1 /*
2 * Copyright (c) 2012, 2013, 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/symbolTable.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "code/codeCache.hpp"
32 #include "memory/filemap.hpp"
33 #include "memory/gcLocker.hpp"
34 #include "memory/metaspace.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "oops/objArrayOop.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "runtime/signature.hpp"
39 #include "runtime/vm_operations.hpp"
40 #include "runtime/vmThread.hpp"
41 #include "utilities/hashtable.inline.hpp"
42
43
44 int MetaspaceShared::_max_alignment = 0;
45
46 ReservedSpace* MetaspaceShared::_shared_rs = NULL;
47
48 // Read/write a data stream for restoring/preserving metadata pointers and
49 // miscellaneous data from/to the shared archive file.
50
51 void MetaspaceShared::serialize(SerializeClosure* soc) {
52 int tag = 0;
53 soc->do_tag(--tag);
54
55 // Verify the sizes of various metadata in the system.
56 soc->do_tag(sizeof(Method));
57 soc->do_tag(sizeof(ConstMethod));
58 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
59 soc->do_tag(sizeof(ConstantPool));
60 soc->do_tag(sizeof(ConstantPoolCache));
61 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
62 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
63 soc->do_tag(sizeof(Symbol));
64
65 // Dump/restore miscellaneous metadata.
66 Universe::serialize(soc, true);
67 soc->do_tag(--tag);
68
69 // Dump/restore references to commonly used names and signatures.
70 vmSymbols::serialize(soc);
71 soc->do_tag(--tag);
72
73 soc->do_tag(666);
74 }
75
76
77 // CDS code for dumping shared archive.
78
79 // Global object for holding classes that have been loaded. Since this
80 // is run at a safepoint just before exit, this is the entire set of classes.
81 static GrowableArray<Klass*>* _global_klass_objects;
82 static void collect_classes(Klass* k) {
83 _global_klass_objects->append_if_missing(k);
84 if (k->oop_is_instance()) {
85 // Add in the array classes too
86 InstanceKlass* ik = InstanceKlass::cast(k);
87 ik->array_klasses_do(collect_classes);
88 }
89 }
90
91 static void remove_unshareable_in_classes() {
92 for (int i = 0; i < _global_klass_objects->length(); i++) {
93 Klass* k = _global_klass_objects->at(i);
94 k->remove_unshareable_info();
95 }
96 }
97
98 // Walk all methods in the class list and assign a fingerprint.
99 // so that this part of the ConstMethod* is read only.
100 static void calculate_fingerprints() {
101 for (int i = 0; i < _global_klass_objects->length(); i++) {
102 Klass* k = _global_klass_objects->at(i);
103 if (k->oop_is_instance()) {
104 InstanceKlass* ik = InstanceKlass::cast(k);
105 for (int i = 0; i < ik->methods()->length(); i++) {
106 Method* m = ik->methods()->at(i);
107 Fingerprinter fp(m);
108 // The side effect of this call sets method's fingerprint field.
109 fp.fingerprint();
110 }
111 }
112 }
113 }
114
115 // Patch C++ vtable pointer in metadata.
116
117 // Klass and other metadata objects contain references to c++ vtables in the
118 // JVM library.
119 // Fix them to point to our constructed vtables. However, don't iterate
120 // across the space while doing this, as that causes the vtables to be
121 // patched, undoing our useful work. Instead, iterate to make a list,
122 // then use the list to do the fixing.
123 //
124 // Our constructed vtables:
125 // Dump time:
126 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
127 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
128 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
129 // associated metadata to point to jump table rather than to current vtbl
130 // Table layout: NOTE FIXED SIZE
131 // 1. vtbl pointers
132 // 2. #Klass X #virtual methods per Klass
133 // 1 entry for each, in the order:
134 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
135 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
136 // ...
137 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
138 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
139 // Sample entry: (Sparc):
140 // save(sp, -256, sp)
141 // ba,pt common_code
142 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
143 //
144 // Restore time:
145 // 1. initialize_shared_space: reserve space for table
146 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
147 //
148 // Execution time:
149 // First virtual method call for any object of these metadata types:
150 // 1. object->klass
151 // 2. vtable entry for that klass points to the jump table entries
152 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
153 // 4. common_code:
154 // Get address of new vtbl pointer for this Klass from updated table
155 // Update new vtbl pointer in the Klass: future virtual calls go direct
156 // Jump to method, using new vtbl pointer and method index
157
158
159 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
160 void* old_vtbl_ptr = *(void**)obj;
161 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
162 if (vtbl_list[i] == old_vtbl_ptr) {
163 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
164 }
165 }
166 ShouldNotReachHere();
167 return NULL;
168 }
169
170 // Assumes the vtable is in first slot in object.
171 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
172 int n = _global_klass_objects->length();
173 for (int i = 0; i < n; i++) {
174 Klass* obj = _global_klass_objects->at(i);
175 // Note oop_is_instance() is a virtual call. After patching vtables
176 // all virtual calls on the dummy vtables will restore the original!
177 if (obj->oop_is_instance()) {
178 InstanceKlass* ik = InstanceKlass::cast(obj);
179 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
180 ConstantPool* cp = ik->constants();
181 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
182 for (int j = 0; j < ik->methods()->length(); j++) {
183 Method* m = ik->methods()->at(j);
184 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
185 }
186 } else {
187 // Array klasses
188 Klass* k = obj;
189 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
190 }
191 }
192 }
193
194 // Closure for serializing initialization data out to a data area to be
195 // written to the shared file.
196
197 class WriteClosure : public SerializeClosure {
198 private:
199 intptr_t* top;
200 char* end;
201
202 inline void check_space() {
203 if ((char*)top + sizeof(intptr_t) > end) {
204 report_out_of_shared_space(SharedMiscData);
205 }
206 }
207
208 public:
209 WriteClosure(char* md_top, char* md_end) {
210 top = (intptr_t*)md_top;
211 end = md_end;
212 }
213
214 char* get_top() { return (char*)top; }
215
216 void do_ptr(void** p) {
217 check_space();
218 *top = (intptr_t)*p;
219 ++top;
220 }
221
222 void do_tag(int tag) {
223 check_space();
224 *top = (intptr_t)tag;
225 ++top;
226 }
227
228 void do_region(u_char* start, size_t size) {
229 if ((char*)top + size > end) {
230 report_out_of_shared_space(SharedMiscData);
231 }
232 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
233 assert(size % sizeof(intptr_t) == 0, "bad size");
234 do_tag((int)size);
235 while (size > 0) {
236 *top = *(intptr_t*)start;
237 ++top;
238 start += sizeof(intptr_t);
239 size -= sizeof(intptr_t);
240 }
241 }
242
243 bool reading() const { return false; }
244 };
245
246 // This is for dumping detailed statistics for the allocations
247 // in the shared spaces.
248 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
249 public:
250
251 // Here's poor man's enum inheritance
252 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
253 METASPACE_OBJ_TYPES_DO(f) \
254 f(SymbolHashentry) \
255 f(SymbolBuckets) \
256 f(Other)
257
258 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
259 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
260
261 enum Type {
262 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
263 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
264 _number_of_types
265 };
266
267 static const char * type_name(Type type) {
268 switch(type) {
269 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
270 default:
271 ShouldNotReachHere();
272 return NULL;
273 }
274 }
275
276 public:
277 enum {
278 RO = 0,
279 RW = 1
280 };
281
282 int _counts[2][_number_of_types];
283 int _bytes [2][_number_of_types];
284 int _which;
285
286 DumpAllocClosure() {
287 memset(_counts, 0, sizeof(_counts));
288 memset(_bytes, 0, sizeof(_bytes));
289 };
290
291 void iterate_metaspace(Metaspace* space, int which) {
292 assert(which == RO || which == RW, "sanity");
293 _which = which;
294 space->iterate(this);
295 }
296
297 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
298 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
299 _counts[_which][type] ++;
300 _bytes [_which][type] += byte_size;
301 }
302
303 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
304 };
305
306 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
307 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
308 int other_bytes = md_all + mc_all;
309
310 // Calculate size of data that was not allocated by Metaspace::allocate()
311 int symbol_count = _counts[RO][MetaspaceObj::SymbolType];
312 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>);
313 int symbuck_count = SymbolTable::the_table()->table_size();
314 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>);
315
316 _counts[RW][SymbolHashentryType] = symbol_count;
317 _bytes [RW][SymbolHashentryType] = symhash_bytes;
318 other_bytes -= symhash_bytes;
319
320 _counts[RW][SymbolBucketsType] = symbuck_count;
321 _bytes [RW][SymbolBucketsType] = symbuck_bytes;
322 other_bytes -= symbuck_bytes;
323
324 // TODO: count things like dictionary, vtable, etc
325 _bytes[RW][OtherType] = other_bytes;
326
327 // prevent divide-by-zero
328 if (ro_all < 1) {
329 ro_all = 1;
330 }
331 if (rw_all < 1) {
332 rw_all = 1;
333 }
334
335 int all_ro_count = 0;
336 int all_ro_bytes = 0;
337 int all_rw_count = 0;
338 int all_rw_bytes = 0;
339
340 const char *fmt = "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f";
341 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
342 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
343
344 tty->print_cr("Detailed metadata info (rw includes md and mc):");
345 tty->print_cr(hdr);
346 tty->print_cr(sep);
347 for (int type = 0; type < int(_number_of_types); type ++) {
348 const char *name = type_name((Type)type);
349 int ro_count = _counts[RO][type];
350 int ro_bytes = _bytes [RO][type];
351 int rw_count = _counts[RW][type];
352 int rw_bytes = _bytes [RW][type];
353 int count = ro_count + rw_count;
354 int bytes = ro_bytes + rw_bytes;
355
356 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
357 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
358 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
359
360 tty->print_cr(fmt, name,
361 ro_count, ro_bytes, ro_perc,
362 rw_count, rw_bytes, rw_perc,
363 count, bytes, perc);
364
365 all_ro_count += ro_count;
366 all_ro_bytes += ro_bytes;
367 all_rw_count += rw_count;
368 all_rw_bytes += rw_bytes;
369 }
370
371 int all_count = all_ro_count + all_rw_count;
372 int all_bytes = all_ro_bytes + all_rw_bytes;
373
374 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
375 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
376 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
377
378 tty->print_cr(sep);
379 tty->print_cr(fmt, "Total",
380 all_ro_count, all_ro_bytes, all_ro_perc,
381 all_rw_count, all_rw_bytes, all_rw_perc,
382 all_count, all_bytes, all_perc);
383
384 assert(all_ro_bytes == ro_all, "everything should have been counted");
385 assert(all_rw_bytes == rw_all, "everything should have been counted");
386 }
387
388 // Populate the shared space.
389
390 class VM_PopulateDumpSharedSpace: public VM_Operation {
391 private:
392 ClassLoaderData* _loader_data;
393 GrowableArray<Klass*> *_class_promote_order;
394 VirtualSpace _md_vs;
395 VirtualSpace _mc_vs;
396
397 public:
398 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
399 GrowableArray<Klass*> *class_promote_order) :
400 _loader_data(loader_data) {
401
402 // Split up and initialize the misc code and data spaces
403 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
404 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
405 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
406 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
407
408 // Now split into misc sections.
409 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
410 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
411 _md_vs.initialize(md_rs, SharedMiscDataSize);
412 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
413 _class_promote_order = class_promote_order;
414 }
415
416 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
417 void doit(); // outline because gdb sucks
418 }; // class VM_PopulateDumpSharedSpace
419
420
421 void VM_PopulateDumpSharedSpace::doit() {
422 Thread* THREAD = VMThread::vm_thread();
423 NOT_PRODUCT(SystemDictionary::verify();)
424 // The following guarantee is meant to ensure that no loader constraints
425 // exist yet, since the constraints table is not shared. This becomes
426 // more important now that we don't re-initialize vtables/itables for
427 // shared classes at runtime, where constraints were previously created.
428 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
429 "loader constraints are not saved");
430 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
431 "placeholders are not saved");
432 // Revisit and implement this if we prelink method handle call sites:
433 guarantee(SystemDictionary::invoke_method_table() == NULL ||
434 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
435 "invoke method table is not saved");
436
437 // At this point, many classes have been loaded.
438 // Gather systemDictionary classes in a global array and do everything to
439 // that so we don't have to walk the SystemDictionary again.
440 _global_klass_objects = new GrowableArray<Klass*>(1000);
441 Universe::basic_type_classes_do(collect_classes);
442 SystemDictionary::classes_do(collect_classes);
443
444 tty->print_cr("Number of classes %d", _global_klass_objects->length());
445
446 // Update all the fingerprints in the shared methods.
447 tty->print("Calculating fingerprints ... ");
448 calculate_fingerprints();
449 tty->print_cr("done. ");
450
451 // Remove all references outside the metadata
452 tty->print("Removing unshareable information ... ");
453 remove_unshareable_in_classes();
454 tty->print_cr("done. ");
455
456 // Set up the share data and shared code segments.
457 char* md_low = _md_vs.low();
458 char* md_top = md_low;
459 char* md_end = _md_vs.high();
460 char* mc_low = _mc_vs.low();
461 char* mc_top = mc_low;
462 char* mc_end = _mc_vs.high();
463
464 // Reserve space for the list of Klass*s whose vtables are used
465 // for patching others as needed.
466
467 void** vtbl_list = (void**)md_top;
468 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
469 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
470
471 md_top += vtbl_list_size * sizeof(void*);
472 void* vtable = md_top;
473
474 // Reserve space for a new dummy vtable for klass objects in the
475 // heap. Generate self-patching vtable entries.
476
477 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
478 &md_top, md_end,
479 &mc_top, mc_end);
480
481 // Reorder the system dictionary. (Moving the symbols affects
482 // how the hash table indices are calculated.)
483 // Not doing this either.
484
485 SystemDictionary::reorder_dictionary();
486
487 NOT_PRODUCT(SystemDictionary::verify();)
488
489 // Copy the the symbol table, and the system dictionary to the shared
490 // space in usable form. Copy the hastable
491 // buckets first [read-write], then copy the linked lists of entries
492 // [read-only].
493
494 SymbolTable::reverse(md_top);
495 NOT_PRODUCT(SymbolTable::verify());
496 SymbolTable::copy_buckets(&md_top, md_end);
497
498 SystemDictionary::reverse();
499 SystemDictionary::copy_buckets(&md_top, md_end);
500
501 ClassLoader::verify();
502 ClassLoader::copy_package_info_buckets(&md_top, md_end);
503 ClassLoader::verify();
504
505 SymbolTable::copy_table(&md_top, md_end);
506 SystemDictionary::copy_table(&md_top, md_end);
507 ClassLoader::verify();
508 ClassLoader::copy_package_info_table(&md_top, md_end);
509 ClassLoader::verify();
510
511 // Write the other data to the output array.
512 WriteClosure wc(md_top, md_end);
513 MetaspaceShared::serialize(&wc);
514 md_top = wc.get_top();
515
516 // Print shared spaces all the time
517 const char* fmt = "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT;
518 Metaspace* ro_space = _loader_data->ro_metaspace();
519 Metaspace* rw_space = _loader_data->rw_metaspace();
520
521 // Allocated size of each space (may not be all occupied)
522 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
523 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
524 const size_t md_alloced = md_end-md_low;
525 const size_t mc_alloced = mc_end-mc_low;
526 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
527
528 // Occupied size of each space.
529 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
530 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
531 const size_t md_bytes = size_t(md_top - md_low);
532 const size_t mc_bytes = size_t(mc_top - mc_low);
533
534 // Percent of total size
535 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
536 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
537 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
538 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
539 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
540
541 // Percent of fullness of each space
542 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
543 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
544 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
545 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
546 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
547
548 tty->print_cr(fmt, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
549 tty->print_cr(fmt, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
550 tty->print_cr(fmt, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
551 tty->print_cr(fmt, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
552 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
553 total_bytes, total_alloced, total_u_perc);
554
555 // Update the vtable pointers in all of the Klass objects in the
556 // heap. They should point to newly generated vtable.
557 patch_klass_vtables(vtbl_list, vtable);
558
559 // dunno what this is for.
560 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
561 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
562 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
563
564 // Create and write the archive file that maps the shared spaces.
565
566 FileMapInfo* mapinfo = new FileMapInfo();
567 mapinfo->populate_header(MetaspaceShared::max_alignment());
568
569 // Pass 1 - update file offsets in header.
570 mapinfo->write_header();
571 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
572 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
573 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
574 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
575 SharedMiscDataSize,
576 false, false);
577 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
578 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
579 SharedMiscCodeSize,
580 true, true);
581
582 // Pass 2 - write data.
583 mapinfo->open_for_write();
584 mapinfo->write_header();
585 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
586 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
587 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
588 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
589 SharedMiscDataSize,
590 false, false);
591 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
592 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
593 SharedMiscCodeSize,
594 true, true);
595 mapinfo->close();
596
597 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
598
599 if (PrintSharedSpaces) {
600 DumpAllocClosure dac;
601 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
602 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
603
604 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
605 }
606 }
607
608 static void link_shared_classes(Klass* obj, TRAPS) {
609 Klass* k = obj;
610 if (k->oop_is_instance()) {
611 InstanceKlass* ik = (InstanceKlass*) k;
612 // Link the class to cause the bytecodes to be rewritten and the
613 // cpcache to be created.
614 if (ik->init_state() < InstanceKlass::linked) {
615 ik->link_class(THREAD);
616 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
617 }
618 }
619 }
620
621
622 // Support for a simple checksum of the contents of the class list
623 // file to prevent trivial tampering. The algorithm matches that in
624 // the MakeClassList program used by the J2SE build process.
625 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
626 static jlong
627 jsum(jlong start, const char *buf, const int len)
628 {
629 jlong h = start;
630 char *p = (char *)buf, *e = p + len;
631 while (p < e) {
632 char c = *p++;
633 if (c <= ' ') {
634 /* Skip spaces and control characters */
635 continue;
636 }
637 h = 31 * h + c;
638 }
639 return h;
640 }
641
642 // Preload classes from a list, populate the shared spaces and dump to a
643 // file.
644 void MetaspaceShared::preload_and_dump(TRAPS) {
645 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
646 ResourceMark rm;
647
648 // Lock out GC - is it necessary? I don't think we care.
649 No_GC_Verifier no_gc;
650
651 // Preload classes to be shared.
652 // Should use some os:: method rather than fopen() here. aB.
653 // Construct the path to the class list (in jre/lib)
654 // Walk up two directories from the location of the VM and
655 // optionally tack on "lib" (depending on platform)
656 char class_list_path[JVM_MAXPATHLEN];
657 os::jvm_path(class_list_path, sizeof(class_list_path));
658 for (int i = 0; i < 3; i++) {
659 char *end = strrchr(class_list_path, *os::file_separator());
660 if (end != NULL) *end = '\0';
661 }
662 int class_list_path_len = (int)strlen(class_list_path);
663 if (class_list_path_len >= 3) {
664 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
665 strcat(class_list_path, os::file_separator());
666 strcat(class_list_path, "lib");
667 }
668 }
669 strcat(class_list_path, os::file_separator());
670 strcat(class_list_path, "classlist");
671
672 FILE* file = fopen(class_list_path, "r");
673 if (file != NULL) {
674 jlong computed_jsum = JSUM_SEED;
675 jlong file_jsum = 0;
676
677 char class_name[256];
678 int class_count = 0;
679 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
680
681 // sun.io.Converters
682 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
683 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
684
685 // java.util.HashMap
686 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
687 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
688
689 tty->print("Loading classes to share ... ");
690 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
691 if (*class_name == '#') {
692 jint fsh, fsl;
693 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
694 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
695 }
696
697 continue;
698 }
699 // Remove trailing newline
700 size_t name_len = strlen(class_name);
701 class_name[name_len-1] = '\0';
702
703 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
704
705 // Got a class name - load it.
706 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
707 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
708 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
709 THREAD);
710 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
711 if (klass != NULL) {
712 if (PrintSharedSpaces && Verbose && WizardMode) {
713 tty->print_cr("Shared spaces preloaded: %s", class_name);
714 }
715
716
717 InstanceKlass* ik = InstanceKlass::cast(klass);
718
719 // Should be class load order as per -XX:+TraceClassLoadingPreorder
720 class_promote_order->append(ik);
721
722 // Link the class to cause the bytecodes to be rewritten and the
723 // cpcache to be created. The linking is done as soon as classes
724 // are loaded in order that the related data structures (klass and
725 // cpCache) are located together.
726
727 if (ik->init_state() < InstanceKlass::linked) {
728 ik->link_class(THREAD);
729 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
730 }
731
732 // TODO: Resolve klasses in constant pool
733 ik->constants()->resolve_class_constants(THREAD);
734
735 class_count++;
736 } else {
737 if (PrintSharedSpaces && Verbose && WizardMode) {
738 tty->cr();
739 tty->print_cr(" Preload failed: %s", class_name);
740 }
741 }
742 file_jsum = 0; // Checksum must be on last line of file
743 }
744 if (computed_jsum != file_jsum) {
745 tty->cr();
746 tty->print_cr("Preload failed: checksum of class list was incorrect.");
747 exit(1);
748 }
749
750 tty->print_cr("done. ");
751
752 if (PrintSharedSpaces) {
753 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
754 }
755
756 // Rewrite and unlink classes.
757 tty->print("Rewriting and linking classes ... ");
758
759 // Link any classes which got missed. (It's not quite clear why
760 // they got missed.) This iteration would be unsafe if we weren't
761 // single-threaded at this point; however we can't do it on the VM
762 // thread because it requires object allocation.
763 SystemDictionary::classes_do(link_shared_classes, CATCH);
764 tty->print_cr("done. ");
765
766 // Create and dump the shared spaces. Everything so far is loaded
767 // with the null class loader.
768 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
769 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
770 VMThread::execute(&op);
771
772 } else {
773 char errmsg[JVM_MAXPATHLEN];
774 os::lasterror(errmsg, JVM_MAXPATHLEN);
775 tty->print_cr("Loading classlist failed: %s", errmsg);
776 exit(1);
777 }
778
779 // Since various initialization steps have been undone by this process,
780 // it is not reasonable to continue running a java process.
781 exit(0);
782 }
783
784
785 // Closure for serializing initialization data in from a data area
786 // (ptr_array) read from the shared file.
787
788 class ReadClosure : public SerializeClosure {
789 private:
790 intptr_t** _ptr_array;
791
792 inline intptr_t nextPtr() {
793 return *(*_ptr_array)++;
794 }
795
796 public:
797 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
798
799 void do_ptr(void** p) {
800 assert(*p == NULL, "initializing previous initialized pointer.");
801 intptr_t obj = nextPtr();
802 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
803 "hit tag while initializing ptrs.");
804 *p = (void*)obj;
805 }
806
807 void do_tag(int tag) {
808 int old_tag;
809 old_tag = (int)(intptr_t)nextPtr();
810 // do_int(&old_tag);
811 assert(tag == old_tag, "old tag doesn't match");
812 FileMapInfo::assert_mark(tag == old_tag);
813 }
814
815 void do_region(u_char* start, size_t size) {
816 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
817 assert(size % sizeof(intptr_t) == 0, "bad size");
818 do_tag((int)size);
819 while (size > 0) {
820 *(intptr_t*)start = nextPtr();
821 start += sizeof(intptr_t);
822 size -= sizeof(intptr_t);
823 }
824 }
825
826 bool reading() const { return true; }
827 };
828
829 // Return true if given address is in the mapped shared space.
830 bool MetaspaceShared::is_in_shared_space(const void* p) {
831 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
832 }
833
834 void MetaspaceShared::print_shared_spaces() {
835 if (UseSharedSpaces) {
836 FileMapInfo::current_info()->print_shared_spaces();
837 }
838 }
839
840
841 // Map shared spaces at requested addresses and return if succeeded.
842 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
843 // call, or is_in_shared_space.
844 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
845 size_t image_alignment = mapinfo->alignment();
846
847 #ifndef _WINDOWS
848 // Map in the shared memory and then map the regions on top of it.
849 // On Windows, don't map the memory here because it will cause the
850 // mappings of the regions to fail.
851 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
852 if (!shared_rs.is_reserved()) return false;
853 #endif
854
855 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
856
857 char* _ro_base = NULL;
858 char* _rw_base = NULL;
859 char* _md_base = NULL;
860 char* _mc_base = NULL;
861
862 // Map each shared region
863 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
864 (_rw_base = mapinfo->map_region(rw)) != NULL &&
865 (_md_base = mapinfo->map_region(md)) != NULL &&
866 (_mc_base = mapinfo->map_region(mc)) != NULL &&
867 (image_alignment == (size_t)max_alignment())) {
868 // Success (no need to do anything)
869 return true;
870 } else {
871 // If there was a failure in mapping any of the spaces, unmap the ones
872 // that succeeded
873 if (_ro_base != NULL) mapinfo->unmap_region(ro);
874 if (_rw_base != NULL) mapinfo->unmap_region(rw);
875 if (_md_base != NULL) mapinfo->unmap_region(md);
876 if (_mc_base != NULL) mapinfo->unmap_region(mc);
877 #ifndef _WINDOWS
878 // Release the entire mapped region
879 shared_rs.release();
880 #endif
881 // If -Xshare:on is specified, print out the error message and exit VM,
882 // otherwise, set UseSharedSpaces to false and continue.
883 if (RequireSharedSpaces) {
884 vm_exit_during_initialization("Unable to use shared archive.", NULL);
885 } else {
886 FLAG_SET_DEFAULT(UseSharedSpaces, false);
887 }
888 return false;
889 }
890 }
891
892 // Read the miscellaneous data from the shared file, and
893 // serialize it out to its various destinations.
894
895 void MetaspaceShared::initialize_shared_spaces() {
896 FileMapInfo *mapinfo = FileMapInfo::current_info();
897
898 char* buffer = mapinfo->region_base(md);
899
900 // Skip over (reserve space for) a list of addresses of C++ vtables
901 // for Klass objects. They get filled in later.
902
903 void** vtbl_list = (void**)buffer;
904 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
905 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
906
907 // Skip over (reserve space for) dummy C++ vtables Klass objects.
908 // They are used as is.
909
910 intptr_t vtable_size = *(intptr_t*)buffer;
911 buffer += sizeof(intptr_t);
912 buffer += vtable_size;
913
914 // Create the symbol table using the bucket array at this spot in the
915 // misc data space. Since the symbol table is often modified, this
916 // region (of mapped pages) will be copy-on-write.
917
918 int symbolTableLen = *(intptr_t*)buffer;
919 buffer += sizeof(intptr_t);
920 int number_of_entries = *(intptr_t*)buffer;
921 buffer += sizeof(intptr_t);
922 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
923 number_of_entries);
924 buffer += symbolTableLen;
925
926 // Create the shared dictionary using the bucket array at this spot in
927 // the misc data space. Since the shared dictionary table is never
928 // modified, this region (of mapped pages) will be (effectively, if
929 // not explicitly) read-only.
930
931 int sharedDictionaryLen = *(intptr_t*)buffer;
932 buffer += sizeof(intptr_t);
933 number_of_entries = *(intptr_t*)buffer;
934 buffer += sizeof(intptr_t);
935 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
936 sharedDictionaryLen,
937 number_of_entries);
938 buffer += sharedDictionaryLen;
939
940 // Create the package info table using the bucket array at this spot in
941 // the misc data space. Since the package info table is never
942 // modified, this region (of mapped pages) will be (effectively, if
943 // not explicitly) read-only.
944
945 int pkgInfoLen = *(intptr_t*)buffer;
946 buffer += sizeof(intptr_t);
947 number_of_entries = *(intptr_t*)buffer;
948 buffer += sizeof(intptr_t);
949 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
950 number_of_entries);
951 buffer += pkgInfoLen;
952 ClassLoader::verify();
953
954 // The following data in the shared misc data region are the linked
955 // list elements (HashtableEntry objects) for the symbol table, string
956 // table, and shared dictionary. The heap objects refered to by the
957 // symbol table, string table, and shared dictionary are permanent and
958 // unmovable. Since new entries added to the string and symbol tables
959 // are always added at the beginning of the linked lists, THESE LINKED
960 // LIST ELEMENTS ARE READ-ONLY.
961
962 int len = *(intptr_t*)buffer; // skip over symbol table entries
963 buffer += sizeof(intptr_t);
964 buffer += len;
965
966 len = *(intptr_t*)buffer; // skip over shared dictionary entries
967 buffer += sizeof(intptr_t);
968 buffer += len;
969
970 len = *(intptr_t*)buffer; // skip over package info table entries
971 buffer += sizeof(intptr_t);
972 buffer += len;
973
974 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
975 buffer += sizeof(intptr_t);
976 buffer += len;
977
978 intptr_t* array = (intptr_t*)buffer;
979 ReadClosure rc(&array);
980 serialize(&rc);
981
982 // Close the mapinfo file
983 mapinfo->close();
984 }
985
986 // JVM/TI RedefineClasses() support:
987 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
988 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
989
990 if (UseSharedSpaces) {
991 // remap the shared readonly space to shared readwrite, private
992 FileMapInfo* mapinfo = FileMapInfo::current_info();
993 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
994 return false;
995 }
996 }
997 return true;
998 }