1 /*
2 * Copyright (c) 2012, 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 int MetaspaceShared::max_alignment() { return _max_alignment; }
46 void MetaspaceShared::set_max_alignment(int alignment) { _max_alignment = alignment; }
47
48 // Accessor functions to save shared space created for metadata, which has
49 // extra space allocated at the end for miscellaneous data and code.
50 ReservedSpace* MetaspaceShared::_shared_rs = NULL;
51 ReservedSpace* MetaspaceShared::shared_rs() { return _shared_rs; }
52 void MetaspaceShared::set_shared_rs(ReservedSpace* rs) { _shared_rs = rs; }
53
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 assert(!UseCompressedOops, "UseCompressedOops doesn't work with shared archive");
62 // Verify the sizes of various metadata in the system.
63 soc->do_tag(sizeof(Method));
64 soc->do_tag(sizeof(ConstMethod));
65 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
66 soc->do_tag(sizeof(ConstantPool));
67 soc->do_tag(sizeof(ConstantPoolCache));
68 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
69 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
70 soc->do_tag(sizeof(Symbol));
71
72 // Dump/restore miscellaneous metadata.
73 Universe::serialize(soc, true);
74 soc->do_tag(--tag);
75
76 // Dump/restore references to commonly used names and signatures.
77 vmSymbols::serialize(soc);
78 soc->do_tag(--tag);
79
80 soc->do_tag(666);
81 }
82
83
84 // CDS code for dumping shared archive.
85
86 // Global object for holding classes that have been loaded. Since this
87 // is run at a safepoint just before exit, this is the entire set of classes.
88 static GrowableArray<Klass*>* _global_klass_objects;
89 static void collect_classes(Klass* k) {
90 _global_klass_objects->append_if_missing(k);
91 if (k->oop_is_instance()) {
92 // Add in the array classes too
93 InstanceKlass* ik = InstanceKlass::cast(k);
94 ik->array_klasses_do(collect_classes);
95 }
96 }
97
98 static void remove_unshareable_in_classes() {
99 for (int i = 0; i < _global_klass_objects->length(); i++) {
100 Klass* k = _global_klass_objects->at(i);
101 k->remove_unshareable_info();
102 }
103 }
104
105 // Walk all methods in the class list and assign a fingerprint.
106 // so that this part of the ConstMethod* is read only.
107 static void calculate_fingerprints() {
108 for (int i = 0; i < _global_klass_objects->length(); i++) {
109 Klass* k = _global_klass_objects->at(i);
110 if (k->oop_is_instance()) {
111 InstanceKlass* ik = InstanceKlass::cast(k);
112 for (int i = 0; i < ik->methods()->length(); i++) {
113 ResourceMark rm;
114 Method* m = ik->methods()->at(i);
115 (new Fingerprinter(m))->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
253 // Populate the shared space.
254
255 class VM_PopulateDumpSharedSpace: public VM_Operation {
256 private:
257 ClassLoaderData* _loader_data;
258 GrowableArray<Klass*> *_class_promote_order;
259 VirtualSpace _md_vs;
260 VirtualSpace _mc_vs;
261
262 public:
263 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
264 GrowableArray<Klass*> *class_promote_order) :
265 _loader_data(loader_data) {
266
267 // Split up and initialize the misc code and data spaces
268 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
269 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
270 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
271 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
272
273 // Now split into misc sections.
274 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
275 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
276 _md_vs.initialize(md_rs, SharedMiscDataSize);
277 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
278 _class_promote_order = class_promote_order;
279 }
280
281 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
282 void doit(); // outline because gdb sucks
283 }; // class VM_PopulateDumpSharedSpace
284
285
286 void VM_PopulateDumpSharedSpace::doit() {
287 Thread* THREAD = VMThread::vm_thread();
288 NOT_PRODUCT(SystemDictionary::verify();)
289 // The following guarantee is meant to ensure that no loader constraints
290 // exist yet, since the constraints table is not shared. This becomes
291 // more important now that we don't re-initialize vtables/itables for
292 // shared classes at runtime, where constraints were previously created.
293 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
294 "loader constraints are not saved");
295 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
296 "placeholders are not saved");
297 // Revisit and implement this if we prelink method handle call sites:
298 guarantee(SystemDictionary::invoke_method_table() == NULL ||
299 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
300 "invoke method table is not saved");
301
302 // At this point, many classes have been loaded.
303 // Gather systemDictionary classes in a global array and do everything to
304 // that so we don't have to walk the SystemDictionary again.
305 _global_klass_objects = new GrowableArray<Klass*>(1000);
306 Universe::basic_type_classes_do(collect_classes);
307 SystemDictionary::classes_do(collect_classes);
308
309 tty->print_cr("Number of classes %d", _global_klass_objects->length());
310
311 // Update all the fingerprints in the shared methods.
312 tty->print("Calculating fingerprints ... ");
313 calculate_fingerprints();
314 tty->print_cr("done. ");
315
316 // Remove all references outside the metadata
317 tty->print("Removing unshareable information ... ");
318 remove_unshareable_in_classes();
319 tty->print_cr("done. ");
320
321 // Set up the share data and shared code segments.
322 char* md_low = _md_vs.low();
323 char* md_top = md_low;
324 char* md_end = _md_vs.high();
325 char* mc_low = _mc_vs.low();
326 char* mc_top = mc_low;
327 char* mc_end = _mc_vs.high();
328
329 // Reserve space for the list of Klass*s whose vtables are used
330 // for patching others as needed.
331
332 void** vtbl_list = (void**)md_top;
333 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
334 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
335
336 md_top += vtbl_list_size * sizeof(void*);
337 void* vtable = md_top;
338
339 // Reserve space for a new dummy vtable for klass objects in the
340 // heap. Generate self-patching vtable entries.
341
342 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
343 &md_top, md_end,
344 &mc_top, mc_end);
345
346 // Reorder the system dictionary. (Moving the symbols affects
347 // how the hash table indices are calculated.)
348 // Not doing this either.
349
350 SystemDictionary::reorder_dictionary();
351
352 NOT_PRODUCT(SystemDictionary::verify();)
353
354 // Copy the the symbol table, and the system dictionary to the shared
355 // space in usable form. Copy the hastable
356 // buckets first [read-write], then copy the linked lists of entries
357 // [read-only].
358
359 SymbolTable::reverse(md_top);
360 NOT_PRODUCT(SymbolTable::verify());
361 SymbolTable::copy_buckets(&md_top, md_end);
362
363 SystemDictionary::reverse();
364 SystemDictionary::copy_buckets(&md_top, md_end);
365
366 ClassLoader::verify();
367 ClassLoader::copy_package_info_buckets(&md_top, md_end);
368 ClassLoader::verify();
369
370 SymbolTable::copy_table(&md_top, md_end);
371 SystemDictionary::copy_table(&md_top, md_end);
372 ClassLoader::verify();
373 ClassLoader::copy_package_info_table(&md_top, md_end);
374 ClassLoader::verify();
375
376 // Write the other data to the output array.
377 WriteClosure wc(md_top, md_end);
378 MetaspaceShared::serialize(&wc);
379 md_top = wc.get_top();
380
381 // Print shared spaces all the time
382 const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " words allocated at " PTR_FORMAT ".";
383 Metaspace* ro_space = _loader_data->ro_metaspace();
384 Metaspace* rw_space = _loader_data->rw_metaspace();
385 tty->print_cr(fmt, "ro", ro_space->used_words(Metaspace::NonClassType),
386 ro_space->capacity_words(Metaspace::NonClassType),
387 ro_space->bottom());
388 tty->print_cr(fmt, "rw", rw_space->used_words(Metaspace::NonClassType),
389 rw_space->capacity_words(Metaspace::NonClassType),
390 rw_space->bottom());
391 tty->print_cr(fmt, "md", md_top - md_low, md_end-md_low, md_low);
392 tty->print_cr(fmt, "mc", mc_top - mc_low, mc_end-mc_low, mc_low);
393
394 // Update the vtable pointers in all of the Klass objects in the
395 // heap. They should point to newly generated vtable.
396 patch_klass_vtables(vtbl_list, vtable);
397
398 // dunno what this is for.
399 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
400 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
401 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
402
403 // Create and write the archive file that maps the shared spaces.
404
405 FileMapInfo* mapinfo = new FileMapInfo();
406 mapinfo->populate_header(MetaspaceShared::max_alignment());
407
408 // Pass 1 - update file offsets in header.
409 mapinfo->write_header();
410 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
411 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
412 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
413 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
414 SharedMiscDataSize,
415 false, false);
416 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
417 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
418 SharedMiscCodeSize,
419 true, true);
420
421 // Pass 2 - write data.
422 mapinfo->open_for_write();
423 mapinfo->write_header();
424 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
425 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
426 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
427 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
428 SharedMiscDataSize,
429 false, false);
430 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
431 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
432 SharedMiscCodeSize,
433 true, true);
434 mapinfo->close();
435
436 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
437 }
438
439 static void link_shared_classes(Klass* obj, TRAPS) {
440 Klass* k = Klass::cast(obj);
441 if (k->oop_is_instance()) {
442 InstanceKlass* ik = (InstanceKlass*) k;
443 // Link the class to cause the bytecodes to be rewritten and the
444 // cpcache to be created.
445 if (ik->init_state() < InstanceKlass::linked) {
446 ik->link_class(THREAD);
447 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
448 }
449 }
450 }
451
452
453 // Support for a simple checksum of the contents of the class list
454 // file to prevent trivial tampering. The algorithm matches that in
455 // the MakeClassList program used by the J2SE build process.
456 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
457 static jlong
458 jsum(jlong start, const char *buf, const int len)
459 {
460 jlong h = start;
461 char *p = (char *)buf, *e = p + len;
462 while (p < e) {
463 char c = *p++;
464 if (c <= ' ') {
465 /* Skip spaces and control characters */
466 continue;
467 }
468 h = 31 * h + c;
469 }
470 return h;
471 }
472
473 // Preload classes from a list, populate the shared spaces and dump to a
474 // file.
475 void MetaspaceShared::preload_and_dump(TRAPS) {
476 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
477 ResourceMark rm;
478
479 // Lock out GC - is it necessary? I don't think we care.
480 No_GC_Verifier no_gc;
481
482 // Preload classes to be shared.
483 // Should use some os:: method rather than fopen() here. aB.
484 // Construct the path to the class list (in jre/lib)
485 // Walk up two directories from the location of the VM and
486 // optionally tack on "lib" (depending on platform)
487 char class_list_path[JVM_MAXPATHLEN];
488 os::jvm_path(class_list_path, sizeof(class_list_path));
489 for (int i = 0; i < 3; i++) {
490 char *end = strrchr(class_list_path, *os::file_separator());
491 if (end != NULL) *end = '\0';
492 }
493 int class_list_path_len = (int)strlen(class_list_path);
494 if (class_list_path_len >= 3) {
495 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
496 strcat(class_list_path, os::file_separator());
497 strcat(class_list_path, "lib");
498 }
499 }
500 strcat(class_list_path, os::file_separator());
501 strcat(class_list_path, "classlist");
502
503 FILE* file = fopen(class_list_path, "r");
504 if (file != NULL) {
505 jlong computed_jsum = JSUM_SEED;
506 jlong file_jsum = 0;
507
508 char class_name[256];
509 int class_count = 0;
510 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
511
512 // sun.io.Converters
513 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
514 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
515
516 // java.util.HashMap
517 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
518 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
519
520 tty->print("Loading classes to share ... ");
521 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
522 if (*class_name == '#') {
523 jint fsh, fsl;
524 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
525 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
526 }
527
528 continue;
529 }
530 // Remove trailing newline
531 size_t name_len = strlen(class_name);
532 class_name[name_len-1] = '\0';
533
534 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
535
536 // Got a class name - load it.
537 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
538 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
539 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
540 THREAD);
541 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
542 if (klass != NULL) {
543 if (PrintSharedSpaces && Verbose && WizardMode) {
544 tty->print_cr("Shared spaces preloaded: %s", class_name);
545 }
546
547
548 InstanceKlass* ik = InstanceKlass::cast(klass);
549
550 // Should be class load order as per -XX:+TraceClassLoadingPreorder
551 class_promote_order->append(ik);
552
553 // Link the class to cause the bytecodes to be rewritten and the
554 // cpcache to be created. The linking is done as soon as classes
555 // are loaded in order that the related data structures (klass and
556 // cpCache) are located together.
557
558 if (ik->init_state() < InstanceKlass::linked) {
559 ik->link_class(THREAD);
560 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
561 }
562
563 // TODO: Resolve klasses in constant pool
564 ik->constants()->resolve_class_constants(THREAD);
565
566 class_count++;
567 } else {
568 if (PrintSharedSpaces && Verbose && WizardMode) {
569 tty->cr();
570 tty->print_cr(" Preload failed: %s", class_name);
571 }
572 }
573 file_jsum = 0; // Checksum must be on last line of file
574 }
575 if (computed_jsum != file_jsum) {
576 tty->cr();
577 tty->print_cr("Preload failed: checksum of class list was incorrect.");
578 exit(1);
579 }
580
581 tty->print_cr("done. ");
582
583 if (PrintSharedSpaces) {
584 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
585 }
586
587 // Rewrite and unlink classes.
588 tty->print("Rewriting and linking classes ... ");
589
590 // Link any classes which got missed. (It's not quite clear why
591 // they got missed.) This iteration would be unsafe if we weren't
592 // single-threaded at this point; however we can't do it on the VM
593 // thread because it requires object allocation.
594 SystemDictionary::classes_do(link_shared_classes, CATCH);
595 tty->print_cr("done. ");
596
597 // Create and dump the shared spaces. Everything so far is loaded
598 // with the null class loader.
599 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
600 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
601 VMThread::execute(&op);
602
603 } else {
604 char errmsg[JVM_MAXPATHLEN];
605 os::lasterror(errmsg, JVM_MAXPATHLEN);
606 tty->print_cr("Loading classlist failed: %s", errmsg);
607 exit(1);
608 }
609
610 // Since various initialization steps have been undone by this process,
611 // it is not reasonable to continue running a java process.
612 exit(0);
613 }
614
615
616 // Closure for serializing initialization data in from a data area
617 // (ptr_array) read from the shared file.
618
619 class ReadClosure : public SerializeClosure {
620 private:
621 intptr_t** _ptr_array;
622
623 inline intptr_t nextPtr() {
624 return *(*_ptr_array)++;
625 }
626
627 public:
628 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
629
630 void do_ptr(void** p) {
631 assert(*p == NULL, "initializing previous initialized pointer.");
632 intptr_t obj = nextPtr();
633 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
634 "hit tag while initializing ptrs.");
635 *p = (void*)obj;
636 }
637
638 void do_tag(int tag) {
639 int old_tag;
640 old_tag = (int)(intptr_t)nextPtr();
641 // do_int(&old_tag);
642 assert(tag == old_tag, "old tag doesn't match");
643 FileMapInfo::assert_mark(tag == old_tag);
644 }
645
646 void do_region(u_char* start, size_t size) {
647 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
648 assert(size % sizeof(intptr_t) == 0, "bad size");
649 do_tag((int)size);
650 while (size > 0) {
651 *(intptr_t*)start = nextPtr();
652 start += sizeof(intptr_t);
653 size -= sizeof(intptr_t);
654 }
655 }
656
657 bool reading() const { return true; }
658 };
659
660
661 // Save bounds of shared spaces mapped in.
662 static char* _ro_base = NULL;
663 static char* _rw_base = NULL;
664 static char* _md_base = NULL;
665 static char* _mc_base = NULL;
666
667 // Return true if given address is in the mapped shared space.
668 bool MetaspaceShared::is_in_shared_space(const void* p) {
669 if (_ro_base == NULL || _rw_base == NULL) {
670 return false;
671 } else {
672 return ((p > _ro_base && p < (_ro_base + SharedReadOnlySize)) ||
673 (p > _rw_base && p < (_rw_base + SharedReadWriteSize)));
674 }
675 }
676
677 void MetaspaceShared::print_shared_spaces() {
678 gclog_or_tty->print_cr("Shared Spaces:");
679 gclog_or_tty->print(" read-only " INTPTR_FORMAT "-" INTPTR_FORMAT,
680 _ro_base, _ro_base + SharedReadOnlySize);
681 gclog_or_tty->print(" read-write " INTPTR_FORMAT "-" INTPTR_FORMAT,
682 _rw_base, _rw_base + SharedReadWriteSize);
683 gclog_or_tty->cr();
684 gclog_or_tty->print(" misc-data " INTPTR_FORMAT "-" INTPTR_FORMAT,
685 _md_base, _md_base + SharedMiscDataSize);
686 gclog_or_tty->print(" misc-code " INTPTR_FORMAT "-" INTPTR_FORMAT,
687 _mc_base, _mc_base + SharedMiscCodeSize);
688 gclog_or_tty->cr();
689 }
690
691
692 // Map shared spaces at requested addresses and return if succeeded.
693 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
694 // call, or is_in_shared_space.
695 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
696 size_t image_alignment = mapinfo->alignment();
697
698 // Map in the shared memory and then map the regions on top of it
699 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
700 if (!shared_rs.is_reserved()) return false;
701
702 // Split reserved memory into pieces (windows needs this)
703 ReservedSpace ro_rs = shared_rs.first_part(SharedReadOnlySize);
704 ReservedSpace tmp_rs1 = shared_rs.last_part(SharedReadOnlySize);
705 ReservedSpace rw_rs = tmp_rs1.first_part(SharedReadWriteSize);
706 ReservedSpace tmp_rs2 = tmp_rs1.last_part(SharedReadWriteSize);
707 ReservedSpace md_rs = tmp_rs2.first_part(SharedMiscDataSize);
708 ReservedSpace mc_rs = tmp_rs2.last_part(SharedMiscDataSize);
709
710 // Map each shared region
711 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
712 (_rw_base = mapinfo->map_region(rw)) != NULL &&
713 (_md_base = mapinfo->map_region(md)) != NULL &&
714 (_mc_base = mapinfo->map_region(mc)) != NULL &&
715 (image_alignment == (size_t)max_alignment())) {
716 // Success (no need to do anything)
717 return true;
718 } else {
719 // If there was a failure in mapping any of the spaces, unmap the ones
720 // that succeeded
721 if (_ro_base != NULL) mapinfo->unmap_region(ro);
722 if (_rw_base != NULL) mapinfo->unmap_region(rw);
723 if (_md_base != NULL) mapinfo->unmap_region(md);
724 if (_mc_base != NULL) mapinfo->unmap_region(mc);
725 // Release the entire mapped region
726 shared_rs.release();
727 // If -Xshare:on is specified, print out the error message and exit VM,
728 // otherwise, set UseSharedSpaces to false and continue.
729 if (RequireSharedSpaces) {
730 vm_exit_during_initialization("Unable to use shared archive.", NULL);
731 } else {
732 FLAG_SET_DEFAULT(UseSharedSpaces, false);
733 }
734 return false;
735 }
736 }
737
738 // Read the miscellaneous data from the shared file, and
739 // serialize it out to its various destinations.
740
741 void MetaspaceShared::initialize_shared_spaces() {
742 FileMapInfo *mapinfo = FileMapInfo::current_info();
743
744 char* buffer = mapinfo->region_base(md);
745
746 // Skip over (reserve space for) a list of addresses of C++ vtables
747 // for Klass objects. They get filled in later.
748
749 void** vtbl_list = (void**)buffer;
750 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
751 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
752
753 // Skip over (reserve space for) dummy C++ vtables Klass objects.
754 // They are used as is.
755
756 intptr_t vtable_size = *(intptr_t*)buffer;
757 buffer += sizeof(intptr_t);
758 buffer += vtable_size;
759
760 // Create the symbol table using the bucket array at this spot in the
761 // misc data space. Since the symbol table is often modified, this
762 // region (of mapped pages) will be copy-on-write.
763
764 int symbolTableLen = *(intptr_t*)buffer;
765 buffer += sizeof(intptr_t);
766 int number_of_entries = *(intptr_t*)buffer;
767 buffer += sizeof(intptr_t);
768 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
769 number_of_entries);
770 buffer += symbolTableLen;
771
772 // Create the shared dictionary using the bucket array at this spot in
773 // the misc data space. Since the shared dictionary table is never
774 // modified, this region (of mapped pages) will be (effectively, if
775 // not explicitly) read-only.
776
777 int sharedDictionaryLen = *(intptr_t*)buffer;
778 buffer += sizeof(intptr_t);
779 number_of_entries = *(intptr_t*)buffer;
780 buffer += sizeof(intptr_t);
781 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
782 sharedDictionaryLen,
783 number_of_entries);
784 buffer += sharedDictionaryLen;
785
786 // Create the package info table using the bucket array at this spot in
787 // the misc data space. Since the package info table is never
788 // modified, this region (of mapped pages) will be (effectively, if
789 // not explicitly) read-only.
790
791 int pkgInfoLen = *(intptr_t*)buffer;
792 buffer += sizeof(intptr_t);
793 number_of_entries = *(intptr_t*)buffer;
794 buffer += sizeof(intptr_t);
795 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
796 number_of_entries);
797 buffer += pkgInfoLen;
798 ClassLoader::verify();
799
800 // The following data in the shared misc data region are the linked
801 // list elements (HashtableEntry objects) for the symbol table, string
802 // table, and shared dictionary. The heap objects refered to by the
803 // symbol table, string table, and shared dictionary are permanent and
804 // unmovable. Since new entries added to the string and symbol tables
805 // are always added at the beginning of the linked lists, THESE LINKED
806 // LIST ELEMENTS ARE READ-ONLY.
807
808 int len = *(intptr_t*)buffer; // skip over symbol table entries
809 buffer += sizeof(intptr_t);
810 buffer += len;
811
812 len = *(intptr_t*)buffer; // skip over shared dictionary entries
813 buffer += sizeof(intptr_t);
814 buffer += len;
815
816 len = *(intptr_t*)buffer; // skip over package info table entries
817 buffer += sizeof(intptr_t);
818 buffer += len;
819
820 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
821 buffer += sizeof(intptr_t);
822 buffer += len;
823
824 intptr_t* array = (intptr_t*)buffer;
825 ReadClosure rc(&array);
826 serialize(&rc);
827
828 // Close the mapinfo file
829 mapinfo->close();
830 }
831
832 // JVM/TI RedefineClasses() support:
833 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
834 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
835
836 if (UseSharedSpaces) {
837 // remap the shared readonly space to shared readwrite, private
838 FileMapInfo* mapinfo = FileMapInfo::current_info();
839 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
840 return false;
841 }
842 }
843 return true;
844 }