614 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
615 // pull relocs out of each section
616 const CodeSection* cs = code_section(n);
617 assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity");
618 if (cs->is_empty()) continue; // skip trivial section
619 relocInfo* lstart = cs->locs_start();
620 relocInfo* lend = cs->locs_end();
621 csize_t lsize = (csize_t)( (address)lend - (address)lstart );
622 csize_t csize = cs->size();
623 code_end_so_far = cs->align_at_start(code_end_so_far);
624
625 if (lsize > 0) {
626 // Figure out how to advance the combined relocation point
627 // first to the beginning of this section.
628 // We'll insert one or more filler relocs to span that gap.
629 // (Don't bother to improve this by editing the first reloc's offset.)
630 csize_t new_code_point = code_end_so_far;
631 for (csize_t jump;
632 code_point_so_far < new_code_point;
633 code_point_so_far += jump) {
634 jump = new_code_point - code_point_so_far;
635 relocInfo filler = filler_relocInfo();
636 if (jump >= filler.addr_offset()) {
637 jump = filler.addr_offset();
638 } else { // else shrink the filler to fit
639 filler = relocInfo(relocInfo::none, jump);
640 }
641 if (buf != NULL) {
642 assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds");
643 *(relocInfo*)(buf+buf_offset) = filler;
644 }
645 buf_offset += sizeof(filler);
646 }
647
648 // Update code point and end to skip past this section:
649 csize_t last_code_point = code_end_so_far + cs->locs_point_off();
650 assert(code_point_so_far <= last_code_point, "sanity");
651 code_point_so_far = last_code_point; // advance past this guy's relocs
652 }
653 code_end_so_far += csize; // advance past this guy's instructions too
654
655 // Done with filler; emit the real relocations:
656 if (buf != NULL && lsize != 0) {
657 assert(buf_offset + lsize <= buf_limit, "target in bounds");
658 assert((uintptr_t)lstart % HeapWordSize == 0, "sane start");
659 if (buf_offset % HeapWordSize == 0) {
660 // Use wordwise copies if possible:
661 Copy::disjoint_words((HeapWord*)lstart,
662 (HeapWord*)(buf+buf_offset),
663 (lsize + HeapWordSize-1) / HeapWordSize);
664 } else {
665 Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize);
666 }
667 }
668 buf_offset += lsize;
669 }
670
671 // Align end of relocation info in target.
672 while (buf_offset % HeapWordSize != 0) {
673 if (buf != NULL) {
674 relocInfo padding = relocInfo(relocInfo::none, 0);
675 assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds");
676 *(relocInfo*)(buf+buf_offset) = padding;
677 }
678 buf_offset += sizeof(relocInfo);
679 }
680
681 assert(code_end_so_far == total_content_size(), "sanity");
682
683 // Account for index:
684 if (buf != NULL) {
685 RelocIterator::create_index(dest->relocation_begin(),
686 buf_offset / sizeof(relocInfo),
687 dest->relocation_end());
688 }
689
690 return buf_offset;
691 }
692
693 void CodeBuffer::copy_code_to(CodeBlob* dest_blob) {
694 #ifndef PRODUCT
695 if (PrintNMethods && (WizardMode || Verbose)) {
696 tty->print("done with CodeBuffer:");
697 ((CodeBuffer*)this)->print();
698 }
699 #endif //PRODUCT
700
701 CodeBuffer dest(dest_blob);
702 assert(dest_blob->content_size() >= total_content_size(), "good sizing");
703 this->compute_final_layout(&dest);
704 relocate_code_to(&dest);
705
706 // transfer strings and comments from buffer to blob
707 dest_blob->set_strings(_strings);
708
709 // Done moving code bytes; were they the right size?
710 assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity");
711
712 // Flush generated code
713 ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size());
714 }
715
716 // Move all my code into another code buffer. Consult applicable
717 // relocs to repair embedded addresses. The layout in the destination
718 // CodeBuffer is different to the source CodeBuffer: the destination
719 // CodeBuffer gets the final layout (consts, insts, stubs in order of
720 // ascending address).
721 void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
722 address dest_end = dest->_total_start + dest->_total_size;
723 address dest_filled = NULL;
724 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
725 // pull code out of each section
726 const CodeSection* cs = code_section(n);
727 if (cs->is_empty()) continue; // skip trivial section
728 CodeSection* dest_cs = dest->code_section(n);
729 assert(cs->size() == dest_cs->size(), "sanity");
730 csize_t usize = dest_cs->size();
731 csize_t wsize = align_size_up(usize, HeapWordSize);
732 assert(dest_cs->start() + wsize <= dest_end, "no overflow");
733 // Copy the code as aligned machine words.
734 // This may also include an uninitialized partial word at the end.
735 Copy::disjoint_words((HeapWord*)cs->start(),
736 (HeapWord*)dest_cs->start(),
737 wsize / HeapWordSize);
738
739 if (dest->blob() == NULL) {
740 // Destination is a final resting place, not just another buffer.
741 // Normalize uninitialized bytes in the final padding.
742 Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(),
743 Assembler::code_fill_byte());
744 }
745 // Keep track of the highest filled address
746 dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining());
747
748 assert(cs->locs_start() != (relocInfo*)badAddress,
749 "this section carries no reloc storage, but reloc was attempted");
750
751 // Make the new code copy use the old copy's relocations:
752 dest_cs->initialize_locs_from(cs);
753 }
754
755 // Do relocation after all sections are copied.
756 // This is necessary if the code uses constants in stubs, which are
757 // relocated when the corresponding instruction in the code (e.g., a
758 // call) is relocated. Stubs are placed behind the main code
759 // section, so that section has to be copied before relocating.
760 for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) {
761 // pull code out of each section
762 const CodeSection* cs = code_section(n);
763 if (cs->is_empty()) continue; // skip trivial section
764 CodeSection* dest_cs = dest->code_section(n);
765 { // Repair the pc relative information in the code after the move
766 RelocIterator iter(dest_cs);
767 while (iter.next()) {
768 iter.reloc()->fix_relocation_after_move(this, dest);
769 }
770 }
771 }
772
773 if (dest->blob() == NULL && dest_filled != NULL) {
774 // Destination is a final resting place, not just another buffer.
775 // Normalize uninitialized bytes in the final padding.
776 Copy::fill_to_bytes(dest_filled, dest_end - dest_filled,
777 Assembler::code_fill_byte());
778
779 }
780 }
781
782 csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
783 csize_t amount,
784 csize_t* new_capacity) {
785 csize_t new_total_cap = 0;
786
787 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
788 const CodeSection* sect = code_section(n);
789
790 if (!sect->is_empty()) {
791 // Compute initial padding; assign it to the previous section,
792 // even if it's empty (e.g. consts section can be empty).
793 // Cf. compute_final_layout
794 csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap;
795 if (padding != 0) {
796 new_total_cap += padding;
797 assert(n - 1 >= SECT_FIRST, "sanity");
798 new_capacity[n - 1] += padding;
799 }
800 }
801
802 csize_t exp = sect->size(); // 100% increase
803 if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase
804 if (sect == which_cs) {
805 if (exp < amount) exp = amount;
806 if (StressCodeBuffers) exp = amount; // expand only slightly
807 } else if (n == SECT_INSTS) {
808 // scale down inst increases to a more modest 25%
809 exp = 4*K + ((exp - 4*K) >> 2);
810 if (StressCodeBuffers) exp = amount / 2; // expand only slightly
811 } else if (sect->is_empty()) {
812 // do not grow an empty secondary section
813 exp = 0;
814 }
815 // Allow for inter-section slop:
816 exp += CodeSection::end_slop();
817 csize_t new_cap = sect->size() + exp;
818 if (new_cap < sect->capacity()) {
819 // No need to expand after all.
820 new_cap = sect->capacity();
821 }
822 new_capacity[n] = new_cap;
823 new_total_cap += new_cap;
824 }
825
826 return new_total_cap;
827 }
828
829 void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) {
830 #ifndef PRODUCT
831 if (PrintNMethods && (WizardMode || Verbose)) {
832 tty->print("expanding CodeBuffer:");
833 this->print();
834 }
835
836 if (StressCodeBuffers && blob() != NULL) {
837 static int expand_count = 0;
838 if (expand_count >= 0) expand_count += 1;
839 if (expand_count > 100 && is_power_of_2(expand_count)) {
840 tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count);
841 // simulate an occasional allocation failure:
842 free_blob();
843 }
844 }
845 #endif //PRODUCT
846
847 // Resizing must be allowed
848 {
849 if (blob() == NULL) return; // caller must check for blob == NULL
850 for (int n = 0; n < (int)SECT_LIMIT; n++) {
851 guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen");
852 }
853 }
854
855 // Figure new capacity for each section.
856 csize_t new_capacity[SECT_LIMIT];
857 csize_t new_total_cap
858 = figure_expanded_capacities(which_cs, amount, new_capacity);
859
860 // Create a new (temporary) code buffer to hold all the new data
861 CodeBuffer cb(name(), new_total_cap, 0);
862 if (cb.blob() == NULL) {
863 // Failed to allocate in code cache.
864 free_blob();
865 return;
866 }
867
868 // Create an old code buffer to remember which addresses used to go where.
869 // This will be useful when we do final assembly into the code cache,
870 // because we will need to know how to warp any internal address that
871 // has been created at any time in this CodeBuffer's past.
872 CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size);
873 bxp->take_over_code_from(this); // remember the old undersized blob
874 DEBUG_ONLY(this->_blob = NULL); // silence a later assert
875 bxp->_before_expand = this->_before_expand;
876 this->_before_expand = bxp;
877
878 // Give each section its required (expanded) capacity.
879 for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) {
880 CodeSection* cb_sect = cb.code_section(n);
881 CodeSection* this_sect = code_section(n);
882 if (new_capacity[n] == 0) continue; // already nulled out
883 if (n != SECT_INSTS) {
884 cb.initialize_section_size(cb_sect, new_capacity[n]);
885 }
886 assert(cb_sect->capacity() >= new_capacity[n], "big enough");
887 address cb_start = cb_sect->start();
888 cb_sect->set_end(cb_start + this_sect->size());
889 if (this_sect->mark() == NULL) {
890 cb_sect->clear_mark();
891 } else {
892 cb_sect->set_mark(cb_start + this_sect->mark_off());
893 }
894 }
895
896 // Move all the code and relocations to the new blob:
897 relocate_code_to(&cb);
898
899 // Copy the temporary code buffer into the current code buffer.
900 // Basically, do {*this = cb}, except for some control information.
901 this->take_over_code_from(&cb);
902 cb.set_blob(NULL);
903
904 // Zap the old code buffer contents, to avoid mistakenly using them.
905 debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size,
906 badCodeHeapFreeVal));
907
908 _decode_begin = NULL; // sanity
909
910 // Make certain that the new sections are all snugly inside the new blob.
911 verify_section_allocation();
912
913 #ifndef PRODUCT
914 if (PrintNMethods && (WizardMode || Verbose)) {
915 tty->print("expanded CodeBuffer:");
916 this->print();
917 }
918 #endif //PRODUCT
919 }
920
921 void CodeBuffer::take_over_code_from(CodeBuffer* cb) {
922 // Must already have disposed of the old blob somehow.
923 assert(blob() == NULL, "must be empty");
924 #ifdef ASSERT
925
926 #endif
927 // Take the new blob away from cb.
928 set_blob(cb->blob());
929 // Take over all the section pointers.
930 for (int n = 0; n < (int)SECT_LIMIT; n++) {
931 CodeSection* cb_sect = cb->code_section(n);
932 CodeSection* this_sect = code_section(n);
933 this_sect->take_over_code_from(cb_sect);
934 }
935 _overflow_arena = cb->_overflow_arena;
936 // Make sure the old cb won't try to use it or free it.
937 DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress);
938 }
939
940 void CodeBuffer::verify_section_allocation() {
941 address tstart = _total_start;
942 if (tstart == badAddress) return; // smashed by set_blob(NULL)
943 address tend = tstart + _total_size;
944 if (_blob != NULL) {
945
946 guarantee(tstart >= _blob->content_begin(), "sanity");
947 guarantee(tend <= _blob->content_end(), "sanity");
948 }
949 // Verify disjointness.
950 for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
951 CodeSection* sect = code_section(n);
952 if (!sect->is_allocated() || sect->is_empty()) continue;
953 guarantee((intptr_t)sect->start() % sect->alignment() == 0
954 || sect->is_empty() || _blob == NULL,
955 "start is aligned");
956 for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) {
957 CodeSection* other = code_section(m);
958 if (!other->is_allocated() || other == sect) continue;
959 guarantee(!other->contains(sect->start() ), "sanity");
960 // limit is an exclusive address and can be the start of another
961 // section.
962 guarantee(!other->contains(sect->limit() - 1), "sanity");
963 }
964 guarantee(sect->end() <= tend, "sanity");
965 guarantee(sect->end() <= sect->limit(), "sanity");
966 }
967 }
968
969 void CodeBuffer::log_section_sizes(const char* name) {
970 if (xtty != NULL) {
971 // log info about buffer usage
972 xtty->print_cr("<blob name='%s' size='%d'>", name, _total_size);
973 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
974 CodeSection* sect = code_section(n);
975 if (!sect->is_allocated() || sect->is_empty()) continue;
976 xtty->print_cr("<sect index='%d' size='" SIZE_FORMAT "' free='" SIZE_FORMAT "'/>",
977 n, sect->limit() - sect->start(), sect->limit() - sect->end());
978 }
979 xtty->print_cr("</blob>");
980 }
981 }
982
983 #ifndef PRODUCT
984
985 void CodeSection::dump() {
986 address ptr = start();
987 for (csize_t step; ptr < end(); ptr += step) {
988 step = end() - ptr;
989 if (step > jintSize * 4) step = jintSize * 4;
990 tty->print(PTR_FORMAT ": ", ptr);
991 while (step > 0) {
992 tty->print(" " PTR32_FORMAT, *(jint*)ptr);
993 ptr += jintSize;
994 }
995 tty->cr();
996 }
997 }
998
999
1000 void CodeSection::decode() {
1001 Disassembler::decode(start(), end());
1002 }
1003
1004
1005 void CodeBuffer::block_comment(intptr_t offset, const char * comment) {
1006 _strings.add_comment(offset, comment);
1007 }
1008
1009 const char* CodeBuffer::code_string(const char* str) {
1010 return _strings.add_string(str);
1011 }
1012
1013 class CodeString: public CHeapObj<mtCode> {
1014 private:
1015 friend class CodeStrings;
1016 const char * _string;
1017 CodeString* _next;
1018 intptr_t _offset;
1019
1020 ~CodeString() {
1021 assert(_next == NULL, "wrong interface for freeing list");
1022 os::free((void*)_string, mtCode);
1023 }
1024
1025 bool is_comment() const { return _offset >= 0; }
1026
1027 public:
1028 CodeString(const char * string, intptr_t offset = -1)
1029 : _next(NULL), _offset(offset) {
1030 _string = os::strdup(string, mtCode);
1031 }
1032
1033 const char * string() const { return _string; }
1034 intptr_t offset() const { assert(_offset >= 0, "offset for non comment?"); return _offset; }
1035 CodeString* next() const { return _next; }
1036
1037 void set_next(CodeString* next) { _next = next; }
1038
1039 CodeString* first_comment() {
1040 if (is_comment()) {
1041 return this;
1042 } else {
1043 return next_comment();
1044 }
1045 }
1046 CodeString* next_comment() const {
1047 CodeString* s = _next;
1048 while (s != NULL && !s->is_comment()) {
1049 s = s->_next;
1050 }
1051 return s;
1052 }
1053 };
1054
1055 CodeString* CodeStrings::find(intptr_t offset) const {
1056 CodeString* a = _strings->first_comment();
1057 while (a != NULL && a->offset() != offset) {
1058 a = a->next_comment();
1059 }
1060 return a;
1061 }
1062
1063 // Convenience for add_comment.
1064 CodeString* CodeStrings::find_last(intptr_t offset) const {
1065 CodeString* a = find(offset);
1066 if (a != NULL) {
1067 CodeString* c = NULL;
1068 while (((c = a->next_comment()) != NULL) && (c->offset() == offset)) {
1069 a = c;
1070 }
1071 }
1072 return a;
1073 }
1074
1075 void CodeStrings::add_comment(intptr_t offset, const char * comment) {
1076 CodeString* c = new CodeString(comment, offset);
1077 CodeString* inspos = (_strings == NULL) ? NULL : find_last(offset);
1078
1079 if (inspos) {
1080 // insert after already existing comments with same offset
1081 c->set_next(inspos->next());
1082 inspos->set_next(c);
1083 } else {
1084 // no comments with such offset, yet. Insert before anything else.
1085 c->set_next(_strings);
1086 _strings = c;
1087 }
1088 }
1089
1090 void CodeStrings::assign(CodeStrings& other) {
1091 _strings = other._strings;
1092 }
1093
1094 void CodeStrings::print_block_comment(outputStream* stream, intptr_t offset) const {
1095 if (_strings != NULL) {
1096 CodeString* c = find(offset);
1097 while (c && c->offset() == offset) {
1098 stream->bol();
1099 stream->print(" ;; ");
1100 stream->print_cr(c->string());
1101 c = c->next_comment();
1102 }
1103 }
1104 }
1105
1106
1107 void CodeStrings::free() {
1108 CodeString* n = _strings;
1109 while (n) {
1110 // unlink the node from the list saving a pointer to the next
1111 CodeString* p = n->next();
1112 n->set_next(NULL);
1113 delete n;
1114 n = p;
1115 }
1116 _strings = NULL;
1117 }
1118
1119 const char* CodeStrings::add_string(const char * string) {
1120 CodeString* s = new CodeString(string);
1121 s->set_next(_strings);
1122 _strings = s;
1123 return s->string();
1124 }
1125
1126 void CodeBuffer::decode() {
1127 ttyLocker ttyl;
1128 Disassembler::decode(decode_begin(), insts_end());
1129 _decode_begin = insts_end();
1130 }
1131
1132
1133 void CodeBuffer::skip_decode() {
1134 _decode_begin = insts_end();
1135 }
1136
1137
1138 void CodeBuffer::decode_all() {
1139 ttyLocker ttyl;
1140 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1141 // dump contents of each section
1142 CodeSection* cs = code_section(n);
1143 tty->print_cr("! %s:", code_section_name(n));
1144 if (cs != consts())
1145 cs->decode();
1146 else
1147 cs->dump();
1148 }
1149 }
1150
1151
1152 void CodeSection::print(const char* name) {
1153 csize_t locs_size = locs_end() - locs_start();
1154 tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s",
1155 name, start(), end(), limit(), size(), capacity(),
1156 is_frozen()? " [frozen]": "");
1157 tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d",
1158 name, locs_start(), locs_end(), locs_limit(), locs_size, locs_capacity(), locs_point_off());
1159 if (PrintRelocations) {
1160 RelocIterator iter(this);
1161 iter.print();
1162 }
1163 }
1164
1165 void CodeBuffer::print() {
1166 if (this == NULL) {
1167 tty->print_cr("NULL CodeBuffer pointer");
1168 return;
1169 }
1170
1171 tty->print_cr("CodeBuffer:");
1172 for (int n = 0; n < (int)SECT_LIMIT; n++) {
1173 // print each section
1174 CodeSection* cs = code_section(n);
1175 cs->print(code_section_name(n));
1176 }
1177 }
1178
1179 #endif // PRODUCT