1 /*
2 * Copyright (c) 2019, 2025, 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 "cds/archiveBuilder.hpp"
26 #include "cds/archiveHeapLoader.inline.hpp"
27 #include "cds/archiveUtils.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/classListParser.hpp"
30 #include "cds/classListWriter.hpp"
31 #include "cds/dynamicArchive.hpp"
32 #include "cds/filemap.hpp"
33 #include "cds/heapShared.hpp"
34 #include "cds/lambdaProxyClassDictionary.hpp"
35 #include "cds/metaspaceShared.hpp"
36 #include "classfile/classLoader.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/vmClasses.hpp"
39 #include "interpreter/bootstrapInfo.hpp"
40 #include "memory/metaspaceUtils.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "oops/compressedOops.inline.hpp"
43 #include "oops/klass.inline.hpp"
44 #include "runtime/arguments.hpp"
45 #include "utilities/bitMap.inline.hpp"
46 #include "utilities/debug.hpp"
47 #include "utilities/formatBuffer.hpp"
48 #include "utilities/globalDefinitions.hpp"
49 #include "utilities/spinYield.hpp"
50
51 CHeapBitMap* ArchivePtrMarker::_ptrmap = nullptr;
52 CHeapBitMap* ArchivePtrMarker::_rw_ptrmap = nullptr;
53 CHeapBitMap* ArchivePtrMarker::_ro_ptrmap = nullptr;
54 CHeapBitMap* ArchivePtrMarker::_cc_ptrmap = nullptr;
55 VirtualSpace* ArchivePtrMarker::_vs;
56
57 bool ArchivePtrMarker::_compacted;
58
59 void ArchivePtrMarker::initialize(CHeapBitMap* ptrmap, VirtualSpace* vs) {
60 assert(_ptrmap == nullptr, "initialize only once");
61 assert(_rw_ptrmap == nullptr, "initialize only once");
62 assert(_ro_ptrmap == nullptr, "initialize only once");
63 assert(_cc_ptrmap == nullptr, "initialize only once");
64 _vs = vs;
65 _compacted = false;
66 _ptrmap = ptrmap;
67
68 // Use this as initial guesstimate. We should need less space in the
69 // archive, but if we're wrong the bitmap will be expanded automatically.
70 size_t estimated_archive_size = MetaspaceGC::capacity_until_GC();
71 // But set it smaller in debug builds so we always test the expansion code.
72 // (Default archive is about 12MB).
73 DEBUG_ONLY(estimated_archive_size = 6 * M);
74
75 // We need one bit per pointer in the archive.
76 _ptrmap->initialize(estimated_archive_size / sizeof(intptr_t));
77 }
78
79 void ArchivePtrMarker::initialize_rw_ro_cc_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap, CHeapBitMap* cc_ptrmap) {
80 address* buff_bottom = (address*)ArchiveBuilder::current()->buffer_bottom();
81 address* rw_bottom = (address*)ArchiveBuilder::current()->rw_region()->base();
82 address* ro_bottom = (address*)ArchiveBuilder::current()->ro_region()->base();
83 address* cc_bottom = (address*)ArchiveBuilder::current()->cc_region()->base();
84
85 // The bit in _ptrmap that cover the very first word in the rw/ro/cc regions.
86 size_t rw_start = rw_bottom - buff_bottom;
87 size_t ro_start = ro_bottom - buff_bottom;
88 size_t cc_start = cc_bottom - buff_bottom;
89
90 // The number of bits used by the rw/ro ptrmaps. We might have lots of zero
91 // bits at the bottom and top of rw/ro ptrmaps, but these zeros will be
92 // removed by FileMapInfo::write_bitmap_region().
93 size_t rw_size = ArchiveBuilder::current()->rw_region()->used() / sizeof(address);
94 size_t ro_size = ArchiveBuilder::current()->ro_region()->used() / sizeof(address);
95 size_t cc_size = ArchiveBuilder::current()->cc_region()->used() / sizeof(address);
96
97 // The last (exclusive) bit in _ptrmap that covers the rw/ro regions.
98 // Note: _ptrmap is dynamically expanded only when an actual pointer is written, so
99 // it may not be as large as we want.
100 size_t rw_end = MIN2<size_t>(rw_start + rw_size, _ptrmap->size());
101 size_t ro_end = MIN2<size_t>(ro_start + ro_size, _ptrmap->size());
102 size_t cc_end = MIN2<size_t>(cc_start + cc_size, _ptrmap->size());
103
104 rw_ptrmap->initialize(rw_size);
105 ro_ptrmap->initialize(ro_size);
106 cc_ptrmap->initialize(cc_size);
107
108 for (size_t rw_bit = rw_start; rw_bit < rw_end; rw_bit++) {
109 rw_ptrmap->at_put(rw_bit - rw_start, _ptrmap->at(rw_bit));
110 }
111
112 for(size_t ro_bit = ro_start; ro_bit < ro_end; ro_bit++) {
113 ro_ptrmap->at_put(ro_bit - ro_start, _ptrmap->at(ro_bit));
114 }
115
116 for (size_t cc_bit = cc_start; cc_bit < cc_end; cc_bit++) {
117 cc_ptrmap->at_put(cc_bit - cc_start, _ptrmap->at(cc_bit));
118 }
119
120 _rw_ptrmap = rw_ptrmap;
121 _ro_ptrmap = ro_ptrmap;
122 _cc_ptrmap = cc_ptrmap;
123 }
124
125 void ArchivePtrMarker::mark_pointer(address* ptr_loc) {
126 assert(_ptrmap != nullptr, "not initialized");
127 assert(!_compacted, "cannot mark anymore");
128
129 if (ptr_base() <= ptr_loc && ptr_loc < ptr_end()) {
130 address value = *ptr_loc;
131 // We don't want any pointer that points to very bottom of the archive, otherwise when
132 // MetaspaceShared::default_base_address()==0, we can't distinguish between a pointer
133 // to nothing (null) vs a pointer to an objects that happens to be at the very bottom
134 // of the archive.
135 assert(value != (address)ptr_base(), "don't point to the bottom of the archive");
136
137 if (value != nullptr) {
138 assert(uintx(ptr_loc) % sizeof(intptr_t) == 0, "pointers must be stored in aligned addresses");
139 size_t idx = ptr_loc - ptr_base();
140 if (_ptrmap->size() <= idx) {
141 _ptrmap->resize((idx + 1) * 2);
142 }
143 assert(idx < _ptrmap->size(), "must be");
144 _ptrmap->set_bit(idx);
145 //tty->print_cr("Marking pointer [" PTR_FORMAT "] -> " PTR_FORMAT " @ %5zu", p2i(ptr_loc), p2i(*ptr_loc), idx);
146 }
147 }
148 }
149
150 void ArchivePtrMarker::clear_pointer(address* ptr_loc) {
151 assert(_ptrmap != nullptr, "not initialized");
152 assert(!_compacted, "cannot clear anymore");
153
154 assert(ptr_base() <= ptr_loc && ptr_loc < ptr_end(), "must be");
155 assert(uintx(ptr_loc) % sizeof(intptr_t) == 0, "pointers must be stored in aligned addresses");
156 size_t idx = ptr_loc - ptr_base();
157 assert(idx < _ptrmap->size(), "cannot clear pointers that have not been marked");
158 _ptrmap->clear_bit(idx);
159 //tty->print_cr("Clearing pointer [" PTR_FORMAT "] -> " PTR_FORMAT " @ %5zu", p2i(ptr_loc), p2i(*ptr_loc), idx);
160 }
161
162 class ArchivePtrBitmapCleaner: public BitMapClosure {
163 CHeapBitMap* _ptrmap;
164 address* _ptr_base;
165 address _relocatable_base;
166 address _relocatable_end;
167 size_t _max_non_null_offset;
168
169 public:
170 ArchivePtrBitmapCleaner(CHeapBitMap* ptrmap, address* ptr_base, address relocatable_base, address relocatable_end) :
171 _ptrmap(ptrmap), _ptr_base(ptr_base),
172 _relocatable_base(relocatable_base), _relocatable_end(relocatable_end), _max_non_null_offset(0) {}
173
174 bool do_bit(size_t offset) {
175 address* ptr_loc = _ptr_base + offset;
176 address ptr_value = *ptr_loc;
177 if (ptr_value != nullptr) {
178 assert(_relocatable_base <= ptr_value && ptr_value < _relocatable_end, "do not point to arbitrary locations!");
179 if (_max_non_null_offset < offset) {
180 _max_non_null_offset = offset;
181 }
182 } else {
183 _ptrmap->clear_bit(offset);
184 DEBUG_ONLY(log_trace(cds, reloc)("Clearing pointer [" PTR_FORMAT "] -> null @ %9zu", p2i(ptr_loc), offset));
185 }
186
187 return true;
188 }
189
190 size_t max_non_null_offset() const { return _max_non_null_offset; }
191 };
192
193 void ArchivePtrMarker::compact(address relocatable_base, address relocatable_end) {
194 assert(!_compacted, "cannot compact again");
195 ArchivePtrBitmapCleaner cleaner(_ptrmap, ptr_base(), relocatable_base, relocatable_end);
196 _ptrmap->iterate(&cleaner);
197 compact(cleaner.max_non_null_offset());
198 }
199
200 void ArchivePtrMarker::compact(size_t max_non_null_offset) {
201 assert(!_compacted, "cannot compact again");
202 _ptrmap->resize(max_non_null_offset + 1);
203 _compacted = true;
204 }
205
206 char* DumpRegion::expand_top_to(char* newtop) {
207 assert(is_allocatable(), "must be initialized and not packed");
208 assert(newtop >= _top, "must not grow backwards");
209 if (newtop > _end) {
210 ArchiveBuilder::current()->report_out_of_space(_name, newtop - _top);
211 ShouldNotReachHere();
212 }
213
214 commit_to(newtop);
215 _top = newtop;
216
217 if (_max_delta > 0) {
218 uintx delta = ArchiveBuilder::current()->buffer_to_offset((address)(newtop-1));
219 if (delta > _max_delta) {
220 // This is just a sanity check and should not appear in any real world usage. This
221 // happens only if you allocate more than 2GB of shared objects and would require
222 // millions of shared classes.
223 log_error(cds)("Out of memory in the CDS archive: Please reduce the number of shared classes.");
224 MetaspaceShared::unrecoverable_writing_error();
225 }
226 }
227
228 return _top;
229 }
230
231 void DumpRegion::commit_to(char* newtop) {
232 assert(CDSConfig::is_dumping_archive(), "sanity");
233 char* base = _rs->base();
234 size_t need_committed_size = newtop - base;
235 size_t has_committed_size = _vs->committed_size();
236 if (need_committed_size < has_committed_size) {
237 return;
238 }
239
240 size_t min_bytes = need_committed_size - has_committed_size;
241 size_t preferred_bytes = 1 * M;
242 size_t uncommitted = _vs->reserved_size() - has_committed_size;
243
244 size_t commit = MAX2(min_bytes, preferred_bytes);
245 commit = MIN2(commit, uncommitted);
246 assert(commit <= uncommitted, "sanity");
247
248 if (!_vs->expand_by(commit, false)) {
249 log_error(cds)("Failed to expand shared space to %zu bytes",
250 need_committed_size);
251 MetaspaceShared::unrecoverable_writing_error();
252 }
253
254 const char* which;
255 if (_rs->base() == (char*)MetaspaceShared::symbol_rs_base()) {
256 which = "symbol";
257 } else {
258 which = "shared";
259 }
260 log_debug(cds)("Expanding %s spaces by %7zu bytes [total %9zu bytes ending at %p]",
261 which, commit, _vs->actual_committed_size(), _vs->high());
262 }
263
264 char* DumpRegion::allocate(size_t num_bytes, size_t alignment) {
265 // Always align to at least minimum alignment
266 alignment = MAX2(SharedSpaceObjectAlignment, alignment);
267 char* p = (char*)align_up(_top, alignment);
268 char* newtop = p + align_up(num_bytes, (size_t)SharedSpaceObjectAlignment);
269 expand_top_to(newtop);
270 memset(p, 0, newtop - p);
271 return p;
272 }
273
274 void DumpRegion::append_intptr_t(intptr_t n, bool need_to_mark) {
275 assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
276 intptr_t *p = (intptr_t*)_top;
277 char* newtop = _top + sizeof(intptr_t);
278 expand_top_to(newtop);
279 *p = n;
280 if (need_to_mark) {
281 ArchivePtrMarker::mark_pointer(p);
282 }
283 }
284
285 void DumpRegion::print(size_t total_bytes) const {
286 char* base = used() > 0 ? ArchiveBuilder::current()->to_requested(_base) : nullptr;
287 log_debug(cds)("%s space: %9zu [ %4.1f%% of total] out of %9zu bytes [%5.1f%% used] at " INTPTR_FORMAT,
288 _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()),
289 p2i(base));
290 }
291
292 void DumpRegion::print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
293 log_error(cds)("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
294 _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
295 if (strcmp(_name, failing_region) == 0) {
296 log_error(cds)(" required = %d", int(needed_bytes));
297 }
298 }
299
300 void DumpRegion::init(ReservedSpace* rs, VirtualSpace* vs) {
301 _rs = rs;
302 _vs = vs;
303 // Start with 0 committed bytes. The memory will be committed as needed.
304 if (!_vs->initialize(*_rs, 0)) {
305 fatal("Unable to allocate memory for shared space");
306 }
307 _base = _top = _rs->base();
308 _end = _rs->end();
309 }
310
311 void DumpRegion::pack(DumpRegion* next) {
312 if (!is_packed()) {
313 _end = (char*)align_up(_top, MetaspaceShared::core_region_alignment());
314 _is_packed = true;
315 }
316 if (next != nullptr) {
317 next->_rs = _rs;
318 next->_vs = _vs;
319 next->_base = next->_top = this->_end;
320 next->_end = _rs->end();
321 }
322 }
323
324 void WriteClosure::do_ptr(void** p) {
325 // Write ptr into the archive; ptr can be:
326 // (a) null -> written as 0
327 // (b) a "buffered" address -> written as is
328 // (c) a "source" address -> convert to "buffered" and write
329 // The common case is (c). E.g., when writing the vmClasses into the archive.
330 // We have (b) only when we don't have a corresponding source object. E.g.,
331 // the archived c++ vtable entries.
332 address ptr = *(address*)p;
333 if (ptr != nullptr && !ArchiveBuilder::current()->is_in_buffer_space(ptr)) {
334 ptr = ArchiveBuilder::current()->get_buffered_addr(ptr);
335 }
336 // null pointers do not need to be converted to offsets
337 if (ptr != nullptr) {
338 ptr = (address)ArchiveBuilder::current()->buffer_to_offset(ptr);
339 }
340 _dump_region->append_intptr_t((intptr_t)ptr, false);
341 }
342
343 void ReadClosure::do_ptr(void** p) {
344 assert(*p == nullptr, "initializing previous initialized pointer.");
345 intptr_t obj = nextPtr();
346 assert(obj >= 0, "sanity.");
347 *p = (obj != 0) ? (void*)(_base_address + obj) : (void*)obj;
348 }
349
350 void ReadClosure::do_u4(u4* p) {
351 intptr_t obj = nextPtr();
352 *p = (u4)(uintx(obj));
353 }
354
355 void ReadClosure::do_int(int* p) {
356 intptr_t obj = nextPtr();
357 *p = (int)(intx(obj));
358 }
359
360 void ReadClosure::do_bool(bool* p) {
361 intptr_t obj = nextPtr();
362 *p = (bool)(uintx(obj));
363 }
364
365 void ReadClosure::do_tag(int tag) {
366 int old_tag;
367 old_tag = (int)(intptr_t)nextPtr();
368 // do_int(&old_tag);
369 assert(tag == old_tag, "tag doesn't match (%d, expected %d)", old_tag, tag);
370 FileMapInfo::assert_mark(tag == old_tag);
371 }
372
373 void ArchiveUtils::log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) {
374 if (ClassListWriter::is_enabled()) {
375 if (LambdaProxyClassDictionary::is_supported_invokedynamic(bootstrap_specifier)) {
376 const constantPoolHandle& pool = bootstrap_specifier->pool();
377 if (SystemDictionaryShared::is_builtin_loader(pool->pool_holder()->class_loader_data())) {
378 // Currently lambda proxy classes are supported only for the built-in loaders.
379 ResourceMark rm(THREAD);
380 int pool_index = bootstrap_specifier->bss_index();
381 ClassListWriter w;
382 w.stream()->print("%s %s", ClassListParser::lambda_proxy_tag(), pool->pool_holder()->name()->as_C_string());
383 CDSIndyInfo cii;
384 ClassListParser::populate_cds_indy_info(pool, pool_index, &cii, CHECK);
385 GrowableArray<const char*>* indy_items = cii.items();
386 for (int i = 0; i < indy_items->length(); i++) {
387 w.stream()->print(" %s", indy_items->at(i));
388 }
389 w.stream()->cr();
390 }
391 }
392 }
393 }
394
395
396 // "boot", "platform", "app" or nullptr
397 const char* ArchiveUtils::builtin_loader_name_or_null(oop loader) {
398 if (loader == nullptr) {
399 return "boot";
400 } else if (loader == SystemDictionary::java_platform_loader()) {
401 return "platform";
402 } else if (loader == SystemDictionary::java_system_loader()) {
403 return "app";
404 } else {
405 return nullptr;
406 }
407 }
408
409 // "boot", "platform", "app". Asserts if not a built-in-loader
410 const char* ArchiveUtils::builtin_loader_name(oop loader) {
411 const char* name = builtin_loader_name_or_null(loader);
412 assert(name != nullptr, "must be a built-in loader");
413 return name;
414 }
415
416 bool ArchiveUtils::builtin_loader_from_type(const char* loader_type, oop* value_ret) {
417 if (strcmp(loader_type, "boot") == 0) {
418 *value_ret = nullptr;
419 return true;
420 } else if (strcmp(loader_type, "platform") == 0) {
421 *value_ret = SystemDictionary::java_platform_loader();
422 return true;
423 } else if (strcmp(loader_type, "app") == 0) {
424 *value_ret = SystemDictionary::java_system_loader();
425 return true;
426 } else {
427 DEBUG_ONLY(*value_ret = cast_to_oop((void*)badOopVal));
428 return false;
429 }
430 }
431
432 oop ArchiveUtils::builtin_loader_from_type(int loader_type) {
433 if (loader_type == ClassLoader::BOOT_LOADER) {
434 return nullptr;
435 } else if (loader_type == ClassLoader::PLATFORM_LOADER) {
436 return SystemDictionary::java_platform_loader();
437 } else if (loader_type == ClassLoader::APP_LOADER) {
438 return SystemDictionary::java_system_loader();
439 } else {
440 ShouldNotReachHere();
441 return nullptr;
442 }
443 }
444
445 bool ArchiveUtils::has_aot_initialized_mirror(InstanceKlass* src_ik) {
446 if (SystemDictionaryShared::is_excluded_class(src_ik)) {
447 assert(!ArchiveBuilder::current()->has_been_buffered(src_ik), "sanity");
448 return false;
449 }
450 return ArchiveBuilder::current()->get_buffered_addr(src_ik)->has_aot_initialized_mirror();
451 }
452
453 size_t HeapRootSegments::size_in_bytes(size_t seg_idx) {
454 assert(seg_idx < _count, "In range");
455 return objArrayOopDesc::object_size(size_in_elems(seg_idx)) * HeapWordSize;
456 }
457
458 int HeapRootSegments::size_in_elems(size_t seg_idx) {
459 assert(seg_idx < _count, "In range");
460 if (seg_idx != _count - 1) {
461 return _max_size_in_elems;
462 } else {
463 // Last slice, leftover
464 return _roots_count % _max_size_in_elems;
465 }
466 }
467
468 size_t HeapRootSegments::segment_offset(size_t seg_idx) {
469 assert(seg_idx < _count, "In range");
470 return _base_offset + seg_idx * _max_size_in_bytes;
471 }
472
473 ArchiveWorkers::ArchiveWorkers() :
474 _end_semaphore(0),
475 _num_workers(max_workers()),
476 _started_workers(0),
477 _finish_tokens(0),
478 _state(UNUSED),
479 _task(nullptr) {}
480
481 ArchiveWorkers::~ArchiveWorkers() {
482 assert(Atomic::load(&_state) != WORKING, "Should not be working");
483 }
484
485 int ArchiveWorkers::max_workers() {
486 // The pool is used for short-lived bursty tasks. We do not want to spend
487 // too much time creating and waking up threads unnecessarily. Plus, we do
488 // not want to overwhelm large machines. This is why we want to be very
489 // conservative about the number of workers actually needed.
490 return MAX2(0, log2i_graceful(os::active_processor_count()));
491 }
492
493 bool ArchiveWorkers::is_parallel() {
494 return _num_workers > 0;
495 }
496
497 void ArchiveWorkers::start_worker_if_needed() {
498 while (true) {
499 int cur = Atomic::load(&_started_workers);
500 if (cur >= _num_workers) {
501 return;
502 }
503 if (Atomic::cmpxchg(&_started_workers, cur, cur + 1, memory_order_relaxed) == cur) {
504 new ArchiveWorkerThread(this);
505 return;
506 }
507 }
508 }
509
510 void ArchiveWorkers::run_task(ArchiveWorkerTask* task) {
511 assert(Atomic::load(&_state) == UNUSED, "Should be unused yet");
512 assert(Atomic::load(&_task) == nullptr, "Should not have running tasks");
513 Atomic::store(&_state, WORKING);
514
515 if (is_parallel()) {
516 run_task_multi(task);
517 } else {
518 run_task_single(task);
519 }
520
521 assert(Atomic::load(&_state) == WORKING, "Should be working");
522 Atomic::store(&_state, SHUTDOWN);
523 }
524
525 void ArchiveWorkers::run_task_single(ArchiveWorkerTask* task) {
526 // Single thread needs no chunking.
527 task->configure_max_chunks(1);
528
529 // Execute the task ourselves, as there are no workers.
530 task->work(0, 1);
531 }
532
533 void ArchiveWorkers::run_task_multi(ArchiveWorkerTask* task) {
534 // Multiple threads can work with multiple chunks.
535 task->configure_max_chunks(_num_workers * CHUNKS_PER_WORKER);
536
537 // Set up the run and publish the task. Issue one additional finish token
538 // to cover the semaphore shutdown path, see below.
539 Atomic::store(&_finish_tokens, _num_workers + 1);
540 Atomic::release_store(&_task, task);
541
542 // Kick off pool startup by starting a single worker, and proceed
543 // immediately to executing the task locally.
544 start_worker_if_needed();
545
546 // Execute the task ourselves, while workers are catching up.
547 // This allows us to hide parts of task handoff latency.
548 task->run();
549
550 // Done executing task locally, wait for any remaining workers to complete.
551 // Once all workers report, we can proceed to termination. To do this safely,
552 // we need to make sure every worker has left. A spin-wait alone would suffice,
553 // but we do not want to burn cycles on it. A semaphore alone would not be safe,
554 // since workers can still be inside it as we proceed from wait here. So we block
555 // on semaphore first, and then spin-wait for all workers to terminate.
556 _end_semaphore.wait();
557 SpinYield spin;
558 while (Atomic::load(&_finish_tokens) != 0) {
559 spin.wait();
560 }
561
562 OrderAccess::fence();
563
564 assert(Atomic::load(&_finish_tokens) == 0, "All tokens are consumed");
565 }
566
567 void ArchiveWorkers::run_as_worker() {
568 assert(is_parallel(), "Should be in parallel mode");
569
570 ArchiveWorkerTask* task = Atomic::load_acquire(&_task);
571 task->run();
572
573 // All work done in threads should be visible to caller.
574 OrderAccess::fence();
575
576 // Signal the pool the work is complete, and we are exiting.
577 // Worker cannot do anything else with the pool after this.
578 if (Atomic::sub(&_finish_tokens, 1, memory_order_relaxed) == 1) {
579 // Last worker leaving. Notify the pool it can unblock to spin-wait.
580 // Then consume the last token and leave.
581 _end_semaphore.signal();
582 int last = Atomic::sub(&_finish_tokens, 1, memory_order_relaxed);
583 assert(last == 0, "Should be");
584 }
585 }
586
587 void ArchiveWorkerTask::run() {
588 while (true) {
589 int chunk = Atomic::load(&_chunk);
590 if (chunk >= _max_chunks) {
591 return;
592 }
593 if (Atomic::cmpxchg(&_chunk, chunk, chunk + 1, memory_order_relaxed) == chunk) {
594 assert(0 <= chunk && chunk < _max_chunks, "Sanity");
595 work(chunk, _max_chunks);
596 }
597 }
598 }
599
600 void ArchiveWorkerTask::configure_max_chunks(int max_chunks) {
601 if (_max_chunks == 0) {
602 _max_chunks = max_chunks;
603 }
604 }
605
606 ArchiveWorkerThread::ArchiveWorkerThread(ArchiveWorkers* pool) : NamedThread(), _pool(pool) {
607 set_name("ArchiveWorkerThread");
608 if (os::create_thread(this, os::os_thread)) {
609 os::start_thread(this);
610 } else {
611 vm_exit_during_initialization("Unable to create archive worker",
612 os::native_thread_creation_failed_msg());
613 }
614 }
615
616 void ArchiveWorkerThread::run() {
617 // Avalanche startup: each worker starts two others.
618 _pool->start_worker_if_needed();
619 _pool->start_worker_if_needed();
620
621 // Set ourselves up.
622 os::set_priority(this, NearMaxPriority);
623
624 // Work.
625 _pool->run_as_worker();
626 }
627
628 void ArchiveWorkerThread::post_run() {
629 this->NamedThread::post_run();
630 delete this;
631 }