1 /*
2 * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/dictionary.hpp"
27 #include "classfile/loaderConstraints.hpp"
28 #include "classfile/placeholders.hpp"
29 #include "classfile/sharedClassUtil.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "code/codeCache.hpp"
33 #include "memory/filemap.hpp"
34 #include "memory/gcLocker.hpp"
35 #include "memory/metaspace.hpp"
36 #include "memory/metaspaceShared.hpp"
37 #include "oops/objArrayOop.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "runtime/os.hpp"
40 #include "runtime/signature.hpp"
41 #include "runtime/vm_operations.hpp"
42 #include "runtime/vmThread.hpp"
43 #include "utilities/hashtable.inline.hpp"
44
45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
46
47 int MetaspaceShared::_max_alignment = 0;
48
49 ReservedSpace* MetaspaceShared::_shared_rs = NULL;
50
51 bool MetaspaceShared::_link_classes_made_progress;
52 bool MetaspaceShared::_check_classes_made_progress;
53 bool MetaspaceShared::_has_error_classes;
54 bool MetaspaceShared::_archive_loading_failed = false;
55 // Read/write a data stream for restoring/preserving metadata pointers and
56 // miscellaneous data from/to the shared archive file.
57
58 void MetaspaceShared::serialize(SerializeClosure* soc) {
59 int tag = 0;
60 soc->do_tag(--tag);
61
62 // Verify the sizes of various metadata in the system.
63 soc->do_tag(sizeof(Method));
64 soc->do_tag(sizeof(ConstMethod));
65 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
66 soc->do_tag(sizeof(ConstantPool));
67 soc->do_tag(sizeof(ConstantPoolCache));
68 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
69 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
70 soc->do_tag(sizeof(Symbol));
71
72 // Dump/restore miscellaneous metadata.
73 Universe::serialize(soc, true);
74 soc->do_tag(--tag);
75
76 // Dump/restore references to commonly used names and signatures.
77 vmSymbols::serialize(soc);
78 soc->do_tag(--tag);
79
80 soc->do_tag(666);
81 }
82
83
84 // CDS code for dumping shared archive.
85
86 // Global object for holding classes that have been loaded. Since this
87 // is run at a safepoint just before exit, this is the entire set of classes.
88 static GrowableArray<Klass*>* _global_klass_objects;
89 static void collect_classes(Klass* k) {
90 _global_klass_objects->append_if_missing(k);
91 if (k->oop_is_instance()) {
92 // Add in the array classes too
93 InstanceKlass* ik = InstanceKlass::cast(k);
94 ik->array_klasses_do(collect_classes);
95 }
96 }
97
98 static void remove_unshareable_in_classes() {
99 for (int i = 0; i < _global_klass_objects->length(); i++) {
100 Klass* k = _global_klass_objects->at(i);
101 k->remove_unshareable_info();
102 }
103 }
104
105 // Walk all methods in the class list and assign a fingerprint.
106 // so that this part of the ConstMethod* is read only.
107 static void calculate_fingerprints() {
108 for (int i = 0; i < _global_klass_objects->length(); i++) {
109 Klass* k = _global_klass_objects->at(i);
110 if (k->oop_is_instance()) {
111 InstanceKlass* ik = InstanceKlass::cast(k);
112 for (int i = 0; i < ik->methods()->length(); i++) {
113 Method* m = ik->methods()->at(i);
114 Fingerprinter fp(m);
115 // The side effect of this call sets method's fingerprint field.
116 fp.fingerprint();
117 }
118 }
119 }
120 }
121
122 // Patch C++ vtable pointer in metadata.
123
124 // Klass and other metadata objects contain references to c++ vtables in the
125 // JVM library.
126 // Fix them to point to our constructed vtables. However, don't iterate
127 // across the space while doing this, as that causes the vtables to be
128 // patched, undoing our useful work. Instead, iterate to make a list,
129 // then use the list to do the fixing.
130 //
131 // Our constructed vtables:
132 // Dump time:
133 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
134 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
135 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
136 // associated metadata to point to jump table rather than to current vtbl
137 // Table layout: NOTE FIXED SIZE
138 // 1. vtbl pointers
139 // 2. #Klass X #virtual methods per Klass
140 // 1 entry for each, in the order:
141 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
142 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
143 // ...
144 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
145 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
146 // Sample entry: (Sparc):
147 // save(sp, -256, sp)
148 // ba,pt common_code
149 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
150 //
151 // Restore time:
152 // 1. initialize_shared_space: reserve space for table
153 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
154 //
155 // Execution time:
156 // First virtual method call for any object of these metadata types:
157 // 1. object->klass
158 // 2. vtable entry for that klass points to the jump table entries
159 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
160 // 4. common_code:
161 // Get address of new vtbl pointer for this Klass from updated table
162 // Update new vtbl pointer in the Klass: future virtual calls go direct
163 // Jump to method, using new vtbl pointer and method index
164
165
166 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
167 void* old_vtbl_ptr = *(void**)obj;
168 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
169 if (vtbl_list[i] == old_vtbl_ptr) {
170 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
171 }
172 }
173 ShouldNotReachHere();
174 return NULL;
175 }
176
177 // Assumes the vtable is in first slot in object.
178 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
179 int n = _global_klass_objects->length();
180 for (int i = 0; i < n; i++) {
181 Klass* obj = _global_klass_objects->at(i);
182 // Note oop_is_instance() is a virtual call. After patching vtables
183 // all virtual calls on the dummy vtables will restore the original!
184 if (obj->oop_is_instance()) {
185 InstanceKlass* ik = InstanceKlass::cast(obj);
186 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
187 ConstantPool* cp = ik->constants();
188 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
189 for (int j = 0; j < ik->methods()->length(); j++) {
190 Method* m = ik->methods()->at(j);
191 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
192 }
193 } else {
194 // Array klasses
195 Klass* k = obj;
196 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
197 }
198 }
199 }
200
201 // Closure for serializing initialization data out to a data area to be
202 // written to the shared file.
203
204 class WriteClosure : public SerializeClosure {
205 private:
206 intptr_t* top;
207 char* end;
208
209 inline void check_space() {
210 if ((char*)top + sizeof(intptr_t) > end) {
211 report_out_of_shared_space(SharedMiscData);
212 }
213 }
214
215 public:
216 WriteClosure(char* md_top, char* md_end) {
217 top = (intptr_t*)md_top;
218 end = md_end;
219 }
220
221 char* get_top() { return (char*)top; }
222
223 void do_ptr(void** p) {
224 check_space();
225 *top = (intptr_t)*p;
226 ++top;
227 }
228
229 void do_tag(int tag) {
230 check_space();
231 *top = (intptr_t)tag;
232 ++top;
233 }
234
235 void do_region(u_char* start, size_t size) {
236 if ((char*)top + size > end) {
237 report_out_of_shared_space(SharedMiscData);
238 }
239 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
240 assert(size % sizeof(intptr_t) == 0, "bad size");
241 do_tag((int)size);
242 while (size > 0) {
243 *top = *(intptr_t*)start;
244 ++top;
245 start += sizeof(intptr_t);
246 size -= sizeof(intptr_t);
247 }
248 }
249
250 bool reading() const { return false; }
251 };
252
253 // This is for dumping detailed statistics for the allocations
254 // in the shared spaces.
255 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
256 public:
257
258 // Here's poor man's enum inheritance
259 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
260 METASPACE_OBJ_TYPES_DO(f) \
261 f(SymbolHashentry) \
262 f(SymbolBuckets) \
263 f(Other)
264
265 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
266 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
267
268 enum Type {
269 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
270 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
271 _number_of_types
272 };
273
274 static const char * type_name(Type type) {
275 switch(type) {
276 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
277 default:
278 ShouldNotReachHere();
279 return NULL;
280 }
281 }
282
283 public:
284 enum {
285 RO = 0,
286 RW = 1
287 };
288
289 int _counts[2][_number_of_types];
290 int _bytes [2][_number_of_types];
291 int _which;
292
293 DumpAllocClosure() {
294 memset(_counts, 0, sizeof(_counts));
295 memset(_bytes, 0, sizeof(_bytes));
296 };
297
298 void iterate_metaspace(Metaspace* space, int which) {
299 assert(which == RO || which == RW, "sanity");
300 _which = which;
301 space->iterate(this);
302 }
303
304 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
305 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
306 _counts[_which][type] ++;
307 _bytes [_which][type] += byte_size;
308 }
309
310 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
311 };
312
313 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
314 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
315 int other_bytes = md_all + mc_all;
316
317 // Calculate size of data that was not allocated by Metaspace::allocate()
318 int symbol_count = _counts[RO][MetaspaceObj::SymbolType];
319 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>);
320 int symbuck_count = SymbolTable::the_table()->table_size();
321 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>);
322
323 _counts[RW][SymbolHashentryType] = symbol_count;
324 _bytes [RW][SymbolHashentryType] = symhash_bytes;
325 other_bytes -= symhash_bytes;
326
327 _counts[RW][SymbolBucketsType] = symbuck_count;
328 _bytes [RW][SymbolBucketsType] = symbuck_bytes;
329 other_bytes -= symbuck_bytes;
330
331 // TODO: count things like dictionary, vtable, etc
332 _bytes[RW][OtherType] = other_bytes;
333
334 // prevent divide-by-zero
335 if (ro_all < 1) {
336 ro_all = 1;
337 }
338 if (rw_all < 1) {
339 rw_all = 1;
340 }
341
342 int all_ro_count = 0;
343 int all_ro_bytes = 0;
344 int all_rw_count = 0;
345 int all_rw_bytes = 0;
346
347 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
348 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
349 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
350 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
351
352 tty->print_cr("Detailed metadata info (rw includes md and mc):");
353 tty->print_cr("%s", hdr);
354 tty->print_cr("%s", sep);
355 for (int type = 0; type < int(_number_of_types); type ++) {
356 const char *name = type_name((Type)type);
357 int ro_count = _counts[RO][type];
358 int ro_bytes = _bytes [RO][type];
359 int rw_count = _counts[RW][type];
360 int rw_bytes = _bytes [RW][type];
361 int count = ro_count + rw_count;
362 int bytes = ro_bytes + rw_bytes;
363
364 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
365 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
366 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
367
368 tty->print_cr(fmt_stats, name,
369 ro_count, ro_bytes, ro_perc,
370 rw_count, rw_bytes, rw_perc,
371 count, bytes, perc);
372
373 all_ro_count += ro_count;
374 all_ro_bytes += ro_bytes;
375 all_rw_count += rw_count;
376 all_rw_bytes += rw_bytes;
377 }
378
379 int all_count = all_ro_count + all_rw_count;
380 int all_bytes = all_ro_bytes + all_rw_bytes;
381
382 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
383 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
384 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
385
386 tty->print_cr("%s", sep);
387 tty->print_cr(fmt_stats, "Total",
388 all_ro_count, all_ro_bytes, all_ro_perc,
389 all_rw_count, all_rw_bytes, all_rw_perc,
390 all_count, all_bytes, all_perc);
391
392 assert(all_ro_bytes == ro_all, "everything should have been counted");
393 assert(all_rw_bytes == rw_all, "everything should have been counted");
394 #undef fmt_stats
395 }
396
397 // Populate the shared space.
398
399 class VM_PopulateDumpSharedSpace: public VM_Operation {
400 private:
401 ClassLoaderData* _loader_data;
402 GrowableArray<Klass*> *_class_promote_order;
403 VirtualSpace _md_vs;
404 VirtualSpace _mc_vs;
405
406 public:
407 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
408 GrowableArray<Klass*> *class_promote_order) :
409 _loader_data(loader_data) {
410
411 // Split up and initialize the misc code and data spaces
412 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
413 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
414 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
415 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
416
417 // Now split into misc sections.
418 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
419 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
420 _md_vs.initialize(md_rs, SharedMiscDataSize);
421 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
422 _class_promote_order = class_promote_order;
423 }
424
425 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
426 void doit(); // outline because gdb sucks
427 }; // class VM_PopulateDumpSharedSpace
428
429
430 void VM_PopulateDumpSharedSpace::doit() {
431 Thread* THREAD = VMThread::vm_thread();
432 NOT_PRODUCT(SystemDictionary::verify();)
433 // The following guarantee is meant to ensure that no loader constraints
434 // exist yet, since the constraints table is not shared. This becomes
435 // more important now that we don't re-initialize vtables/itables for
436 // shared classes at runtime, where constraints were previously created.
437 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
438 "loader constraints are not saved");
439 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
440 "placeholders are not saved");
441 // Revisit and implement this if we prelink method handle call sites:
442 guarantee(SystemDictionary::invoke_method_table() == NULL ||
443 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
444 "invoke method table is not saved");
445
446 // At this point, many classes have been loaded.
447 // Gather systemDictionary classes in a global array and do everything to
448 // that so we don't have to walk the SystemDictionary again.
449 _global_klass_objects = new GrowableArray<Klass*>(1000);
450 Universe::basic_type_classes_do(collect_classes);
451 SystemDictionary::classes_do(collect_classes);
452
453 tty->print_cr("Number of classes %d", _global_klass_objects->length());
454 {
455 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
456 for (int i = 0; i < _global_klass_objects->length(); i++) {
457 Klass* k = _global_klass_objects->at(i);
458 if (k->oop_is_instance()) {
459 num_inst ++;
460 } else if (k->oop_is_objArray()) {
461 num_obj_array ++;
462 } else {
463 assert(k->oop_is_typeArray(), "sanity");
464 num_type_array ++;
465 }
466 }
467 tty->print_cr(" instance classes = %5d", num_inst);
468 tty->print_cr(" obj array classes = %5d", num_obj_array);
469 tty->print_cr(" type array classes = %5d", num_type_array);
470 }
471
472 // Update all the fingerprints in the shared methods.
473 tty->print("Calculating fingerprints ... ");
474 calculate_fingerprints();
475 tty->print_cr("done. ");
476
477 // Remove all references outside the metadata
478 tty->print("Removing unshareable information ... ");
479 remove_unshareable_in_classes();
480 tty->print_cr("done. ");
481
482 // Set up the share data and shared code segments.
483 char* md_low = _md_vs.low();
484 char* md_top = md_low;
485 char* md_end = _md_vs.high();
486 char* mc_low = _mc_vs.low();
487 char* mc_top = mc_low;
488 char* mc_end = _mc_vs.high();
489
490 // Reserve space for the list of Klass*s whose vtables are used
491 // for patching others as needed.
492
493 void** vtbl_list = (void**)md_top;
494 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
495 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
496
497 md_top += vtbl_list_size * sizeof(void*);
498 void* vtable = md_top;
499
500 // Reserve space for a new dummy vtable for klass objects in the
501 // heap. Generate self-patching vtable entries.
502
503 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
504 &md_top, md_end,
505 &mc_top, mc_end);
506
507 // Reorder the system dictionary. (Moving the symbols affects
508 // how the hash table indices are calculated.)
509 // Not doing this either.
510
511 SystemDictionary::reorder_dictionary();
512
513 NOT_PRODUCT(SystemDictionary::verify();)
514
515 // Copy the the symbol table, and the system dictionary to the shared
516 // space in usable form. Copy the hashtable
517 // buckets first [read-write], then copy the linked lists of entries
518 // [read-only].
519
520 SymbolTable::reverse(md_top);
521 NOT_PRODUCT(SymbolTable::verify());
522 SymbolTable::copy_buckets(&md_top, md_end);
523
524 SystemDictionary::reverse();
525 SystemDictionary::copy_buckets(&md_top, md_end);
526
527 ClassLoader::verify();
528 ClassLoader::copy_package_info_buckets(&md_top, md_end);
529 ClassLoader::verify();
530
531 SymbolTable::copy_table(&md_top, md_end);
532 SystemDictionary::copy_table(&md_top, md_end);
533 ClassLoader::verify();
534 ClassLoader::copy_package_info_table(&md_top, md_end);
535 ClassLoader::verify();
536
537 // Write the other data to the output array.
538 WriteClosure wc(md_top, md_end);
539 MetaspaceShared::serialize(&wc);
540 md_top = wc.get_top();
541
542 // Print shared spaces all the time
543 // To make fmt_space be a syntactic constant (for format warnings), use #define.
544 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT
545 Metaspace* ro_space = _loader_data->ro_metaspace();
546 Metaspace* rw_space = _loader_data->rw_metaspace();
547
548 // Allocated size of each space (may not be all occupied)
549 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
550 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
551 const size_t md_alloced = md_end-md_low;
552 const size_t mc_alloced = mc_end-mc_low;
553 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
554
555 // Occupied size of each space.
556 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
557 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
558 const size_t md_bytes = size_t(md_top - md_low);
559 const size_t mc_bytes = size_t(mc_top - mc_low);
560
561 // Percent of total size
562 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
563 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
564 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
565 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
566 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
567
568 // Percent of fullness of each space
569 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
570 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
571 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
572 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
573 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
574
575 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
576 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
577 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
578 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
579 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
580 total_bytes, total_alloced, total_u_perc);
581
582 // Update the vtable pointers in all of the Klass objects in the
583 // heap. They should point to newly generated vtable.
584 patch_klass_vtables(vtbl_list, vtable);
585
586 // dunno what this is for.
587 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
588 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
589 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
590
591 // Create and write the archive file that maps the shared spaces.
592
593 FileMapInfo* mapinfo = new FileMapInfo();
594 mapinfo->populate_header(MetaspaceShared::max_alignment());
595
596 // Pass 1 - update file offsets in header.
597 mapinfo->write_header();
598 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
599 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
600 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
601 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
602 SharedMiscDataSize,
603 false, false);
604 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
605 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
606 SharedMiscCodeSize,
607 true, true);
608
609 // Pass 2 - write data.
610 mapinfo->open_for_write();
611 mapinfo->write_header();
612 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
613 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
614 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
615 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
616 SharedMiscDataSize,
617 false, false);
618 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
619 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
620 SharedMiscCodeSize,
621 true, true);
622 mapinfo->close();
623
624 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
625
626 if (PrintSharedSpaces) {
627 DumpAllocClosure dac;
628 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
629 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
630
631 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
632 }
633 #undef fmt_space
634 }
635
636
637 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) {
638 Klass* k = obj;
639 if (k->oop_is_instance()) {
640 InstanceKlass* ik = (InstanceKlass*) k;
641 // Link the class to cause the bytecodes to be rewritten and the
642 // cpcache to be created. Class verification is done according
643 // to -Xverify setting.
644 _link_classes_made_progress |= try_link_class(ik, THREAD);
645 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
646 }
647 }
648
649 void MetaspaceShared::check_one_shared_class(Klass* k) {
650 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
651 _check_classes_made_progress = true;
652 }
653 }
654
655 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
656 // We need to iterate because verification may cause additional classes
657 // to be loaded.
658 do {
659 _link_classes_made_progress = false;
660 SystemDictionary::classes_do(link_one_shared_class, THREAD);
661 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
662 } while (_link_classes_made_progress);
663
664 if (_has_error_classes) {
665 // Mark all classes whose super class or interfaces failed verification.
666 do {
667 // Not completely sure if we need to do this iteratively. Anyway,
668 // we should come here only if there are unverifiable classes, which
669 // shouldn't happen in normal cases. So better safe than sorry.
670 _check_classes_made_progress = false;
671 SystemDictionary::classes_do(check_one_shared_class);
672 } while (_check_classes_made_progress);
673
674 if (IgnoreUnverifiableClassesDuringDump) {
675 // This is useful when running JCK or SQE tests. You should not
676 // enable this when running real apps.
677 SystemDictionary::remove_classes_in_error_state();
678 } else {
679 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
680 exit(1);
681 }
682 }
683 }
684
685 void MetaspaceShared::prepare_for_dumping() {
686 ClassLoader::initialize_shared_path();
687 FileMapInfo::allocate_classpath_entry_table();
688 }
689
690 // Preload classes from a list, populate the shared spaces and dump to a
691 // file.
692 void MetaspaceShared::preload_and_dump(TRAPS) {
693 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
694 ResourceMark rm;
695
696 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
697 MetaspaceShared::shared_rs()->size(),
698 MetaspaceShared::shared_rs()->base());
699
700 // Preload classes to be shared.
701 // Should use some os:: method rather than fopen() here. aB.
702 const char* class_list_path;
703 if (SharedClassListFile == NULL) {
704 // Construct the path to the class list (in jre/lib)
705 // Walk up two directories from the location of the VM and
706 // optionally tack on "lib" (depending on platform)
707 char class_list_path_str[JVM_MAXPATHLEN];
708 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
709 for (int i = 0; i < 3; i++) {
710 char *end = strrchr(class_list_path_str, *os::file_separator());
711 if (end != NULL) *end = '\0';
712 }
713 int class_list_path_len = (int)strlen(class_list_path_str);
714 if (class_list_path_len >= 3) {
715 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
716 strcat(class_list_path_str, os::file_separator());
717 strcat(class_list_path_str, "lib");
718 }
719 }
720 strcat(class_list_path_str, os::file_separator());
721 strcat(class_list_path_str, "classlist");
722 class_list_path = class_list_path_str;
723 } else {
724 class_list_path = SharedClassListFile;
725 }
726
727 int class_count = 0;
728 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
729
730 // sun.io.Converters
731 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
732 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
733
734 // java.util.HashMap
735 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
736 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
737
738 tty->print_cr("Loading classes to share ...");
739 _has_error_classes = false;
740 class_count += preload_and_dump(class_list_path, class_promote_order,
741 THREAD);
742 if (ExtraSharedClassListFile) {
743 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
744 THREAD);
745 }
746 tty->print_cr("Loading classes to share: done.");
747
748 if (PrintSharedSpaces) {
749 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
750 }
751
752 // Rewrite and link classes
753 tty->print_cr("Rewriting and linking classes ...");
754
755 // Link any classes which got missed. This would happen if we have loaded classes that
756 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
757 // fails verification, all other interfaces that were not specified in the classlist but
758 // are implemented by K are not verified.
759 link_and_cleanup_shared_classes(CATCH);
760 tty->print_cr("Rewriting and linking classes: done");
761
762 // Create and dump the shared spaces. Everything so far is loaded
763 // with the null class loader.
764 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
765 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
766 VMThread::execute(&op);
767
768 // Since various initialization steps have been undone by this process,
769 // it is not reasonable to continue running a java process.
770 exit(0);
771 }
772
773 int MetaspaceShared::preload_and_dump(const char * class_list_path,
774 GrowableArray<Klass*>* class_promote_order,
775 TRAPS) {
776 FILE* file = fopen(class_list_path, "r");
777 char class_name[256];
778 int class_count = 0;
779
780 if (file != NULL) {
781 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
782 if (*class_name == '#') { // comment
783 continue;
784 }
785 // Remove trailing newline
786 size_t name_len = strlen(class_name);
787 if (class_name[name_len-1] == '\n') {
788 class_name[name_len-1] = '\0';
789 }
790
791 // Got a class name - load it.
792 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
793 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
794 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
795 THREAD);
796 CLEAR_PENDING_EXCEPTION;
797 if (klass != NULL) {
798 if (PrintSharedSpaces && Verbose && WizardMode) {
799 tty->print_cr("Shared spaces preloaded: %s", class_name);
800 }
801
802 InstanceKlass* ik = InstanceKlass::cast(klass);
803
804 // Should be class load order as per -XX:+TraceClassLoadingPreorder
805 class_promote_order->append(ik);
806
807 // Link the class to cause the bytecodes to be rewritten and the
808 // cpcache to be created. The linking is done as soon as classes
809 // are loaded in order that the related data structures (klass and
810 // cpCache) are located together.
811 try_link_class(ik, THREAD);
812 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
813
814 class_count++;
815 } else {
816 //tty->print_cr("Preload failed: %s", class_name);
817 }
818 }
819 } else {
820 char errmsg[JVM_MAXPATHLEN];
821 os::lasterror(errmsg, JVM_MAXPATHLEN);
822 tty->print_cr("Loading classlist failed: %s", errmsg);
823 exit(1);
824 }
825
826 return class_count;
827 }
828
829 // Returns true if the class's status has changed
830 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
831 assert(DumpSharedSpaces, "should only be called during dumping");
832 if (ik->init_state() < InstanceKlass::linked) {
833 bool saved = BytecodeVerificationLocal;
834 if (!SharedClassUtil::is_shared_boot_class(ik)) {
835 // The verification decision is based on BytecodeVerificationRemote
836 // for non-system classes. Since we are using the NULL classloader
837 // to load non-system classes during dumping, we need to temporarily
838 // change BytecodeVerificationLocal to be the same as
839 // BytecodeVerificationRemote. Note this can cause the parent system
840 // classes also being verified. The extra overhead is acceptable during
841 // dumping.
842 BytecodeVerificationLocal = BytecodeVerificationRemote;
843 }
844 ik->link_class(THREAD);
845 if (HAS_PENDING_EXCEPTION) {
846 ResourceMark rm;
847 tty->print_cr("Preload Error: Verification failed for %s",
848 ik->external_name());
849 CLEAR_PENDING_EXCEPTION;
850 ik->set_in_error_state();
851 _has_error_classes = true;
852 }
853 BytecodeVerificationLocal = saved;
854 return true;
855 } else {
856 return false;
857 }
858 }
859
860 // Closure for serializing initialization data in from a data area
861 // (ptr_array) read from the shared file.
862
863 class ReadClosure : public SerializeClosure {
864 private:
865 intptr_t** _ptr_array;
866
867 inline intptr_t nextPtr() {
868 return *(*_ptr_array)++;
869 }
870
871 public:
872 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
873
874 void do_ptr(void** p) {
875 assert(*p == NULL, "initializing previous initialized pointer.");
876 intptr_t obj = nextPtr();
877 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
878 "hit tag while initializing ptrs.");
879 *p = (void*)obj;
880 }
881
882 void do_tag(int tag) {
883 int old_tag;
884 old_tag = (int)(intptr_t)nextPtr();
885 // do_int(&old_tag);
886 assert(tag == old_tag, "old tag doesn't match");
887 FileMapInfo::assert_mark(tag == old_tag);
888 }
889
890 void do_region(u_char* start, size_t size) {
891 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
892 assert(size % sizeof(intptr_t) == 0, "bad size");
893 do_tag((int)size);
894 while (size > 0) {
895 *(intptr_t*)start = nextPtr();
896 start += sizeof(intptr_t);
897 size -= sizeof(intptr_t);
898 }
899 }
900
901 bool reading() const { return true; }
902 };
903
904 // Return true if given address is in the mapped shared space.
905 bool MetaspaceShared::is_in_shared_space(const void* p) {
906 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
907 }
908
909 void MetaspaceShared::print_shared_spaces() {
910 if (UseSharedSpaces) {
911 FileMapInfo::current_info()->print_shared_spaces();
912 }
913 }
914
915
916 // Map shared spaces at requested addresses and return if succeeded.
917 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
918 // call, or is_in_shared_space.
919 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
920 size_t image_alignment = mapinfo->alignment();
921
922 #ifndef _WINDOWS
923 // Map in the shared memory and then map the regions on top of it.
924 // On Windows, don't map the memory here because it will cause the
925 // mappings of the regions to fail.
926 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
927 if (!shared_rs.is_reserved()) return false;
928 #endif
929
930 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
931
932 char* _ro_base = NULL;
933 char* _rw_base = NULL;
934 char* _md_base = NULL;
935 char* _mc_base = NULL;
936
937 // Map each shared region
938 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
939 (_rw_base = mapinfo->map_region(rw)) != NULL &&
940 (_md_base = mapinfo->map_region(md)) != NULL &&
941 (_mc_base = mapinfo->map_region(mc)) != NULL &&
942 (image_alignment == (size_t)max_alignment()) &&
943 mapinfo->validate_classpath_entry_table()) {
944 // Success (no need to do anything)
945 return true;
946 } else {
947 // If there was a failure in mapping any of the spaces, unmap the ones
948 // that succeeded
949 if (_ro_base != NULL) mapinfo->unmap_region(ro);
950 if (_rw_base != NULL) mapinfo->unmap_region(rw);
951 if (_md_base != NULL) mapinfo->unmap_region(md);
952 if (_mc_base != NULL) mapinfo->unmap_region(mc);
953 #ifndef _WINDOWS
954 // Release the entire mapped region
955 shared_rs.release();
956 #endif
957 // If -Xshare:on is specified, print out the error message and exit VM,
958 // otherwise, set UseSharedSpaces to false and continue.
959 if (RequireSharedSpaces) {
960 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
961 } else {
962 FLAG_SET_DEFAULT(UseSharedSpaces, false);
963 }
964 return false;
965 }
966 }
967
968 // Read the miscellaneous data from the shared file, and
969 // serialize it out to its various destinations.
970
971 void MetaspaceShared::initialize_shared_spaces() {
972 FileMapInfo *mapinfo = FileMapInfo::current_info();
973
974 char* buffer = mapinfo->region_base(md);
975
976 // Skip over (reserve space for) a list of addresses of C++ vtables
977 // for Klass objects. They get filled in later.
978
979 void** vtbl_list = (void**)buffer;
980 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
981 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
982
983 // Skip over (reserve space for) dummy C++ vtables Klass objects.
984 // They are used as is.
985
986 intptr_t vtable_size = *(intptr_t*)buffer;
987 buffer += sizeof(intptr_t);
988 buffer += vtable_size;
989
990 // Create the symbol table using the bucket array at this spot in the
991 // misc data space. Since the symbol table is often modified, this
992 // region (of mapped pages) will be copy-on-write.
993
994 int symbolTableLen = *(intptr_t*)buffer;
995 buffer += sizeof(intptr_t);
996 int number_of_entries = *(intptr_t*)buffer;
997 buffer += sizeof(intptr_t);
998 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
999 number_of_entries);
1000 buffer += symbolTableLen;
1001
1002 // Create the shared dictionary using the bucket array at this spot in
1003 // the misc data space. Since the shared dictionary table is never
1004 // modified, this region (of mapped pages) will be (effectively, if
1005 // not explicitly) read-only.
1006
1007 int sharedDictionaryLen = *(intptr_t*)buffer;
1008 buffer += sizeof(intptr_t);
1009 number_of_entries = *(intptr_t*)buffer;
1010 buffer += sizeof(intptr_t);
1011 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1012 sharedDictionaryLen,
1013 number_of_entries);
1014 buffer += sharedDictionaryLen;
1015
1016 // Create the package info table using the bucket array at this spot in
1017 // the misc data space. Since the package info table is never
1018 // modified, this region (of mapped pages) will be (effectively, if
1019 // not explicitly) read-only.
1020
1021 int pkgInfoLen = *(intptr_t*)buffer;
1022 buffer += sizeof(intptr_t);
1023 number_of_entries = *(intptr_t*)buffer;
1024 buffer += sizeof(intptr_t);
1025 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1026 number_of_entries);
1027 buffer += pkgInfoLen;
1028 ClassLoader::verify();
1029
1030 // The following data in the shared misc data region are the linked
1031 // list elements (HashtableEntry objects) for the symbol table, string
1032 // table, and shared dictionary. The heap objects referred to by the
1033 // symbol table, string table, and shared dictionary are permanent and
1034 // unmovable. Since new entries added to the string and symbol tables
1035 // are always added at the beginning of the linked lists, THESE LINKED
1036 // LIST ELEMENTS ARE READ-ONLY.
1037
1038 int len = *(intptr_t*)buffer; // skip over symbol table entries
1039 buffer += sizeof(intptr_t);
1040 buffer += len;
1041
1042 len = *(intptr_t*)buffer; // skip over shared dictionary entries
1043 buffer += sizeof(intptr_t);
1044 buffer += len;
1045
1046 len = *(intptr_t*)buffer; // skip over package info table entries
1047 buffer += sizeof(intptr_t);
1048 buffer += len;
1049
1050 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
1051 buffer += sizeof(intptr_t);
1052 buffer += len;
1053
1054 intptr_t* array = (intptr_t*)buffer;
1055 ReadClosure rc(&array);
1056 serialize(&rc);
1057
1058 // Close the mapinfo file
1059 mapinfo->close();
1060
1061 if (PrintSharedArchiveAndExit) {
1062 if (PrintSharedDictionary) {
1063 tty->print_cr("\nShared classes:\n");
1064 SystemDictionary::print_shared(false);
1065 }
1066 if (_archive_loading_failed) {
1067 tty->print_cr("archive is invalid");
1068 vm_exit(1);
1069 } else {
1070 tty->print_cr("archive is valid");
1071 vm_exit(0);
1072 }
1073 }
1074 }
1075
1076 // JVM/TI RedefineClasses() support:
1077 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1078 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1079
1080 if (UseSharedSpaces) {
1081 // remap the shared readonly space to shared readwrite, private
1082 FileMapInfo* mapinfo = FileMapInfo::current_info();
1083 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1084 return false;
1085 }
1086 }
1087 return true;
1088 }