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 MetaspaceSharedStats MetaspaceShared::_stats;
52
53 bool MetaspaceShared::_link_classes_made_progress;
54 bool MetaspaceShared::_check_classes_made_progress;
55 bool MetaspaceShared::_has_error_classes;
56 bool MetaspaceShared::_archive_loading_failed = false;
57 // Read/write a data stream for restoring/preserving metadata pointers and
58 // miscellaneous data from/to the shared archive file.
59
60 void MetaspaceShared::serialize(SerializeClosure* soc) {
61 int tag = 0;
62 soc->do_tag(--tag);
63
64 // Verify the sizes of various metadata in the system.
65 soc->do_tag(sizeof(Method));
66 soc->do_tag(sizeof(ConstMethod));
67 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
68 soc->do_tag(sizeof(ConstantPool));
69 soc->do_tag(sizeof(ConstantPoolCache));
70 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
71 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
72 soc->do_tag(sizeof(Symbol));
73
74 // Dump/restore miscellaneous metadata.
75 Universe::serialize(soc, true);
76 soc->do_tag(--tag);
77
78 // Dump/restore references to commonly used names and signatures.
79 vmSymbols::serialize(soc);
80 soc->do_tag(--tag);
81
82 soc->do_tag(666);
83 }
84
85
86 // CDS code for dumping shared archive.
87
88 // Global object for holding classes that have been loaded. Since this
89 // is run at a safepoint just before exit, this is the entire set of classes.
90 static GrowableArray<Klass*>* _global_klass_objects;
91 static void collect_classes(Klass* k) {
92 _global_klass_objects->append_if_missing(k);
93 if (k->oop_is_instance()) {
94 // Add in the array classes too
95 InstanceKlass* ik = InstanceKlass::cast(k);
96 ik->array_klasses_do(collect_classes);
97 }
98 }
99
100 static void remove_unshareable_in_classes() {
101 for (int i = 0; i < _global_klass_objects->length(); i++) {
102 Klass* k = _global_klass_objects->at(i);
103 k->remove_unshareable_info();
104 }
105 }
106
107 // Walk all methods in the class list and assign a fingerprint.
108 // so that this part of the ConstMethod* is read only.
109 static void calculate_fingerprints() {
110 for (int i = 0; i < _global_klass_objects->length(); i++) {
111 Klass* k = _global_klass_objects->at(i);
112 if (k->oop_is_instance()) {
113 InstanceKlass* ik = InstanceKlass::cast(k);
114 for (int i = 0; i < ik->methods()->length(); i++) {
115 Method* m = ik->methods()->at(i);
116 Fingerprinter fp(m);
117 // The side effect of this call sets method's fingerprint field.
118 fp.fingerprint();
119 }
120 }
121 }
122 }
123
124 // Patch C++ vtable pointer in metadata.
125
126 // Klass and other metadata objects contain references to c++ vtables in the
127 // JVM library.
128 // Fix them to point to our constructed vtables. However, don't iterate
129 // across the space while doing this, as that causes the vtables to be
130 // patched, undoing our useful work. Instead, iterate to make a list,
131 // then use the list to do the fixing.
132 //
133 // Our constructed vtables:
134 // Dump time:
135 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
136 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
137 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
138 // associated metadata to point to jump table rather than to current vtbl
139 // Table layout: NOTE FIXED SIZE
140 // 1. vtbl pointers
141 // 2. #Klass X #virtual methods per Klass
142 // 1 entry for each, in the order:
143 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
144 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
145 // ...
146 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
147 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
148 // Sample entry: (Sparc):
149 // save(sp, -256, sp)
150 // ba,pt common_code
151 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
152 //
153 // Restore time:
154 // 1. initialize_shared_space: reserve space for table
155 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
156 //
157 // Execution time:
158 // First virtual method call for any object of these metadata types:
159 // 1. object->klass
160 // 2. vtable entry for that klass points to the jump table entries
161 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
162 // 4. common_code:
163 // Get address of new vtbl pointer for this Klass from updated table
164 // Update new vtbl pointer in the Klass: future virtual calls go direct
165 // Jump to method, using new vtbl pointer and method index
166
167
168 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
169 void* old_vtbl_ptr = *(void**)obj;
170 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
171 if (vtbl_list[i] == old_vtbl_ptr) {
172 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
173 }
174 }
175 ShouldNotReachHere();
176 return NULL;
177 }
178
179 // Assumes the vtable is in first slot in object.
180 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
181 int n = _global_klass_objects->length();
182 for (int i = 0; i < n; i++) {
183 Klass* obj = _global_klass_objects->at(i);
184 // Note oop_is_instance() is a virtual call. After patching vtables
185 // all virtual calls on the dummy vtables will restore the original!
186 if (obj->oop_is_instance()) {
187 InstanceKlass* ik = InstanceKlass::cast(obj);
188 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
189 ConstantPool* cp = ik->constants();
190 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
191 for (int j = 0; j < ik->methods()->length(); j++) {
192 Method* m = ik->methods()->at(j);
193 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
194 }
195 } else {
196 // Array klasses
197 Klass* k = obj;
198 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
199 }
200 }
201 }
202
203 // Closure for serializing initialization data out to a data area to be
204 // written to the shared file.
205
206 class WriteClosure : public SerializeClosure {
207 private:
208 intptr_t* top;
209 char* end;
210
211 inline void check_space() {
212 if ((char*)top + sizeof(intptr_t) > end) {
213 report_out_of_shared_space(SharedMiscData);
214 }
215 }
216
217 public:
218 WriteClosure(char* md_top, char* md_end) {
219 top = (intptr_t*)md_top;
220 end = md_end;
221 }
222
223 char* get_top() { return (char*)top; }
224
225 void do_ptr(void** p) {
226 check_space();
227 *top = (intptr_t)*p;
228 ++top;
229 }
230
231 void do_tag(int tag) {
232 check_space();
233 *top = (intptr_t)tag;
234 ++top;
235 }
236
237 void do_region(u_char* start, size_t size) {
238 if ((char*)top + size > end) {
239 report_out_of_shared_space(SharedMiscData);
240 }
241 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
242 assert(size % sizeof(intptr_t) == 0, "bad size");
243 do_tag((int)size);
244 while (size > 0) {
245 *top = *(intptr_t*)start;
246 ++top;
247 start += sizeof(intptr_t);
248 size -= sizeof(intptr_t);
249 }
250 }
251
252 bool reading() const { return false; }
253 };
254
255 // This is for dumping detailed statistics for the allocations
256 // in the shared spaces.
257 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
258 public:
259
260 // Here's poor man's enum inheritance
261 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
262 METASPACE_OBJ_TYPES_DO(f) \
263 f(SymbolHashentry) \
264 f(SymbolBucket) \
265 f(Other)
266
267 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
268 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
269
270 enum Type {
271 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
272 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
273 _number_of_types
274 };
275
276 static const char * type_name(Type type) {
277 switch(type) {
278 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
279 default:
280 ShouldNotReachHere();
281 return NULL;
282 }
283 }
284
285 public:
286 enum {
287 RO = 0,
288 RW = 1
289 };
290
291 int _counts[2][_number_of_types];
292 int _bytes [2][_number_of_types];
293 int _which;
294
295 DumpAllocClosure() {
296 memset(_counts, 0, sizeof(_counts));
297 memset(_bytes, 0, sizeof(_bytes));
298 };
299
300 void iterate_metaspace(Metaspace* space, int which) {
301 assert(which == RO || which == RW, "sanity");
302 _which = which;
303 space->iterate(this);
304 }
305
306 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
307 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
308 _counts[_which][type] ++;
309 _bytes [_which][type] += byte_size;
310 }
311
312 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
313 };
314
315 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
316 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
317 int other_bytes = md_all + mc_all;
318
319 // Calculate size of data that was not allocated by Metaspace::allocate()
320 MetaspaceSharedStats *stats = MetaspaceShared::stats();
321
322 // symbols
323 _counts[RW][SymbolHashentryType] = stats->symbol.hashentry_count;
324 _bytes [RW][SymbolHashentryType] = stats->symbol.hashentry_bytes;
325 other_bytes -= stats->symbol.hashentry_bytes;
326
327 _counts[RW][SymbolBucketType] = stats->symbol.bucket_count;
328 _bytes [RW][SymbolBucketType] = stats->symbol.bucket_bytes;
329 other_bytes -= stats->symbol.bucket_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
428 private:
429 void handle_misc_data_space_failure(bool success) {
430 if (!success) {
431 report_out_of_shared_space(SharedMiscData);
432 }
433 }
434 }; // class VM_PopulateDumpSharedSpace
435
436
437 void VM_PopulateDumpSharedSpace::doit() {
438 Thread* THREAD = VMThread::vm_thread();
439 NOT_PRODUCT(SystemDictionary::verify();)
440 // The following guarantee is meant to ensure that no loader constraints
441 // exist yet, since the constraints table is not shared. This becomes
442 // more important now that we don't re-initialize vtables/itables for
443 // shared classes at runtime, where constraints were previously created.
444 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
445 "loader constraints are not saved");
446 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
447 "placeholders are not saved");
448 // Revisit and implement this if we prelink method handle call sites:
449 guarantee(SystemDictionary::invoke_method_table() == NULL ||
450 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
451 "invoke method table is not saved");
452
453 // At this point, many classes have been loaded.
454 // Gather systemDictionary classes in a global array and do everything to
455 // that so we don't have to walk the SystemDictionary again.
456 _global_klass_objects = new GrowableArray<Klass*>(1000);
457 Universe::basic_type_classes_do(collect_classes);
458 SystemDictionary::classes_do(collect_classes);
459
460 tty->print_cr("Number of classes %d", _global_klass_objects->length());
461 {
462 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
463 for (int i = 0; i < _global_klass_objects->length(); i++) {
464 Klass* k = _global_klass_objects->at(i);
465 if (k->oop_is_instance()) {
466 num_inst ++;
467 } else if (k->oop_is_objArray()) {
468 num_obj_array ++;
469 } else {
470 assert(k->oop_is_typeArray(), "sanity");
471 num_type_array ++;
472 }
473 }
474 tty->print_cr(" instance classes = %5d", num_inst);
475 tty->print_cr(" obj array classes = %5d", num_obj_array);
476 tty->print_cr(" type array classes = %5d", num_type_array);
477 }
478
479 // Update all the fingerprints in the shared methods.
480 tty->print("Calculating fingerprints ... ");
481 calculate_fingerprints();
482 tty->print_cr("done. ");
483
484 // Remove all references outside the metadata
485 tty->print("Removing unshareable information ... ");
486 remove_unshareable_in_classes();
487 tty->print_cr("done. ");
488
489 // Set up the share data and shared code segments.
490 char* md_low = _md_vs.low();
491 char* md_top = md_low;
492 char* md_end = _md_vs.high();
493 char* mc_low = _mc_vs.low();
494 char* mc_top = mc_low;
495 char* mc_end = _mc_vs.high();
496
497 // Reserve space for the list of Klass*s whose vtables are used
498 // for patching others as needed.
499
500 void** vtbl_list = (void**)md_top;
501 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
502 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
503
504 md_top += vtbl_list_size * sizeof(void*);
505 void* vtable = md_top;
506
507 // Reserve space for a new dummy vtable for klass objects in the
508 // heap. Generate self-patching vtable entries.
509
510 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
511 &md_top, md_end,
512 &mc_top, mc_end);
513
514 // Reorder the system dictionary. (Moving the symbols affects
515 // how the hash table indices are calculated.)
516 // Not doing this either.
517
518 SystemDictionary::reorder_dictionary();
519
520 NOT_PRODUCT(SystemDictionary::verify();)
521
522 // Copy the the symbol table, and the system dictionary to the shared
523 // space in usable form. Copy the hashtable
524 // buckets first [read-write], then copy the linked lists of entries
525 // [read-only].
526
527 NOT_PRODUCT(SymbolTable::verify());
528 handle_misc_data_space_failure(SymbolTable::copy_compact_table(&md_top, md_end));
529
530 SystemDictionary::reverse();
531 SystemDictionary::copy_buckets(&md_top, md_end);
532
533 ClassLoader::verify();
534 ClassLoader::copy_package_info_buckets(&md_top, md_end);
535 ClassLoader::verify();
536
537 SystemDictionary::copy_table(&md_top, md_end);
538 ClassLoader::verify();
539 ClassLoader::copy_package_info_table(&md_top, md_end);
540 ClassLoader::verify();
541
542 // Write the other data to the output array.
543 WriteClosure wc(md_top, md_end);
544 MetaspaceShared::serialize(&wc);
545 md_top = wc.get_top();
546
547 // Print shared spaces all the time
548 // To make fmt_space be a syntactic constant (for format warnings), use #define.
549 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT
550 Metaspace* ro_space = _loader_data->ro_metaspace();
551 Metaspace* rw_space = _loader_data->rw_metaspace();
552
553 // Allocated size of each space (may not be all occupied)
554 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
555 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
556 const size_t md_alloced = md_end-md_low;
557 const size_t mc_alloced = mc_end-mc_low;
558 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
559
560 // Occupied size of each space.
561 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
562 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
563 const size_t md_bytes = size_t(md_top - md_low);
564 const size_t mc_bytes = size_t(mc_top - mc_low);
565
566 // Percent of total size
567 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
568 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
569 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
570 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
571 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
572
573 // Percent of fullness of each space
574 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
575 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
576 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
577 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
578 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
579
580 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
581 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
582 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
583 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
584 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
585 total_bytes, total_alloced, total_u_perc);
586
587 // Update the vtable pointers in all of the Klass objects in the
588 // heap. They should point to newly generated vtable.
589 patch_klass_vtables(vtbl_list, vtable);
590
591 // dunno what this is for.
592 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
593 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
594 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
595
596 // Create and write the archive file that maps the shared spaces.
597
598 FileMapInfo* mapinfo = new FileMapInfo();
599 mapinfo->populate_header(MetaspaceShared::max_alignment());
600
601 // Pass 1 - update file offsets in header.
602 mapinfo->write_header();
603 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
604 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
605 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
606 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
607 SharedMiscDataSize,
608 false, false);
609 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
610 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
611 SharedMiscCodeSize,
612 true, true);
613
614 // Pass 2 - write data.
615 mapinfo->open_for_write();
616 mapinfo->set_header_crc(mapinfo->compute_header_crc());
617 mapinfo->write_header();
618 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
619 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
620 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
621 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
622 SharedMiscDataSize,
623 false, false);
624 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
625 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
626 SharedMiscCodeSize,
627 true, true);
628 mapinfo->close();
629
630 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
631
632 if (PrintSharedSpaces) {
633 DumpAllocClosure dac;
634 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
635 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
636
637 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
638 }
639 #undef fmt_space
640 }
641
642
643 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) {
644 Klass* k = obj;
645 if (k->oop_is_instance()) {
646 InstanceKlass* ik = (InstanceKlass*) k;
647 // Link the class to cause the bytecodes to be rewritten and the
648 // cpcache to be created. Class verification is done according
649 // to -Xverify setting.
650 _link_classes_made_progress |= try_link_class(ik, THREAD);
651 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
652 }
653 }
654
655 void MetaspaceShared::check_one_shared_class(Klass* k) {
656 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
657 _check_classes_made_progress = true;
658 }
659 }
660
661 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
662 // We need to iterate because verification may cause additional classes
663 // to be loaded.
664 do {
665 _link_classes_made_progress = false;
666 SystemDictionary::classes_do(link_one_shared_class, THREAD);
667 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
668 } while (_link_classes_made_progress);
669
670 if (_has_error_classes) {
671 // Mark all classes whose super class or interfaces failed verification.
672 do {
673 // Not completely sure if we need to do this iteratively. Anyway,
674 // we should come here only if there are unverifiable classes, which
675 // shouldn't happen in normal cases. So better safe than sorry.
676 _check_classes_made_progress = false;
677 SystemDictionary::classes_do(check_one_shared_class);
678 } while (_check_classes_made_progress);
679
680 if (IgnoreUnverifiableClassesDuringDump) {
681 // This is useful when running JCK or SQE tests. You should not
682 // enable this when running real apps.
683 SystemDictionary::remove_classes_in_error_state();
684 } else {
685 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
686 exit(1);
687 }
688 }
689 }
690
691 void MetaspaceShared::prepare_for_dumping() {
692 ClassLoader::initialize_shared_path();
693 FileMapInfo::allocate_classpath_entry_table();
694 }
695
696 // Preload classes from a list, populate the shared spaces and dump to a
697 // file.
698 void MetaspaceShared::preload_and_dump(TRAPS) {
699 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
700 ResourceMark rm;
701
702 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
703 MetaspaceShared::shared_rs()->size(),
704 MetaspaceShared::shared_rs()->base());
705
706 // Preload classes to be shared.
707 // Should use some os:: method rather than fopen() here. aB.
708 const char* class_list_path;
709 if (SharedClassListFile == NULL) {
710 // Construct the path to the class list (in jre/lib)
711 // Walk up two directories from the location of the VM and
712 // optionally tack on "lib" (depending on platform)
713 char class_list_path_str[JVM_MAXPATHLEN];
714 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
715 for (int i = 0; i < 3; i++) {
716 char *end = strrchr(class_list_path_str, *os::file_separator());
717 if (end != NULL) *end = '\0';
718 }
719 int class_list_path_len = (int)strlen(class_list_path_str);
720 if (class_list_path_len >= 3) {
721 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
722 if (class_list_path_len < JVM_MAXPATHLEN - 4) {
723 jio_snprintf(class_list_path_str + class_list_path_len,
724 sizeof(class_list_path_str) - class_list_path_len,
725 "%slib", os::file_separator());
726 class_list_path_len += 4;
727 }
728 }
729 }
730 if (class_list_path_len < JVM_MAXPATHLEN - 10) {
731 jio_snprintf(class_list_path_str + class_list_path_len,
732 sizeof(class_list_path_str) - class_list_path_len,
733 "%sclasslist", os::file_separator());
734 }
735 class_list_path = class_list_path_str;
736 } else {
737 class_list_path = SharedClassListFile;
738 }
739
740 int class_count = 0;
741 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
742
743 // sun.io.Converters
744 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
745 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
746
747 // java.util.HashMap
748 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
749 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
750
751 tty->print_cr("Loading classes to share ...");
752 _has_error_classes = false;
753 class_count += preload_and_dump(class_list_path, class_promote_order,
754 THREAD);
755 if (ExtraSharedClassListFile) {
756 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
757 THREAD);
758 }
759 tty->print_cr("Loading classes to share: done.");
760
761 if (PrintSharedSpaces) {
762 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
763 }
764
765 // Rewrite and link classes
766 tty->print_cr("Rewriting and linking classes ...");
767
768 // Link any classes which got missed. This would happen if we have loaded classes that
769 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
770 // fails verification, all other interfaces that were not specified in the classlist but
771 // are implemented by K are not verified.
772 link_and_cleanup_shared_classes(CATCH);
773 tty->print_cr("Rewriting and linking classes: done");
774
775 // Create and dump the shared spaces. Everything so far is loaded
776 // with the null class loader.
777 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
778 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
779 VMThread::execute(&op);
780
781 // Since various initialization steps have been undone by this process,
782 // it is not reasonable to continue running a java process.
783 exit(0);
784 }
785
786 int MetaspaceShared::preload_and_dump(const char * class_list_path,
787 GrowableArray<Klass*>* class_promote_order,
788 TRAPS) {
789 FILE* file = fopen(class_list_path, "r");
790 char class_name[256];
791 int class_count = 0;
792
793 if (file != NULL) {
794 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
795 if (*class_name == '#') { // comment
796 continue;
797 }
798 // Remove trailing newline
799 size_t name_len = strlen(class_name);
800 if (class_name[name_len-1] == '\n') {
801 class_name[name_len-1] = '\0';
802 }
803
804 // Got a class name - load it.
805 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
806 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
807 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
808 THREAD);
809 CLEAR_PENDING_EXCEPTION;
810 if (klass != NULL) {
811 if (PrintSharedSpaces && Verbose && WizardMode) {
812 tty->print_cr("Shared spaces preloaded: %s", class_name);
813 }
814
815 InstanceKlass* ik = InstanceKlass::cast(klass);
816
817 // Should be class load order as per -XX:+TraceClassLoadingPreorder
818 class_promote_order->append(ik);
819
820 // Link the class to cause the bytecodes to be rewritten and the
821 // cpcache to be created. The linking is done as soon as classes
822 // are loaded in order that the related data structures (klass and
823 // cpCache) are located together.
824 try_link_class(ik, THREAD);
825 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
826
827 class_count++;
828 } else {
829 //tty->print_cr("Preload failed: %s", class_name);
830 }
831 }
832 fclose(file);
833 } else {
834 char errmsg[JVM_MAXPATHLEN];
835 os::lasterror(errmsg, JVM_MAXPATHLEN);
836 tty->print_cr("Loading classlist failed: %s", errmsg);
837 exit(1);
838 }
839
840 return class_count;
841 }
842
843 // Returns true if the class's status has changed
844 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
845 assert(DumpSharedSpaces, "should only be called during dumping");
846 if (ik->init_state() < InstanceKlass::linked) {
847 bool saved = BytecodeVerificationLocal;
848 if (!SharedClassUtil::is_shared_boot_class(ik)) {
849 // The verification decision is based on BytecodeVerificationRemote
850 // for non-system classes. Since we are using the NULL classloader
851 // to load non-system classes during dumping, we need to temporarily
852 // change BytecodeVerificationLocal to be the same as
853 // BytecodeVerificationRemote. Note this can cause the parent system
854 // classes also being verified. The extra overhead is acceptable during
855 // dumping.
856 BytecodeVerificationLocal = BytecodeVerificationRemote;
857 }
858 ik->link_class(THREAD);
859 if (HAS_PENDING_EXCEPTION) {
860 ResourceMark rm;
861 tty->print_cr("Preload Warning: Verification failed for %s",
862 ik->external_name());
863 CLEAR_PENDING_EXCEPTION;
864 ik->set_in_error_state();
865 _has_error_classes = true;
866 }
867 BytecodeVerificationLocal = saved;
868 return true;
869 } else {
870 return false;
871 }
872 }
873
874 // Closure for serializing initialization data in from a data area
875 // (ptr_array) read from the shared file.
876
877 class ReadClosure : public SerializeClosure {
878 private:
879 intptr_t** _ptr_array;
880
881 inline intptr_t nextPtr() {
882 return *(*_ptr_array)++;
883 }
884
885 public:
886 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
887
888 void do_ptr(void** p) {
889 assert(*p == NULL, "initializing previous initialized pointer.");
890 intptr_t obj = nextPtr();
891 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
892 "hit tag while initializing ptrs.");
893 *p = (void*)obj;
894 }
895
896 void do_tag(int tag) {
897 int old_tag;
898 old_tag = (int)(intptr_t)nextPtr();
899 // do_int(&old_tag);
900 assert(tag == old_tag, "old tag doesn't match");
901 FileMapInfo::assert_mark(tag == old_tag);
902 }
903
904 void do_region(u_char* start, size_t size) {
905 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
906 assert(size % sizeof(intptr_t) == 0, "bad size");
907 do_tag((int)size);
908 while (size > 0) {
909 *(intptr_t*)start = nextPtr();
910 start += sizeof(intptr_t);
911 size -= sizeof(intptr_t);
912 }
913 }
914
915 bool reading() const { return true; }
916 };
917
918 // Return true if given address is in the mapped shared space.
919 bool MetaspaceShared::is_in_shared_space(const void* p) {
920 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
921 }
922
923 void MetaspaceShared::print_shared_spaces() {
924 if (UseSharedSpaces) {
925 FileMapInfo::current_info()->print_shared_spaces();
926 }
927 }
928
929
930 // Map shared spaces at requested addresses and return if succeeded.
931 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
932 // call, or is_in_shared_space.
933 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
934 size_t image_alignment = mapinfo->alignment();
935
936 #ifndef _WINDOWS
937 // Map in the shared memory and then map the regions on top of it.
938 // On Windows, don't map the memory here because it will cause the
939 // mappings of the regions to fail.
940 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
941 if (!shared_rs.is_reserved()) return false;
942 #endif
943
944 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
945
946 char* _ro_base = NULL;
947 char* _rw_base = NULL;
948 char* _md_base = NULL;
949 char* _mc_base = NULL;
950
951 // Map each shared region
952 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
953 mapinfo->verify_region_checksum(ro) &&
954 (_rw_base = mapinfo->map_region(rw)) != NULL &&
955 mapinfo->verify_region_checksum(rw) &&
956 (_md_base = mapinfo->map_region(md)) != NULL &&
957 mapinfo->verify_region_checksum(md) &&
958 (_mc_base = mapinfo->map_region(mc)) != NULL &&
959 mapinfo->verify_region_checksum(mc) &&
960 (image_alignment == (size_t)max_alignment()) &&
961 mapinfo->validate_classpath_entry_table()) {
962 // Success (no need to do anything)
963 return true;
964 } else {
965 // If there was a failure in mapping any of the spaces, unmap the ones
966 // that succeeded
967 if (_ro_base != NULL) mapinfo->unmap_region(ro);
968 if (_rw_base != NULL) mapinfo->unmap_region(rw);
969 if (_md_base != NULL) mapinfo->unmap_region(md);
970 if (_mc_base != NULL) mapinfo->unmap_region(mc);
971 #ifndef _WINDOWS
972 // Release the entire mapped region
973 shared_rs.release();
974 #endif
975 // If -Xshare:on is specified, print out the error message and exit VM,
976 // otherwise, set UseSharedSpaces to false and continue.
977 if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
978 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
979 } else {
980 FLAG_SET_DEFAULT(UseSharedSpaces, false);
981 }
982 return false;
983 }
984 }
985
986 // Read the miscellaneous data from the shared file, and
987 // serialize it out to its various destinations.
988
989 void MetaspaceShared::initialize_shared_spaces() {
990 FileMapInfo *mapinfo = FileMapInfo::current_info();
991
992 char* buffer = mapinfo->region_base(md);
993
994 // Skip over (reserve space for) a list of addresses of C++ vtables
995 // for Klass objects. They get filled in later.
996
997 void** vtbl_list = (void**)buffer;
998 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
999 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
1000
1001 // Skip over (reserve space for) dummy C++ vtables Klass objects.
1002 // They are used as is.
1003
1004 intptr_t vtable_size = *(intptr_t*)buffer;
1005 buffer += sizeof(intptr_t);
1006 buffer += vtable_size;
1007
1008 // Create the shared symbol table using the bucket array at this spot in the
1009 // misc data space. (Todo: move this to read-only space. Currently
1010 // this is mapped copy-on-write but will never be written into).
1011
1012 buffer = (char*)SymbolTable::init_shared_table(buffer);
1013 SymbolTable::create_table();
1014
1015 // Create the shared dictionary using the bucket array at this spot in
1016 // the misc data space. Since the shared dictionary table is never
1017 // modified, this region (of mapped pages) will be (effectively, if
1018 // not explicitly) read-only.
1019
1020 int sharedDictionaryLen = *(intptr_t*)buffer;
1021 buffer += sizeof(intptr_t);
1022 int number_of_entries = *(intptr_t*)buffer;
1023 buffer += sizeof(intptr_t);
1024 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1025 sharedDictionaryLen,
1026 number_of_entries);
1027 buffer += sharedDictionaryLen;
1028
1029 // Create the package info table using the bucket array at this spot in
1030 // the misc data space. Since the package info table is never
1031 // modified, this region (of mapped pages) will be (effectively, if
1032 // not explicitly) read-only.
1033
1034 int pkgInfoLen = *(intptr_t*)buffer;
1035 buffer += sizeof(intptr_t);
1036 number_of_entries = *(intptr_t*)buffer;
1037 buffer += sizeof(intptr_t);
1038 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1039 number_of_entries);
1040 buffer += pkgInfoLen;
1041 ClassLoader::verify();
1042
1043 // The following data in the shared misc data region are the linked
1044 // list elements (HashtableEntry objects) for the shared dictionary
1045 // and package info table.
1046
1047 int len = *(intptr_t*)buffer; // skip over shared dictionary entries
1048 buffer += sizeof(intptr_t);
1049 buffer += len;
1050
1051 len = *(intptr_t*)buffer; // skip over package info table entries
1052 buffer += sizeof(intptr_t);
1053 buffer += len;
1054
1055 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
1056 buffer += sizeof(intptr_t);
1057 buffer += len;
1058
1059 intptr_t* array = (intptr_t*)buffer;
1060 ReadClosure rc(&array);
1061 serialize(&rc);
1062
1063 // Close the mapinfo file
1064 mapinfo->close();
1065
1066 if (PrintSharedArchiveAndExit) {
1067 if (PrintSharedDictionary) {
1068 tty->print_cr("\nShared classes:\n");
1069 SystemDictionary::print_shared(false);
1070 }
1071 if (_archive_loading_failed) {
1072 tty->print_cr("archive is invalid");
1073 vm_exit(1);
1074 } else {
1075 tty->print_cr("archive is valid");
1076 vm_exit(0);
1077 }
1078 }
1079 }
1080
1081 // JVM/TI RedefineClasses() support:
1082 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1083 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1084
1085 if (UseSharedSpaces) {
1086 // remap the shared readonly space to shared readwrite, private
1087 FileMapInfo* mapinfo = FileMapInfo::current_info();
1088 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1089 return false;
1090 }
1091 }
1092 return true;
1093 }
1094
1095 int MetaspaceShared::count_class(const char* classlist_file) {
1096 if (classlist_file == NULL) {
1097 return 0;
1098 }
1099 char class_name[256];
1100 int class_count = 0;
1101 FILE* file = fopen(classlist_file, "r");
1102 if (file != NULL) {
1103 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
1104 if (*class_name == '#') { // comment
1105 continue;
1106 }
1107 class_count++;
1108 }
1109 fclose(file);
1110 } else {
1111 char errmsg[JVM_MAXPATHLEN];
1112 os::lasterror(errmsg, JVM_MAXPATHLEN);
1113 tty->print_cr("Loading classlist failed: %s", errmsg);
1114 exit(1);
1115 }
1116
1117 return class_count;
1118 }
1119
1120 // the sizes are good for typical large applications that have a lot of shared
1121 // classes
1122 void MetaspaceShared::estimate_regions_size() {
1123 int class_count = count_class(SharedClassListFile);
1124 class_count += count_class(ExtraSharedClassListFile);
1125
1126 if (class_count > LargeThresholdClassCount) {
1127 if (class_count < HugeThresholdClassCount) {
1128 SET_ESTIMATED_SIZE(Large, ReadOnly);
1129 SET_ESTIMATED_SIZE(Large, ReadWrite);
1130 SET_ESTIMATED_SIZE(Large, MiscData);
1131 SET_ESTIMATED_SIZE(Large, MiscCode);
1132 } else {
1133 SET_ESTIMATED_SIZE(Huge, ReadOnly);
1134 SET_ESTIMATED_SIZE(Huge, ReadWrite);
1135 SET_ESTIMATED_SIZE(Huge, MiscData);
1136 SET_ESTIMATED_SIZE(Huge, MiscCode);
1137 }
1138 }
1139 }