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