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
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 assert(!UseCompressedOops, "UseCompressedOops doesn't work with shared archive");
56 // Verify the sizes of various metadata in the system.
57 soc->do_tag(sizeof(Method));
58 soc->do_tag(sizeof(ConstMethod));
59 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
60 soc->do_tag(sizeof(ConstantPool));
61 soc->do_tag(sizeof(ConstantPoolCache));
62 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
63 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
64 soc->do_tag(sizeof(Symbol));
65
66 // Dump/restore miscellaneous metadata.
67 Universe::serialize(soc, true);
68 soc->do_tag(--tag);
69
70 // Dump/restore references to commonly used names and signatures.
71 vmSymbols::serialize(soc);
72 soc->do_tag(--tag);
73
74 soc->do_tag(666);
75 }
76
77
78 // CDS code for dumping shared archive.
79
80 // Global object for holding classes that have been loaded. Since this
81 // is run at a safepoint just before exit, this is the entire set of classes.
82 static GrowableArray<Klass*>* _global_klass_objects;
83 static void collect_classes(Klass* k) {
84 _global_klass_objects->append_if_missing(k);
85 if (k->oop_is_instance()) {
86 // Add in the array classes too
87 InstanceKlass* ik = InstanceKlass::cast(k);
88 ik->array_klasses_do(collect_classes);
89 }
90 }
91
92 static void remove_unshareable_in_classes() {
93 for (int i = 0; i < _global_klass_objects->length(); i++) {
94 Klass* k = _global_klass_objects->at(i);
95 k->remove_unshareable_info();
96 }
97 }
98
99 // Walk all methods in the class list and assign a fingerprint.
100 // so that this part of the ConstMethod* is read only.
101 static void calculate_fingerprints() {
102 for (int i = 0; i < _global_klass_objects->length(); i++) {
103 Klass* k = _global_klass_objects->at(i);
104 if (k->oop_is_instance()) {
105 InstanceKlass* ik = InstanceKlass::cast(k);
106 for (int i = 0; i < ik->methods()->length(); i++) {
107 ResourceMark rm;
108 Method* m = ik->methods()->at(i);
109 (new Fingerprinter(m))->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
247 // Populate the shared space.
248
249 class VM_PopulateDumpSharedSpace: public VM_Operation {
250 private:
251 ClassLoaderData* _loader_data;
252 GrowableArray<Klass*> *_class_promote_order;
253 VirtualSpace _md_vs;
254 VirtualSpace _mc_vs;
255
256 public:
257 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
258 GrowableArray<Klass*> *class_promote_order) :
259 _loader_data(loader_data) {
260
261 // Split up and initialize the misc code and data spaces
262 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
263 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
264 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
265 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
266
267 // Now split into misc sections.
268 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
269 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
270 _md_vs.initialize(md_rs, SharedMiscDataSize);
271 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
272 _class_promote_order = class_promote_order;
273 }
274
275 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
276 void doit(); // outline because gdb sucks
277 }; // class VM_PopulateDumpSharedSpace
278
279
280 void VM_PopulateDumpSharedSpace::doit() {
281 Thread* THREAD = VMThread::vm_thread();
282 NOT_PRODUCT(SystemDictionary::verify();)
283 // The following guarantee is meant to ensure that no loader constraints
284 // exist yet, since the constraints table is not shared. This becomes
285 // more important now that we don't re-initialize vtables/itables for
286 // shared classes at runtime, where constraints were previously created.
287 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
288 "loader constraints are not saved");
289 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
290 "placeholders are not saved");
291 // Revisit and implement this if we prelink method handle call sites:
292 guarantee(SystemDictionary::invoke_method_table() == NULL ||
293 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
294 "invoke method table is not saved");
295
296 // At this point, many classes have been loaded.
297 // Gather systemDictionary classes in a global array and do everything to
298 // that so we don't have to walk the SystemDictionary again.
299 _global_klass_objects = new GrowableArray<Klass*>(1000);
300 Universe::basic_type_classes_do(collect_classes);
301 SystemDictionary::classes_do(collect_classes);
302
303 tty->print_cr("Number of classes %d", _global_klass_objects->length());
304
305 // Update all the fingerprints in the shared methods.
306 tty->print("Calculating fingerprints ... ");
307 calculate_fingerprints();
308 tty->print_cr("done. ");
309
310 // Remove all references outside the metadata
311 tty->print("Removing unshareable information ... ");
312 remove_unshareable_in_classes();
313 tty->print_cr("done. ");
314
315 // Set up the share data and shared code segments.
316 char* md_low = _md_vs.low();
317 char* md_top = md_low;
318 char* md_end = _md_vs.high();
319 char* mc_low = _mc_vs.low();
320 char* mc_top = mc_low;
321 char* mc_end = _mc_vs.high();
322
323 // Reserve space for the list of Klass*s whose vtables are used
324 // for patching others as needed.
325
326 void** vtbl_list = (void**)md_top;
327 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
328 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
329
330 md_top += vtbl_list_size * sizeof(void*);
331 void* vtable = md_top;
332
333 // Reserve space for a new dummy vtable for klass objects in the
334 // heap. Generate self-patching vtable entries.
335
336 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
337 &md_top, md_end,
338 &mc_top, mc_end);
339
340 // Reorder the system dictionary. (Moving the symbols affects
341 // how the hash table indices are calculated.)
342 // Not doing this either.
343
344 SystemDictionary::reorder_dictionary();
345
346 NOT_PRODUCT(SystemDictionary::verify();)
347
348 // Copy the the symbol table, and the system dictionary to the shared
349 // space in usable form. Copy the hastable
350 // buckets first [read-write], then copy the linked lists of entries
351 // [read-only].
352
353 SymbolTable::reverse(md_top);
354 NOT_PRODUCT(SymbolTable::verify());
355 SymbolTable::copy_buckets(&md_top, md_end);
356
357 SystemDictionary::reverse();
358 SystemDictionary::copy_buckets(&md_top, md_end);
359
360 ClassLoader::verify();
361 ClassLoader::copy_package_info_buckets(&md_top, md_end);
362 ClassLoader::verify();
363
364 SymbolTable::copy_table(&md_top, md_end);
365 SystemDictionary::copy_table(&md_top, md_end);
366 ClassLoader::verify();
367 ClassLoader::copy_package_info_table(&md_top, md_end);
368 ClassLoader::verify();
369
370 // Write the other data to the output array.
371 WriteClosure wc(md_top, md_end);
372 MetaspaceShared::serialize(&wc);
373 md_top = wc.get_top();
374
375 // Print shared spaces all the time
376 const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " words allocated at " PTR_FORMAT ".";
377 Metaspace* ro_space = _loader_data->ro_metaspace();
378 Metaspace* rw_space = _loader_data->rw_metaspace();
379 tty->print_cr(fmt, "ro", ro_space->used_words(Metaspace::NonClassType),
380 ro_space->capacity_words(Metaspace::NonClassType),
381 ro_space->bottom());
382 tty->print_cr(fmt, "rw", rw_space->used_words(Metaspace::NonClassType),
383 rw_space->capacity_words(Metaspace::NonClassType),
384 rw_space->bottom());
385 tty->print_cr(fmt, "md", md_top - md_low, md_end-md_low, md_low);
386 tty->print_cr(fmt, "mc", mc_top - mc_low, mc_end-mc_low, mc_low);
387
388 // Update the vtable pointers in all of the Klass objects in the
389 // heap. They should point to newly generated vtable.
390 patch_klass_vtables(vtbl_list, vtable);
391
392 // dunno what this is for.
393 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
394 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
395 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
396
397 // Create and write the archive file that maps the shared spaces.
398
399 FileMapInfo* mapinfo = new FileMapInfo();
400 mapinfo->populate_header(MetaspaceShared::max_alignment());
401
402 // Pass 1 - update file offsets in header.
403 mapinfo->write_header();
404 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
405 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
406 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
407 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
408 SharedMiscDataSize,
409 false, false);
410 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
411 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
412 SharedMiscCodeSize,
413 true, true);
414
415 // Pass 2 - write data.
416 mapinfo->open_for_write();
417 mapinfo->write_header();
418 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
419 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
420 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
421 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
422 SharedMiscDataSize,
423 false, false);
424 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
425 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
426 SharedMiscCodeSize,
427 true, true);
428 mapinfo->close();
429
430 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
431 }
432
433 static void link_shared_classes(Klass* obj, TRAPS) {
434 Klass* k = Klass::cast(obj);
435 if (k->oop_is_instance()) {
436 InstanceKlass* ik = (InstanceKlass*) k;
437 // Link the class to cause the bytecodes to be rewritten and the
438 // cpcache to be created.
439 if (ik->init_state() < InstanceKlass::linked) {
440 ik->link_class(THREAD);
441 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
442 }
443 }
444 }
445
446
447 // Support for a simple checksum of the contents of the class list
448 // file to prevent trivial tampering. The algorithm matches that in
449 // the MakeClassList program used by the J2SE build process.
450 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
451 static jlong
452 jsum(jlong start, const char *buf, const int len)
453 {
454 jlong h = start;
455 char *p = (char *)buf, *e = p + len;
456 while (p < e) {
457 char c = *p++;
458 if (c <= ' ') {
459 /* Skip spaces and control characters */
460 continue;
461 }
462 h = 31 * h + c;
463 }
464 return h;
465 }
466
467 // Preload classes from a list, populate the shared spaces and dump to a
468 // file.
469 void MetaspaceShared::preload_and_dump(TRAPS) {
470 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
471 ResourceMark rm;
472
473 // Lock out GC - is it necessary? I don't think we care.
474 No_GC_Verifier no_gc;
475
476 // Preload classes to be shared.
477 // Should use some os:: method rather than fopen() here. aB.
478 // Construct the path to the class list (in jre/lib)
479 // Walk up two directories from the location of the VM and
480 // optionally tack on "lib" (depending on platform)
481 char class_list_path[JVM_MAXPATHLEN];
482 os::jvm_path(class_list_path, sizeof(class_list_path));
483 for (int i = 0; i < 3; i++) {
484 char *end = strrchr(class_list_path, *os::file_separator());
485 if (end != NULL) *end = '\0';
486 }
487 int class_list_path_len = (int)strlen(class_list_path);
488 if (class_list_path_len >= 3) {
489 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
490 strcat(class_list_path, os::file_separator());
491 strcat(class_list_path, "lib");
492 }
493 }
494 strcat(class_list_path, os::file_separator());
495 strcat(class_list_path, "classlist");
496
497 FILE* file = fopen(class_list_path, "r");
498 if (file != NULL) {
499 jlong computed_jsum = JSUM_SEED;
500 jlong file_jsum = 0;
501
502 char class_name[256];
503 int class_count = 0;
504 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
505
506 // sun.io.Converters
507 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
508 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
509
510 // java.util.HashMap
511 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
512 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
513
514 tty->print("Loading classes to share ... ");
515 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
516 if (*class_name == '#') {
517 jint fsh, fsl;
518 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
519 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
520 }
521
522 continue;
523 }
524 // Remove trailing newline
525 size_t name_len = strlen(class_name);
526 class_name[name_len-1] = '\0';
527
528 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
529
530 // Got a class name - load it.
531 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
532 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
533 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
534 THREAD);
535 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
536 if (klass != NULL) {
537 if (PrintSharedSpaces && Verbose && WizardMode) {
538 tty->print_cr("Shared spaces preloaded: %s", class_name);
539 }
540
541
542 InstanceKlass* ik = InstanceKlass::cast(klass);
543
544 // Should be class load order as per -XX:+TraceClassLoadingPreorder
545 class_promote_order->append(ik);
546
547 // Link the class to cause the bytecodes to be rewritten and the
548 // cpcache to be created. The linking is done as soon as classes
549 // are loaded in order that the related data structures (klass and
550 // cpCache) are located together.
551
552 if (ik->init_state() < InstanceKlass::linked) {
553 ik->link_class(THREAD);
554 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
555 }
556
557 // TODO: Resolve klasses in constant pool
558 ik->constants()->resolve_class_constants(THREAD);
559
560 class_count++;
561 } else {
562 if (PrintSharedSpaces && Verbose && WizardMode) {
563 tty->cr();
564 tty->print_cr(" Preload failed: %s", class_name);
565 }
566 }
567 file_jsum = 0; // Checksum must be on last line of file
568 }
569 if (computed_jsum != file_jsum) {
570 tty->cr();
571 tty->print_cr("Preload failed: checksum of class list was incorrect.");
572 exit(1);
573 }
574
575 tty->print_cr("done. ");
576
577 if (PrintSharedSpaces) {
578 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
579 }
580
581 // Rewrite and unlink classes.
582 tty->print("Rewriting and linking classes ... ");
583
584 // Link any classes which got missed. (It's not quite clear why
585 // they got missed.) This iteration would be unsafe if we weren't
586 // single-threaded at this point; however we can't do it on the VM
587 // thread because it requires object allocation.
588 SystemDictionary::classes_do(link_shared_classes, CATCH);
589 tty->print_cr("done. ");
590
591 // Create and dump the shared spaces. Everything so far is loaded
592 // with the null class loader.
593 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
594 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
595 VMThread::execute(&op);
596
597 } else {
598 char errmsg[JVM_MAXPATHLEN];
599 os::lasterror(errmsg, JVM_MAXPATHLEN);
600 tty->print_cr("Loading classlist failed: %s", errmsg);
601 exit(1);
602 }
603
604 // Since various initialization steps have been undone by this process,
605 // it is not reasonable to continue running a java process.
606 exit(0);
607 }
608
609
610 // Closure for serializing initialization data in from a data area
611 // (ptr_array) read from the shared file.
612
613 class ReadClosure : public SerializeClosure {
614 private:
615 intptr_t** _ptr_array;
616
617 inline intptr_t nextPtr() {
618 return *(*_ptr_array)++;
619 }
620
621 public:
622 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
623
624 void do_ptr(void** p) {
625 assert(*p == NULL, "initializing previous initialized pointer.");
626 intptr_t obj = nextPtr();
627 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
628 "hit tag while initializing ptrs.");
629 *p = (void*)obj;
630 }
631
632 void do_tag(int tag) {
633 int old_tag;
634 old_tag = (int)(intptr_t)nextPtr();
635 // do_int(&old_tag);
636 assert(tag == old_tag, "old tag doesn't match");
637 FileMapInfo::assert_mark(tag == old_tag);
638 }
639
640 void do_region(u_char* start, size_t size) {
641 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
642 assert(size % sizeof(intptr_t) == 0, "bad size");
643 do_tag((int)size);
644 while (size > 0) {
645 *(intptr_t*)start = nextPtr();
646 start += sizeof(intptr_t);
647 size -= sizeof(intptr_t);
648 }
649 }
650
651 bool reading() const { return true; }
652 };
653
654
655 // Save bounds of shared spaces mapped in.
656 static char* _ro_base = NULL;
657 static char* _rw_base = NULL;
658 static char* _md_base = NULL;
659 static char* _mc_base = NULL;
660
661 // Return true if given address is in the mapped shared space.
662 bool MetaspaceShared::is_in_shared_space(const void* p) {
663 if (_ro_base == NULL || _rw_base == NULL) {
664 return false;
665 } else {
666 return ((p > _ro_base && p < (_ro_base + SharedReadOnlySize)) ||
667 (p > _rw_base && p < (_rw_base + SharedReadWriteSize)));
668 }
669 }
670
671 void MetaspaceShared::print_shared_spaces() {
672 gclog_or_tty->print_cr("Shared Spaces:");
673 gclog_or_tty->print(" read-only " INTPTR_FORMAT "-" INTPTR_FORMAT,
674 _ro_base, _ro_base + SharedReadOnlySize);
675 gclog_or_tty->print(" read-write " INTPTR_FORMAT "-" INTPTR_FORMAT,
676 _rw_base, _rw_base + SharedReadWriteSize);
677 gclog_or_tty->cr();
678 gclog_or_tty->print(" misc-data " INTPTR_FORMAT "-" INTPTR_FORMAT,
679 _md_base, _md_base + SharedMiscDataSize);
680 gclog_or_tty->print(" misc-code " INTPTR_FORMAT "-" INTPTR_FORMAT,
681 _mc_base, _mc_base + SharedMiscCodeSize);
682 gclog_or_tty->cr();
683 }
684
685
686 // Map shared spaces at requested addresses and return if succeeded.
687 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
688 // call, or is_in_shared_space.
689 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
690 size_t image_alignment = mapinfo->alignment();
691
692 // Map in the shared memory and then map the regions on top of it
693 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
694 if (!shared_rs.is_reserved()) return false;
695
696 // Split reserved memory into pieces (windows needs this)
697 ReservedSpace ro_rs = shared_rs.first_part(SharedReadOnlySize);
698 ReservedSpace tmp_rs1 = shared_rs.last_part(SharedReadOnlySize);
699 ReservedSpace rw_rs = tmp_rs1.first_part(SharedReadWriteSize);
700 ReservedSpace tmp_rs2 = tmp_rs1.last_part(SharedReadWriteSize);
701 ReservedSpace md_rs = tmp_rs2.first_part(SharedMiscDataSize);
702 ReservedSpace mc_rs = tmp_rs2.last_part(SharedMiscDataSize);
703
704 // Map each shared region
705 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
706 (_rw_base = mapinfo->map_region(rw)) != NULL &&
707 (_md_base = mapinfo->map_region(md)) != NULL &&
708 (_mc_base = mapinfo->map_region(mc)) != NULL &&
709 (image_alignment == (size_t)max_alignment())) {
710 // Success (no need to do anything)
711 return true;
712 } else {
713 // If there was a failure in mapping any of the spaces, unmap the ones
714 // that succeeded
715 if (_ro_base != NULL) mapinfo->unmap_region(ro);
716 if (_rw_base != NULL) mapinfo->unmap_region(rw);
717 if (_md_base != NULL) mapinfo->unmap_region(md);
718 if (_mc_base != NULL) mapinfo->unmap_region(mc);
719 // Release the entire mapped region
720 shared_rs.release();
721 // If -Xshare:on is specified, print out the error message and exit VM,
722 // otherwise, set UseSharedSpaces to false and continue.
723 if (RequireSharedSpaces) {
724 vm_exit_during_initialization("Unable to use shared archive.", NULL);
725 } else {
726 FLAG_SET_DEFAULT(UseSharedSpaces, false);
727 }
728 return false;
729 }
730 }
731
732 // Read the miscellaneous data from the shared file, and
733 // serialize it out to its various destinations.
734
735 void MetaspaceShared::initialize_shared_spaces() {
736 FileMapInfo *mapinfo = FileMapInfo::current_info();
737
738 char* buffer = mapinfo->region_base(md);
739
740 // Skip over (reserve space for) a list of addresses of C++ vtables
741 // for Klass objects. They get filled in later.
742
743 void** vtbl_list = (void**)buffer;
744 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
745 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
746
747 // Skip over (reserve space for) dummy C++ vtables Klass objects.
748 // They are used as is.
749
750 intptr_t vtable_size = *(intptr_t*)buffer;
751 buffer += sizeof(intptr_t);
752 buffer += vtable_size;
753
754 // Create the symbol table using the bucket array at this spot in the
755 // misc data space. Since the symbol table is often modified, this
756 // region (of mapped pages) will be copy-on-write.
757
758 int symbolTableLen = *(intptr_t*)buffer;
759 buffer += sizeof(intptr_t);
760 int number_of_entries = *(intptr_t*)buffer;
761 buffer += sizeof(intptr_t);
762 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
763 number_of_entries);
764 buffer += symbolTableLen;
765
766 // Create the shared dictionary using the bucket array at this spot in
767 // the misc data space. Since the shared dictionary table is never
768 // modified, this region (of mapped pages) will be (effectively, if
769 // not explicitly) read-only.
770
771 int sharedDictionaryLen = *(intptr_t*)buffer;
772 buffer += sizeof(intptr_t);
773 number_of_entries = *(intptr_t*)buffer;
774 buffer += sizeof(intptr_t);
775 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
776 sharedDictionaryLen,
777 number_of_entries);
778 buffer += sharedDictionaryLen;
779
780 // Create the package info table using the bucket array at this spot in
781 // the misc data space. Since the package info table is never
782 // modified, this region (of mapped pages) will be (effectively, if
783 // not explicitly) read-only.
784
785 int pkgInfoLen = *(intptr_t*)buffer;
786 buffer += sizeof(intptr_t);
787 number_of_entries = *(intptr_t*)buffer;
788 buffer += sizeof(intptr_t);
789 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
790 number_of_entries);
791 buffer += pkgInfoLen;
792 ClassLoader::verify();
793
794 // The following data in the shared misc data region are the linked
795 // list elements (HashtableEntry objects) for the symbol table, string
796 // table, and shared dictionary. The heap objects refered to by the
797 // symbol table, string table, and shared dictionary are permanent and
798 // unmovable. Since new entries added to the string and symbol tables
799 // are always added at the beginning of the linked lists, THESE LINKED
800 // LIST ELEMENTS ARE READ-ONLY.
801
802 int len = *(intptr_t*)buffer; // skip over symbol table entries
803 buffer += sizeof(intptr_t);
804 buffer += len;
805
806 len = *(intptr_t*)buffer; // skip over shared dictionary entries
807 buffer += sizeof(intptr_t);
808 buffer += len;
809
810 len = *(intptr_t*)buffer; // skip over package info table entries
811 buffer += sizeof(intptr_t);
812 buffer += len;
813
814 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
815 buffer += sizeof(intptr_t);
816 buffer += len;
817
818 intptr_t* array = (intptr_t*)buffer;
819 ReadClosure rc(&array);
820 serialize(&rc);
821
822 // Close the mapinfo file
823 mapinfo->close();
824 }
825
826 // JVM/TI RedefineClasses() support:
827 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
828 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
829
830 if (UseSharedSpaces) {
831 // remap the shared readonly space to shared readwrite, private
832 FileMapInfo* mapinfo = FileMapInfo::current_info();
833 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
834 return false;
835 }
836 }
837 return true;
838 }