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_failure(bool success, const char* what) {
430 if (!success) {
431 tty->print_cr("Insufficient shared space: please increase -XX:%s= to increase its size", what);
432 exit(1);
433 }
434 }
435 void handle_misc_data_space_failure(bool success) {
436 handle_failure(success, "SharedMiscDataSize");
437 }
438 }; // class VM_PopulateDumpSharedSpace
439
440
441 void VM_PopulateDumpSharedSpace::doit() {
442 Thread* THREAD = VMThread::vm_thread();
443 NOT_PRODUCT(SystemDictionary::verify();)
444 // The following guarantee is meant to ensure that no loader constraints
445 // exist yet, since the constraints table is not shared. This becomes
446 // more important now that we don't re-initialize vtables/itables for
447 // shared classes at runtime, where constraints were previously created.
448 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
449 "loader constraints are not saved");
450 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
451 "placeholders are not saved");
452 // Revisit and implement this if we prelink method handle call sites:
453 guarantee(SystemDictionary::invoke_method_table() == NULL ||
454 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
455 "invoke method table is not saved");
456
457 // At this point, many classes have been loaded.
458 // Gather systemDictionary classes in a global array and do everything to
459 // that so we don't have to walk the SystemDictionary again.
460 _global_klass_objects = new GrowableArray<Klass*>(1000);
461 Universe::basic_type_classes_do(collect_classes);
462 SystemDictionary::classes_do(collect_classes);
463
464 tty->print_cr("Number of classes %d", _global_klass_objects->length());
465 {
466 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
467 for (int i = 0; i < _global_klass_objects->length(); i++) {
468 Klass* k = _global_klass_objects->at(i);
469 if (k->oop_is_instance()) {
470 num_inst ++;
471 } else if (k->oop_is_objArray()) {
472 num_obj_array ++;
473 } else {
474 assert(k->oop_is_typeArray(), "sanity");
475 num_type_array ++;
476 }
477 }
478 tty->print_cr(" instance classes = %5d", num_inst);
479 tty->print_cr(" obj array classes = %5d", num_obj_array);
480 tty->print_cr(" type array classes = %5d", num_type_array);
481 }
482
483 // Update all the fingerprints in the shared methods.
484 tty->print("Calculating fingerprints ... ");
485 calculate_fingerprints();
486 tty->print_cr("done. ");
487
488 // Remove all references outside the metadata
489 tty->print("Removing unshareable information ... ");
490 remove_unshareable_in_classes();
491 tty->print_cr("done. ");
492
493 // Set up the share data and shared code segments.
494 char* md_low = _md_vs.low();
495 char* md_top = md_low;
496 char* md_end = _md_vs.high();
497 char* mc_low = _mc_vs.low();
498 char* mc_top = mc_low;
499 char* mc_end = _mc_vs.high();
500
501 // Reserve space for the list of Klass*s whose vtables are used
502 // for patching others as needed.
503
504 void** vtbl_list = (void**)md_top;
505 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
506 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
507
508 md_top += vtbl_list_size * sizeof(void*);
509 void* vtable = md_top;
510
511 // Reserve space for a new dummy vtable for klass objects in the
512 // heap. Generate self-patching vtable entries.
513
514 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
515 &md_top, md_end,
516 &mc_top, mc_end);
517
518 // Reorder the system dictionary. (Moving the symbols affects
519 // how the hash table indices are calculated.)
520 // Not doing this either.
521
522 SystemDictionary::reorder_dictionary();
523
524 NOT_PRODUCT(SystemDictionary::verify();)
525
526 // Copy the the symbol table, and the system dictionary to the shared
527 // space in usable form. Copy the hashtable
528 // buckets first [read-write], then copy the linked lists of entries
529 // [read-only].
530
531 NOT_PRODUCT(SymbolTable::verify());
532 handle_misc_data_space_failure(SymbolTable::copy_compact_table(&md_top, md_end));
533
534 SystemDictionary::reverse();
535 SystemDictionary::copy_buckets(&md_top, md_end);
536
537 ClassLoader::verify();
538 ClassLoader::copy_package_info_buckets(&md_top, md_end);
539 ClassLoader::verify();
540
541 SystemDictionary::copy_table(&md_top, md_end);
542 ClassLoader::verify();
543 ClassLoader::copy_package_info_table(&md_top, md_end);
544 ClassLoader::verify();
545
546 // Write the other data to the output array.
547 WriteClosure wc(md_top, md_end);
548 MetaspaceShared::serialize(&wc);
549 md_top = wc.get_top();
550
551 // Print shared spaces all the time
552 // To make fmt_space be a syntactic constant (for format warnings), use #define.
553 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT
554 Metaspace* ro_space = _loader_data->ro_metaspace();
555 Metaspace* rw_space = _loader_data->rw_metaspace();
556
557 // Allocated size of each space (may not be all occupied)
558 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
559 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
560 const size_t md_alloced = md_end-md_low;
561 const size_t mc_alloced = mc_end-mc_low;
562 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
563
564 // Occupied size of each space.
565 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
566 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
567 const size_t md_bytes = size_t(md_top - md_low);
568 const size_t mc_bytes = size_t(mc_top - mc_low);
569
570 // Percent of total size
571 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
572 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
573 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
574 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
575 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
576
577 // Percent of fullness of each space
578 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
579 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
580 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
581 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
582 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
583
584 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
585 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
586 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
587 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
588 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
589 total_bytes, total_alloced, total_u_perc);
590
591 // Update the vtable pointers in all of the Klass objects in the
592 // heap. They should point to newly generated vtable.
593 patch_klass_vtables(vtbl_list, vtable);
594
595 // dunno what this is for.
596 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
597 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
598 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
599
600 // Create and write the archive file that maps the shared spaces.
601
602 FileMapInfo* mapinfo = new FileMapInfo();
603 mapinfo->populate_header(MetaspaceShared::max_alignment());
604
605 // Pass 1 - update file offsets in header.
606 mapinfo->write_header();
607 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
608 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
609 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
610 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
611 SharedMiscDataSize,
612 false, false);
613 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
614 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
615 SharedMiscCodeSize,
616 true, true);
617
618 // Pass 2 - write data.
619 mapinfo->open_for_write();
620 mapinfo->set_header_crc(mapinfo->compute_header_crc());
621 mapinfo->write_header();
622 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
623 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
624 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
625 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
626 SharedMiscDataSize,
627 false, false);
628 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
629 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
630 SharedMiscCodeSize,
631 true, true);
632 mapinfo->close();
633
634 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
635
636 if (PrintSharedSpaces) {
637 DumpAllocClosure dac;
638 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
639 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
640
641 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
642 }
643 #undef fmt_space
644 }
645
646
647 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) {
648 Klass* k = obj;
649 if (k->oop_is_instance()) {
650 InstanceKlass* ik = (InstanceKlass*) k;
651 // Link the class to cause the bytecodes to be rewritten and the
652 // cpcache to be created. Class verification is done according
653 // to -Xverify setting.
654 _link_classes_made_progress |= try_link_class(ik, THREAD);
655 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
656 }
657 }
658
659 void MetaspaceShared::check_one_shared_class(Klass* k) {
660 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
661 _check_classes_made_progress = true;
662 }
663 }
664
665 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
666 // We need to iterate because verification may cause additional classes
667 // to be loaded.
668 do {
669 _link_classes_made_progress = false;
670 SystemDictionary::classes_do(link_one_shared_class, THREAD);
671 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
672 } while (_link_classes_made_progress);
673
674 if (_has_error_classes) {
675 // Mark all classes whose super class or interfaces failed verification.
676 do {
677 // Not completely sure if we need to do this iteratively. Anyway,
678 // we should come here only if there are unverifiable classes, which
679 // shouldn't happen in normal cases. So better safe than sorry.
680 _check_classes_made_progress = false;
681 SystemDictionary::classes_do(check_one_shared_class);
682 } while (_check_classes_made_progress);
683
684 if (IgnoreUnverifiableClassesDuringDump) {
685 // This is useful when running JCK or SQE tests. You should not
686 // enable this when running real apps.
687 SystemDictionary::remove_classes_in_error_state();
688 } else {
689 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
690 exit(1);
691 }
692 }
693 }
694
695 void MetaspaceShared::prepare_for_dumping() {
696 ClassLoader::initialize_shared_path();
697 FileMapInfo::allocate_classpath_entry_table();
698 }
699
700 // Preload classes from a list, populate the shared spaces and dump to a
701 // file.
702 void MetaspaceShared::preload_and_dump(TRAPS) {
703 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
704 ResourceMark rm;
705
706 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
707 MetaspaceShared::shared_rs()->size(),
708 MetaspaceShared::shared_rs()->base());
709
710 // Preload classes to be shared.
711 // Should use some os:: method rather than fopen() here. aB.
712 const char* class_list_path;
713 if (SharedClassListFile == NULL) {
714 // Construct the path to the class list (in jre/lib)
715 // Walk up two directories from the location of the VM and
716 // optionally tack on "lib" (depending on platform)
717 char class_list_path_str[JVM_MAXPATHLEN];
718 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
719 for (int i = 0; i < 3; i++) {
720 char *end = strrchr(class_list_path_str, *os::file_separator());
721 if (end != NULL) *end = '\0';
722 }
723 int class_list_path_len = (int)strlen(class_list_path_str);
724 if (class_list_path_len >= 3) {
725 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
726 if (class_list_path_len < JVM_MAXPATHLEN - 4) {
727 jio_snprintf(class_list_path_str + class_list_path_len,
728 sizeof(class_list_path_str) - class_list_path_len,
729 "%slib", os::file_separator());
730 class_list_path_len += 4;
731 }
732 }
733 }
734 if (class_list_path_len < JVM_MAXPATHLEN - 10) {
735 jio_snprintf(class_list_path_str + class_list_path_len,
736 sizeof(class_list_path_str) - class_list_path_len,
737 "%sclasslist", os::file_separator());
738 }
739 class_list_path = class_list_path_str;
740 } else {
741 class_list_path = SharedClassListFile;
742 }
743
744 int class_count = 0;
745 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
746
747 // sun.io.Converters
748 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
749 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
750
751 // java.util.HashMap
752 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
753 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
754
755 tty->print_cr("Loading classes to share ...");
756 _has_error_classes = false;
757 class_count += preload_and_dump(class_list_path, class_promote_order,
758 THREAD);
759 if (ExtraSharedClassListFile) {
760 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
761 THREAD);
762 }
763 tty->print_cr("Loading classes to share: done.");
764
765 if (PrintSharedSpaces) {
766 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
767 }
768
769 // Rewrite and link classes
770 tty->print_cr("Rewriting and linking classes ...");
771
772 // Link any classes which got missed. This would happen if we have loaded classes that
773 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
774 // fails verification, all other interfaces that were not specified in the classlist but
775 // are implemented by K are not verified.
776 link_and_cleanup_shared_classes(CATCH);
777 tty->print_cr("Rewriting and linking classes: done");
778
779 // Create and dump the shared spaces. Everything so far is loaded
780 // with the null class loader.
781 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
782 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
783 VMThread::execute(&op);
784
785 // Since various initialization steps have been undone by this process,
786 // it is not reasonable to continue running a java process.
787 exit(0);
788 }
789
790 int MetaspaceShared::preload_and_dump(const char * class_list_path,
791 GrowableArray<Klass*>* class_promote_order,
792 TRAPS) {
793 FILE* file = fopen(class_list_path, "r");
794 char class_name[256];
795 int class_count = 0;
796
797 if (file != NULL) {
798 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
799 if (*class_name == '#') { // comment
800 continue;
801 }
802 // Remove trailing newline
803 size_t name_len = strlen(class_name);
804 if (class_name[name_len-1] == '\n') {
805 class_name[name_len-1] = '\0';
806 }
807
808 // Got a class name - load it.
809 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
810 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
811 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
812 THREAD);
813 CLEAR_PENDING_EXCEPTION;
814 if (klass != NULL) {
815 if (PrintSharedSpaces && Verbose && WizardMode) {
816 tty->print_cr("Shared spaces preloaded: %s", class_name);
817 }
818
819 InstanceKlass* ik = InstanceKlass::cast(klass);
820
821 // Should be class load order as per -XX:+TraceClassLoadingPreorder
822 class_promote_order->append(ik);
823
824 // Link the class to cause the bytecodes to be rewritten and the
825 // cpcache to be created. The linking is done as soon as classes
826 // are loaded in order that the related data structures (klass and
827 // cpCache) are located together.
828 try_link_class(ik, THREAD);
829 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
830
831 class_count++;
832 } else {
833 //tty->print_cr("Preload failed: %s", class_name);
834 }
835 }
836 fclose(file);
837 } else {
838 char errmsg[JVM_MAXPATHLEN];
839 os::lasterror(errmsg, JVM_MAXPATHLEN);
840 tty->print_cr("Loading classlist failed: %s", errmsg);
841 exit(1);
842 }
843
844 return class_count;
845 }
846
847 // Returns true if the class's status has changed
848 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
849 assert(DumpSharedSpaces, "should only be called during dumping");
850 if (ik->init_state() < InstanceKlass::linked) {
851 bool saved = BytecodeVerificationLocal;
852 if (!SharedClassUtil::is_shared_boot_class(ik)) {
853 // The verification decision is based on BytecodeVerificationRemote
854 // for non-system classes. Since we are using the NULL classloader
855 // to load non-system classes during dumping, we need to temporarily
856 // change BytecodeVerificationLocal to be the same as
857 // BytecodeVerificationRemote. Note this can cause the parent system
858 // classes also being verified. The extra overhead is acceptable during
859 // dumping.
860 BytecodeVerificationLocal = BytecodeVerificationRemote;
861 }
862 ik->link_class(THREAD);
863 if (HAS_PENDING_EXCEPTION) {
864 ResourceMark rm;
865 tty->print_cr("Preload Warning: Verification failed for %s",
866 ik->external_name());
867 CLEAR_PENDING_EXCEPTION;
868 ik->set_in_error_state();
869 _has_error_classes = true;
870 }
871 BytecodeVerificationLocal = saved;
872 return true;
873 } else {
874 return false;
875 }
876 }
877
878 // Closure for serializing initialization data in from a data area
879 // (ptr_array) read from the shared file.
880
881 class ReadClosure : public SerializeClosure {
882 private:
883 intptr_t** _ptr_array;
884
885 inline intptr_t nextPtr() {
886 return *(*_ptr_array)++;
887 }
888
889 public:
890 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
891
892 void do_ptr(void** p) {
893 assert(*p == NULL, "initializing previous initialized pointer.");
894 intptr_t obj = nextPtr();
895 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
896 "hit tag while initializing ptrs.");
897 *p = (void*)obj;
898 }
899
900 void do_tag(int tag) {
901 int old_tag;
902 old_tag = (int)(intptr_t)nextPtr();
903 // do_int(&old_tag);
904 assert(tag == old_tag, "old tag doesn't match");
905 FileMapInfo::assert_mark(tag == old_tag);
906 }
907
908 void do_region(u_char* start, size_t size) {
909 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
910 assert(size % sizeof(intptr_t) == 0, "bad size");
911 do_tag((int)size);
912 while (size > 0) {
913 *(intptr_t*)start = nextPtr();
914 start += sizeof(intptr_t);
915 size -= sizeof(intptr_t);
916 }
917 }
918
919 bool reading() const { return true; }
920 };
921
922 // Return true if given address is in the mapped shared space.
923 bool MetaspaceShared::is_in_shared_space(const void* p) {
924 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
925 }
926
927 void MetaspaceShared::print_shared_spaces() {
928 if (UseSharedSpaces) {
929 FileMapInfo::current_info()->print_shared_spaces();
930 }
931 }
932
933
934 // Map shared spaces at requested addresses and return if succeeded.
935 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
936 // call, or is_in_shared_space.
937 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
938 size_t image_alignment = mapinfo->alignment();
939
940 #ifndef _WINDOWS
941 // Map in the shared memory and then map the regions on top of it.
942 // On Windows, don't map the memory here because it will cause the
943 // mappings of the regions to fail.
944 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
945 if (!shared_rs.is_reserved()) return false;
946 #endif
947
948 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
949
950 char* _ro_base = NULL;
951 char* _rw_base = NULL;
952 char* _md_base = NULL;
953 char* _mc_base = NULL;
954
955 // Map each shared region
956 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
957 mapinfo->verify_region_checksum(ro) &&
958 (_rw_base = mapinfo->map_region(rw)) != NULL &&
959 mapinfo->verify_region_checksum(rw) &&
960 (_md_base = mapinfo->map_region(md)) != NULL &&
961 mapinfo->verify_region_checksum(md) &&
962 (_mc_base = mapinfo->map_region(mc)) != NULL &&
963 mapinfo->verify_region_checksum(mc) &&
964 (image_alignment == (size_t)max_alignment()) &&
965 mapinfo->validate_classpath_entry_table()) {
966 // Success (no need to do anything)
967 return true;
968 } else {
969 // If there was a failure in mapping any of the spaces, unmap the ones
970 // that succeeded
971 if (_ro_base != NULL) mapinfo->unmap_region(ro);
972 if (_rw_base != NULL) mapinfo->unmap_region(rw);
973 if (_md_base != NULL) mapinfo->unmap_region(md);
974 if (_mc_base != NULL) mapinfo->unmap_region(mc);
975 #ifndef _WINDOWS
976 // Release the entire mapped region
977 shared_rs.release();
978 #endif
979 // If -Xshare:on is specified, print out the error message and exit VM,
980 // otherwise, set UseSharedSpaces to false and continue.
981 if (RequireSharedSpaces) {
982 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
983 } else {
984 FLAG_SET_DEFAULT(UseSharedSpaces, false);
985 }
986 return false;
987 }
988 }
989
990 // Read the miscellaneous data from the shared file, and
991 // serialize it out to its various destinations.
992
993 void MetaspaceShared::initialize_shared_spaces() {
994 FileMapInfo *mapinfo = FileMapInfo::current_info();
995
996 char* buffer = mapinfo->region_base(md);
997
998 // Skip over (reserve space for) a list of addresses of C++ vtables
999 // for Klass objects. They get filled in later.
1000
1001 void** vtbl_list = (void**)buffer;
1002 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
1003 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
1004
1005 // Skip over (reserve space for) dummy C++ vtables Klass objects.
1006 // They are used as is.
1007
1008 intptr_t vtable_size = *(intptr_t*)buffer;
1009 buffer += sizeof(intptr_t);
1010 buffer += vtable_size;
1011
1012 // Create the shared symbol table using the bucket array at this spot in the
1013 // misc data space. (Todo: move this to read-only space. Currently
1014 // this is mapped copy-on-write but will never be written into).
1015
1016 buffer = (char*)SymbolTable::init_shared_table(buffer);
1017 SymbolTable::create_table();
1018
1019 // Create the shared dictionary using the bucket array at this spot in
1020 // the misc data space. Since the shared dictionary table is never
1021 // modified, this region (of mapped pages) will be (effectively, if
1022 // not explicitly) read-only.
1023
1024 int sharedDictionaryLen = *(intptr_t*)buffer;
1025 buffer += sizeof(intptr_t);
1026 int number_of_entries = *(intptr_t*)buffer;
1027 buffer += sizeof(intptr_t);
1028 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1029 sharedDictionaryLen,
1030 number_of_entries);
1031 buffer += sharedDictionaryLen;
1032
1033 // Create the package info table using the bucket array at this spot in
1034 // the misc data space. Since the package info table is never
1035 // modified, this region (of mapped pages) will be (effectively, if
1036 // not explicitly) read-only.
1037
1038 int pkgInfoLen = *(intptr_t*)buffer;
1039 buffer += sizeof(intptr_t);
1040 number_of_entries = *(intptr_t*)buffer;
1041 buffer += sizeof(intptr_t);
1042 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1043 number_of_entries);
1044 buffer += pkgInfoLen;
1045 ClassLoader::verify();
1046
1047 // The following data in the shared misc data region are the linked
1048 // list elements (HashtableEntry objects) for the shared dictionary
1049 // and package info table.
1050
1051 int len = *(intptr_t*)buffer; // skip over shared dictionary entries
1052 buffer += sizeof(intptr_t);
1053 buffer += len;
1054
1055 len = *(intptr_t*)buffer; // skip over package info table entries
1056 buffer += sizeof(intptr_t);
1057 buffer += len;
1058
1059 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
1060 buffer += sizeof(intptr_t);
1061 buffer += len;
1062
1063 intptr_t* array = (intptr_t*)buffer;
1064 ReadClosure rc(&array);
1065 serialize(&rc);
1066
1067 // Close the mapinfo file
1068 mapinfo->close();
1069
1070 if (PrintSharedArchiveAndExit) {
1071 if (PrintSharedDictionary) {
1072 tty->print_cr("\nShared classes:\n");
1073 SystemDictionary::print_shared(false);
1074 }
1075 if (_archive_loading_failed) {
1076 tty->print_cr("archive is invalid");
1077 vm_exit(1);
1078 } else {
1079 tty->print_cr("archive is valid");
1080 vm_exit(0);
1081 }
1082 }
1083 }
1084
1085 // JVM/TI RedefineClasses() support:
1086 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1087 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1088
1089 if (UseSharedSpaces) {
1090 // remap the shared readonly space to shared readwrite, private
1091 FileMapInfo* mapinfo = FileMapInfo::current_info();
1092 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1093 return false;
1094 }
1095 }
1096 return true;
1097 }
1098
1099 int MetaspaceShared::count_class(const char* classlist_file) {
1100 if (classlist_file == NULL) {
1101 return 0;
1102 }
1103 char class_name[256];
1104 int class_count = 0;
1105 FILE* file = fopen(classlist_file, "r");
1106 if (file != NULL) {
1107 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
1108 if (*class_name == '#') { // comment
1109 continue;
1110 }
1111 class_count++;
1112 }
1113 fclose(file);
1114 } else {
1115 char errmsg[JVM_MAXPATHLEN];
1116 os::lasterror(errmsg, JVM_MAXPATHLEN);
1117 tty->print_cr("Loading classlist failed: %s", errmsg);
1118 exit(1);
1119 }
1120
1121 return class_count;
1122 }
1123
1124 // the sizes are good for typical large applications that have a lot of shared
1125 // classes
1126 void MetaspaceShared::estimate_regions_size() {
1127 int class_count = count_class(SharedClassListFile);
1128 class_count += count_class(ExtraSharedClassListFile);
1129
1130 if (class_count > LargeThresholdClassCount) {
1131 if (class_count < HugeThresholdClassCount) {
1132 SET_ESTIMATED_SIZE(Large, ReadOnly);
1133 SET_ESTIMATED_SIZE(Large, ReadWrite);
1134 SET_ESTIMATED_SIZE(Large, MiscData);
1135 SET_ESTIMATED_SIZE(Large, MiscCode);
1136 } else {
1137 SET_ESTIMATED_SIZE(Huge, ReadOnly);
1138 SET_ESTIMATED_SIZE(Huge, ReadWrite);
1139 SET_ESTIMATED_SIZE(Huge, MiscData);
1140 SET_ESTIMATED_SIZE(Huge, MiscCode);
1141 }
1142 }
1143 }