Sat, 24 Oct 2020 16:43:47 +0800
Merge
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 bool MetaspaceShared::_remapped_readwrite = false;
58 // Read/write a data stream for restoring/preserving metadata pointers and
59 // miscellaneous data from/to the shared archive file.
61 void MetaspaceShared::serialize(SerializeClosure* soc) {
62 int tag = 0;
63 soc->do_tag(--tag);
65 // Verify the sizes of various metadata in the system.
66 soc->do_tag(sizeof(Method));
67 soc->do_tag(sizeof(ConstMethod));
68 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
69 soc->do_tag(sizeof(ConstantPool));
70 soc->do_tag(sizeof(ConstantPoolCache));
71 soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
72 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
73 soc->do_tag(sizeof(Symbol));
75 // Dump/restore miscellaneous metadata.
76 Universe::serialize(soc, true);
77 soc->do_tag(--tag);
79 // Dump/restore references to commonly used names and signatures.
80 vmSymbols::serialize(soc);
81 soc->do_tag(--tag);
83 soc->do_tag(666);
84 }
87 // CDS code for dumping shared archive.
89 // Global object for holding classes that have been loaded. Since this
90 // is run at a safepoint just before exit, this is the entire set of classes.
91 static GrowableArray<Klass*>* _global_klass_objects;
92 static void collect_classes(Klass* k) {
93 _global_klass_objects->append_if_missing(k);
94 if (k->oop_is_instance()) {
95 // Add in the array classes too
96 InstanceKlass* ik = InstanceKlass::cast(k);
97 ik->array_klasses_do(collect_classes);
98 }
99 }
101 static void remove_unshareable_in_classes() {
102 for (int i = 0; i < _global_klass_objects->length(); i++) {
103 Klass* k = _global_klass_objects->at(i);
104 k->remove_unshareable_info();
105 }
106 }
108 // Walk all methods in the class list and assign a fingerprint.
109 // so that this part of the ConstMethod* is read only.
110 static void calculate_fingerprints() {
111 for (int i = 0; i < _global_klass_objects->length(); i++) {
112 Klass* k = _global_klass_objects->at(i);
113 if (k->oop_is_instance()) {
114 InstanceKlass* ik = InstanceKlass::cast(k);
115 for (int i = 0; i < ik->methods()->length(); i++) {
116 Method* m = ik->methods()->at(i);
117 Fingerprinter fp(m);
118 // The side effect of this call sets method's fingerprint field.
119 fp.fingerprint();
120 }
121 }
122 }
123 }
125 // Patch C++ vtable pointer in metadata.
127 // Klass and other metadata objects contain references to c++ vtables in the
128 // JVM library.
129 // Fix them to point to our constructed vtables. However, don't iterate
130 // across the space while doing this, as that causes the vtables to be
131 // patched, undoing our useful work. Instead, iterate to make a list,
132 // then use the list to do the fixing.
133 //
134 // Our constructed vtables:
135 // Dump time:
136 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
137 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list
138 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
139 // associated metadata to point to jump table rather than to current vtbl
140 // Table layout: NOTE FIXED SIZE
141 // 1. vtbl pointers
142 // 2. #Klass X #virtual methods per Klass
143 // 1 entry for each, in the order:
144 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
145 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
146 // ...
147 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
148 // ... Klass<vtbl_list_size>:method<num_virtuals> entry
149 // Sample entry: (Sparc):
150 // save(sp, -256, sp)
151 // ba,pt common_code
152 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255)
153 //
154 // Restore time:
155 // 1. initialize_shared_space: reserve space for table
156 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
157 //
158 // Execution time:
159 // First virtual method call for any object of these metadata types:
160 // 1. object->klass
161 // 2. vtable entry for that klass points to the jump table entries
162 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
163 // 4. common_code:
164 // Get address of new vtbl pointer for this Klass from updated table
165 // Update new vtbl pointer in the Klass: future virtual calls go direct
166 // Jump to method, using new vtbl pointer and method index
169 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
170 void* old_vtbl_ptr = *(void**)obj;
171 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
172 if (vtbl_list[i] == old_vtbl_ptr) {
173 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
174 }
175 }
176 ShouldNotReachHere();
177 return NULL;
178 }
180 // Assumes the vtable is in first slot in object.
181 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
182 int n = _global_klass_objects->length();
183 for (int i = 0; i < n; i++) {
184 Klass* obj = _global_klass_objects->at(i);
185 // Note oop_is_instance() is a virtual call. After patching vtables
186 // all virtual calls on the dummy vtables will restore the original!
187 if (obj->oop_is_instance()) {
188 InstanceKlass* ik = InstanceKlass::cast(obj);
189 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
190 ConstantPool* cp = ik->constants();
191 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
192 for (int j = 0; j < ik->methods()->length(); j++) {
193 Method* m = ik->methods()->at(j);
194 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
195 }
196 } else {
197 // Array klasses
198 Klass* k = obj;
199 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
200 }
201 }
202 }
204 // Closure for serializing initialization data out to a data area to be
205 // written to the shared file.
207 class WriteClosure : public SerializeClosure {
208 private:
209 intptr_t* top;
210 char* end;
212 inline void check_space() {
213 if ((char*)top + sizeof(intptr_t) > end) {
214 report_out_of_shared_space(SharedMiscData);
215 }
216 }
218 public:
219 WriteClosure(char* md_top, char* md_end) {
220 top = (intptr_t*)md_top;
221 end = md_end;
222 }
224 char* get_top() { return (char*)top; }
226 void do_ptr(void** p) {
227 check_space();
228 *top = (intptr_t)*p;
229 ++top;
230 }
232 void do_tag(int tag) {
233 check_space();
234 *top = (intptr_t)tag;
235 ++top;
236 }
238 void do_region(u_char* start, size_t size) {
239 if ((char*)top + size > end) {
240 report_out_of_shared_space(SharedMiscData);
241 }
242 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
243 assert(size % sizeof(intptr_t) == 0, "bad size");
244 do_tag((int)size);
245 while (size > 0) {
246 *top = *(intptr_t*)start;
247 ++top;
248 start += sizeof(intptr_t);
249 size -= sizeof(intptr_t);
250 }
251 }
253 bool reading() const { return false; }
254 };
256 // This is for dumping detailed statistics for the allocations
257 // in the shared spaces.
258 class DumpAllocClosure : public Metaspace::AllocRecordClosure {
259 public:
261 // Here's poor man's enum inheritance
262 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
263 METASPACE_OBJ_TYPES_DO(f) \
264 f(SymbolHashentry) \
265 f(SymbolBuckets) \
266 f(Other)
268 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type,
269 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
271 enum Type {
272 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
273 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE)
274 _number_of_types
275 };
277 static const char * type_name(Type type) {
278 switch(type) {
279 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE)
280 default:
281 ShouldNotReachHere();
282 return NULL;
283 }
284 }
286 public:
287 enum {
288 RO = 0,
289 RW = 1
290 };
292 int _counts[2][_number_of_types];
293 int _bytes [2][_number_of_types];
294 int _which;
296 DumpAllocClosure() {
297 memset(_counts, 0, sizeof(_counts));
298 memset(_bytes, 0, sizeof(_bytes));
299 };
301 void iterate_metaspace(Metaspace* space, int which) {
302 assert(which == RO || which == RW, "sanity");
303 _which = which;
304 space->iterate(this);
305 }
307 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) {
308 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
309 _counts[_which][type] ++;
310 _bytes [_which][type] += byte_size;
311 }
313 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all);
314 };
316 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) {
317 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write
318 int other_bytes = md_all + mc_all;
320 // Calculate size of data that was not allocated by Metaspace::allocate()
321 int symbol_count = _counts[RO][MetaspaceObj::SymbolType];
322 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>);
323 int symbuck_count = SymbolTable::the_table()->table_size();
324 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>);
326 _counts[RW][SymbolHashentryType] = symbol_count;
327 _bytes [RW][SymbolHashentryType] = symhash_bytes;
328 other_bytes -= symhash_bytes;
330 _counts[RW][SymbolBucketsType] = symbuck_count;
331 _bytes [RW][SymbolBucketsType] = symbuck_bytes;
332 other_bytes -= symbuck_bytes;
334 // TODO: count things like dictionary, vtable, etc
335 _bytes[RW][OtherType] = other_bytes;
337 // prevent divide-by-zero
338 if (ro_all < 1) {
339 ro_all = 1;
340 }
341 if (rw_all < 1) {
342 rw_all = 1;
343 }
345 int all_ro_count = 0;
346 int all_ro_bytes = 0;
347 int all_rw_count = 0;
348 int all_rw_bytes = 0;
350 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
351 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
352 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
353 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %";
355 tty->print_cr("Detailed metadata info (rw includes md and mc):");
356 tty->print_cr("%s", hdr);
357 tty->print_cr("%s", sep);
358 for (int type = 0; type < int(_number_of_types); type ++) {
359 const char *name = type_name((Type)type);
360 int ro_count = _counts[RO][type];
361 int ro_bytes = _bytes [RO][type];
362 int rw_count = _counts[RW][type];
363 int rw_bytes = _bytes [RW][type];
364 int count = ro_count + rw_count;
365 int bytes = ro_bytes + rw_bytes;
367 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
368 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
369 double perc = 100.0 * double(bytes) / double(ro_all + rw_all);
371 tty->print_cr(fmt_stats, name,
372 ro_count, ro_bytes, ro_perc,
373 rw_count, rw_bytes, rw_perc,
374 count, bytes, perc);
376 all_ro_count += ro_count;
377 all_ro_bytes += ro_bytes;
378 all_rw_count += rw_count;
379 all_rw_bytes += rw_bytes;
380 }
382 int all_count = all_ro_count + all_rw_count;
383 int all_bytes = all_ro_bytes + all_rw_bytes;
385 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
386 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
387 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all);
389 tty->print_cr("%s", sep);
390 tty->print_cr(fmt_stats, "Total",
391 all_ro_count, all_ro_bytes, all_ro_perc,
392 all_rw_count, all_rw_bytes, all_rw_perc,
393 all_count, all_bytes, all_perc);
395 assert(all_ro_bytes == ro_all, "everything should have been counted");
396 assert(all_rw_bytes == rw_all, "everything should have been counted");
397 #undef fmt_stats
398 }
400 // Populate the shared space.
402 class VM_PopulateDumpSharedSpace: public VM_Operation {
403 private:
404 ClassLoaderData* _loader_data;
405 GrowableArray<Klass*> *_class_promote_order;
406 VirtualSpace _md_vs;
407 VirtualSpace _mc_vs;
409 public:
410 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
411 GrowableArray<Klass*> *class_promote_order) :
412 _loader_data(loader_data) {
414 // Split up and initialize the misc code and data spaces
415 ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
416 int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
417 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
418 ReservedSpace misc_section = shared_rs->last_part(metadata_size);
420 // Now split into misc sections.
421 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize);
422 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize);
423 _md_vs.initialize(md_rs, SharedMiscDataSize);
424 _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
425 _class_promote_order = class_promote_order;
426 }
428 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
429 void doit(); // outline because gdb sucks
430 }; // class VM_PopulateDumpSharedSpace
433 void VM_PopulateDumpSharedSpace::doit() {
434 Thread* THREAD = VMThread::vm_thread();
435 NOT_PRODUCT(SystemDictionary::verify();)
436 // The following guarantee is meant to ensure that no loader constraints
437 // exist yet, since the constraints table is not shared. This becomes
438 // more important now that we don't re-initialize vtables/itables for
439 // shared classes at runtime, where constraints were previously created.
440 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
441 "loader constraints are not saved");
442 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
443 "placeholders are not saved");
444 // Revisit and implement this if we prelink method handle call sites:
445 guarantee(SystemDictionary::invoke_method_table() == NULL ||
446 SystemDictionary::invoke_method_table()->number_of_entries() == 0,
447 "invoke method table is not saved");
449 // At this point, many classes have been loaded.
450 // Gather systemDictionary classes in a global array and do everything to
451 // that so we don't have to walk the SystemDictionary again.
452 _global_klass_objects = new GrowableArray<Klass*>(1000);
453 Universe::basic_type_classes_do(collect_classes);
454 SystemDictionary::classes_do(collect_classes);
456 tty->print_cr("Number of classes %d", _global_klass_objects->length());
457 {
458 int num_type_array = 0, num_obj_array = 0, num_inst = 0;
459 for (int i = 0; i < _global_klass_objects->length(); i++) {
460 Klass* k = _global_klass_objects->at(i);
461 if (k->oop_is_instance()) {
462 num_inst ++;
463 } else if (k->oop_is_objArray()) {
464 num_obj_array ++;
465 } else {
466 assert(k->oop_is_typeArray(), "sanity");
467 num_type_array ++;
468 }
469 }
470 tty->print_cr(" instance classes = %5d", num_inst);
471 tty->print_cr(" obj array classes = %5d", num_obj_array);
472 tty->print_cr(" type array classes = %5d", num_type_array);
473 }
475 // Update all the fingerprints in the shared methods.
476 tty->print("Calculating fingerprints ... ");
477 calculate_fingerprints();
478 tty->print_cr("done. ");
480 // Remove all references outside the metadata
481 tty->print("Removing unshareable information ... ");
482 remove_unshareable_in_classes();
483 tty->print_cr("done. ");
485 // Set up the share data and shared code segments.
486 char* md_low = _md_vs.low();
487 char* md_top = md_low;
488 char* md_end = _md_vs.high();
489 char* mc_low = _mc_vs.low();
490 char* mc_top = mc_low;
491 char* mc_end = _mc_vs.high();
493 // Reserve space for the list of Klass*s whose vtables are used
494 // for patching others as needed.
496 void** vtbl_list = (void**)md_top;
497 int vtbl_list_size = MetaspaceShared::vtbl_list_size;
498 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
500 md_top += vtbl_list_size * sizeof(void*);
501 void* vtable = md_top;
503 // Reserve space for a new dummy vtable for klass objects in the
504 // heap. Generate self-patching vtable entries.
506 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
507 &md_top, md_end,
508 &mc_top, mc_end);
510 // Reorder the system dictionary. (Moving the symbols affects
511 // how the hash table indices are calculated.)
512 // Not doing this either.
514 SystemDictionary::reorder_dictionary();
516 NOT_PRODUCT(SystemDictionary::verify();)
518 // Copy the the symbol table, and the system dictionary to the shared
519 // space in usable form. Copy the hastable
520 // buckets first [read-write], then copy the linked lists of entries
521 // [read-only].
523 SymbolTable::reverse(md_top);
524 NOT_PRODUCT(SymbolTable::verify());
525 SymbolTable::copy_buckets(&md_top, md_end);
527 SystemDictionary::reverse();
528 SystemDictionary::copy_buckets(&md_top, md_end);
530 ClassLoader::verify();
531 ClassLoader::copy_package_info_buckets(&md_top, md_end);
532 ClassLoader::verify();
534 SymbolTable::copy_table(&md_top, md_end);
535 SystemDictionary::copy_table(&md_top, md_end);
536 ClassLoader::verify();
537 ClassLoader::copy_package_info_table(&md_top, md_end);
538 ClassLoader::verify();
540 ClassLoaderExt::copy_lookup_cache_to_archive(&md_top, md_end);
542 // Write the other data to the output array.
543 WriteClosure wc(md_top, md_end);
544 MetaspaceShared::serialize(&wc);
545 md_top = wc.get_top();
547 // Print shared spaces all the time
548 // To make fmt_space be a syntactic constant (for format warnings), use #define.
549 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT
550 Metaspace* ro_space = _loader_data->ro_metaspace();
551 Metaspace* rw_space = _loader_data->rw_metaspace();
553 // Allocated size of each space (may not be all occupied)
554 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
555 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
556 const size_t md_alloced = md_end-md_low;
557 const size_t mc_alloced = mc_end-mc_low;
558 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
560 // Occupied size of each space.
561 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
562 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
563 const size_t md_bytes = size_t(md_top - md_low);
564 const size_t mc_bytes = size_t(mc_top - mc_low);
566 // Percent of total size
567 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
568 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
569 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
570 const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
571 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
573 // Percent of fullness of each space
574 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
575 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
576 const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
577 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
578 const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
580 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
581 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
582 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
583 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
584 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
585 total_bytes, total_alloced, total_u_perc);
587 // Update the vtable pointers in all of the Klass objects in the
588 // heap. They should point to newly generated vtable.
589 patch_klass_vtables(vtbl_list, vtable);
591 // dunno what this is for.
592 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
593 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
594 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
596 // Create and write the archive file that maps the shared spaces.
598 FileMapInfo* mapinfo = new FileMapInfo();
599 mapinfo->populate_header(MetaspaceShared::max_alignment());
601 // Pass 1 - update file offsets in header.
602 mapinfo->write_header();
603 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
604 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
605 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
606 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
607 SharedMiscDataSize,
608 false, false);
609 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
610 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
611 SharedMiscCodeSize,
612 true, true);
614 // Pass 2 - write data.
615 mapinfo->open_for_write();
616 mapinfo->set_header_crc(mapinfo->compute_header_crc());
617 mapinfo->write_header();
618 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
619 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
620 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
621 pointer_delta(md_top, _md_vs.low(), sizeof(char)),
622 SharedMiscDataSize,
623 false, false);
624 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
625 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
626 SharedMiscCodeSize,
627 true, true);
628 mapinfo->close();
630 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
632 if (PrintSharedSpaces) {
633 DumpAllocClosure dac;
634 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO);
635 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW);
637 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
638 }
639 #undef fmt_space
640 }
643 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) {
644 Klass* k = obj;
645 if (k->oop_is_instance()) {
646 InstanceKlass* ik = (InstanceKlass*) k;
647 // Link the class to cause the bytecodes to be rewritten and the
648 // cpcache to be created. Class verification is done according
649 // to -Xverify setting.
650 _link_classes_made_progress |= try_link_class(ik, THREAD);
651 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
652 }
653 }
655 void MetaspaceShared::check_one_shared_class(Klass* k) {
656 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
657 _check_classes_made_progress = true;
658 }
659 }
661 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
662 // We need to iterate because verification may cause additional classes
663 // to be loaded.
664 do {
665 _link_classes_made_progress = false;
666 SystemDictionary::classes_do(link_one_shared_class, THREAD);
667 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
668 } while (_link_classes_made_progress);
670 if (_has_error_classes) {
671 // Mark all classes whose super class or interfaces failed verification.
672 do {
673 // Not completely sure if we need to do this iteratively. Anyway,
674 // we should come here only if there are unverifiable classes, which
675 // shouldn't happen in normal cases. So better safe than sorry.
676 _check_classes_made_progress = false;
677 SystemDictionary::classes_do(check_one_shared_class);
678 } while (_check_classes_made_progress);
680 if (IgnoreUnverifiableClassesDuringDump) {
681 // This is useful when running JCK or SQE tests. You should not
682 // enable this when running real apps.
683 SystemDictionary::remove_classes_in_error_state();
684 } else {
685 tty->print_cr("Please remove the unverifiable classes from your class list and try again");
686 exit(1);
687 }
688 }
690 // Copy the dependencies from C_HEAP-alloced GrowableArrays to RO-alloced
691 // Arrays
692 SystemDictionaryShared::finalize_verification_dependencies();
693 }
695 void MetaspaceShared::prepare_for_dumping() {
696 ClassLoader::initialize_shared_path();
697 FileMapInfo::allocate_classpath_entry_table();
698 }
700 // Preload classes from a list, populate the shared spaces and dump to a
701 // file.
702 void MetaspaceShared::preload_and_dump(TRAPS) {
703 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
704 ResourceMark rm;
706 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
707 MetaspaceShared::shared_rs()->size(),
708 MetaspaceShared::shared_rs()->base());
710 // Preload classes to be shared.
711 // Should use some os:: method rather than fopen() here. aB.
712 const char* class_list_path;
713 if (SharedClassListFile == NULL) {
714 // Construct the path to the class list (in jre/lib)
715 // Walk up two directories from the location of the VM and
716 // optionally tack on "lib" (depending on platform)
717 char class_list_path_str[JVM_MAXPATHLEN];
718 os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
719 for (int i = 0; i < 3; i++) {
720 char *end = strrchr(class_list_path_str, *os::file_separator());
721 if (end != NULL) *end = '\0';
722 }
723 int class_list_path_len = (int)strlen(class_list_path_str);
724 if (class_list_path_len >= 3) {
725 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
726 jio_snprintf(class_list_path_str + class_list_path_len,
727 sizeof(class_list_path_str) - class_list_path_len,
728 "%slib", os::file_separator());
729 class_list_path_len += 4;
730 }
731 }
732 jio_snprintf(class_list_path_str + class_list_path_len,
733 sizeof(class_list_path_str) - class_list_path_len,
734 "%sclasslist", os::file_separator());
735 class_list_path = class_list_path_str;
736 } else {
737 class_list_path = SharedClassListFile;
738 }
740 int class_count = 0;
741 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
743 // sun.io.Converters
744 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
745 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
747 // java.util.HashMap
748 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
749 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
751 tty->print_cr("Loading classes to share ...");
752 _has_error_classes = false;
753 class_count += preload_and_dump(class_list_path, class_promote_order,
754 THREAD);
755 if (ExtraSharedClassListFile) {
756 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
757 THREAD);
758 }
759 tty->print_cr("Loading classes to share: done.");
761 ClassLoaderExt::init_lookup_cache(THREAD);
763 if (PrintSharedSpaces) {
764 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
765 }
767 // Rewrite and link classes
768 tty->print_cr("Rewriting and linking classes ...");
770 // Link any classes which got missed. This would happen if we have loaded classes that
771 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
772 // fails verification, all other interfaces that were not specified in the classlist but
773 // are implemented by K are not verified.
774 link_and_cleanup_shared_classes(CATCH);
775 tty->print_cr("Rewriting and linking classes: done");
777 // Create and dump the shared spaces. Everything so far is loaded
778 // with the null class loader.
779 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
780 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
781 VMThread::execute(&op);
783 // Since various initialization steps have been undone by this process,
784 // it is not reasonable to continue running a java process.
785 exit(0);
786 }
788 int MetaspaceShared::preload_and_dump(const char * class_list_path,
789 GrowableArray<Klass*>* class_promote_order,
790 TRAPS) {
791 FILE* file = fopen(class_list_path, "r");
792 char class_name[256];
793 int class_count = 0;
795 if (file != NULL) {
796 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
797 if (*class_name == '#') { // comment
798 continue;
799 }
800 // Remove trailing newline
801 size_t name_len = strlen(class_name);
802 if (class_name[name_len-1] == '\n') {
803 class_name[name_len-1] = '\0';
804 }
806 // Got a class name - load it.
807 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
808 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
809 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
810 THREAD);
811 CLEAR_PENDING_EXCEPTION;
812 if (klass != NULL) {
813 if (PrintSharedSpaces && Verbose && WizardMode) {
814 tty->print_cr("Shared spaces preloaded: %s", class_name);
815 }
817 InstanceKlass* ik = InstanceKlass::cast(klass);
819 // Should be class load order as per -XX:+TraceClassLoadingPreorder
820 class_promote_order->append(ik);
822 // Link the class to cause the bytecodes to be rewritten and the
823 // cpcache to be created. The linking is done as soon as classes
824 // are loaded in order that the related data structures (klass and
825 // cpCache) are located together.
826 try_link_class(ik, THREAD);
827 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
829 class_count++;
830 } else {
831 //tty->print_cr("Preload failed: %s", class_name);
832 }
833 }
834 fclose(file);
835 } else {
836 char errmsg[JVM_MAXPATHLEN];
837 os::lasterror(errmsg, JVM_MAXPATHLEN);
838 tty->print_cr("Loading classlist failed: %s", errmsg);
839 exit(1);
840 }
842 return class_count;
843 }
845 // Returns true if the class's status has changed
846 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
847 assert(DumpSharedSpaces, "should only be called during dumping");
848 if (ik->init_state() < InstanceKlass::linked) {
849 bool saved = BytecodeVerificationLocal;
850 if (!SharedClassUtil::is_shared_boot_class(ik)) {
851 // The verification decision is based on BytecodeVerificationRemote
852 // for non-system classes. Since we are using the NULL classloader
853 // to load non-system classes during dumping, we need to temporarily
854 // change BytecodeVerificationLocal to be the same as
855 // BytecodeVerificationRemote. Note this can cause the parent system
856 // classes also being verified. The extra overhead is acceptable during
857 // dumping.
858 BytecodeVerificationLocal = BytecodeVerificationRemote;
859 }
860 ik->link_class(THREAD);
861 if (HAS_PENDING_EXCEPTION) {
862 ResourceMark rm;
863 tty->print_cr("Preload Warning: Verification failed for %s",
864 ik->external_name());
865 CLEAR_PENDING_EXCEPTION;
866 ik->set_in_error_state();
867 _has_error_classes = true;
868 }
869 BytecodeVerificationLocal = saved;
870 return true;
871 } else {
872 return false;
873 }
874 }
876 // Closure for serializing initialization data in from a data area
877 // (ptr_array) read from the shared file.
879 class ReadClosure : public SerializeClosure {
880 private:
881 intptr_t** _ptr_array;
883 inline intptr_t nextPtr() {
884 return *(*_ptr_array)++;
885 }
887 public:
888 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
890 void do_ptr(void** p) {
891 assert(*p == NULL, "initializing previous initialized pointer.");
892 intptr_t obj = nextPtr();
893 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
894 "hit tag while initializing ptrs.");
895 *p = (void*)obj;
896 }
898 void do_tag(int tag) {
899 int old_tag;
900 old_tag = (int)(intptr_t)nextPtr();
901 // do_int(&old_tag);
902 assert(tag == old_tag, "old tag doesn't match");
903 FileMapInfo::assert_mark(tag == old_tag);
904 }
906 void do_region(u_char* start, size_t size) {
907 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
908 assert(size % sizeof(intptr_t) == 0, "bad size");
909 do_tag((int)size);
910 while (size > 0) {
911 *(intptr_t*)start = nextPtr();
912 start += sizeof(intptr_t);
913 size -= sizeof(intptr_t);
914 }
915 }
917 bool reading() const { return true; }
918 };
920 // Return true if given address is in the mapped shared space.
921 bool MetaspaceShared::is_in_shared_space(const void* p) {
922 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p);
923 }
925 void MetaspaceShared::print_shared_spaces() {
926 if (UseSharedSpaces) {
927 FileMapInfo::current_info()->print_shared_spaces();
928 }
929 }
932 // Map shared spaces at requested addresses and return if succeeded.
933 // Need to keep the bounds of the ro and rw space for the Metaspace::contains
934 // call, or is_in_shared_space.
935 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
936 size_t image_alignment = mapinfo->alignment();
938 #ifndef _WINDOWS
939 // Map in the shared memory and then map the regions on top of it.
940 // On Windows, don't map the memory here because it will cause the
941 // mappings of the regions to fail.
942 ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
943 if (!shared_rs.is_reserved()) return false;
944 #endif
946 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
948 char* _ro_base = NULL;
949 char* _rw_base = NULL;
950 char* _md_base = NULL;
951 char* _mc_base = NULL;
953 // Map each shared region
954 if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
955 mapinfo->verify_region_checksum(ro) &&
956 (_rw_base = mapinfo->map_region(rw)) != NULL &&
957 mapinfo->verify_region_checksum(rw) &&
958 (_md_base = mapinfo->map_region(md)) != NULL &&
959 mapinfo->verify_region_checksum(md) &&
960 (_mc_base = mapinfo->map_region(mc)) != NULL &&
961 mapinfo->verify_region_checksum(mc) &&
962 (image_alignment == (size_t)max_alignment()) &&
963 mapinfo->validate_classpath_entry_table()) {
964 // Success (no need to do anything)
965 return true;
966 } else {
967 // If there was a failure in mapping any of the spaces, unmap the ones
968 // that succeeded
969 if (_ro_base != NULL) mapinfo->unmap_region(ro);
970 if (_rw_base != NULL) mapinfo->unmap_region(rw);
971 if (_md_base != NULL) mapinfo->unmap_region(md);
972 if (_mc_base != NULL) mapinfo->unmap_region(mc);
973 #ifndef _WINDOWS
974 // Release the entire mapped region
975 shared_rs.release();
976 #endif
977 // If -Xshare:on is specified, print out the error message and exit VM,
978 // otherwise, set UseSharedSpaces to false and continue.
979 if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
980 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
981 } else {
982 FLAG_SET_DEFAULT(UseSharedSpaces, false);
983 }
984 return false;
985 }
986 }
988 // Read the miscellaneous data from the shared file, and
989 // serialize it out to its various destinations.
991 void MetaspaceShared::initialize_shared_spaces() {
992 FileMapInfo *mapinfo = FileMapInfo::current_info();
994 char* buffer = mapinfo->region_base(md);
996 // Skip over (reserve space for) a list of addresses of C++ vtables
997 // for Klass objects. They get filled in later.
999 void** vtbl_list = (void**)buffer;
1000 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
1001 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
1003 // Skip over (reserve space for) dummy C++ vtables Klass objects.
1004 // They are used as is.
1006 intptr_t vtable_size = *(intptr_t*)buffer;
1007 buffer += sizeof(intptr_t);
1008 buffer += vtable_size;
1010 // Create the symbol table using the bucket array at this spot in the
1011 // misc data space. Since the symbol table is often modified, this
1012 // region (of mapped pages) will be copy-on-write.
1014 int symbolTableLen = *(intptr_t*)buffer;
1015 buffer += sizeof(intptr_t);
1016 int number_of_entries = *(intptr_t*)buffer;
1017 buffer += sizeof(intptr_t);
1018 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
1019 number_of_entries);
1020 buffer += symbolTableLen;
1022 // Create the shared dictionary using the bucket array at this spot in
1023 // the misc data space. Since the shared dictionary table is never
1024 // modified, this region (of mapped pages) will be (effectively, if
1025 // not explicitly) read-only.
1027 int sharedDictionaryLen = *(intptr_t*)buffer;
1028 buffer += sizeof(intptr_t);
1029 number_of_entries = *(intptr_t*)buffer;
1030 buffer += sizeof(intptr_t);
1031 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
1032 sharedDictionaryLen,
1033 number_of_entries);
1034 buffer += sharedDictionaryLen;
1036 // Create the package info table using the bucket array at this spot in
1037 // the misc data space. Since the package info table is never
1038 // modified, this region (of mapped pages) will be (effectively, if
1039 // not explicitly) read-only.
1041 int pkgInfoLen = *(intptr_t*)buffer;
1042 buffer += sizeof(intptr_t);
1043 number_of_entries = *(intptr_t*)buffer;
1044 buffer += sizeof(intptr_t);
1045 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
1046 number_of_entries);
1047 buffer += pkgInfoLen;
1048 ClassLoader::verify();
1050 // The following data in the shared misc data region are the linked
1051 // list elements (HashtableEntry objects) for the symbol table, string
1052 // table, and shared dictionary. The heap objects refered to by the
1053 // symbol table, string table, and shared dictionary are permanent and
1054 // unmovable. Since new entries added to the string and symbol tables
1055 // are always added at the beginning of the linked lists, THESE LINKED
1056 // LIST ELEMENTS ARE READ-ONLY.
1058 int len = *(intptr_t*)buffer; // skip over symbol table entries
1059 buffer += sizeof(intptr_t);
1060 buffer += len;
1062 len = *(intptr_t*)buffer; // skip over shared dictionary entries
1063 buffer += sizeof(intptr_t);
1064 buffer += len;
1066 len = *(intptr_t*)buffer; // skip over package info table entries
1067 buffer += sizeof(intptr_t);
1068 buffer += len;
1070 len = *(intptr_t*)buffer; // skip over package info table char[] arrays.
1071 buffer += sizeof(intptr_t);
1072 buffer += len;
1074 buffer = ClassLoaderExt::restore_lookup_cache_from_archive(buffer);
1076 intptr_t* array = (intptr_t*)buffer;
1077 ReadClosure rc(&array);
1078 serialize(&rc);
1080 // Close the mapinfo file
1081 mapinfo->close();
1083 if (PrintSharedArchiveAndExit) {
1084 if (PrintSharedDictionary) {
1085 tty->print_cr("\nShared classes:\n");
1086 SystemDictionary::print_shared(false);
1087 }
1088 if (_archive_loading_failed) {
1089 tty->print_cr("archive is invalid");
1090 vm_exit(1);
1091 } else {
1092 tty->print_cr("archive is valid");
1093 vm_exit(0);
1094 }
1095 }
1096 }
1098 // JVM/TI RedefineClasses() support:
1099 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1100 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1102 if (UseSharedSpaces) {
1103 // remap the shared readonly space to shared readwrite, private
1104 FileMapInfo* mapinfo = FileMapInfo::current_info();
1105 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1106 return false;
1107 }
1108 _remapped_readwrite = true;
1109 }
1110 return true;
1111 }
1113 int MetaspaceShared::count_class(const char* classlist_file) {
1114 if (classlist_file == NULL) {
1115 return 0;
1116 }
1117 char class_name[256];
1118 int class_count = 0;
1119 FILE* file = fopen(classlist_file, "r");
1120 if (file != NULL) {
1121 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
1122 if (*class_name == '#') { // comment
1123 continue;
1124 }
1125 class_count++;
1126 }
1127 fclose(file);
1128 } else {
1129 char errmsg[JVM_MAXPATHLEN];
1130 os::lasterror(errmsg, JVM_MAXPATHLEN);
1131 tty->print_cr("Loading classlist failed: %s", errmsg);
1132 exit(1);
1133 }
1135 return class_count;
1136 }
1138 // the sizes are good for typical large applications that have a lot of shared
1139 // classes
1140 void MetaspaceShared::estimate_regions_size() {
1141 int class_count = count_class(SharedClassListFile);
1142 class_count += count_class(ExtraSharedClassListFile);
1144 if (class_count > LargeThresholdClassCount) {
1145 if (class_count < HugeThresholdClassCount) {
1146 SET_ESTIMATED_SIZE(Large, ReadOnly);
1147 SET_ESTIMATED_SIZE(Large, ReadWrite);
1148 SET_ESTIMATED_SIZE(Large, MiscData);
1149 SET_ESTIMATED_SIZE(Large, MiscCode);
1150 } else {
1151 SET_ESTIMATED_SIZE(Huge, ReadOnly);
1152 SET_ESTIMATED_SIZE(Huge, ReadWrite);
1153 SET_ESTIMATED_SIZE(Huge, MiscData);
1154 SET_ESTIMATED_SIZE(Huge, MiscCode);
1155 }
1156 }
1157 }