Thu, 24 Mar 2016 21:38:15 -0700
8150752: Share Class Data
Reviewed-by: acorn, hseigel, mschoene
1 /*
2 * Copyright (c) 2012, 2016, 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 */
25 #include "precompiled.hpp"
26 #include "classfile/dictionary.hpp"
27 #include "classfile/classLoaderExt.hpp"
28 #include "classfile/loaderConstraints.hpp"
29 #include "classfile/placeholders.hpp"
30 #include "classfile/sharedClassUtil.hpp"
31 #include "classfile/symbolTable.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/systemDictionaryShared.hpp"
34 #include "code/codeCache.hpp"
35 #include "memory/filemap.hpp"
36 #include "memory/gcLocker.hpp"
37 #include "memory/metaspace.hpp"
38 #include "memory/metaspaceShared.hpp"
39 #include "oops/objArrayOop.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/signature.hpp"
42 #include "runtime/vm_operations.hpp"
43 #include "runtime/vmThread.hpp"
44 #include "utilities/hashtable.hpp"
45 #include "utilities/hashtable.inline.hpp"
47 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
49 int MetaspaceShared::_max_alignment = 0;
51 ReservedSpace* MetaspaceShared::_shared_rs = NULL;
53 bool MetaspaceShared::_link_classes_made_progress;
54 bool MetaspaceShared::_check_classes_made_progress;
55 bool MetaspaceShared::_has_error_classes;
56 bool MetaspaceShared::_archive_loading_failed = false;
57 // Read/write a data stream for restoring/preserving metadata pointers and
58 // miscellaneous data from/to the shared archive file.
60 void MetaspaceShared::serialize(SerializeClosure* soc) {
61 int tag = 0;
62 soc->do_tag(--tag);
64 // Verify the sizes of various metadata in the system.
65 soc->do_tag(sizeof(Method));
66 soc->do_tag(sizeof(ConstMethod));
67 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
68 soc->do_tag(sizeof(ConstantPool));
69 soc->do_tag(sizeof(ConstantPoolCache));
70 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
71 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
72 soc->do_tag(sizeof(Symbol));
74 // Dump/restore miscellaneous metadata.
75 Universe::serialize(soc, true);
76 soc->do_tag(--tag);
78 // Dump/restore references to commonly used names and signatures.
79 vmSymbols::serialize(soc);
80 soc->do_tag(--tag);
82 soc->do_tag(666);
83 }
86 // CDS code for dumping shared archive.
88 // Global object for holding classes that have been loaded. Since this
89 // is run at a safepoint just before exit, this is the entire set of classes.
90 static GrowableArray<Klass*>* _global_klass_objects;
91 static void collect_classes(Klass* k) {
92 _global_klass_objects->append_if_missing(k);
93 if (k->oop_is_instance()) {
94 // Add in the array classes too
95 InstanceKlass* ik = InstanceKlass::cast(k);
96 ik->array_klasses_do(collect_classes);
97 }
98 }
100 static void remove_unshareable_in_classes() {
101 for (int i = 0; i < _global_klass_objects->length(); i++) {
102 Klass* k = _global_klass_objects->at(i);
103 k->remove_unshareable_info();
104 }
105 }
107 // Walk all methods in the class list and assign a fingerprint.
108 // so that this part of the ConstMethod* is read only.
109 static void calculate_fingerprints() {
110 for (int i = 0; i < _global_klass_objects->length(); i++) {
111 Klass* k = _global_klass_objects->at(i);
112 if (k->oop_is_instance()) {
113 InstanceKlass* ik = InstanceKlass::cast(k);
114 for (int i = 0; i < ik->methods()->length(); i++) {
115 Method* m = ik->methods()->at(i);
116 Fingerprinter fp(m);
117 // The side effect of this call sets method's fingerprint field.
118 fp.fingerprint();
119 }
120 }
121 }
122 }
124 // Patch C++ vtable pointer in metadata.
126 // Klass and other metadata objects contain references to c++ vtables in the
127 // JVM library.
128 // Fix them to point to our constructed vtables. However, don't iterate
129 // across the space while doing this, as that causes the vtables to be
130 // patched, undoing our useful work. Instead, iterate to make a list,
131 // then use the list to do the fixing.
132 //
133 // Our constructed vtables:
134 // Dump time:
135 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
136 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
137 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
138 // associated metadata to point to jump table rather than to current vtbl
139 // Table layout: NOTE FIXED SIZE
140 // 1. vtbl pointers
141 // 2. #Klass X #virtual methods per Klass
142 // 1 entry for each, in the order:
143 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
144 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
145 // ...
146 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
147 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
148 // Sample entry: (Sparc):
149 // save(sp, -256, sp)
150 // ba,pt common_code
151 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
152 //
153 // Restore time:
154 // 1. initialize_shared_space: reserve space for table
155 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
156 //
157 // Execution time:
158 // First virtual method call for any object of these metadata types:
159 // 1. object->klass
160 // 2. vtable entry for that klass points to the jump table entries
161 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
162 // 4. common_code:
163 // Get address of new vtbl pointer for this Klass from updated table
164 // Update new vtbl pointer in the Klass: future virtual calls go direct
165 // Jump to method, using new vtbl pointer and method index
168 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
169 void* old_vtbl_ptr = *(void**)obj;
170 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
171 if (vtbl_list[i] == old_vtbl_ptr) {
172 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
173 }
174 }
175 ShouldNotReachHere();
176 return NULL;
177 }
179 // Assumes the vtable is in first slot in object.
180 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
181 int n = _global_klass_objects->length();
182 for (int i = 0; i < n; i++) {
183 Klass* obj = _global_klass_objects->at(i);
184 // Note oop_is_instance() is a virtual call. After patching vtables
185 // all virtual calls on the dummy vtables will restore the original!
186 if (obj->oop_is_instance()) {
187 InstanceKlass* ik = InstanceKlass::cast(obj);
188 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
189 ConstantPool* cp = ik->constants();
190 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
191 for (int j = 0; j < ik->methods()->length(); j++) {
192 Method* m = ik->methods()->at(j);
193 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
194 }
195 } else {
196 // Array klasses
197 Klass* k = obj;
198 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
199 }
200 }
201 }
203 // Closure for serializing initialization data out to a data area to be
204 // written to the shared file.
206 class WriteClosure : public SerializeClosure {
207 private:
208 intptr_t* top;
209 char* end;
211 inline void check_space() {
212 if ((char*)top + sizeof(intptr_t) > end) {
213 report_out_of_shared_space(SharedMiscData);
214 }
215 }
217 public:
218 WriteClosure(char* md_top, char* md_end) {
219 top = (intptr_t*)md_top;
220 end = md_end;
221 }
223 char* get_top() { return (char*)top; }
225 void do_ptr(void** p) {
226 check_space();
227 *top = (intptr_t)*p;
228 ++top;
229 }
231 void do_tag(int tag) {
232 check_space();
233 *top = (intptr_t)tag;
234 ++top;
235 }
237 void do_region(u_char* start, size_t size) {
238 if ((char*)top + size > end) {
239 report_out_of_shared_space(SharedMiscData);
240 }
241 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
242 assert(size % sizeof(intptr_t) == 0, "bad size");
243 do_tag((int)size);
244 while (size > 0) {
245 *top = *(intptr_t*)start;
246 ++top;
247 start += sizeof(intptr_t);
248 size -= sizeof(intptr_t);
249 }
250 }
252 bool reading() const { return false; }
253 };
255 // This is for dumping detailed statistics for the allocations
256 // in the shared spaces.
257 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
258 public:
260 // Here's poor man's enum inheritance
261 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
262 METASPACE_OBJ_TYPES_DO(f) \
263 f(SymbolHashentry) \
264 f(SymbolBuckets) \
265 f(Other)
267 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
268 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
270 enum Type {
271 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
272 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
273 _number_of_types
274 };
276 static const char * type_name(Type type) {
277 switch(type) {
278 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
279 default:
280 ShouldNotReachHere();
281 return NULL;
282 }
283 }
285 public:
286 enum {
287 RO = 0,
288 RW = 1
289 };
291 int _counts[2][_number_of_types];
292 int _bytes [2][_number_of_types];
293 int _which;
295 DumpAllocClosure() {
296 memset(_counts, 0, sizeof(_counts));
297 memset(_bytes, 0, sizeof(_bytes));
298 };
300 void iterate_metaspace(Metaspace* space, int which) {
301 assert(which == RO || which == RW, "sanity");
302 _which = which;
303 space->iterate(this);
304 }
306 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
307 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
308 _counts[_which][type] ++;
309 _bytes [_which][type] += byte_size;
310 }
312 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
313 };
315 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
316 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
317 int other_bytes = md_all + mc_all;
319 // Calculate size of data that was not allocated by Metaspace::allocate()
320 int symbol_count = _counts[RO][MetaspaceObj::SymbolType];
321 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>);
322 int symbuck_count = SymbolTable::the_table()->table_size();
323 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>);
325 _counts[RW][SymbolHashentryType] = symbol_count;
326 _bytes [RW][SymbolHashentryType] = symhash_bytes;
327 other_bytes -= symhash_bytes;
329 _counts[RW][SymbolBucketsType] = symbuck_count;
330 _bytes [RW][SymbolBucketsType] = symbuck_bytes;
331 other_bytes -= symbuck_bytes;
333 // TODO: count things like dictionary, vtable, etc
334 _bytes[RW][OtherType] = other_bytes;
336 // prevent divide-by-zero
337 if (ro_all < 1) {
338 ro_all = 1;
339 }
340 if (rw_all < 1) {
341 rw_all = 1;
342 }
344 int all_ro_count = 0;
345 int all_ro_bytes = 0;
346 int all_rw_count = 0;
347 int all_rw_bytes = 0;
349 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
350 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
351 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
352 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
354 tty->print_cr("Detailed metadata info (rw includes md and mc):");
355 tty->print_cr("%s", hdr);
356 tty->print_cr("%s", sep);
357 for (int type = 0; type < int(_number_of_types); type ++) {
358 const char *name = type_name((Type)type);
359 int ro_count = _counts[RO][type];
360 int ro_bytes = _bytes [RO][type];
361 int rw_count = _counts[RW][type];
362 int rw_bytes = _bytes [RW][type];
363 int count = ro_count + rw_count;
364 int bytes = ro_bytes + rw_bytes;
366 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
367 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
368 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
370 tty->print_cr(fmt_stats, name,
371 ro_count, ro_bytes, ro_perc,
372 rw_count, rw_bytes, rw_perc,
373 count, bytes, perc);
375 all_ro_count += ro_count;
376 all_ro_bytes += ro_bytes;
377 all_rw_count += rw_count;
378 all_rw_bytes += rw_bytes;
379 }
381 int all_count = all_ro_count + all_rw_count;
382 int all_bytes = all_ro_bytes + all_rw_bytes;
384 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
385 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
386 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
388 tty->print_cr("%s", sep);
389 tty->print_cr(fmt_stats, "Total",
390 all_ro_count, all_ro_bytes, all_ro_perc,
391 all_rw_count, all_rw_bytes, all_rw_perc,
392 all_count, all_bytes, all_perc);
394 assert(all_ro_bytes == ro_all, "everything should have been counted");
395 assert(all_rw_bytes == rw_all, "everything should have been counted");
396 #undef fmt_stats
397 }
399 // Populate the shared space.
401 class VM_PopulateDumpSharedSpace: public VM_Operation {
402 private:
403 ClassLoaderData* _loader_data;
404 GrowableArray<Klass*> *_class_promote_order;
405 VirtualSpace _md_vs;
406 VirtualSpace _mc_vs;
408 public:
409 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
410 GrowableArray<Klass*> *class_promote_order) :
411 _loader_data(loader_data) {
413 // Split up and initialize the misc code and data spaces
414 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
415 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
416 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
417 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
419 // Now split into misc sections.
420 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
421 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
422 _md_vs.initialize(md_rs, SharedMiscDataSize);
423 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
424 _class_promote_order = class_promote_order;
425 }
427 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
428 void doit(); // outline because gdb sucks
429 }; // class VM_PopulateDumpSharedSpace
432 void VM_PopulateDumpSharedSpace::doit() {
433 Thread* THREAD = VMThread::vm_thread();
434 NOT_PRODUCT(SystemDictionary::verify();)
435 // The following guarantee is meant to ensure that no loader constraints
436 // exist yet, since the constraints table is not shared. This becomes
437 // more important now that we don't re-initialize vtables/itables for
438 // shared classes at runtime, where constraints were previously created.
439 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
440 "loader constraints are not saved");
441 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
442 "placeholders are not saved");
443 // Revisit and implement this if we prelink method handle call sites:
444 guarantee(SystemDictionary::invoke_method_table() == NULL ||
445 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
446 "invoke method table is not saved");
448 // At this point, many classes have been loaded.
449 // Gather systemDictionary classes in a global array and do everything to
450 // that so we don't have to walk the SystemDictionary again.
451 _global_klass_objects = new GrowableArray<Klass*>(1000);
452 Universe::basic_type_classes_do(collect_classes);
453 SystemDictionary::classes_do(collect_classes);
455 tty->print_cr("Number of classes %d", _global_klass_objects->length());
456 {
457 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
458 for (int i = 0; i < _global_klass_objects->length(); i++) {
459 Klass* k = _global_klass_objects->at(i);
460 if (k->oop_is_instance()) {
461 num_inst ++;
462 } else if (k->oop_is_objArray()) {
463 num_obj_array ++;
464 } else {
465 assert(k->oop_is_typeArray(), "sanity");
466 num_type_array ++;
467 }
468 }
469 tty->print_cr(" instance classes = %5d", num_inst);
470 tty->print_cr(" obj array classes = %5d", num_obj_array);
471 tty->print_cr(" type array classes = %5d", num_type_array);
472 }
474 // Update all the fingerprints in the shared methods.
475 tty->print("Calculating fingerprints ... ");
476 calculate_fingerprints();
477 tty->print_cr("done. ");
479 // Remove all references outside the metadata
480 tty->print("Removing unshareable information ... ");
481 remove_unshareable_in_classes();
482 tty->print_cr("done. ");
484 // Set up the share data and shared code segments.
485 char* md_low = _md_vs.low();
486 char* md_top = md_low;
487 char* md_end = _md_vs.high();
488 char* mc_low = _mc_vs.low();
489 char* mc_top = mc_low;
490 char* mc_end = _mc_vs.high();
492 // Reserve space for the list of Klass*s whose vtables are used
493 // for patching others as needed.
495 void** vtbl_list = (void**)md_top;
496 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
497 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
499 md_top += vtbl_list_size * sizeof(void*);
500 void* vtable = md_top;
502 // Reserve space for a new dummy vtable for klass objects in the
503 // heap. Generate self-patching vtable entries.
505 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
506 &md_top, md_end,
507 &mc_top, mc_end);
509 // Reorder the system dictionary. (Moving the symbols affects
510 // how the hash table indices are calculated.)
511 // Not doing this either.
513 SystemDictionary::reorder_dictionary();
515 NOT_PRODUCT(SystemDictionary::verify();)
517 // Copy the the symbol table, and the system dictionary to the shared
518 // space in usable form. Copy the hastable
519 // buckets first [read-write], then copy the linked lists of entries
520 // [read-only].
522 SymbolTable::reverse(md_top);
523 NOT_PRODUCT(SymbolTable::verify());
524 SymbolTable::copy_buckets(&md_top, md_end);
526 SystemDictionary::reverse();
527 SystemDictionary::copy_buckets(&md_top, md_end);
529 ClassLoader::verify();
530 ClassLoader::copy_package_info_buckets(&md_top, md_end);
531 ClassLoader::verify();
533 SymbolTable::copy_table(&md_top, md_end);
534 SystemDictionary::copy_table(&md_top, md_end);
535 ClassLoader::verify();
536 ClassLoader::copy_package_info_table(&md_top, md_end);
537 ClassLoader::verify();
539 ClassLoaderExt::copy_lookup_cache_to_archive(&md_top, md_end);
541 // Write the other data to the output array.
542 WriteClosure wc(md_top, md_end);
543 MetaspaceShared::serialize(&wc);
544 md_top = wc.get_top();
546 // Print shared spaces all the time
547 // To make fmt_space be a syntactic constant (for format warnings), use #define.
548 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT
549 Metaspace* ro_space = _loader_data->ro_metaspace();
550 Metaspace* rw_space = _loader_data->rw_metaspace();
552 // Allocated size of each space (may not be all occupied)
553 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
554 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
555 const size_t md_alloced = md_end-md_low;
556 const size_t mc_alloced = mc_end-mc_low;
557 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
559 // Occupied size of each space.
560 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
561 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
562 const size_t md_bytes = size_t(md_top - md_low);
563 const size_t mc_bytes = size_t(mc_top - mc_low);
565 // Percent of total size
566 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
567 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
568 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
569 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
570 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
572 // Percent of fullness of each space
573 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
574 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
575 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
576 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
577 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
579 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
580 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
581 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
582 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
583 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
584 total_bytes, total_alloced, total_u_perc);
586 // Update the vtable pointers in all of the Klass objects in the
587 // heap. They should point to newly generated vtable.
588 patch_klass_vtables(vtbl_list, vtable);
590 // dunno what this is for.
591 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
592 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
593 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
595 // Create and write the archive file that maps the shared spaces.
597 FileMapInfo* mapinfo = new FileMapInfo();
598 mapinfo->populate_header(MetaspaceShared::max_alignment());
600 // Pass 1 - update file offsets in header.
601 mapinfo->write_header();
602 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
603 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
604 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
605 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
606 SharedMiscDataSize,
607 false, false);
608 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
609 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
610 SharedMiscCodeSize,
611 true, true);
613 // Pass 2 - write data.
614 mapinfo->open_for_write();
615 mapinfo->set_header_crc(mapinfo->compute_header_crc());
616 mapinfo->write_header();
617 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
618 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
619 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
620 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
621 SharedMiscDataSize,
622 false, false);
623 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
624 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
625 SharedMiscCodeSize,
626 true, true);
627 mapinfo->close();
629 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
631 if (PrintSharedSpaces) {
632 DumpAllocClosure dac;
633 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
634 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
636 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
637 }
638 #undef fmt_space
639 }
642 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) {
643 Klass* k = obj;
644 if (k->oop_is_instance()) {
645 InstanceKlass* ik = (InstanceKlass*) k;
646 // Link the class to cause the bytecodes to be rewritten and the
647 // cpcache to be created. Class verification is done according
648 // to -Xverify setting.
649 _link_classes_made_progress |= try_link_class(ik, THREAD);
650 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
651 }
652 }
654 void MetaspaceShared::check_one_shared_class(Klass* k) {
655 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
656 _check_classes_made_progress = true;
657 }
658 }
660 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
661 // We need to iterate because verification may cause additional classes
662 // to be loaded.
663 do {
664 _link_classes_made_progress = false;
665 SystemDictionary::classes_do(link_one_shared_class, THREAD);
666 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
667 } while (_link_classes_made_progress);
669 if (_has_error_classes) {
670 // Mark all classes whose super class or interfaces failed verification.
671 do {
672 // Not completely sure if we need to do this iteratively. Anyway,
673 // we should come here only if there are unverifiable classes, which
674 // shouldn't happen in normal cases. So better safe than sorry.
675 _check_classes_made_progress = false;
676 SystemDictionary::classes_do(check_one_shared_class);
677 } while (_check_classes_made_progress);
679 if (IgnoreUnverifiableClassesDuringDump) {
680 // This is useful when running JCK or SQE tests. You should not
681 // enable this when running real apps.
682 SystemDictionary::remove_classes_in_error_state();
683 } else {
684 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
685 exit(1);
686 }
687 }
689 // Copy the dependencies from C_HEAP-alloced GrowableArrays to RO-alloced
690 // Arrays
691 SystemDictionaryShared::finalize_verification_dependencies();
692 }
694 void MetaspaceShared::prepare_for_dumping() {
695 ClassLoader::initialize_shared_path();
696 FileMapInfo::allocate_classpath_entry_table();
697 }
699 // Preload classes from a list, populate the shared spaces and dump to a
700 // file.
701 void MetaspaceShared::preload_and_dump(TRAPS) {
702 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
703 ResourceMark rm;
705 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
706 MetaspaceShared::shared_rs()->size(),
707 MetaspaceShared::shared_rs()->base());
709 // Preload classes to be shared.
710 // Should use some os:: method rather than fopen() here. aB.
711 const char* class_list_path;
712 if (SharedClassListFile == NULL) {
713 // Construct the path to the class list (in jre/lib)
714 // Walk up two directories from the location of the VM and
715 // optionally tack on "lib" (depending on platform)
716 char class_list_path_str[JVM_MAXPATHLEN];
717 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
718 for (int i = 0; i < 3; i++) {
719 char *end = strrchr(class_list_path_str, *os::file_separator());
720 if (end != NULL) *end = '\0';
721 }
722 int class_list_path_len = (int)strlen(class_list_path_str);
723 if (class_list_path_len >= 3) {
724 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
725 strcat(class_list_path_str, os::file_separator());
726 strcat(class_list_path_str, "lib");
727 }
728 }
729 strcat(class_list_path_str, os::file_separator());
730 strcat(class_list_path_str, "classlist");
731 class_list_path = class_list_path_str;
732 } else {
733 class_list_path = SharedClassListFile;
734 }
736 int class_count = 0;
737 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
739 // sun.io.Converters
740 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
741 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
743 // java.util.HashMap
744 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
745 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
747 tty->print_cr("Loading classes to share ...");
748 _has_error_classes = false;
749 class_count += preload_and_dump(class_list_path, class_promote_order,
750 THREAD);
751 if (ExtraSharedClassListFile) {
752 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
753 THREAD);
754 }
755 tty->print_cr("Loading classes to share: done.");
757 ClassLoaderExt::init_lookup_cache(THREAD);
759 if (PrintSharedSpaces) {
760 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
761 }
763 // Rewrite and link classes
764 tty->print_cr("Rewriting and linking classes ...");
766 // Link any classes which got missed. This would happen if we have loaded classes that
767 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
768 // fails verification, all other interfaces that were not specified in the classlist but
769 // are implemented by K are not verified.
770 link_and_cleanup_shared_classes(CATCH);
771 tty->print_cr("Rewriting and linking classes: done");
773 // Create and dump the shared spaces. Everything so far is loaded
774 // with the null class loader.
775 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
776 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
777 VMThread::execute(&op);
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 }
784 int MetaspaceShared::preload_and_dump(const char * class_list_path,
785 GrowableArray<Klass*>* class_promote_order,
786 TRAPS) {
787 FILE* file = fopen(class_list_path, "r");
788 char class_name[256];
789 int class_count = 0;
791 if (file != NULL) {
792 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
793 if (*class_name == '#') { // comment
794 continue;
795 }
796 // Remove trailing newline
797 size_t name_len = strlen(class_name);
798 if (class_name[name_len-1] == '\n') {
799 class_name[name_len-1] = '\0';
800 }
802 // Got a class name - load it.
803 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
804 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
805 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
806 THREAD);
807 CLEAR_PENDING_EXCEPTION;
808 if (klass != NULL) {
809 if (PrintSharedSpaces && Verbose && WizardMode) {
810 tty->print_cr("Shared spaces preloaded: %s", class_name);
811 }
813 InstanceKlass* ik = InstanceKlass::cast(klass);
815 // Should be class load order as per -XX:+TraceClassLoadingPreorder
816 class_promote_order->append(ik);
818 // Link the class to cause the bytecodes to be rewritten and the
819 // cpcache to be created. The linking is done as soon as classes
820 // are loaded in order that the related data structures (klass and
821 // cpCache) are located together.
822 try_link_class(ik, THREAD);
823 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
825 class_count++;
826 } else {
827 //tty->print_cr("Preload failed: %s", class_name);
828 }
829 }
830 fclose(file);
831 } else {
832 char errmsg[JVM_MAXPATHLEN];
833 os::lasterror(errmsg, JVM_MAXPATHLEN);
834 tty->print_cr("Loading classlist failed: %s", errmsg);
835 exit(1);
836 }
838 return class_count;
839 }
841 // Returns true if the class's status has changed
842 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
843 assert(DumpSharedSpaces, "should only be called during dumping");
844 if (ik->init_state() < InstanceKlass::linked) {
845 bool saved = BytecodeVerificationLocal;
846 if (!SharedClassUtil::is_shared_boot_class(ik)) {
847 // The verification decision is based on BytecodeVerificationRemote
848 // for non-system classes. Since we are using the NULL classloader
849 // to load non-system classes during dumping, we need to temporarily
850 // change BytecodeVerificationLocal to be the same as
851 // BytecodeVerificationRemote. Note this can cause the parent system
852 // classes also being verified. The extra overhead is acceptable during
853 // dumping.
854 BytecodeVerificationLocal = BytecodeVerificationRemote;
855 }
856 ik->link_class(THREAD);
857 if (HAS_PENDING_EXCEPTION) {
858 ResourceMark rm;
859 tty->print_cr("Preload Warning: Verification failed for %s",
860 ik->external_name());
861 CLEAR_PENDING_EXCEPTION;
862 ik->set_in_error_state();
863 _has_error_classes = true;
864 }
865 BytecodeVerificationLocal = saved;
866 return true;
867 } else {
868 return false;
869 }
870 }
872 // Closure for serializing initialization data in from a data area
873 // (ptr_array) read from the shared file.
875 class ReadClosure : public SerializeClosure {
876 private:
877 intptr_t** _ptr_array;
879 inline intptr_t nextPtr() {
880 return *(*_ptr_array)++;
881 }
883 public:
884 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
886 void do_ptr(void** p) {
887 assert(*p == NULL, "initializing previous initialized pointer.");
888 intptr_t obj = nextPtr();
889 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
890 "hit tag while initializing ptrs.");
891 *p = (void*)obj;
892 }
894 void do_tag(int tag) {
895 int old_tag;
896 old_tag = (int)(intptr_t)nextPtr();
897 // do_int(&old_tag);
898 assert(tag == old_tag, "old tag doesn't match");
899 FileMapInfo::assert_mark(tag == old_tag);
900 }
902 void do_region(u_char* start, size_t size) {
903 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
904 assert(size % sizeof(intptr_t) == 0, "bad size");
905 do_tag((int)size);
906 while (size > 0) {
907 *(intptr_t*)start = nextPtr();
908 start += sizeof(intptr_t);
909 size -= sizeof(intptr_t);
910 }
911 }
913 bool reading() const { return true; }
914 };
916 // Return true if given address is in the mapped shared space.
917 bool MetaspaceShared::is_in_shared_space(const void* p) {
918 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
919 }
921 void MetaspaceShared::print_shared_spaces() {
922 if (UseSharedSpaces) {
923 FileMapInfo::current_info()->print_shared_spaces();
924 }
925 }
928 // Map shared spaces at requested addresses and return if succeeded.
929 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
930 // call, or is_in_shared_space.
931 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
932 size_t image_alignment = mapinfo->alignment();
934 #ifndef _WINDOWS
935 // Map in the shared memory and then map the regions on top of it.
936 // On Windows, don't map the memory here because it will cause the
937 // mappings of the regions to fail.
938 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
939 if (!shared_rs.is_reserved()) return false;
940 #endif
942 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
944 char* _ro_base = NULL;
945 char* _rw_base = NULL;
946 char* _md_base = NULL;
947 char* _mc_base = NULL;
949 // Map each shared region
950 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
951 mapinfo->verify_region_checksum(ro) &&
952 (_rw_base = mapinfo->map_region(rw)) != NULL &&
953 mapinfo->verify_region_checksum(rw) &&
954 (_md_base = mapinfo->map_region(md)) != NULL &&
955 mapinfo->verify_region_checksum(md) &&
956 (_mc_base = mapinfo->map_region(mc)) != NULL &&
957 mapinfo->verify_region_checksum(mc) &&
958 (image_alignment == (size_t)max_alignment()) &&
959 mapinfo->validate_classpath_entry_table()) {
960 // Success (no need to do anything)
961 return true;
962 } else {
963 // If there was a failure in mapping any of the spaces, unmap the ones
964 // that succeeded
965 if (_ro_base != NULL) mapinfo->unmap_region(ro);
966 if (_rw_base != NULL) mapinfo->unmap_region(rw);
967 if (_md_base != NULL) mapinfo->unmap_region(md);
968 if (_mc_base != NULL) mapinfo->unmap_region(mc);
969 #ifndef _WINDOWS
970 // Release the entire mapped region
971 shared_rs.release();
972 #endif
973 // If -Xshare:on is specified, print out the error message and exit VM,
974 // otherwise, set UseSharedSpaces to false and continue.
975 if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
976 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
977 } else {
978 FLAG_SET_DEFAULT(UseSharedSpaces, false);
979 }
980 return false;
981 }
982 }
984 // Read the miscellaneous data from the shared file, and
985 // serialize it out to its various destinations.
987 void MetaspaceShared::initialize_shared_spaces() {
988 FileMapInfo *mapinfo = FileMapInfo::current_info();
990 char* buffer = mapinfo->region_base(md);
992 // Skip over (reserve space for) a list of addresses of C++ vtables
993 // for Klass objects. They get filled in later.
995 void** vtbl_list = (void**)buffer;
996 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
997 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
999 // Skip over (reserve space for) dummy C++ vtables Klass objects.
1000 // They are used as is.
1002 intptr_t vtable_size = *(intptr_t*)buffer;
1003 buffer += sizeof(intptr_t);
1004 buffer += vtable_size;
1006 // Create the symbol table using the bucket array at this spot in the
1007 // misc data space. Since the symbol table is often modified, this
1008 // region (of mapped pages) will be copy-on-write.
1010 int symbolTableLen = *(intptr_t*)buffer;
1011 buffer += sizeof(intptr_t);
1012 int number_of_entries = *(intptr_t*)buffer;
1013 buffer += sizeof(intptr_t);
1014 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
1015 number_of_entries);
1016 buffer += symbolTableLen;
1018 // Create the shared dictionary using the bucket array at this spot in
1019 // the misc data space. Since the shared dictionary table is never
1020 // modified, this region (of mapped pages) will be (effectively, if
1021 // not explicitly) read-only.
1023 int sharedDictionaryLen = *(intptr_t*)buffer;
1024 buffer += sizeof(intptr_t);
1025 number_of_entries = *(intptr_t*)buffer;
1026 buffer += sizeof(intptr_t);
1027 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1028 sharedDictionaryLen,
1029 number_of_entries);
1030 buffer += sharedDictionaryLen;
1032 // Create the package info table using the bucket array at this spot in
1033 // the misc data space. Since the package info table is never
1034 // modified, this region (of mapped pages) will be (effectively, if
1035 // not explicitly) read-only.
1037 int pkgInfoLen = *(intptr_t*)buffer;
1038 buffer += sizeof(intptr_t);
1039 number_of_entries = *(intptr_t*)buffer;
1040 buffer += sizeof(intptr_t);
1041 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1042 number_of_entries);
1043 buffer += pkgInfoLen;
1044 ClassLoader::verify();
1046 // The following data in the shared misc data region are the linked
1047 // list elements (HashtableEntry objects) for the symbol table, string
1048 // table, and shared dictionary. The heap objects refered to by the
1049 // symbol table, string table, and shared dictionary are permanent and
1050 // unmovable. Since new entries added to the string and symbol tables
1051 // are always added at the beginning of the linked lists, THESE LINKED
1052 // LIST ELEMENTS ARE READ-ONLY.
1054 int len = *(intptr_t*)buffer; // skip over symbol table entries
1055 buffer += sizeof(intptr_t);
1056 buffer += len;
1058 len = *(intptr_t*)buffer; // skip over shared dictionary entries
1059 buffer += sizeof(intptr_t);
1060 buffer += len;
1062 len = *(intptr_t*)buffer; // skip over package info table entries
1063 buffer += sizeof(intptr_t);
1064 buffer += len;
1066 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
1067 buffer += sizeof(intptr_t);
1068 buffer += len;
1070 buffer = ClassLoaderExt::restore_lookup_cache_from_archive(buffer);
1072 intptr_t* array = (intptr_t*)buffer;
1073 ReadClosure rc(&array);
1074 serialize(&rc);
1076 // Close the mapinfo file
1077 mapinfo->close();
1079 if (PrintSharedArchiveAndExit) {
1080 if (PrintSharedDictionary) {
1081 tty->print_cr("\nShared classes:\n");
1082 SystemDictionary::print_shared(false);
1083 }
1084 if (_archive_loading_failed) {
1085 tty->print_cr("archive is invalid");
1086 vm_exit(1);
1087 } else {
1088 tty->print_cr("archive is valid");
1089 vm_exit(0);
1090 }
1091 }
1092 }
1094 // JVM/TI RedefineClasses() support:
1095 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1096 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1098 if (UseSharedSpaces) {
1099 // remap the shared readonly space to shared readwrite, private
1100 FileMapInfo* mapinfo = FileMapInfo::current_info();
1101 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1102 return false;
1103 }
1104 }
1105 return true;
1106 }
1108 int MetaspaceShared::count_class(const char* classlist_file) {
1109 if (classlist_file == NULL) {
1110 return 0;
1111 }
1112 char class_name[256];
1113 int class_count = 0;
1114 FILE* file = fopen(classlist_file, "r");
1115 if (file != NULL) {
1116 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
1117 if (*class_name == '#') { // comment
1118 continue;
1119 }
1120 class_count++;
1121 }
1122 fclose(file);
1123 } else {
1124 char errmsg[JVM_MAXPATHLEN];
1125 os::lasterror(errmsg, JVM_MAXPATHLEN);
1126 tty->print_cr("Loading classlist failed: %s", errmsg);
1127 exit(1);
1128 }
1130 return class_count;
1131 }
1133 // the sizes are good for typical large applications that have a lot of shared
1134 // classes
1135 void MetaspaceShared::estimate_regions_size() {
1136 int class_count = count_class(SharedClassListFile);
1137 class_count += count_class(ExtraSharedClassListFile);
1139 if (class_count > LargeThresholdClassCount) {
1140 if (class_count < HugeThresholdClassCount) {
1141 SET_ESTIMATED_SIZE(Large, ReadOnly);
1142 SET_ESTIMATED_SIZE(Large, ReadWrite);
1143 SET_ESTIMATED_SIZE(Large, MiscData);
1144 SET_ESTIMATED_SIZE(Large, MiscCode);
1145 } else {
1146 SET_ESTIMATED_SIZE(Huge, ReadOnly);
1147 SET_ESTIMATED_SIZE(Huge, ReadWrite);
1148 SET_ESTIMATED_SIZE(Huge, MiscData);
1149 SET_ESTIMATED_SIZE(Huge, MiscCode);
1150 }
1151 }
1152 }