1 /*
2 * Copyright (c) 2012, 2017, 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 "classfile/classListParser.hpp"
27 #include "classfile/classLoaderExt.hpp"
28 #include "classfile/dictionary.hpp"
29 #include "classfile/loaderConstraints.hpp"
30 #include "classfile/placeholders.hpp"
31 #include "classfile/sharedClassUtil.hpp"
32 #include "classfile/symbolTable.hpp"
33 #include "classfile/stringTable.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "code/codeCache.hpp"
37 #if INCLUDE_ALL_GCS
38 #include "gc/g1/g1Allocator.inline.hpp"
39 #include "gc/g1/g1CollectedHeap.hpp"
40 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
41 #endif
42 #include "gc/shared/gcLocker.hpp"
43 #include "interpreter/bytecodeStream.hpp"
44 #include "interpreter/bytecodes.hpp"
45 #include "logging/log.hpp"
46 #include "logging/logMessage.hpp"
47 #include "memory/filemap.hpp"
48 #include "memory/metaspace.hpp"
49 #include "memory/metaspaceShared.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "oops/instanceClassLoaderKlass.hpp"
52 #include "oops/instanceMirrorKlass.hpp"
53 #include "oops/instanceRefKlass.hpp"
54 #include "oops/objArrayKlass.hpp"
55 #include "oops/objArrayOop.hpp"
56 #include "oops/oop.inline.hpp"
57 #include "oops/typeArrayKlass.hpp"
58 #include "prims/jvm.h"
59 #include "prims/jvmtiRedefineClasses.hpp"
60 #include "runtime/timerTrace.hpp"
61 #include "runtime/os.hpp"
62 #include "runtime/signature.hpp"
63 #include "runtime/vmThread.hpp"
64 #include "runtime/vm_operations.hpp"
65 #include "utilities/align.hpp"
66 #include "utilities/defaultStream.hpp"
67 #include "utilities/hashtable.inline.hpp"
68 #include "memory/metaspaceClosure.hpp"
69
70 ReservedSpace MetaspaceShared::_shared_rs;
71 VirtualSpace MetaspaceShared::_shared_vs;
72 MetaspaceSharedStats MetaspaceShared::_stats;
73 bool MetaspaceShared::_has_error_classes;
74 bool MetaspaceShared::_archive_loading_failed = false;
75 bool MetaspaceShared::_remapped_readwrite = false;
76 bool MetaspaceShared::_open_archive_heap_region_mapped = false;
77 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
78 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
79 size_t MetaspaceShared::_core_spaces_size = 0;
80
81 // The CDS archive is divided into the following regions:
82 // mc - misc code (the method entry trampolines)
83 // rw - read-write metadata
84 // ro - read-only metadata and read-only tables
85 // md - misc data (the c++ vtables)
86 // od - optional data (original class files)
87 //
88 // s0 - shared strings(closed archive heap space) #0
89 // s1 - shared strings(closed archive heap space) #1 (may be empty)
90 // oa0 - open archive heap space #0
91 // oa1 - open archive heap space #1 (may be empty)
92 //
93 // The mc, rw, ro, md and od regions are linearly allocated, starting from
94 // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions
95 // are page-aligned, and there's no gap between any consecutive regions.
96 //
97 // These 5 regions are populated in the following steps:
98 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
99 // temporarily allocated outside of the shared regions. Only the method entry
100 // trampolines are written into the mc region.
101 // [2] ArchiveCompactor copies RW metadata into the rw region.
102 // [3] ArchiveCompactor copies RO metadata into the ro region.
103 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
104 // are copied into the ro region as read-only tables.
105 // [5] C++ vtables are copied into the md region.
106 // [6] Original class files are copied into the od region.
107 //
108 // The s0/s1 and oa0/oa1 regions are populated inside MetaspaceShared::dump_java_heap_objects.
109 // Their layout is independent of the other 5 regions.
110
111 class DumpRegion {
112 private:
113 const char* _name;
114 char* _base;
115 char* _top;
116 char* _end;
117 bool _is_packed;
118
119 char* expand_top_to(char* newtop) {
120 assert(is_allocatable(), "must be initialized and not packed");
121 assert(newtop >= _top, "must not grow backwards");
122 if (newtop > _end) {
123 MetaspaceShared::report_out_of_space(_name, newtop - _top);
124 ShouldNotReachHere();
125 }
126 MetaspaceShared::commit_shared_space_to(newtop);
127 _top = newtop;
128 return _top;
129 }
130
131 public:
132 DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
133
134 char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
135 char* p = (char*)align_up(_top, alignment);
136 char* newtop = p + align_up(num_bytes, alignment);
137 expand_top_to(newtop);
138 memset(p, 0, newtop - p);
139 return p;
140 }
141
142 void append_intptr_t(intptr_t n) {
143 assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
144 intptr_t *p = (intptr_t*)_top;
145 char* newtop = _top + sizeof(intptr_t);
146 expand_top_to(newtop);
147 *p = n;
148 }
149
150 char* base() const { return _base; }
151 char* top() const { return _top; }
152 char* end() const { return _end; }
153 size_t reserved() const { return _end - _base; }
154 size_t used() const { return _top - _base; }
155 bool is_packed() const { return _is_packed; }
156 bool is_allocatable() const {
157 return !is_packed() && _base != NULL;
158 }
159
160 double perc(size_t used, size_t total) const {
161 if (total == 0) {
162 total = 1;
163 }
164 return used / double(total) * 100.0;
165 }
166
167 void print(size_t total_bytes) const {
168 tty->print_cr("%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,
169 _name, used(), perc(used(), total_bytes), reserved(), perc(used(), reserved()), p2i(_base));
170 }
171 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
172 tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
173 _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
174 if (strcmp(_name, failing_region) == 0) {
175 tty->print_cr(" required = %d", int(needed_bytes));
176 } else {
177 tty->cr();
178 }
179 }
180
181 void init(const ReservedSpace* rs) {
182 _base = _top = rs->base();
183 _end = rs->end();
184 }
185 void init(char* b, char* t, char* e) {
186 _base = b;
187 _top = t;
188 _end = e;
189 }
190
191 void pack(DumpRegion* next = NULL) {
192 assert(!is_packed(), "sanity");
193 _end = (char*)align_up(_top, Metaspace::reserve_alignment());
194 _is_packed = true;
195 if (next != NULL) {
196 next->_base = next->_top = this->_end;
197 next->_end = MetaspaceShared::shared_rs()->end();
198 }
199 }
200 bool contains(char* p) {
201 return base() <= p && p < top();
202 }
203 };
204
205
206 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
207 size_t _total_string_region_size = 0, _total_open_archive_region_size = 0;
208
209 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
210 return _mc_region.allocate(num_bytes);
211 }
212
213 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
214 return _ro_region.allocate(num_bytes);
215 }
216
217 void MetaspaceShared::initialize_shared_rs() {
218 const size_t reserve_alignment = Metaspace::reserve_alignment();
219 bool large_pages = false; // No large pages when dumping the CDS archive.
220 char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
221
222 #ifdef _LP64
223 // On 64-bit VM, the heap and class space layout will be the same as if
224 // you're running in -Xshare:on mode:
225 //
226 // +-- SharedBaseAddress (default = 0x800000000)
227 // v
228 // +-..---------+----+ ... +----+----+----+----+----+---------------+
229 // | Heap | ST | | MC | RW | RO | MD | OD | class space |
230 // +-..---------+----+ ... +----+----+----+----+----+---------------+
231 // |<--MaxHeapSize->| |<-- UnscaledClassSpaceMax = 4GB ------->|
232 //
233 const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
234 const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
235 #else
236 // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
237 size_t cds_total = align_down(256*M, reserve_alignment);
238 #endif
239
240 // First try to reserve the space at the specified SharedBaseAddress.
241 _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
242 if (_shared_rs.is_reserved()) {
243 assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
244 } else {
245 // Get a mmap region anywhere if the SharedBaseAddress fails.
246 _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
247 }
248 if (!_shared_rs.is_reserved()) {
249 vm_exit_during_initialization("Unable to reserve memory for shared space",
250 err_msg(SIZE_FORMAT " bytes.", cds_total));
251 }
252
253 #ifdef _LP64
254 // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
255 // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
256 // will store Klasses into this space.
257 // + The lower 3 GB is used for the archive -- when preload_classes() is done,
258 // ArchiveCompactor will copy the class metadata into this space, first the RW parts,
259 // then the RO parts.
260
261 assert(UseCompressedOops && UseCompressedClassPointers,
262 "UseCompressedOops and UseCompressedClassPointers must be set");
263
264 size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
265 ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
266 CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
267 _shared_rs = _shared_rs.first_part(max_archive_size);
268
269 // Set up compress class pointers.
270 Universe::set_narrow_klass_base((address)_shared_rs.base());
271 if (UseAOT || cds_total > UnscaledClassSpaceMax) {
272 // AOT forces narrow_klass_shift=LogKlassAlignmentInBytes
273 Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
274 } else {
275 Universe::set_narrow_klass_shift(0);
276 }
277
278 Metaspace::initialize_class_space(tmp_class_space);
279 tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
280 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
281
282 tty->print_cr("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
283 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
284 #endif
285
286 // Start with 0 committed bytes. The memory will be committed as needed by
287 // MetaspaceShared::commit_shared_space_to().
288 if (!_shared_vs.initialize(_shared_rs, 0)) {
289 vm_exit_during_initialization("Unable to allocate memory for shared space");
290 }
291
292 _mc_region.init(&_shared_rs);
293 tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
294 _shared_rs.size(), p2i(_shared_rs.base()));
295 }
296
297 void MetaspaceShared::commit_shared_space_to(char* newtop) {
298 assert(DumpSharedSpaces, "dump-time only");
299 char* base = _shared_rs.base();
300 size_t need_committed_size = newtop - base;
301 size_t has_committed_size = _shared_vs.committed_size();
302 if (need_committed_size < has_committed_size) {
303 return;
304 }
305
306 size_t min_bytes = need_committed_size - has_committed_size;
307 size_t preferred_bytes = 1 * M;
308 size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
309
310 size_t commit = MAX2(min_bytes, preferred_bytes);
311 assert(commit <= uncommitted, "sanity");
312
313 bool result = _shared_vs.expand_by(commit, false);
314 if (!result) {
315 vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
316 need_committed_size));
317 }
318
319 log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9) " bytes ending at %p]",
320 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
321 }
322
323 // Read/write a data stream for restoring/preserving metadata pointers and
324 // miscellaneous data from/to the shared archive file.
325
326 void MetaspaceShared::serialize(SerializeClosure* soc) {
327 int tag = 0;
328 soc->do_tag(--tag);
329
330 // Verify the sizes of various metadata in the system.
331 soc->do_tag(sizeof(Method));
332 soc->do_tag(sizeof(ConstMethod));
333 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
334 soc->do_tag(sizeof(ConstantPool));
335 soc->do_tag(sizeof(ConstantPoolCache));
336 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
337 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
338 soc->do_tag(sizeof(Symbol));
339
340 // Dump/restore miscellaneous metadata.
341 Universe::serialize(soc, true);
342 soc->do_tag(--tag);
343
344 // Dump/restore references to commonly used names and signatures.
345 vmSymbols::serialize(soc);
346 soc->do_tag(--tag);
347
348 // Dump/restore the symbol and string tables
349 SymbolTable::serialize(soc);
350 StringTable::serialize(soc);
351 soc->do_tag(--tag);
352
353 soc->do_tag(666);
354 }
355
356 address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {
357 if (DumpSharedSpaces) {
358 if (_cds_i2i_entry_code_buffers == NULL) {
359 _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);
360 _cds_i2i_entry_code_buffers_size = total_size;
361 }
362 } else if (UseSharedSpaces) {
363 assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");
364 } else {
365 return NULL;
366 }
367
368 assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");
369 return _cds_i2i_entry_code_buffers;
370 }
371
372 // CDS code for dumping shared archive.
373
374 // Global object for holding classes that have been loaded. Since this
375 // is run at a safepoint just before exit, this is the entire set of classes.
376 static GrowableArray<Klass*>* _global_klass_objects;
377 class CollectClassesClosure : public KlassClosure {
378 void do_klass(Klass* k) {
379 if (!(k->is_instance_klass() && InstanceKlass::cast(k)->is_in_error_state())) {
380 _global_klass_objects->append_if_missing(k);
381 }
382 }
383 };
384
385 static void remove_unshareable_in_classes() {
386 for (int i = 0; i < _global_klass_objects->length(); i++) {
387 Klass* k = _global_klass_objects->at(i);
388 k->remove_unshareable_info();
389 }
390 }
391
392 static void rewrite_nofast_bytecode(Method* method) {
393 RawBytecodeStream bcs(method);
394 while (!bcs.is_last_bytecode()) {
395 Bytecodes::Code opcode = bcs.raw_next();
396 switch (opcode) {
397 case Bytecodes::_getfield: *bcs.bcp() = Bytecodes::_nofast_getfield; break;
398 case Bytecodes::_putfield: *bcs.bcp() = Bytecodes::_nofast_putfield; break;
399 case Bytecodes::_aload_0: *bcs.bcp() = Bytecodes::_nofast_aload_0; break;
400 case Bytecodes::_iload: {
401 if (!bcs.is_wide()) {
402 *bcs.bcp() = Bytecodes::_nofast_iload;
403 }
404 break;
405 }
406 default: break;
407 }
408 }
409 }
410
411 // Walk all methods in the class list to ensure that they won't be modified at
412 // run time. This includes:
413 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
414 // at run time by RewriteBytecodes/RewriteFrequentPairs
415 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
416 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
417 for (int i = 0; i < _global_klass_objects->length(); i++) {
418 Klass* k = _global_klass_objects->at(i);
419 if (k->is_instance_klass()) {
420 InstanceKlass* ik = InstanceKlass::cast(k);
421 for (int i = 0; i < ik->methods()->length(); i++) {
422 Method* m = ik->methods()->at(i);
423 rewrite_nofast_bytecode(m);
424 Fingerprinter fp(m);
425 // The side effect of this call sets method's fingerprint field.
426 fp.fingerprint();
427 }
428 }
429 }
430 }
431
432 static void relocate_cached_class_file() {
433 for (int i = 0; i < _global_klass_objects->length(); i++) {
434 Klass* k = _global_klass_objects->at(i);
435 if (k->is_instance_klass()) {
436 InstanceKlass* ik = InstanceKlass::cast(k);
437 JvmtiCachedClassFileData* p = ik->get_archived_class_data();
438 if (p != NULL) {
439 int size = offset_of(JvmtiCachedClassFileData, data) + p->length;
440 JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);
441 q->length = p->length;
442 memcpy(q->data, p->data, p->length);
443 ik->set_archived_class_data(q);
444 }
445 }
446 }
447 }
448
449 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
450 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
451 //
452 // Addresses of the vtables and the methods may be different across JVM runs,
453 // if libjvm.so is dynamically loaded at a different base address.
454 //
455 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
456 //
457 // + at dump time: we redirect the _vptr to point to our own vtables inside
458 // the CDS image
459 // + at run time: we clone the actual contents of the vtables from libjvm.so
460 // into our own tables.
461
462 // Currently, the archive contain ONLY the following types of objects that have C++ vtables.
463 #define CPP_VTABLE_PATCH_TYPES_DO(f) \
464 f(ConstantPool) \
465 f(InstanceKlass) \
466 f(InstanceClassLoaderKlass) \
467 f(InstanceMirrorKlass) \
468 f(InstanceRefKlass) \
469 f(Method) \
470 f(ObjArrayKlass) \
471 f(TypeArrayKlass)
472
473 class CppVtableInfo {
474 intptr_t _vtable_size;
475 intptr_t _cloned_vtable[1];
476 public:
477 static int num_slots(int vtable_size) {
478 return 1 + vtable_size; // Need to add the space occupied by _vtable_size;
479 }
480 int vtable_size() { return int(uintx(_vtable_size)); }
481 void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
482 intptr_t* cloned_vtable() { return &_cloned_vtable[0]; }
483 void zero() { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }
484 // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
485 static size_t byte_size(int vtable_size) {
486 CppVtableInfo i;
487 return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));
488 }
489 };
490
491 template <class T> class CppVtableCloner : public T {
492 static intptr_t* vtable_of(Metadata& m) {
493 return *((intptr_t**)&m);
494 }
495 static CppVtableInfo* _info;
496
497 static int get_vtable_length(const char* name);
498
499 public:
500 // Allocate and initialize the C++ vtable, starting from top, but do not go past end.
501 static intptr_t* allocate(const char* name);
502
503 // Clone the vtable to ...
504 static intptr_t* clone_vtable(const char* name, CppVtableInfo* info);
505
506 static void zero_vtable_clone() {
507 assert(DumpSharedSpaces, "dump-time only");
508 _info->zero();
509 }
510
511 // Switch the vtable pointer to point to the cloned vtable.
512 static void patch(Metadata* obj) {
513 assert(DumpSharedSpaces, "dump-time only");
514 *(void**)obj = (void*)(_info->cloned_vtable());
515 }
516
517 static bool is_valid_shared_object(const T* obj) {
518 intptr_t* vptr = *(intptr_t**)obj;
519 return vptr == _info->cloned_vtable();
520 }
521 };
522
523 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
524
525 template <class T>
526 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
527 assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
528 int n = get_vtable_length(name);
529 _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
530 _info->set_vtable_size(n);
531
532 intptr_t* p = clone_vtable(name, _info);
533 assert((char*)p == _md_region.top(), "must be");
534
535 return p;
536 }
537
538 template <class T>
539 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
540 if (!DumpSharedSpaces) {
541 assert(_info == 0, "_info is initialized only at dump time");
542 _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
543 }
544 T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
545 int n = info->vtable_size();
546 intptr_t* srcvtable = vtable_of(tmp);
547 intptr_t* dstvtable = info->cloned_vtable();
548
549 // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are
550 // safe to do memcpy.
551 log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name);
552 memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n);
553 return dstvtable + n;
554 }
555
556 // To determine the size of the vtable for each type, we use the following
557 // trick by declaring 2 subclasses:
558 //
559 // class CppVtableTesterA: public InstanceKlass {virtual int last_virtual_method() {return 1;} };
560 // class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; };
561 //
562 // CppVtableTesterA and CppVtableTesterB's vtables have the following properties:
563 // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N)
564 // - The first N entries have are exactly the same as in InstanceKlass's vtable.
565 // - Their last entry is different.
566 //
567 // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables
568 // and find the first entry that's different.
569 //
570 // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more
571 // esoteric compilers.
572
573 template <class T> class CppVtableTesterB: public T {
574 public:
575 virtual int last_virtual_method() {return 1;}
576 };
577
578 template <class T> class CppVtableTesterA : public T {
579 public:
580 virtual void* last_virtual_method() {
581 // Make this different than CppVtableTesterB::last_virtual_method so the C++
582 // compiler/linker won't alias the two functions.
583 return NULL;
584 }
585 };
586
587 template <class T>
588 int CppVtableCloner<T>::get_vtable_length(const char* name) {
589 CppVtableTesterA<T> a;
590 CppVtableTesterB<T> b;
591
592 intptr_t* avtable = vtable_of(a);
593 intptr_t* bvtable = vtable_of(b);
594
595 // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc)
596 int vtable_len = 1;
597 for (; ; vtable_len++) {
598 if (avtable[vtable_len] != bvtable[vtable_len]) {
599 break;
600 }
601 }
602 log_debug(cds, vtables)("Found %3d vtable entries for %s", vtable_len, name);
603
604 return vtable_len;
605 }
606
607 #define ALLOC_CPP_VTABLE_CLONE(c) \
608 CppVtableCloner<c>::allocate(#c);
609
610 #define CLONE_CPP_VTABLE(c) \
611 p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
612
613 #define ZERO_CPP_VTABLE(c) \
614 CppVtableCloner<c>::zero_vtable_clone();
615
616 // This can be called at both dump time and run time.
617 intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) {
618 assert(DumpSharedSpaces || UseSharedSpaces, "sanity");
619 CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE);
620 return p;
621 }
622
623 void MetaspaceShared::zero_cpp_vtable_clones_for_writing() {
624 assert(DumpSharedSpaces, "dump-time only");
625 CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE);
626 }
627
628 // Allocate and initialize the C++ vtables, starting from top, but do not go past end.
629 void MetaspaceShared::allocate_cpp_vtable_clones() {
630 assert(DumpSharedSpaces, "dump-time only");
631 // Layout (each slot is a intptr_t):
632 // [number of slots in the first vtable = n1]
633 // [ <n1> slots for the first vtable]
634 // [number of slots in the first second = n2]
635 // [ <n2> slots for the second vtable]
636 // ...
637 // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro.
638 CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE);
639 }
640
641 // Switch the vtable pointer to point to the cloned vtable. We assume the
642 // vtable pointer is in first slot in object.
643 void MetaspaceShared::patch_cpp_vtable_pointers() {
644 int n = _global_klass_objects->length();
645 for (int i = 0; i < n; i++) {
646 Klass* obj = _global_klass_objects->at(i);
647 if (obj->is_instance_klass()) {
648 InstanceKlass* ik = InstanceKlass::cast(obj);
649 if (ik->is_class_loader_instance_klass()) {
650 CppVtableCloner<InstanceClassLoaderKlass>::patch(ik);
651 } else if (ik->is_reference_instance_klass()) {
652 CppVtableCloner<InstanceRefKlass>::patch(ik);
653 } else if (ik->is_mirror_instance_klass()) {
654 CppVtableCloner<InstanceMirrorKlass>::patch(ik);
655 } else {
656 CppVtableCloner<InstanceKlass>::patch(ik);
657 }
658 ConstantPool* cp = ik->constants();
659 CppVtableCloner<ConstantPool>::patch(cp);
660 for (int j = 0; j < ik->methods()->length(); j++) {
661 Method* m = ik->methods()->at(j);
662 CppVtableCloner<Method>::patch(m);
663 assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
664 }
665 } else if (obj->is_objArray_klass()) {
666 CppVtableCloner<ObjArrayKlass>::patch(obj);
667 } else {
668 assert(obj->is_typeArray_klass(), "sanity");
669 CppVtableCloner<TypeArrayKlass>::patch(obj);
670 }
671 }
672 }
673
674 bool MetaspaceShared::is_valid_shared_method(const Method* m) {
675 assert(is_in_shared_space(m), "must be");
676 return CppVtableCloner<Method>::is_valid_shared_object(m);
677 }
678
679 // Closure for serializing initialization data out to a data area to be
680 // written to the shared file.
681
682 class WriteClosure : public SerializeClosure {
683 private:
684 DumpRegion* _dump_region;
685
686 public:
687 WriteClosure(DumpRegion* r) {
688 _dump_region = r;
689 }
690
691 void do_ptr(void** p) {
692 _dump_region->append_intptr_t((intptr_t)*p);
693 }
694
695 void do_u4(u4* p) {
696 void* ptr = (void*)(uintx(*p));
697 do_ptr(&ptr);
698 }
699
700 void do_tag(int tag) {
701 _dump_region->append_intptr_t((intptr_t)tag);
702 }
703
704 void do_region(u_char* start, size_t size) {
705 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
706 assert(size % sizeof(intptr_t) == 0, "bad size");
707 do_tag((int)size);
708 while (size > 0) {
709 _dump_region->append_intptr_t(*(intptr_t*)start);
710 start += sizeof(intptr_t);
711 size -= sizeof(intptr_t);
712 }
713 }
714
715 bool reading() const { return false; }
716 };
717
718 // This is for dumping detailed statistics for the allocations
719 // in the shared spaces.
720 class DumpAllocStats : public ResourceObj {
721 public:
722
723 // Here's poor man's enum inheritance
724 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
725 METASPACE_OBJ_TYPES_DO(f) \
726 f(SymbolHashentry) \
727 f(SymbolBucket) \
728 f(StringHashentry) \
729 f(StringBucket) \
730 f(Other)
731
732 enum Type {
733 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
734 SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
735 _number_of_types
736 };
737
738 static const char * type_name(Type type) {
739 switch(type) {
740 SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
741 default:
742 ShouldNotReachHere();
743 return NULL;
744 }
745 }
746
747 public:
748 enum { RO = 0, RW = 1 };
749
750 int _counts[2][_number_of_types];
751 int _bytes [2][_number_of_types];
752
753 DumpAllocStats() {
754 memset(_counts, 0, sizeof(_counts));
755 memset(_bytes, 0, sizeof(_bytes));
756 };
757
758 void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
759 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
760 int which = (read_only) ? RO : RW;
761 _counts[which][type] ++;
762 _bytes [which][type] += byte_size;
763 }
764
765 void record_other_type(int byte_size, bool read_only) {
766 int which = (read_only) ? RO : RW;
767 _bytes [which][OtherType] += byte_size;
768 }
769 void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
770 };
771
772 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
773 // Calculate size of data that was not allocated by Metaspace::allocate()
774 MetaspaceSharedStats *stats = MetaspaceShared::stats();
775
776 // symbols
777 _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
778 _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
779
780 _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
781 _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
782
783 // strings
784 _counts[RO][StringHashentryType] = stats->string.hashentry_count;
785 _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
786
787 _counts[RO][StringBucketType] = stats->string.bucket_count;
788 _bytes [RO][StringBucketType] = stats->string.bucket_bytes;
789
790 // TODO: count things like dictionary, vtable, etc
791 _bytes[RW][OtherType] += mc_all + md_all;
792 rw_all += mc_all + md_all; // mc/md are mapped Read/Write
793
794 // prevent divide-by-zero
795 if (ro_all < 1) {
796 ro_all = 1;
797 }
798 if (rw_all < 1) {
799 rw_all = 1;
800 }
801
802 int all_ro_count = 0;
803 int all_ro_bytes = 0;
804 int all_rw_count = 0;
805 int all_rw_bytes = 0;
806
807 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
808 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
809 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
810 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
811
812 ResourceMark rm;
813 LogMessage(cds) msg;
814 stringStream info_stream;
815
816 info_stream.print_cr("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
817 info_stream.print_cr("%s", hdr);
818 info_stream.print_cr("%s", sep);
819 for (int type = 0; type < int(_number_of_types); type ++) {
820 const char *name = type_name((Type)type);
821 int ro_count = _counts[RO][type];
822 int ro_bytes = _bytes [RO][type];
823 int rw_count = _counts[RW][type];
824 int rw_bytes = _bytes [RW][type];
825 int count = ro_count + rw_count;
826 int bytes = ro_bytes + rw_bytes;
827
828 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
829 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
830 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
831
832 info_stream.print_cr(fmt_stats, name,
833 ro_count, ro_bytes, ro_perc,
834 rw_count, rw_bytes, rw_perc,
835 count, bytes, perc);
836
837 all_ro_count += ro_count;
838 all_ro_bytes += ro_bytes;
839 all_rw_count += rw_count;
840 all_rw_bytes += rw_bytes;
841 }
842
843 int all_count = all_ro_count + all_rw_count;
844 int all_bytes = all_ro_bytes + all_rw_bytes;
845
846 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
847 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
848 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
849
850 info_stream.print_cr("%s", sep);
851 info_stream.print_cr(fmt_stats, "Total",
852 all_ro_count, all_ro_bytes, all_ro_perc,
853 all_rw_count, all_rw_bytes, all_rw_perc,
854 all_count, all_bytes, all_perc);
855
856 assert(all_ro_bytes == ro_all, "everything should have been counted");
857 assert(all_rw_bytes == rw_all, "everything should have been counted");
858
859 msg.info("%s", info_stream.as_string());
860 #undef fmt_stats
861 }
862
863 // Populate the shared space.
864
865 class VM_PopulateDumpSharedSpace: public VM_Operation {
866 private:
867 GrowableArray<MemRegion> *_string_regions;
868 GrowableArray<MemRegion> *_open_archive_heap_regions;
869
870 void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
871 void dump_symbols();
872 char* dump_read_only_tables();
873 void print_region_stats();
874 void print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
875 const char *name, const size_t total_size);
876 public:
877
878 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
879 void doit(); // outline because gdb sucks
880 static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only, bool allow_exec);
881 }; // class VM_PopulateDumpSharedSpace
882
883 class SortedSymbolClosure: public SymbolClosure {
884 GrowableArray<Symbol*> _symbols;
885 virtual void do_symbol(Symbol** sym) {
886 assert((*sym)->is_permanent(), "archived symbols must be permanent");
887 _symbols.append(*sym);
888 }
889 static int compare_symbols_by_address(Symbol** a, Symbol** b) {
890 if (a[0] < b[0]) {
891 return -1;
892 } else if (a[0] == b[0]) {
893 return 0;
894 } else {
895 return 1;
896 }
897 }
898
899 public:
900 SortedSymbolClosure() {
901 SymbolTable::symbols_do(this);
902 _symbols.sort(compare_symbols_by_address);
903 }
904 GrowableArray<Symbol*>* get_sorted_symbols() {
905 return &_symbols;
906 }
907 };
908
909 // ArchiveCompactor --
910 //
911 // This class is the central piece of shared archive compaction -- all metaspace data are
912 // initially allocated outside of the shared regions. ArchiveCompactor copies the
913 // metaspace data into their final location in the shared regions.
914
915 class ArchiveCompactor : AllStatic {
916 static DumpAllocStats* _alloc_stats;
917 static SortedSymbolClosure* _ssc;
918
919 static unsigned my_hash(const address& a) {
920 return primitive_hash<address>(a);
921 }
922 static bool my_equals(const address& a0, const address& a1) {
923 return primitive_equals<address>(a0, a1);
924 }
925 typedef ResourceHashtable<
926 address, address,
927 ArchiveCompactor::my_hash, // solaris compiler doesn't like: primitive_hash<address>
928 ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
929 16384, ResourceObj::C_HEAP> RelocationTable;
930 static RelocationTable* _new_loc_table;
931
932 public:
933 static void initialize() {
934 _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
935 _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)RelocationTable;
936 }
937 static DumpAllocStats* alloc_stats() {
938 return _alloc_stats;
939 }
940
941 static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
942 address obj = ref->obj();
943 int bytes = ref->size() * BytesPerWord;
944 char* p;
945 size_t alignment = BytesPerWord;
946 char* oldtop;
947 char* newtop;
948
949 if (read_only) {
950 oldtop = _ro_region.top();
951 p = _ro_region.allocate(bytes, alignment);
952 newtop = _ro_region.top();
953 } else {
954 oldtop = _rw_region.top();
955 p = _rw_region.allocate(bytes, alignment);
956 newtop = _rw_region.top();
957 }
958 memcpy(p, obj, bytes);
959 bool isnew = _new_loc_table->put(obj, (address)p);
960 assert(isnew, "must be");
961 log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
962
963 _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
964 if (ref->msotype() == MetaspaceObj::SymbolType) {
965 uintx delta = MetaspaceShared::object_delta(p);
966 if (delta > MAX_SHARED_DELTA) {
967 // This is just a sanity check and should not appear in any real world usage. This
968 // happens only if you allocate more than 2GB of Symbols and would require
969 // millions of shared classes.
970 vm_exit_during_initialization("Too many Symbols in the CDS archive",
971 "Please reduce the number of shared classes.");
972 }
973 }
974 }
975
976 static address get_new_loc(MetaspaceClosure::Ref* ref) {
977 address* pp = _new_loc_table->get(ref->obj());
978 assert(pp != NULL, "must be");
979 return *pp;
980 }
981
982 private:
983 // Makes a shallow copy of visited MetaspaceObj's
984 class ShallowCopier: public UniqueMetaspaceClosure {
985 bool _read_only;
986 public:
987 ShallowCopier(bool read_only) : _read_only(read_only) {}
988
989 virtual void do_unique_ref(Ref* ref, bool read_only) {
990 if (read_only == _read_only) {
991 allocate(ref, read_only);
992 }
993 }
994 };
995
996 // Relocate embedded pointers within a MetaspaceObj's shallow copy
997 class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
998 public:
999 virtual void do_unique_ref(Ref* ref, bool read_only) {
1000 address new_loc = get_new_loc(ref);
1001 RefRelocator refer;
1002 ref->metaspace_pointers_do_at(&refer, new_loc);
1003 }
1004 };
1005
1006 // Relocate a reference to point to its shallow copy
1007 class RefRelocator: public MetaspaceClosure {
1008 public:
1009 virtual bool do_ref(Ref* ref, bool read_only) {
1010 if (ref->not_null()) {
1011 ref->update(get_new_loc(ref));
1012 }
1013 return false; // Do not recurse.
1014 }
1015 };
1016
1017 #ifdef ASSERT
1018 class IsRefInArchiveChecker: public MetaspaceClosure {
1019 public:
1020 virtual bool do_ref(Ref* ref, bool read_only) {
1021 if (ref->not_null()) {
1022 char* obj = (char*)ref->obj();
1023 assert(_ro_region.contains(obj) || _rw_region.contains(obj),
1024 "must be relocated to point to CDS archive");
1025 }
1026 return false; // Do not recurse.
1027 }
1028 };
1029 #endif
1030
1031 public:
1032 static void copy_and_compact() {
1033 // We should no longer allocate anything from the metaspace, so that
1034 // we can have a stable set of MetaspaceObjs to work with.
1035 Metaspace::freeze();
1036
1037 ResourceMark rm;
1038 SortedSymbolClosure the_ssc; // StackObj
1039 _ssc = &the_ssc;
1040
1041 tty->print_cr("Scanning all metaspace objects ... ");
1042 {
1043 // allocate and shallow-copy RW objects, immediately following the MC region
1044 tty->print_cr("Allocating RW objects ... ");
1045 _mc_region.pack(&_rw_region);
1046
1047 ResourceMark rm;
1048 ShallowCopier rw_copier(false);
1049 iterate_roots(&rw_copier);
1050 }
1051 {
1052 // allocate and shallow-copy of RO object, immediately following the RW region
1053 tty->print_cr("Allocating RO objects ... ");
1054 _rw_region.pack(&_ro_region);
1055
1056 ResourceMark rm;
1057 ShallowCopier ro_copier(true);
1058 iterate_roots(&ro_copier);
1059 }
1060 {
1061 tty->print_cr("Relocating embedded pointers ... ");
1062 ResourceMark rm;
1063 ShallowCopyEmbeddedRefRelocator emb_reloc;
1064 iterate_roots(&emb_reloc);
1065 }
1066 {
1067 tty->print_cr("Relocating external roots ... ");
1068 ResourceMark rm;
1069 RefRelocator ext_reloc;
1070 iterate_roots(&ext_reloc);
1071 }
1072
1073 #ifdef ASSERT
1074 {
1075 tty->print_cr("Verifying external roots ... ");
1076 ResourceMark rm;
1077 IsRefInArchiveChecker checker;
1078 iterate_roots(&checker);
1079 }
1080 #endif
1081
1082
1083 // cleanup
1084 _ssc = NULL;
1085 }
1086
1087 // We must relocate the System::_well_known_klasses only after we have copied the
1088 // java objects in during dump_java_heap_objects(): during the object copy, we operate on
1089 // old objects which assert that their klass is the original klass.
1090 static void relocate_well_known_klasses() {
1091 {
1092 tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1093 ResourceMark rm;
1094 RefRelocator ext_reloc;
1095 SystemDictionary::well_known_klasses_do(&ext_reloc);
1096 }
1097 // NOTE: after this point, we shouldn't have any globals that can reach the old
1098 // objects.
1099
1100 // We cannot use any of the objects in the heap anymore (except for the objects
1101 // in the CDS shared string regions) because their headers no longer point to
1102 // valid Klasses.
1103 }
1104
1105 static void iterate_roots(MetaspaceClosure* it) {
1106 GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1107 for (int i=0; i<symbols->length(); i++) {
1108 it->push(symbols->adr_at(i));
1109 }
1110 if (_global_klass_objects != NULL) {
1111 // Need to fix up the pointers
1112 for (int i = 0; i < _global_klass_objects->length(); i++) {
1113 // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed.
1114 it->push(_global_klass_objects->adr_at(i));
1115 }
1116 }
1117 FileMapInfo::metaspace_pointers_do(it);
1118 SystemDictionary::classes_do(it);
1119 Universe::metaspace_pointers_do(it);
1120 SymbolTable::metaspace_pointers_do(it);
1121 vmSymbols::metaspace_pointers_do(it);
1122 }
1123
1124 static Klass* get_relocated_klass(Klass* orig_klass) {
1125 address* pp = _new_loc_table->get((address)orig_klass);
1126 assert(pp != NULL, "must be");
1127 Klass* klass = (Klass*)(*pp);
1128 assert(klass->is_klass(), "must be");
1129 return klass;
1130 }
1131 };
1132
1133 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1134 SortedSymbolClosure* ArchiveCompactor::_ssc;
1135 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1136
1137 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1138 DumpRegion* dump_region, bool read_only, bool allow_exec) {
1139 mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1140 }
1141
1142 void VM_PopulateDumpSharedSpace::dump_symbols() {
1143 tty->print_cr("Dumping symbol table ...");
1144
1145 NOT_PRODUCT(SymbolTable::verify());
1146 SymbolTable::write_to_archive();
1147 }
1148
1149 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1150 char* oldtop = _ro_region.top();
1151 // Reorder the system dictionary. Moving the symbols affects
1152 // how the hash table indices are calculated.
1153 SystemDictionary::reorder_dictionary_for_sharing();
1154 NOT_PRODUCT(SystemDictionary::verify();)
1155
1156 size_t buckets_bytes = SystemDictionary::count_bytes_for_buckets();
1157 char* buckets_top = _ro_region.allocate(buckets_bytes, sizeof(intptr_t));
1158 SystemDictionary::copy_buckets(buckets_top, _ro_region.top());
1159
1160 size_t table_bytes = SystemDictionary::count_bytes_for_table();
1161 char* table_top = _ro_region.allocate(table_bytes, sizeof(intptr_t));
1162 SystemDictionary::copy_table(table_top, _ro_region.top());
1163
1164 // Write the other data to the output array.
1165 WriteClosure wc(&_ro_region);
1166 MetaspaceShared::serialize(&wc);
1167
1168 char* newtop = _ro_region.top();
1169 ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - oldtop), true);
1170 return buckets_top;
1171 }
1172
1173 void VM_PopulateDumpSharedSpace::doit() {
1174 Thread* THREAD = VMThread::vm_thread();
1175
1176 NOT_PRODUCT(SystemDictionary::verify();)
1177 // The following guarantee is meant to ensure that no loader constraints
1178 // exist yet, since the constraints table is not shared. This becomes
1179 // more important now that we don't re-initialize vtables/itables for
1180 // shared classes at runtime, where constraints were previously created.
1181 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1182 "loader constraints are not saved");
1183 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1184 "placeholders are not saved");
1185 // Revisit and implement this if we prelink method handle call sites:
1186 guarantee(SystemDictionary::invoke_method_table() == NULL ||
1187 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
1188 "invoke method table is not saved");
1189
1190 // At this point, many classes have been loaded.
1191 // Gather systemDictionary classes in a global array and do everything to
1192 // that so we don't have to walk the SystemDictionary again.
1193 _global_klass_objects = new GrowableArray<Klass*>(1000);
1194 CollectClassesClosure collect_classes;
1195 ClassLoaderDataGraph::loaded_classes_do(&collect_classes);
1196
1197 tty->print_cr("Number of classes %d", _global_klass_objects->length());
1198 {
1199 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
1200 for (int i = 0; i < _global_klass_objects->length(); i++) {
1201 Klass* k = _global_klass_objects->at(i);
1202 if (k->is_instance_klass()) {
1203 num_inst ++;
1204 } else if (k->is_objArray_klass()) {
1205 num_obj_array ++;
1206 } else {
1207 assert(k->is_typeArray_klass(), "sanity");
1208 num_type_array ++;
1209 }
1210 }
1211 tty->print_cr(" instance classes = %5d", num_inst);
1212 tty->print_cr(" obj array classes = %5d", num_obj_array);
1213 tty->print_cr(" type array classes = %5d", num_type_array);
1214 }
1215
1216 // Ensure the ConstMethods won't be modified at run-time
1217 tty->print("Updating ConstMethods ... ");
1218 rewrite_nofast_bytecodes_and_calculate_fingerprints();
1219 tty->print_cr("done. ");
1220
1221 // Remove all references outside the metadata
1222 tty->print("Removing unshareable information ... ");
1223 remove_unshareable_in_classes();
1224 tty->print_cr("done. ");
1225
1226 ArchiveCompactor::initialize();
1227 ArchiveCompactor::copy_and_compact();
1228
1229 dump_symbols();
1230
1231 // Dump supported java heap objects
1232 _string_regions = NULL;
1233 _open_archive_heap_regions = NULL;
1234 dump_java_heap_objects();
1235
1236 ArchiveCompactor::relocate_well_known_klasses();
1237
1238 char* read_only_tables_start = dump_read_only_tables();
1239 _ro_region.pack(&_md_region);
1240
1241 char* vtbl_list = _md_region.top();
1242 MetaspaceShared::allocate_cpp_vtable_clones();
1243 _md_region.pack(&_od_region);
1244
1245 // Relocate the archived class file data into the od region
1246 relocate_cached_class_file();
1247 _od_region.pack();
1248
1249 // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1250 // is just the spaces between the two ends.
1251 size_t core_spaces_size = _od_region.end() - _mc_region.base();
1252 assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1253 "should already be aligned");
1254
1255 // During patching, some virtual methods may be called, so at this point
1256 // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1257 MetaspaceShared::patch_cpp_vtable_pointers();
1258
1259 // The vtable clones contain addresses of the current process.
1260 // We don't want to write these addresses into the archive.
1261 MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1262
1263 // Create and write the archive file that maps the shared spaces.
1264
1265 FileMapInfo* mapinfo = new FileMapInfo();
1266 mapinfo->populate_header(os::vm_allocation_granularity());
1267 mapinfo->set_read_only_tables_start(read_only_tables_start);
1268 mapinfo->set_misc_data_patching_start(vtbl_list);
1269 mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1270 mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1271 mapinfo->set_core_spaces_size(core_spaces_size);
1272
1273 for (int pass=1; pass<=2; pass++) {
1274 if (pass == 1) {
1275 // The first pass doesn't actually write the data to disk. All it
1276 // does is to update the fields in the mapinfo->_header.
1277 } else {
1278 // After the first pass, the contents of mapinfo->_header are finalized,
1279 // so we can compute the header's CRC, and write the contents of the header
1280 // and the regions into disk.
1281 mapinfo->open_for_write();
1282 mapinfo->set_header_crc(mapinfo->compute_header_crc());
1283 }
1284 mapinfo->write_header();
1285
1286 // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1287 // so it needs to be read/write.
1288 write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1289 write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1290 write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1291 write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1292 write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1293
1294 _total_string_region_size = mapinfo->write_archive_heap_regions(
1295 _string_regions,
1296 MetaspaceShared::first_string,
1297 MetaspaceShared::max_strings);
1298 _total_open_archive_region_size = mapinfo->write_archive_heap_regions(
1299 _open_archive_heap_regions,
1300 MetaspaceShared::first_open_archive_heap_region,
1301 MetaspaceShared::max_open_archive_heap_region);
1302 }
1303
1304 mapinfo->close();
1305
1306 // Restore the vtable in case we invoke any virtual methods.
1307 MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1308
1309 print_region_stats();
1310
1311 if (log_is_enabled(Info, cds)) {
1312 ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1313 int(_mc_region.used()), int(_md_region.used()));
1314 }
1315 }
1316
1317 void VM_PopulateDumpSharedSpace::print_region_stats() {
1318 // Print statistics of all the regions
1319 const size_t total_reserved = _ro_region.reserved() + _rw_region.reserved() +
1320 _mc_region.reserved() + _md_region.reserved() +
1321 _od_region.reserved() +
1322 _total_string_region_size +
1323 _total_open_archive_region_size;
1324 const size_t total_bytes = _ro_region.used() + _rw_region.used() +
1325 _mc_region.used() + _md_region.used() +
1326 _od_region.used() +
1327 _total_string_region_size +
1328 _total_open_archive_region_size;
1329 const double total_u_perc = total_bytes / double(total_reserved) * 100.0;
1330
1331 _mc_region.print(total_reserved);
1332 _rw_region.print(total_reserved);
1333 _ro_region.print(total_reserved);
1334 _md_region.print(total_reserved);
1335 _od_region.print(total_reserved);
1336 print_heap_region_stats(_string_regions, "st", total_reserved);
1337 print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved);
1338
1339 tty->print_cr("total : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1340 total_bytes, total_reserved, total_u_perc);
1341 }
1342
1343 void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1344 const char *name, const size_t total_size) {
1345 int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1346 for (int i = 0; i < arr_len; i++) {
1347 char* start = (char*)heap_mem->at(i).start();
1348 size_t size = heap_mem->at(i).byte_size();
1349 char* top = start + size;
1350 tty->print_cr("%s%d space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [100%% used] at " INTPTR_FORMAT,
1351 name, i, size, size/double(total_size)*100.0, size, p2i(start));
1352
1353 }
1354 }
1355
1356 // Update a Java object to point its Klass* to the new location after
1357 // shared archive has been compacted.
1358 void MetaspaceShared::relocate_klass_ptr(oop o) {
1359 assert(DumpSharedSpaces, "sanity");
1360 Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1361 o->set_klass(k);
1362 }
1363
1364 class LinkSharedClassesClosure : public KlassClosure {
1365 Thread* THREAD;
1366 bool _made_progress;
1367 public:
1368 LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1369
1370 void reset() { _made_progress = false; }
1371 bool made_progress() const { return _made_progress; }
1372
1373 void do_klass(Klass* k) {
1374 if (k->is_instance_klass()) {
1375 InstanceKlass* ik = InstanceKlass::cast(k);
1376 // Link the class to cause the bytecodes to be rewritten and the
1377 // cpcache to be created. Class verification is done according
1378 // to -Xverify setting.
1379 _made_progress |= MetaspaceShared::try_link_class(ik, THREAD);
1380 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1381
1382 ik->constants()->resolve_class_constants(THREAD);
1383 }
1384 }
1385 };
1386
1387 class CheckSharedClassesClosure : public KlassClosure {
1388 bool _made_progress;
1389 public:
1390 CheckSharedClassesClosure() : _made_progress(false) {}
1391
1392 void reset() { _made_progress = false; }
1393 bool made_progress() const { return _made_progress; }
1394 void do_klass(Klass* k) {
1395 if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) {
1396 _made_progress = true;
1397 }
1398 }
1399 };
1400
1401 void MetaspaceShared::check_shared_class_loader_type(Klass* k) {
1402 if (k->is_instance_klass()) {
1403 InstanceKlass* ik = InstanceKlass::cast(k);
1404 u2 loader_type = ik->loader_type();
1405 ResourceMark rm;
1406 guarantee(loader_type != 0,
1407 "Class loader type is not set for this class %s", ik->name()->as_C_string());
1408 }
1409 }
1410
1411 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
1412 // We need to iterate because verification may cause additional classes
1413 // to be loaded.
1414 LinkSharedClassesClosure link_closure(THREAD);
1415 do {
1416 link_closure.reset();
1417 ClassLoaderDataGraph::loaded_classes_do(&link_closure);
1418 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1419 } while (link_closure.made_progress());
1420
1421 if (_has_error_classes) {
1422 // Mark all classes whose super class or interfaces failed verification.
1423 CheckSharedClassesClosure check_closure;
1424 do {
1425 // Not completely sure if we need to do this iteratively. Anyway,
1426 // we should come here only if there are unverifiable classes, which
1427 // shouldn't happen in normal cases. So better safe than sorry.
1428 check_closure.reset();
1429 ClassLoaderDataGraph::loaded_classes_do(&check_closure);
1430 } while (check_closure.made_progress());
1431
1432 if (IgnoreUnverifiableClassesDuringDump) {
1433 // This is useful when running JCK or SQE tests. You should not
1434 // enable this when running real apps.
1435 SystemDictionary::remove_classes_in_error_state();
1436 } else {
1437 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
1438 exit(1);
1439 }
1440 }
1441
1442 // Copy the verification constraints from C_HEAP-alloced GrowableArrays to RO-alloced
1443 // Arrays
1444 SystemDictionaryShared::finalize_verification_constraints();
1445 }
1446
1447 void MetaspaceShared::prepare_for_dumping() {
1448 Arguments::check_unsupported_dumping_properties();
1449 ClassLoader::initialize_shared_path();
1450 FileMapInfo::allocate_classpath_entry_table();
1451 }
1452
1453 // Preload classes from a list, populate the shared spaces and dump to a
1454 // file.
1455 void MetaspaceShared::preload_and_dump(TRAPS) {
1456 { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime));
1457 ResourceMark rm;
1458 char class_list_path_str[JVM_MAXPATHLEN];
1459 // Preload classes to be shared.
1460 // Should use some os:: method rather than fopen() here. aB.
1461 const char* class_list_path;
1462 if (SharedClassListFile == NULL) {
1463 // Construct the path to the class list (in jre/lib)
1464 // Walk up two directories from the location of the VM and
1465 // optionally tack on "lib" (depending on platform)
1466 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
1467 for (int i = 0; i < 3; i++) {
1468 char *end = strrchr(class_list_path_str, *os::file_separator());
1469 if (end != NULL) *end = '\0';
1470 }
1471 int class_list_path_len = (int)strlen(class_list_path_str);
1472 if (class_list_path_len >= 3) {
1473 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
1474 if (class_list_path_len < JVM_MAXPATHLEN - 4) {
1475 jio_snprintf(class_list_path_str + class_list_path_len,
1476 sizeof(class_list_path_str) - class_list_path_len,
1477 "%slib", os::file_separator());
1478 class_list_path_len += 4;
1479 }
1480 }
1481 }
1482 if (class_list_path_len < JVM_MAXPATHLEN - 10) {
1483 jio_snprintf(class_list_path_str + class_list_path_len,
1484 sizeof(class_list_path_str) - class_list_path_len,
1485 "%sclasslist", os::file_separator());
1486 }
1487 class_list_path = class_list_path_str;
1488 } else {
1489 class_list_path = SharedClassListFile;
1490 }
1491
1492 tty->print_cr("Loading classes to share ...");
1493 _has_error_classes = false;
1494 int class_count = preload_classes(class_list_path, THREAD);
1495 if (ExtraSharedClassListFile) {
1496 class_count += preload_classes(ExtraSharedClassListFile, THREAD);
1497 }
1498 tty->print_cr("Loading classes to share: done.");
1499
1500 log_info(cds)("Shared spaces: preloaded %d classes", class_count);
1501
1502 // Rewrite and link classes
1503 tty->print_cr("Rewriting and linking classes ...");
1504
1505 // Link any classes which got missed. This would happen if we have loaded classes that
1506 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1507 // fails verification, all other interfaces that were not specified in the classlist but
1508 // are implemented by K are not verified.
1509 link_and_cleanup_shared_classes(CATCH);
1510 tty->print_cr("Rewriting and linking classes: done");
1511
1512 VM_PopulateDumpSharedSpace op;
1513 VMThread::execute(&op);
1514 }
1515
1516 if (PrintSystemDictionaryAtExit) {
1517 SystemDictionary::print();
1518 }
1519
1520 // Since various initialization steps have been undone by this process,
1521 // it is not reasonable to continue running a java process.
1522 exit(0);
1523 }
1524
1525
1526 int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) {
1527 ClassListParser parser(class_list_path);
1528 int class_count = 0;
1529
1530 while (parser.parse_one_line()) {
1531 Klass* klass = ClassLoaderExt::load_one_class(&parser, THREAD);
1532
1533 CLEAR_PENDING_EXCEPTION;
1534 if (klass != NULL) {
1535 if (log_is_enabled(Trace, cds)) {
1536 ResourceMark rm;
1537 log_trace(cds)("Shared spaces preloaded: %s", klass->external_name());
1538 }
1539
1540 InstanceKlass* ik = InstanceKlass::cast(klass);
1541
1542 // Link the class to cause the bytecodes to be rewritten and the
1543 // cpcache to be created. The linking is done as soon as classes
1544 // are loaded in order that the related data structures (klass and
1545 // cpCache) are located together.
1546 try_link_class(ik, THREAD);
1547 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1548
1549 class_count++;
1550 }
1551 }
1552
1553 return class_count;
1554 }
1555
1556 // Returns true if the class's status has changed
1557 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
1558 assert(DumpSharedSpaces, "should only be called during dumping");
1559 if (ik->init_state() < InstanceKlass::linked) {
1560 bool saved = BytecodeVerificationLocal;
1561 if (!(ik->is_shared_boot_class())) {
1562 // The verification decision is based on BytecodeVerificationRemote
1563 // for non-system classes. Since we are using the NULL classloader
1564 // to load non-system classes during dumping, we need to temporarily
1565 // change BytecodeVerificationLocal to be the same as
1566 // BytecodeVerificationRemote. Note this can cause the parent system
1567 // classes also being verified. The extra overhead is acceptable during
1568 // dumping.
1569 BytecodeVerificationLocal = BytecodeVerificationRemote;
1570 }
1571 ik->link_class(THREAD);
1572 if (HAS_PENDING_EXCEPTION) {
1573 ResourceMark rm;
1574 tty->print_cr("Preload Warning: Verification failed for %s",
1575 ik->external_name());
1576 CLEAR_PENDING_EXCEPTION;
1577 ik->set_in_error_state();
1578 _has_error_classes = true;
1579 }
1580 BytecodeVerificationLocal = saved;
1581 return true;
1582 } else {
1583 return false;
1584 }
1585 }
1586
1587 #if INCLUDE_CDS_JAVA_HEAP
1588 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1589 if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
1590 if (log_is_enabled(Info, cds)) {
1591 log_info(cds)(
1592 "Archived java heap is not supported as UseG1GC, "
1593 "UseCompressedOops and UseCompressedClassPointers are required."
1594 "Current settings: UseG1GC=%s, UseCompressedOops=%s, UseCompressedClassPointers=%s.",
1595 BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedOops),
1596 BOOL_TO_STR(UseCompressedClassPointers));
1597 }
1598 return;
1599 }
1600
1601 NoSafepointVerifier nsv;
1602
1603 // Cache for recording where the archived objects are copied to
1604 MetaspaceShared::create_archive_object_cache();
1605
1606 tty->print_cr("Dumping String objects to closed archive heap region ...");
1607 NOT_PRODUCT(StringTable::verify());
1608 // The string space has maximum two regions. See FileMapInfo::write_archive_heap_regions() for details.
1609 _string_regions = new GrowableArray<MemRegion>(2);
1610 StringTable::write_to_archive(_string_regions);
1611
1612 tty->print_cr("Dumping objects to open archive heap region ...");
1613 _open_archive_heap_regions = new GrowableArray<MemRegion>(2);
1614 MetaspaceShared::dump_open_archive_heap_objects(_open_archive_heap_regions);
1615 }
1616
1617 void MetaspaceShared::dump_open_archive_heap_objects(
1618 GrowableArray<MemRegion> * open_archive) {
1619 assert(UseG1GC, "Only support G1 GC");
1620 assert(UseCompressedOops && UseCompressedClassPointers,
1621 "Only support UseCompressedOops and UseCompressedClassPointers enabled");
1622
1623 Thread* THREAD = Thread::current();
1624 G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
1625
1626 MetaspaceShared::archive_resolved_constants(THREAD);
1627
1628 G1CollectedHeap::heap()->end_archive_alloc_range(open_archive,
1629 os::vm_allocation_granularity());
1630 }
1631
1632 MetaspaceShared::ArchivedObjectCache* MetaspaceShared::_archive_object_cache = NULL;
1633 oop MetaspaceShared::archive_heap_object(oop obj, Thread* THREAD) {
1634 assert(DumpSharedSpaces, "dump-time only");
1635
1636 ArchivedObjectCache* cache = MetaspaceShared::archive_object_cache();
1637 oop* p = cache->get(obj);
1638 if (p != NULL) {
1639 // already archived
1640 return *p;
1641 }
1642
1643 int len = obj->size();
1644 if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
1645 return NULL;
1646 }
1647
1648 int hash = obj->identity_hash();
1649 oop archived_oop = (oop)G1CollectedHeap::heap()->archive_mem_allocate(len);
1650 if (archived_oop != NULL) {
1651 Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)archived_oop, len);
1652 relocate_klass_ptr(archived_oop);
1653 cache->put(obj, archived_oop);
1654 }
1655 return archived_oop;
1656 }
1657
1658 void MetaspaceShared::archive_resolved_constants(Thread* THREAD) {
1659 int i;
1660 for (i = 0; i < _global_klass_objects->length(); i++) {
1661 Klass* k = _global_klass_objects->at(i);
1662 if (k->is_instance_klass()) {
1663 InstanceKlass* ik = InstanceKlass::cast(k);
1664 ik->constants()->archive_resolved_references(THREAD);
1665 }
1666 }
1667 }
1668
1669 void MetaspaceShared::fixup_mapped_heap_regions() {
1670 FileMapInfo *mapinfo = FileMapInfo::current_info();
1671 mapinfo->fixup_mapped_heap_regions();
1672 }
1673 #endif // INCLUDE_CDS_JAVA_HEAP
1674
1675 // Closure for serializing initialization data in from a data area
1676 // (ptr_array) read from the shared file.
1677
1678 class ReadClosure : public SerializeClosure {
1679 private:
1680 intptr_t** _ptr_array;
1681
1682 inline intptr_t nextPtr() {
1683 return *(*_ptr_array)++;
1684 }
1685
1686 public:
1687 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
1688
1689 void do_ptr(void** p) {
1690 assert(*p == NULL, "initializing previous initialized pointer.");
1691 intptr_t obj = nextPtr();
1692 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
1693 "hit tag while initializing ptrs.");
1694 *p = (void*)obj;
1695 }
1696
1697 void do_u4(u4* p) {
1698 intptr_t obj = nextPtr();
1699 *p = (u4)(uintx(obj));
1700 }
1701
1702 void do_tag(int tag) {
1703 int old_tag;
1704 old_tag = (int)(intptr_t)nextPtr();
1705 // do_int(&old_tag);
1706 assert(tag == old_tag, "old tag doesn't match");
1707 FileMapInfo::assert_mark(tag == old_tag);
1708 }
1709
1710 void do_region(u_char* start, size_t size) {
1711 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
1712 assert(size % sizeof(intptr_t) == 0, "bad size");
1713 do_tag((int)size);
1714 while (size > 0) {
1715 *(intptr_t*)start = nextPtr();
1716 start += sizeof(intptr_t);
1717 size -= sizeof(intptr_t);
1718 }
1719 }
1720
1721 bool reading() const { return true; }
1722 };
1723
1724 // Return true if given address is in the mapped shared space.
1725 bool MetaspaceShared::is_in_shared_space(const void* p) {
1726 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
1727 }
1728
1729 // Return true if given address is in the misc data region
1730 bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
1731 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
1732 }
1733
1734 bool MetaspaceShared::is_in_trampoline_frame(address addr) {
1735 if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
1736 return true;
1737 }
1738 return false;
1739 }
1740
1741 void MetaspaceShared::print_shared_spaces() {
1742 if (UseSharedSpaces) {
1743 FileMapInfo::current_info()->print_shared_spaces();
1744 }
1745 }
1746
1747
1748 // Map shared spaces at requested addresses and return if succeeded.
1749 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
1750 size_t image_alignment = mapinfo->alignment();
1751
1752 #ifndef _WINDOWS
1753 // Map in the shared memory and then map the regions on top of it.
1754 // On Windows, don't map the memory here because it will cause the
1755 // mappings of the regions to fail.
1756 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
1757 if (!shared_rs.is_reserved()) return false;
1758 #endif
1759
1760 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
1761
1762 char* _ro_base = NULL;
1763 char* _rw_base = NULL;
1764 char* _mc_base = NULL;
1765 char* _md_base = NULL;
1766 char* _od_base = NULL;
1767
1768 // Map each shared region
1769 if ((_mc_base = mapinfo->map_region(mc)) != NULL &&
1770 mapinfo->verify_region_checksum(mc) &&
1771 (_rw_base = mapinfo->map_region(rw)) != NULL &&
1772 mapinfo->verify_region_checksum(rw) &&
1773 (_ro_base = mapinfo->map_region(ro)) != NULL &&
1774 mapinfo->verify_region_checksum(ro) &&
1775 (_md_base = mapinfo->map_region(md)) != NULL &&
1776 mapinfo->verify_region_checksum(md) &&
1777 (_od_base = mapinfo->map_region(od)) != NULL &&
1778 mapinfo->verify_region_checksum(od) &&
1779 (image_alignment == (size_t)os::vm_allocation_granularity()) &&
1780 mapinfo->validate_classpath_entry_table()) {
1781 // Success (no need to do anything)
1782 return true;
1783 } else {
1784 // If there was a failure in mapping any of the spaces, unmap the ones
1785 // that succeeded
1786 if (_ro_base != NULL) mapinfo->unmap_region(ro);
1787 if (_rw_base != NULL) mapinfo->unmap_region(rw);
1788 if (_mc_base != NULL) mapinfo->unmap_region(mc);
1789 if (_md_base != NULL) mapinfo->unmap_region(md);
1790 if (_od_base != NULL) mapinfo->unmap_region(od);
1791 #ifndef _WINDOWS
1792 // Release the entire mapped region
1793 shared_rs.release();
1794 #endif
1795 // If -Xshare:on is specified, print out the error message and exit VM,
1796 // otherwise, set UseSharedSpaces to false and continue.
1797 if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
1798 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
1799 } else {
1800 FLAG_SET_DEFAULT(UseSharedSpaces, false);
1801 }
1802 return false;
1803 }
1804 }
1805
1806 // Read the miscellaneous data from the shared file, and
1807 // serialize it out to its various destinations.
1808
1809 void MetaspaceShared::initialize_shared_spaces() {
1810 FileMapInfo *mapinfo = FileMapInfo::current_info();
1811 _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
1812 _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
1813 _core_spaces_size = mapinfo->core_spaces_size();
1814 char* buffer = mapinfo->misc_data_patching_start();
1815 clone_cpp_vtables((intptr_t*)buffer);
1816
1817 // The rest of the data is now stored in the RW region
1818 buffer = mapinfo->read_only_tables_start();
1819 int sharedDictionaryLen = *(intptr_t*)buffer;
1820 buffer += sizeof(intptr_t);
1821 int number_of_entries = *(intptr_t*)buffer;
1822 buffer += sizeof(intptr_t);
1823 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1824 sharedDictionaryLen,
1825 number_of_entries);
1826 buffer += sharedDictionaryLen;
1827
1828 // The following data are the linked list elements
1829 // (HashtableEntry objects) for the shared dictionary table.
1830
1831 int len = *(intptr_t*)buffer; // skip over shared dictionary entries
1832 buffer += sizeof(intptr_t);
1833 buffer += len;
1834
1835 // Verify various attributes of the archive, plus initialize the
1836 // shared string/symbol tables
1837 intptr_t* array = (intptr_t*)buffer;
1838 ReadClosure rc(&array);
1839 serialize(&rc);
1840
1841 // Initialize the run-time symbol table.
1842 SymbolTable::create_table();
1843
1844 // Close the mapinfo file
1845 mapinfo->close();
1846
1847 if (PrintSharedArchiveAndExit) {
1848 if (PrintSharedDictionary) {
1849 tty->print_cr("\nShared classes:\n");
1850 SystemDictionary::print_shared(tty);
1851 }
1852 if (_archive_loading_failed) {
1853 tty->print_cr("archive is invalid");
1854 vm_exit(1);
1855 } else {
1856 tty->print_cr("archive is valid");
1857 vm_exit(0);
1858 }
1859 }
1860 }
1861
1862 // JVM/TI RedefineClasses() support:
1863 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1864 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1865
1866 if (UseSharedSpaces) {
1867 // remap the shared readonly space to shared readwrite, private
1868 FileMapInfo* mapinfo = FileMapInfo::current_info();
1869 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1870 return false;
1871 }
1872 _remapped_readwrite = true;
1873 }
1874 return true;
1875 }
1876
1877 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
1878 // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
1879 // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
1880 // or so.
1881 _mc_region.print_out_of_space_msg(name, needed_bytes);
1882 _rw_region.print_out_of_space_msg(name, needed_bytes);
1883 _ro_region.print_out_of_space_msg(name, needed_bytes);
1884 _md_region.print_out_of_space_msg(name, needed_bytes);
1885 _od_region.print_out_of_space_msg(name, needed_bytes);
1886
1887 vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
1888 "Please reduce the number of shared classes.");
1889 }