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/signature.hpp"
40 #include "runtime/vm_operations.hpp"
41 #include "runtime/vmThread.hpp"
42 #include "utilities/hashtable.inline.hpp"
43
44 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
45
46 int MetaspaceShared::_max_alignment = 0;
47
48 ReservedSpace* MetaspaceShared::_shared_rs = NULL;
49
50 bool MetaspaceShared::_link_classes_made_progress;
51 bool MetaspaceShared::_check_classes_made_progress;
52 bool MetaspaceShared::_has_error_classes;
53 bool MetaspaceShared::_archive_loading_failed = false;
54 // Read/write a data stream for restoring/preserving metadata pointers and
55 // miscellaneous data from/to the shared archive file.
56
57 void MetaspaceShared::serialize(SerializeClosure* soc) {
58 int tag = 0;
59 soc->do_tag(--tag);
60
61 // Verify the sizes of various metadata in the system.
62 soc->do_tag(sizeof(Method));
63 soc->do_tag(sizeof(ConstMethod));
64 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
65 soc->do_tag(sizeof(ConstantPool));
66 soc->do_tag(sizeof(ConstantPoolCache));
67 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
68 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
69 soc->do_tag(sizeof(Symbol));
70
71 // Dump/restore miscellaneous metadata.
72 Universe::serialize(soc, true);
73 soc->do_tag(--tag);
74
75 // Dump/restore references to commonly used names and signatures.
76 vmSymbols::serialize(soc);
77 soc->do_tag(--tag);
78
79 soc->do_tag(666);
80 }
81
82
83 // CDS code for dumping shared archive.
84
85 // Global object for holding classes that have been loaded. Since this
86 // is run at a safepoint just before exit, this is the entire set of classes.
87 static GrowableArray<Klass*>* _global_klass_objects;
88 static void collect_classes(Klass* k) {
89 _global_klass_objects->append_if_missing(k);
90 if (k->oop_is_instance()) {
91 // Add in the array classes too
92 InstanceKlass* ik = InstanceKlass::cast(k);
93 ik->array_klasses_do(collect_classes);
94 }
95 }
96
97 static void remove_unshareable_in_classes() {
98 for (int i = 0; i < _global_klass_objects->length(); i++) {
99 Klass* k = _global_klass_objects->at(i);
100 k->remove_unshareable_info();
101 }
102 }
103
104 // Walk all methods in the class list and assign a fingerprint.
105 // so that this part of the ConstMethod* is read only.
106 static void calculate_fingerprints() {
107 for (int i = 0; i < _global_klass_objects->length(); i++) {
108 Klass* k = _global_klass_objects->at(i);
109 if (k->oop_is_instance()) {
110 InstanceKlass* ik = InstanceKlass::cast(k);
111 for (int i = 0; i < ik->methods()->length(); i++) {
112 Method* m = ik->methods()->at(i);
113 Fingerprinter fp(m);
114 // The side effect of this call sets method's fingerprint field.
115 fp.fingerprint();
116 }
117 }
118 }
119 }
120
121 // Patch C++ vtable pointer in metadata.
122
123 // Klass and other metadata objects contain references to c++ vtables in the
124 // JVM library.
125 // Fix them to point to our constructed vtables. However, don't iterate
126 // across the space while doing this, as that causes the vtables to be
127 // patched, undoing our useful work. Instead, iterate to make a list,
128 // then use the list to do the fixing.
129 //
130 // Our constructed vtables:
131 // Dump time:
132 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
133 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
134 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
135 // associated metadata to point to jump table rather than to current vtbl
136 // Table layout: NOTE FIXED SIZE
137 // 1. vtbl pointers
138 // 2. #Klass X #virtual methods per Klass
139 // 1 entry for each, in the order:
140 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
141 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
142 // ...
143 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
144 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
145 // Sample entry: (Sparc):
146 // save(sp, -256, sp)
147 // ba,pt common_code
148 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
149 //
150 // Restore time:
151 // 1. initialize_shared_space: reserve space for table
152 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
153 //
154 // Execution time:
155 // First virtual method call for any object of these metadata types:
156 // 1. object->klass
157 // 2. vtable entry for that klass points to the jump table entries
158 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
159 // 4. common_code:
160 // Get address of new vtbl pointer for this Klass from updated table
161 // Update new vtbl pointer in the Klass: future virtual calls go direct
162 // Jump to method, using new vtbl pointer and method index
163
164
165 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
166 void* old_vtbl_ptr = *(void**)obj;
167 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
168 if (vtbl_list[i] == old_vtbl_ptr) {
169 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
170 }
171 }
172 ShouldNotReachHere();
173 return NULL;
174 }
175
176 // Assumes the vtable is in first slot in object.
177 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
178 int n = _global_klass_objects->length();
179 for (int i = 0; i < n; i++) {
180 Klass* obj = _global_klass_objects->at(i);
181 // Note oop_is_instance() is a virtual call. After patching vtables
182 // all virtual calls on the dummy vtables will restore the original!
183 if (obj->oop_is_instance()) {
184 InstanceKlass* ik = InstanceKlass::cast(obj);
185 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
186 ConstantPool* cp = ik->constants();
187 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
188 for (int j = 0; j < ik->methods()->length(); j++) {
189 Method* m = ik->methods()->at(j);
190 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
191 }
192 } else {
193 // Array klasses
194 Klass* k = obj;
195 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
196 }
197 }
198 }
199
200 // Closure for serializing initialization data out to a data area to be
201 // written to the shared file.
202
203 class WriteClosure : public SerializeClosure {
204 private:
205 intptr_t* top;
206 char* end;
207
208 inline void check_space() {
209 if ((char*)top + sizeof(intptr_t) > end) {
210 report_out_of_shared_space(SharedMiscData);
211 }
212 }
213
214 public:
215 WriteClosure(char* md_top, char* md_end) {
216 top = (intptr_t*)md_top;
217 end = md_end;
218 }
219
220 char* get_top() { return (char*)top; }
221
222 void do_ptr(void** p) {
223 check_space();
224 *top = (intptr_t)*p;
225 ++top;
226 }
227
228 void do_tag(int tag) {
229 check_space();
230 *top = (intptr_t)tag;
231 ++top;
232 }
233
234 void do_region(u_char* start, size_t size) {
235 if ((char*)top + size > end) {
236 report_out_of_shared_space(SharedMiscData);
237 }
238 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
239 assert(size % sizeof(intptr_t) == 0, "bad size");
240 do_tag((int)size);
241 while (size > 0) {
242 *top = *(intptr_t*)start;
243 ++top;
244 start += sizeof(intptr_t);
245 size -= sizeof(intptr_t);
246 }
247 }
248
249 bool reading() const { return false; }
250 };
251
252 // This is for dumping detailed statistics for the allocations
253 // in the shared spaces.
254 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
255 public:
256
257 // Here's poor man's enum inheritance
258 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
259 METASPACE_OBJ_TYPES_DO(f) \
260 f(SymbolHashentry) \
261 f(SymbolBuckets) \
262 f(Other)
263
264 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
265 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
266
267 enum Type {
268 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
269 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
270 _number_of_types
271 };
272
273 static const char * type_name(Type type) {
274 switch(type) {
275 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
276 default:
277 ShouldNotReachHere();
278 return NULL;
279 }
280 }
281
282 public:
283 enum {
284 RO = 0,
285 RW = 1
286 };
287
288 int _counts[2][_number_of_types];
289 int _bytes [2][_number_of_types];
290 int _which;
291
292 DumpAllocClosure() {
293 memset(_counts, 0, sizeof(_counts));
294 memset(_bytes, 0, sizeof(_bytes));
295 };
296
297 void iterate_metaspace(Metaspace* space, int which) {
298 assert(which == RO || which == RW, "sanity");
299 _which = which;
300 space->iterate(this);
301 }
302
303 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
304 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
305 _counts[_which][type] ++;
306 _bytes [_which][type] += byte_size;
307 }
308
309 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
310 };
311
312 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
313 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
314 int other_bytes = md_all + mc_all;
315
316 // Calculate size of data that was not allocated by Metaspace::allocate()
317 int symbol_count = _counts[RO][MetaspaceObj::SymbolType];
318 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>);
319 int symbuck_count = SymbolTable::the_table()->table_size();
320 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>);
321
322 _counts[RW][SymbolHashentryType] = symbol_count;
323 _bytes [RW][SymbolHashentryType] = symhash_bytes;
324 other_bytes -= symhash_bytes;
325
326 _counts[RW][SymbolBucketsType] = symbuck_count;
327 _bytes [RW][SymbolBucketsType] = symbuck_bytes;
328 other_bytes -= symbuck_bytes;
329
330 // TODO: count things like dictionary, vtable, etc
331 _bytes[RW][OtherType] = other_bytes;
332
333 // prevent divide-by-zero
334 if (ro_all < 1) {
335 ro_all = 1;
336 }
337 if (rw_all < 1) {
338 rw_all = 1;
339 }
340
341 int all_ro_count = 0;
342 int all_ro_bytes = 0;
343 int all_rw_count = 0;
344 int all_rw_bytes = 0;
345
346 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
347 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
348 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
349 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
350
351 tty->print_cr("Detailed metadata info (rw includes md and mc):");
352 tty->print_cr("%s", hdr);
353 tty->print_cr("%s", sep);
354 for (int type = 0; type < int(_number_of_types); type ++) {
355 const char *name = type_name((Type)type);
356 int ro_count = _counts[RO][type];
357 int ro_bytes = _bytes [RO][type];
358 int rw_count = _counts[RW][type];
359 int rw_bytes = _bytes [RW][type];
360 int count = ro_count + rw_count;
361 int bytes = ro_bytes + rw_bytes;
362
363 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
364 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
365 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
366
367 tty->print_cr(fmt_stats, name,
368 ro_count, ro_bytes, ro_perc,
369 rw_count, rw_bytes, rw_perc,
370 count, bytes, perc);
371
372 all_ro_count += ro_count;
373 all_ro_bytes += ro_bytes;
374 all_rw_count += rw_count;
375 all_rw_bytes += rw_bytes;
376 }
377
378 int all_count = all_ro_count + all_rw_count;
379 int all_bytes = all_ro_bytes + all_rw_bytes;
380
381 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
382 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
383 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
384
385 tty->print_cr("%s", sep);
386 tty->print_cr(fmt_stats, "Total",
387 all_ro_count, all_ro_bytes, all_ro_perc,
388 all_rw_count, all_rw_bytes, all_rw_perc,
389 all_count, all_bytes, all_perc);
390
391 assert(all_ro_bytes == ro_all, "everything should have been counted");
392 assert(all_rw_bytes == rw_all, "everything should have been counted");
393 #undef fmt_stats
394 }
395
396 // Populate the shared space.
397
398 class VM_PopulateDumpSharedSpace: public VM_Operation {
399 private:
400 ClassLoaderData* _loader_data;
401 GrowableArray<Klass*> *_class_promote_order;
402 VirtualSpace _md_vs;
403 VirtualSpace _mc_vs;
404
405 public:
406 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
407 GrowableArray<Klass*> *class_promote_order) :
408 _loader_data(loader_data) {
409
410 // Split up and initialize the misc code and data spaces
411 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
412 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
413 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
414 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
415
416 // Now split into misc sections.
417 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
418 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
419 _md_vs.initialize(md_rs, SharedMiscDataSize);
420 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
421 _class_promote_order = class_promote_order;
422 }
423
424 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
425 void doit(); // outline because gdb sucks
426 }; // class VM_PopulateDumpSharedSpace
427
428
429 void VM_PopulateDumpSharedSpace::doit() {
430 Thread* THREAD = VMThread::vm_thread();
431 NOT_PRODUCT(SystemDictionary::verify();)
432 // The following guarantee is meant to ensure that no loader constraints
433 // exist yet, since the constraints table is not shared. This becomes
434 // more important now that we don't re-initialize vtables/itables for
435 // shared classes at runtime, where constraints were previously created.
436 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
437 "loader constraints are not saved");
438 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
439 "placeholders are not saved");
440 // Revisit and implement this if we prelink method handle call sites:
441 guarantee(SystemDictionary::invoke_method_table() == NULL ||
442 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
443 "invoke method table is not saved");
444
445 // At this point, many classes have been loaded.
446 // Gather systemDictionary classes in a global array and do everything to
447 // that so we don't have to walk the SystemDictionary again.
448 _global_klass_objects = new GrowableArray<Klass*>(1000);
449 Universe::basic_type_classes_do(collect_classes);
450 SystemDictionary::classes_do(collect_classes);
451
452 tty->print_cr("Number of classes %d", _global_klass_objects->length());
453 {
454 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
455 for (int i = 0; i < _global_klass_objects->length(); i++) {
456 Klass* k = _global_klass_objects->at(i);
457 if (k->oop_is_instance()) {
458 num_inst ++;
459 } else if (k->oop_is_objArray()) {
460 num_obj_array ++;
461 } else {
462 assert(k->oop_is_typeArray(), "sanity");
463 num_type_array ++;
464 }
465 }
466 tty->print_cr(" instance classes = %5d", num_inst);
467 tty->print_cr(" obj array classes = %5d", num_obj_array);
468 tty->print_cr(" type array classes = %5d", num_type_array);
469 }
470
471 // Update all the fingerprints in the shared methods.
472 tty->print("Calculating fingerprints ... ");
473 calculate_fingerprints();
474 tty->print_cr("done. ");
475
476 // Remove all references outside the metadata
477 tty->print("Removing unshareable information ... ");
478 remove_unshareable_in_classes();
479 tty->print_cr("done. ");
480
481 // Set up the share data and shared code segments.
482 char* md_low = _md_vs.low();
483 char* md_top = md_low;
484 char* md_end = _md_vs.high();
485 char* mc_low = _mc_vs.low();
486 char* mc_top = mc_low;
487 char* mc_end = _mc_vs.high();
488
489 // Reserve space for the list of Klass*s whose vtables are used
490 // for patching others as needed.
491
492 void** vtbl_list = (void**)md_top;
493 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
494 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
495
496 md_top += vtbl_list_size * sizeof(void*);
497 void* vtable = md_top;
498
499 // Reserve space for a new dummy vtable for klass objects in the
500 // heap. Generate self-patching vtable entries.
501
502 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
503 &md_top, md_end,
504 &mc_top, mc_end);
505
506 // Reorder the system dictionary. (Moving the symbols affects
507 // how the hash table indices are calculated.)
508 // Not doing this either.
509
510 SystemDictionary::reorder_dictionary();
511
512 NOT_PRODUCT(SystemDictionary::verify();)
513
514 // Copy the the symbol table, and the system dictionary to the shared
515 // space in usable form. Copy the hastable
516 // buckets first [read-write], then copy the linked lists of entries
517 // [read-only].
518
519 SymbolTable::reverse(md_top);
520 NOT_PRODUCT(SymbolTable::verify());
521 SymbolTable::copy_buckets(&md_top, md_end);
522
523 SystemDictionary::reverse();
524 SystemDictionary::copy_buckets(&md_top, md_end);
525
526 ClassLoader::verify();
527 ClassLoader::copy_package_info_buckets(&md_top, md_end);
528 ClassLoader::verify();
529
530 SymbolTable::copy_table(&md_top, md_end);
531 SystemDictionary::copy_table(&md_top, md_end);
532 ClassLoader::verify();
533 ClassLoader::copy_package_info_table(&md_top, md_end);
534 ClassLoader::verify();
535
536 // Write the other data to the output array.
537 WriteClosure wc(md_top, md_end);
538 MetaspaceShared::serialize(&wc);
539 md_top = wc.get_top();
540
541 // Print shared spaces all the time
542 // To make fmt_space be a syntactic constant (for format warnings), use #define.
543 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT
544 Metaspace* ro_space = _loader_data->ro_metaspace();
545 Metaspace* rw_space = _loader_data->rw_metaspace();
546
547 // Allocated size of each space (may not be all occupied)
548 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
549 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
550 const size_t md_alloced = md_end-md_low;
551 const size_t mc_alloced = mc_end-mc_low;
552 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
553
554 // Occupied size of each space.
555 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
556 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
557 const size_t md_bytes = size_t(md_top - md_low);
558 const size_t mc_bytes = size_t(mc_top - mc_low);
559
560 // Percent of total size
561 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
562 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
563 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
564 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
565 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
566
567 // Percent of fullness of each space
568 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
569 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
570 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
571 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
572 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
573
574 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
575 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
576 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
577 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
578 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
579 total_bytes, total_alloced, total_u_perc);
580
581 // Update the vtable pointers in all of the Klass objects in the
582 // heap. They should point to newly generated vtable.
583 patch_klass_vtables(vtbl_list, vtable);
584
585 // dunno what this is for.
586 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
587 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
588 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
589
590 // Create and write the archive file that maps the shared spaces.
591
592 FileMapInfo* mapinfo = new FileMapInfo();
593 mapinfo->populate_header(MetaspaceShared::max_alignment());
594
595 // Pass 1 - update file offsets in header.
596 mapinfo->write_header();
597 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
598 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
599 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
600 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
601 SharedMiscDataSize,
602 false, false);
603 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
604 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
605 SharedMiscCodeSize,
606 true, true);
607
608 // Pass 2 - write data.
609 mapinfo->open_for_write();
610 mapinfo->set_header_crc(mapinfo->compute_header_crc());
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 fclose(file);
820 } else {
821 char errmsg[JVM_MAXPATHLEN];
822 os::lasterror(errmsg, JVM_MAXPATHLEN);
823 tty->print_cr("Loading classlist failed: %s", errmsg);
824 exit(1);
825 }
826
827 return class_count;
828 }
829
830 // Returns true if the class's status has changed
831 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
832 assert(DumpSharedSpaces, "should only be called during dumping");
833 if (ik->init_state() < InstanceKlass::linked) {
834 bool saved = BytecodeVerificationLocal;
835 if (!SharedClassUtil::is_shared_boot_class(ik)) {
836 // The verification decision is based on BytecodeVerificationRemote
837 // for non-system classes. Since we are using the NULL classloader
838 // to load non-system classes during dumping, we need to temporarily
839 // change BytecodeVerificationLocal to be the same as
840 // BytecodeVerificationRemote. Note this can cause the parent system
841 // classes also being verified. The extra overhead is acceptable during
842 // dumping.
843 BytecodeVerificationLocal = BytecodeVerificationRemote;
844 }
845 ik->link_class(THREAD);
846 if (HAS_PENDING_EXCEPTION) {
847 ResourceMark rm;
848 tty->print_cr("Preload Error: Verification failed for %s",
849 ik->external_name());
850 CLEAR_PENDING_EXCEPTION;
851 ik->set_in_error_state();
852 _has_error_classes = true;
853 }
854 BytecodeVerificationLocal = saved;
855 return true;
856 } else {
857 return false;
858 }
859 }
860
861 // Closure for serializing initialization data in from a data area
862 // (ptr_array) read from the shared file.
863
864 class ReadClosure : public SerializeClosure {
865 private:
866 intptr_t** _ptr_array;
867
868 inline intptr_t nextPtr() {
869 return *(*_ptr_array)++;
870 }
871
872 public:
873 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
874
875 void do_ptr(void** p) {
876 assert(*p == NULL, "initializing previous initialized pointer.");
877 intptr_t obj = nextPtr();
878 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
879 "hit tag while initializing ptrs.");
880 *p = (void*)obj;
881 }
882
883 void do_tag(int tag) {
884 int old_tag;
885 old_tag = (int)(intptr_t)nextPtr();
886 // do_int(&old_tag);
887 assert(tag == old_tag, "old tag doesn't match");
888 FileMapInfo::assert_mark(tag == old_tag);
889 }
890
891 void do_region(u_char* start, size_t size) {
892 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
893 assert(size % sizeof(intptr_t) == 0, "bad size");
894 do_tag((int)size);
895 while (size > 0) {
896 *(intptr_t*)start = nextPtr();
897 start += sizeof(intptr_t);
898 size -= sizeof(intptr_t);
899 }
900 }
901
902 bool reading() const { return true; }
903 };
904
905 // Return true if given address is in the mapped shared space.
906 bool MetaspaceShared::is_in_shared_space(const void* p) {
907 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
908 }
909
910 void MetaspaceShared::print_shared_spaces() {
911 if (UseSharedSpaces) {
912 FileMapInfo::current_info()->print_shared_spaces();
913 }
914 }
915
916
917 // Map shared spaces at requested addresses and return if succeeded.
918 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
919 // call, or is_in_shared_space.
920 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
921 size_t image_alignment = mapinfo->alignment();
922
923 #ifndef _WINDOWS
924 // Map in the shared memory and then map the regions on top of it.
925 // On Windows, don't map the memory here because it will cause the
926 // mappings of the regions to fail.
927 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
928 if (!shared_rs.is_reserved()) return false;
929 #endif
930
931 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
932
933 char* _ro_base = NULL;
934 char* _rw_base = NULL;
935 char* _md_base = NULL;
936 char* _mc_base = NULL;
937
938 // Map each shared region
939 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
940 mapinfo->verify_region_checksum(ro) &&
941 (_rw_base = mapinfo->map_region(rw)) != NULL &&
942 mapinfo->verify_region_checksum(rw) &&
943 (_md_base = mapinfo->map_region(md)) != NULL &&
944 mapinfo->verify_region_checksum(md) &&
945 (_mc_base = mapinfo->map_region(mc)) != NULL &&
946 mapinfo->verify_region_checksum(mc) &&
947 (image_alignment == (size_t)max_alignment()) &&
948 mapinfo->validate_classpath_entry_table()) {
949 // Success (no need to do anything)
950 return true;
951 } else {
952 // If there was a failure in mapping any of the spaces, unmap the ones
953 // that succeeded
954 if (_ro_base != NULL) mapinfo->unmap_region(ro);
955 if (_rw_base != NULL) mapinfo->unmap_region(rw);
956 if (_md_base != NULL) mapinfo->unmap_region(md);
957 if (_mc_base != NULL) mapinfo->unmap_region(mc);
958 #ifndef _WINDOWS
959 // Release the entire mapped region
960 shared_rs.release();
961 #endif
962 // If -Xshare:on is specified, print out the error message and exit VM,
963 // otherwise, set UseSharedSpaces to false and continue.
964 if (RequireSharedSpaces) {
965 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
966 } else {
967 FLAG_SET_DEFAULT(UseSharedSpaces, false);
968 }
969 return false;
970 }
971 }
972
973 // Read the miscellaneous data from the shared file, and
974 // serialize it out to its various destinations.
975
976 void MetaspaceShared::initialize_shared_spaces() {
977 FileMapInfo *mapinfo = FileMapInfo::current_info();
978
979 char* buffer = mapinfo->region_base(md);
980
981 // Skip over (reserve space for) a list of addresses of C++ vtables
982 // for Klass objects. They get filled in later.
983
984 void** vtbl_list = (void**)buffer;
985 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
986 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
987
988 // Skip over (reserve space for) dummy C++ vtables Klass objects.
989 // They are used as is.
990
991 intptr_t vtable_size = *(intptr_t*)buffer;
992 buffer += sizeof(intptr_t);
993 buffer += vtable_size;
994
995 // Create the symbol table using the bucket array at this spot in the
996 // misc data space. Since the symbol table is often modified, this
997 // region (of mapped pages) will be copy-on-write.
998
999 int symbolTableLen = *(intptr_t*)buffer;
1000 buffer += sizeof(intptr_t);
1001 int number_of_entries = *(intptr_t*)buffer;
1002 buffer += sizeof(intptr_t);
1003 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
1004 number_of_entries);
1005 buffer += symbolTableLen;
1006
1007 // Create the shared dictionary using the bucket array at this spot in
1008 // the misc data space. Since the shared dictionary table is never
1009 // modified, this region (of mapped pages) will be (effectively, if
1010 // not explicitly) read-only.
1011
1012 int sharedDictionaryLen = *(intptr_t*)buffer;
1013 buffer += sizeof(intptr_t);
1014 number_of_entries = *(intptr_t*)buffer;
1015 buffer += sizeof(intptr_t);
1016 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1017 sharedDictionaryLen,
1018 number_of_entries);
1019 buffer += sharedDictionaryLen;
1020
1021 // Create the package info table using the bucket array at this spot in
1022 // the misc data space. Since the package info table is never
1023 // modified, this region (of mapped pages) will be (effectively, if
1024 // not explicitly) read-only.
1025
1026 int pkgInfoLen = *(intptr_t*)buffer;
1027 buffer += sizeof(intptr_t);
1028 number_of_entries = *(intptr_t*)buffer;
1029 buffer += sizeof(intptr_t);
1030 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1031 number_of_entries);
1032 buffer += pkgInfoLen;
1033 ClassLoader::verify();
1034
1035 // The following data in the shared misc data region are the linked
1036 // list elements (HashtableEntry objects) for the symbol table, string
1037 // table, and shared dictionary. The heap objects refered to by the
1038 // symbol table, string table, and shared dictionary are permanent and
1039 // unmovable. Since new entries added to the string and symbol tables
1040 // are always added at the beginning of the linked lists, THESE LINKED
1041 // LIST ELEMENTS ARE READ-ONLY.
1042
1043 int len = *(intptr_t*)buffer; // skip over symbol table entries
1044 buffer += sizeof(intptr_t);
1045 buffer += len;
1046
1047 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 }