1 /*
2 * Copyright (c) 2003, 2019, 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 "jvm.h"
27 #include "classfile/classFileStream.hpp"
28 #include "classfile/classLoader.inline.hpp"
29 #include "classfile/classLoaderData.inline.hpp"
30 #include "classfile/classLoaderExt.hpp"
31 #include "classfile/symbolTable.hpp"
32 #include "classfile/systemDictionaryShared.hpp"
33 #include "classfile/altHashing.hpp"
34 #include "logging/log.hpp"
35 #include "logging/logStream.hpp"
36 #include "logging/logMessage.hpp"
37 #include "memory/dynamicArchive.hpp"
38 #include "memory/filemap.hpp"
39 #include "memory/heapShared.inline.hpp"
40 #include "memory/iterator.inline.hpp"
41 #include "memory/metadataFactory.hpp"
42 #include "memory/metaspaceClosure.hpp"
43 #include "memory/metaspaceShared.hpp"
44 #include "memory/oopFactory.hpp"
45 #include "memory/universe.hpp"
46 #include "oops/compressedOops.hpp"
47 #include "oops/compressedOops.inline.hpp"
48 #include "oops/objArrayOop.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "prims/jvmtiExport.hpp"
51 #include "runtime/arguments.hpp"
52 #include "runtime/java.hpp"
53 #include "runtime/mutexLocker.hpp"
54 #include "runtime/os.inline.hpp"
55 #include "runtime/vm_version.hpp"
56 #include "services/memTracker.hpp"
57 #include "utilities/align.hpp"
58 #include "utilities/defaultStream.hpp"
59 #if INCLUDE_G1GC
60 #include "gc/g1/g1CollectedHeap.hpp"
61 #include "gc/g1/heapRegion.hpp"
62 #endif
63
64 # include <sys/stat.h>
65 # include <errno.h>
66
67 #ifndef O_BINARY // if defined (Win32) use binary files.
68 #define O_BINARY 0 // otherwise do nothing.
69 #endif
70
71 extern address JVM_FunctionAtStart();
72 extern address JVM_FunctionAtEnd();
73
74 // Complain and stop. All error conditions occurring during the writing of
75 // an archive file should stop the process. Unrecoverable errors during
76 // the reading of the archive file should stop the process.
77
78 static void fail(const char *msg, va_list ap) {
79 // This occurs very early during initialization: tty is not initialized.
80 jio_fprintf(defaultStream::error_stream(),
81 "An error has occurred while processing the"
82 " shared archive file.\n");
83 jio_vfprintf(defaultStream::error_stream(), msg, ap);
84 jio_fprintf(defaultStream::error_stream(), "\n");
85 // Do not change the text of the below message because some tests check for it.
86 vm_exit_during_initialization("Unable to use shared archive.", NULL);
87 }
88
89
90 void FileMapInfo::fail_stop(const char *msg, ...) {
91 va_list ap;
92 va_start(ap, msg);
93 fail(msg, ap); // Never returns.
94 va_end(ap); // for completeness.
95 }
96
97
98 // Complain and continue. Recoverable errors during the reading of the
99 // archive file may continue (with sharing disabled).
100 //
101 // If we continue, then disable shared spaces and close the file.
102
103 void FileMapInfo::fail_continue(const char *msg, ...) {
104 va_list ap;
105 va_start(ap, msg);
106 if (_dynamic_archive_info == NULL) {
107 MetaspaceShared::set_archive_loading_failed();
108 } else {
109 // _dynamic_archive_info has been setup after mapping the base archive
110 DynamicArchive::disable();
111 }
112 if (PrintSharedArchiveAndExit && _validating_shared_path_table) {
113 // If we are doing PrintSharedArchiveAndExit and some of the classpath entries
114 // do not validate, we can still continue "limping" to validate the remaining
115 // entries. No need to quit.
116 tty->print("[");
117 tty->vprint(msg, ap);
118 tty->print_cr("]");
119 } else {
120 if (RequireSharedSpaces) {
121 fail(msg, ap);
122 } else {
123 if (log_is_enabled(Info, cds)) {
124 ResourceMark rm;
125 LogStream ls(Log(cds)::info());
126 ls.print("UseSharedSpaces: ");
127 ls.vprint_cr(msg, ap);
128 }
129 }
130 if (_dynamic_archive_info == NULL) {
131 UseSharedSpaces = false;
132 assert(current_info() != NULL, "singleton must be registered");
133 current_info()->close();
134 } else {
135 // We are failing when loading the top archive, but the base archive should
136 // continue to work.
137 log_warning(cds, dynamic)("Unable to use shared archive. The top archive failed to load: %s", _dynamic_archive_info->_full_path);
138 }
139 }
140 va_end(ap);
141 }
142
143 // Fill in the fileMapInfo structure with data about this VM instance.
144
145 // This method copies the vm version info into header_version. If the version is too
146 // long then a truncated version, which has a hash code appended to it, is copied.
147 //
148 // Using a template enables this method to verify that header_version is an array of
149 // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and
150 // the code that reads the CDS file will both use the same size buffer. Hence, will
151 // use identical truncation. This is necessary for matching of truncated versions.
152 template <int N> static void get_header_version(char (&header_version) [N]) {
153 assert(N == JVM_IDENT_MAX, "Bad header_version size");
154
155 const char *vm_version = VM_Version::internal_vm_info_string();
156 const int version_len = (int)strlen(vm_version);
157
158 memset(header_version, 0, JVM_IDENT_MAX);
159
160 if (version_len < (JVM_IDENT_MAX-1)) {
161 strcpy(header_version, vm_version);
162
163 } else {
164 // Get the hash value. Use a static seed because the hash needs to return the same
165 // value over multiple jvm invocations.
166 unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);
167
168 // Truncate the ident, saving room for the 8 hex character hash value.
169 strncpy(header_version, vm_version, JVM_IDENT_MAX-9);
170
171 // Append the hash code as eight hex digits.
172 sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);
173 header_version[JVM_IDENT_MAX-1] = 0; // Null terminate.
174 }
175
176 assert(header_version[JVM_IDENT_MAX-1] == 0, "must be");
177 }
178
179 FileMapInfo::FileMapInfo(bool is_static) {
180 memset((void*)this, 0, sizeof(FileMapInfo));
181 _is_static = is_static;
182 size_t header_size;
183 if (is_static) {
184 assert(_current_info == NULL, "must be singleton"); // not thread safe
185 _current_info = this;
186 header_size = sizeof(FileMapHeader);
187 } else {
188 assert(_dynamic_archive_info == NULL, "must be singleton"); // not thread safe
189 _dynamic_archive_info = this;
190 header_size = sizeof(DynamicArchiveHeader);
191 }
192 _header = (FileMapHeader*)os::malloc(header_size, mtInternal);
193 memset((void*)_header, 0, header_size);
194 _header->_header_size = header_size;
195 _header->_version = INVALID_CDS_ARCHIVE_VERSION;
196 _header->_has_platform_or_app_classes = true;
197 _file_offset = 0;
198 _file_open = false;
199 }
200
201 FileMapInfo::~FileMapInfo() {
202 if (_is_static) {
203 assert(_current_info == this, "must be singleton"); // not thread safe
204 _current_info = NULL;
205 } else {
206 assert(_dynamic_archive_info == this, "must be singleton"); // not thread safe
207 _dynamic_archive_info = NULL;
208 }
209 }
210
211 void FileMapInfo::populate_header(size_t alignment) {
212 _header->populate(this, alignment);
213 }
214
215 void FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {
216 if (DynamicDumpSharedSpaces) {
217 _magic = CDS_DYNAMIC_ARCHIVE_MAGIC;
218 } else {
219 _magic = CDS_ARCHIVE_MAGIC;
220 }
221 _version = CURRENT_CDS_ARCHIVE_VERSION;
222 _alignment = alignment;
223 _obj_alignment = ObjectAlignmentInBytes;
224 _compact_strings = CompactStrings;
225 _narrow_oop_mode = CompressedOops::mode();
226 _narrow_oop_base = CompressedOops::base();
227 _narrow_oop_shift = CompressedOops::shift();
228 _max_heap_size = MaxHeapSize;
229 _narrow_klass_base = CompressedKlassPointers::base();
230 _narrow_klass_shift = CompressedKlassPointers::shift();
231 _shared_path_table = mapinfo->_shared_path_table;
232 if (HeapShared::is_heap_object_archiving_allowed()) {
233 _heap_reserved = Universe::heap()->reserved_region();
234 }
235
236 // The following fields are for sanity checks for whether this archive
237 // will function correctly with this JVM and the bootclasspath it's
238 // invoked with.
239
240 // JVM version string ... changes on each build.
241 get_header_version(_jvm_ident);
242
243 ClassLoaderExt::finalize_shared_paths_misc_info();
244 _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();
245 _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();
246 _num_module_paths = ClassLoader::num_module_path_entries();
247 _max_used_path_index = ClassLoaderExt::max_used_path_index();
248
249 _verify_local = BytecodeVerificationLocal;
250 _verify_remote = BytecodeVerificationRemote;
251 _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();
252 _shared_base_address = SharedBaseAddress;
253 _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;
254 // the following 2 fields will be set in write_header for dynamic archive header
255 _base_archive_name_size = 0;
256 _base_archive_is_default = false;
257 }
258
259 void SharedClassPathEntry::init(const char* name, bool is_modules_image, TRAPS) {
260 assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "dump time only");
261 _timestamp = 0;
262 _filesize = 0;
263
264 struct stat st;
265 if (os::stat(name, &st) == 0) {
266 if ((st.st_mode & S_IFMT) == S_IFDIR) {
267 _type = dir_entry;
268 } else {
269 // The timestamp of the modules_image is not checked at runtime.
270 if (is_modules_image) {
271 _type = modules_image_entry;
272 } else {
273 _type = jar_entry;
274 _timestamp = st.st_mtime;
275 }
276 _filesize = st.st_size;
277 }
278 } else {
279 // The file/dir must exist, or it would not have been added
280 // into ClassLoader::classpath_entry().
281 //
282 // If we can't access a jar file in the boot path, then we can't
283 // make assumptions about where classes get loaded from.
284 FileMapInfo::fail_stop("Unable to open file %s.", name);
285 }
286
287 size_t len = strlen(name) + 1;
288 _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, THREAD);
289 strcpy(_name->data(), name);
290 }
291
292 bool SharedClassPathEntry::validate(bool is_class_path) {
293 assert(UseSharedSpaces, "runtime only");
294
295 struct stat st;
296 const char* name;
297
298 // In order to validate the runtime modules image file size against the archived
299 // size information, we need to obtain the runtime modules image path. The recorded
300 // dump time modules image path in the archive may be different from the runtime path
301 // if the JDK image has beed moved after generating the archive.
302 if (is_modules_image()) {
303 name = ClassLoader::get_jrt_entry()->name();
304 } else {
305 name = this->name();
306 }
307
308 bool ok = true;
309 log_info(class, path)("checking shared classpath entry: %s", name);
310 if (os::stat(name, &st) != 0 && is_class_path) {
311 // If the archived module path entry does not exist at runtime, it is not fatal
312 // (no need to invalid the shared archive) because the shared runtime visibility check
313 // filters out any archived module classes that do not have a matching runtime
314 // module path location.
315 FileMapInfo::fail_continue("Required classpath entry does not exist: %s", name);
316 ok = false;
317 } else if (is_dir()) {
318 if (!os::dir_is_empty(name)) {
319 FileMapInfo::fail_continue("directory is not empty: %s", name);
320 ok = false;
321 }
322 } else if ((has_timestamp() && _timestamp != st.st_mtime) ||
323 _filesize != st.st_size) {
324 ok = false;
325 if (PrintSharedArchiveAndExit) {
326 FileMapInfo::fail_continue(_timestamp != st.st_mtime ?
327 "Timestamp mismatch" :
328 "File size mismatch");
329 } else {
330 FileMapInfo::fail_continue("A jar file is not the one used while building"
331 " the shared archive file: %s", name);
332 }
333 }
334
335 if (PrintSharedArchiveAndExit && !ok) {
336 // If PrintSharedArchiveAndExit is enabled, don't report failure to the
337 // caller. Please see above comments for more details.
338 ok = true;
339 MetaspaceShared::set_archive_loading_failed();
340 }
341 return ok;
342 }
343
344 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
345 it->push(&_name);
346 it->push(&_manifest);
347 }
348
349 void SharedPathTable::metaspace_pointers_do(MetaspaceClosure* it) {
350 it->push(&_table);
351 for (int i=0; i<_size; i++) {
352 path_at(i)->metaspace_pointers_do(it);
353 }
354 }
355
356 void SharedPathTable::dumptime_init(ClassLoaderData* loader_data, Thread* THREAD) {
357 size_t entry_size = sizeof(SharedClassPathEntry);
358 int num_boot_classpath_entries = ClassLoader::num_boot_classpath_entries();
359 int num_app_classpath_entries = ClassLoader::num_app_classpath_entries();
360 int num_module_path_entries = ClassLoader::num_module_path_entries();
361 int num_entries = num_boot_classpath_entries + num_app_classpath_entries + num_module_path_entries;
362 size_t bytes = entry_size * num_entries;
363
364 _table = MetadataFactory::new_array<u8>(loader_data, (int)(bytes + 7 / 8), THREAD);
365 _size = num_entries;
366 }
367
368 void FileMapInfo::allocate_shared_path_table() {
369 assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "Sanity");
370
371 Thread* THREAD = Thread::current();
372 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
373 ClassPathEntry* jrt = ClassLoader::get_jrt_entry();
374
375 assert(jrt != NULL,
376 "No modular java runtime image present when allocating the CDS classpath entry table");
377
378 _shared_path_table.dumptime_init(loader_data, THREAD);
379
380 // 1. boot class path
381 int i = 0;
382 ClassPathEntry* cpe = jrt;
383 while (cpe != NULL) {
384 bool is_jrt = (cpe == jrt);
385 const char* type = (is_jrt ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));
386 log_info(class, path)("add main shared path (%s) %s", type, cpe->name());
387 SharedClassPathEntry* ent = shared_path(i);
388 ent->init(cpe->name(), is_jrt, THREAD);
389 if (!is_jrt) { // No need to do the modules image.
390 EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.
391 update_shared_classpath(cpe, ent, THREAD);
392 }
393 cpe = ClassLoader::get_next_boot_classpath_entry(cpe);
394 i++;
395 }
396 assert(i == ClassLoader::num_boot_classpath_entries(),
397 "number of boot class path entry mismatch");
398
399 // 2. app class path
400 ClassPathEntry *acpe = ClassLoader::app_classpath_entries();
401 while (acpe != NULL) {
402 log_info(class, path)("add app shared path %s", acpe->name());
403 SharedClassPathEntry* ent = shared_path(i);
404 ent->init(acpe->name(), false, THREAD);
405 EXCEPTION_MARK;
406 update_shared_classpath(acpe, ent, THREAD);
407 acpe = acpe->next();
408 i++;
409 }
410
411 // 3. module path
412 ClassPathEntry *mpe = ClassLoader::module_path_entries();
413 while (mpe != NULL) {
414 log_info(class, path)("add module path %s",mpe->name());
415 SharedClassPathEntry* ent = shared_path(i);
416 ent->init(mpe->name(), false, THREAD);
417 EXCEPTION_MARK;
418 update_shared_classpath(mpe, ent, THREAD);
419 mpe = mpe->next();
420 i++;
421 }
422 assert(i == _shared_path_table.size(), "number of shared path entry mismatch");
423 }
424
425 void FileMapInfo::check_nonempty_dir_in_shared_path_table() {
426 assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "dump time only");
427
428 bool has_nonempty_dir = false;
429
430 int last = _shared_path_table.size() - 1;
431 if (last > ClassLoaderExt::max_used_path_index()) {
432 // no need to check any path beyond max_used_path_index
433 last = ClassLoaderExt::max_used_path_index();
434 }
435
436 for (int i = 0; i <= last; i++) {
437 SharedClassPathEntry *e = shared_path(i);
438 if (e->is_dir()) {
439 const char* path = e->name();
440 if (!os::dir_is_empty(path)) {
441 tty->print_cr("Error: non-empty directory '%s'", path);
442 has_nonempty_dir = true;
443 }
444 }
445 }
446
447 if (has_nonempty_dir) {
448 ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", NULL);
449 }
450 }
451
452 class ManifestStream: public ResourceObj {
453 private:
454 u1* _buffer_start; // Buffer bottom
455 u1* _buffer_end; // Buffer top (one past last element)
456 u1* _current; // Current buffer position
457
458 public:
459 // Constructor
460 ManifestStream(u1* buffer, int length) : _buffer_start(buffer),
461 _current(buffer) {
462 _buffer_end = buffer + length;
463 }
464
465 static bool is_attr(u1* attr, const char* name) {
466 return strncmp((const char*)attr, name, strlen(name)) == 0;
467 }
468
469 static char* copy_attr(u1* value, size_t len) {
470 char* buf = NEW_RESOURCE_ARRAY(char, len + 1);
471 strncpy(buf, (char*)value, len);
472 buf[len] = 0;
473 return buf;
474 }
475
476 // The return value indicates if the JAR is signed or not
477 bool check_is_signed() {
478 u1* attr = _current;
479 bool isSigned = false;
480 while (_current < _buffer_end) {
481 if (*_current == '\n') {
482 *_current = '\0';
483 u1* value = (u1*)strchr((char*)attr, ':');
484 if (value != NULL) {
485 assert(*(value+1) == ' ', "Unrecognized format" );
486 if (strstr((char*)attr, "-Digest") != NULL) {
487 isSigned = true;
488 break;
489 }
490 }
491 *_current = '\n'; // restore
492 attr = _current + 1;
493 }
494 _current ++;
495 }
496 return isSigned;
497 }
498 };
499
500 void FileMapInfo::update_shared_classpath(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {
501 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
502 ResourceMark rm(THREAD);
503 jint manifest_size;
504
505 if (cpe->is_jar_file()) {
506 assert(ent->is_jar(), "the shared class path entry is not a JAR file");
507 char* manifest = ClassLoaderExt::read_manifest(cpe, &manifest_size, CHECK);
508 if (manifest != NULL) {
509 ManifestStream* stream = new ManifestStream((u1*)manifest,
510 manifest_size);
511 if (stream->check_is_signed()) {
512 ent->set_is_signed();
513 } else {
514 // Copy the manifest into the shared archive
515 manifest = ClassLoaderExt::read_raw_manifest(cpe, &manifest_size, CHECK);
516 Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,
517 manifest_size,
518 THREAD);
519 char* p = (char*)(buf->data());
520 memcpy(p, manifest, manifest_size);
521 ent->set_manifest(buf);
522 }
523 }
524 }
525 }
526
527
528 bool FileMapInfo::validate_shared_path_table() {
529 assert(UseSharedSpaces, "runtime only");
530
531 _validating_shared_path_table = true;
532
533 // Load the shared path table info from the archive header
534 _shared_path_table = _header->_shared_path_table;
535 if (DynamicDumpSharedSpaces) {
536 // Only support dynamic dumping with the usage of the default CDS archive
537 // or a simple base archive.
538 // If the base layer archive contains additional path component besides
539 // the runtime image and the -cp, dynamic dumping is disabled.
540 //
541 // When dynamic archiving is enabled, the _shared_path_table is overwritten
542 // to include the application path and stored in the top layer archive.
543 assert(shared_path(0)->is_modules_image(), "first shared_path must be the modules image");
544 if (_header->_app_class_paths_start_index > 1) {
545 DynamicDumpSharedSpaces = false;
546 warning(
547 "Dynamic archiving is disabled because base layer archive has appended boot classpath");
548 }
549 if (_header->_num_module_paths > 0) {
550 DynamicDumpSharedSpaces = false;
551 warning(
552 "Dynamic archiving is disabled because base layer archive has module path");
553 }
554 }
555
556 int module_paths_start_index = _header->_app_module_paths_start_index;
557
558 // validate the path entries up to the _max_used_path_index
559 for (int i=0; i < _header->_max_used_path_index + 1; i++) {
560 if (i < module_paths_start_index) {
561 if (shared_path(i)->validate()) {
562 log_info(class, path)("ok");
563 } else {
564 if (_dynamic_archive_info != NULL && _dynamic_archive_info->_is_static) {
565 assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
566 }
567 return false;
568 }
569 } else if (i >= module_paths_start_index) {
570 if (shared_path(i)->validate(false /* not a class path entry */)) {
571 log_info(class, path)("ok");
572 } else {
573 if (_dynamic_archive_info != NULL && _dynamic_archive_info->_is_static) {
574 assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");
575 }
576 return false;
577 }
578 }
579 }
580
581 _validating_shared_path_table = false;
582
583 #if INCLUDE_JVMTI
584 if (_classpath_entries_for_jvmti != NULL) {
585 os::free(_classpath_entries_for_jvmti);
586 }
587 size_t sz = sizeof(ClassPathEntry*) * get_number_of_shared_paths();
588 _classpath_entries_for_jvmti = (ClassPathEntry**)os::malloc(sz, mtClass);
589 memset((void*)_classpath_entries_for_jvmti, 0, sz);
590 #endif
591
592 return true;
593 }
594
595 bool FileMapInfo::same_files(const char* file1, const char* file2) {
596 if (strcmp(file1, file2) == 0) {
597 return true;
598 }
599
600 bool is_same = false;
601 // if the two paths diff only in case
602 struct stat st1;
603 struct stat st2;
604 int ret1;
605 int ret2;
606 ret1 = os::stat(file1, &st1);
607 ret2 = os::stat(file2, &st2);
608 if (ret1 < 0 || ret2 < 0) {
609 // one of the files is invalid. So they are not the same.
610 is_same = false;
611 } else if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) {
612 // different files
613 is_same = false;
614 #ifndef _WINDOWS
615 } else if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
616 // same files
617 is_same = true;
618 #else
619 } else if ((st1.st_size == st2.st_size) && (st1.st_ctime == st2.st_ctime) &&
620 (st1.st_mtime == st2.st_mtime)) {
621 // same files
622 is_same = true;
623 #endif
624 }
625 return is_same;
626 }
627
628 bool FileMapInfo::check_archive(const char* archive_name, bool is_static) {
629 int fd = os::open(archive_name, O_RDONLY | O_BINARY, 0);
630 if (fd < 0) {
631 // do not vm_exit_during_initialization here because Arguments::init_shared_archive_paths()
632 // requires a shared archive name. The open_for_read() function will log a message regarding
633 // failure in opening a shared archive.
634 return false;
635 }
636
637 size_t sz = is_static ? sizeof(FileMapHeader) : sizeof(DynamicArchiveHeader);
638 void* header = os::malloc(sz, mtInternal);
639 memset(header, 0, sz);
640 size_t n = os::read(fd, header, (unsigned int)sz);
641 if (n != sz) {
642 os::free(header);
643 os::close(fd);
644 vm_exit_during_initialization("Unable to read header from shared archive", archive_name);
645 return false;
646 }
647 if (is_static) {
648 FileMapHeader* static_header = (FileMapHeader*)header;
649 if (static_header->_magic != CDS_ARCHIVE_MAGIC) {
650 os::free(header);
651 os::close(fd);
652 vm_exit_during_initialization("Not a base shared archive", archive_name);
653 return false;
654 }
655 } else {
656 DynamicArchiveHeader* dynamic_header = (DynamicArchiveHeader*)header;
657 if (dynamic_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
658 os::free(header);
659 os::close(fd);
660 vm_exit_during_initialization("Not a top shared archive", archive_name);
661 return false;
662 }
663 }
664 os::free(header);
665 os::close(fd);
666 return true;
667 }
668
669 bool FileMapInfo::get_base_archive_name_from_header(const char* archive_name,
670 int* size, char** base_archive_name) {
671 int fd = os::open(archive_name, O_RDONLY | O_BINARY, 0);
672 if (fd < 0) {
673 *size = 0;
674 return false;
675 }
676
677 // read the header as a dynamic archive header
678 size_t sz = sizeof(DynamicArchiveHeader);
679 DynamicArchiveHeader* dynamic_header = (DynamicArchiveHeader*)os::malloc(sz, mtInternal);
680 size_t n = os::read(fd, dynamic_header, (unsigned int)sz);
681 if (n != sz) {
682 fail_continue("Unable to read the file header.");
683 os::free(dynamic_header);
684 os::close(fd);
685 return false;
686 }
687 if (dynamic_header->_magic != CDS_DYNAMIC_ARCHIVE_MAGIC) {
688 // Not a dynamic header, no need to proceed further.
689 *size = 0;
690 os::free(dynamic_header);
691 os::close(fd);
692 return false;
693 }
694 if (dynamic_header->_base_archive_is_default) {
695 *base_archive_name = Arguments::get_default_shared_archive_path();
696 } else {
697 // skip over the _paths_misc_info
698 sz = dynamic_header->_paths_misc_info_size;
699 lseek(fd, (long)sz, SEEK_CUR);
700 // read the base archive name
701 size_t name_size = dynamic_header->_base_archive_name_size;
702 if (name_size == 0) {
703 os::free(dynamic_header);
704 os::close(fd);
705 return false;
706 }
707 *base_archive_name = NEW_C_HEAP_ARRAY(char, name_size, mtInternal);
708 n = os::read(fd, *base_archive_name, (unsigned int)name_size);
709 if (n != name_size) {
710 fail_continue("Unable to read the base archive name from the header.");
711 FREE_C_HEAP_ARRAY(char, *base_archive_name);
712 *base_archive_name = NULL;
713 os::free(dynamic_header);
714 os::close(fd);
715 return false;
716 }
717 }
718
719 os::free(dynamic_header);
720 os::close(fd);
721 return true;
722 }
723
724 void FileMapInfo::restore_shared_path_table() {
725 _shared_path_table = _current_info->_header->_shared_path_table;
726 }
727
728 // Read the FileMapInfo information from the file.
729
730 bool FileMapInfo::init_from_file(int fd, bool is_static) {
731 size_t sz = is_static ? sizeof(FileMapHeader) : sizeof(DynamicArchiveHeader);
732 size_t n = os::read(fd, _header, (unsigned int)sz);
733 if (n != sz) {
734 fail_continue("Unable to read the file header.");
735 return false;
736 }
737
738 if (!Arguments::has_jimage()) {
739 FileMapInfo::fail_continue("The shared archive file cannot be used with an exploded module build.");
740 return false;
741 }
742
743 unsigned int expected_magic = is_static ? CDS_ARCHIVE_MAGIC : CDS_DYNAMIC_ARCHIVE_MAGIC;
744 if (_header->_magic != expected_magic) {
745 log_info(cds)("_magic expected: 0x%08x", expected_magic);
746 log_info(cds)(" actual: 0x%08x", _header->_magic);
747 FileMapInfo::fail_continue("The shared archive file has a bad magic number.");
748 return false;
749 }
750
751 if (_header->_version != CURRENT_CDS_ARCHIVE_VERSION) {
752 log_info(cds)("_version expected: %d", CURRENT_CDS_ARCHIVE_VERSION);
753 log_info(cds)(" actual: %d", _header->_version);
754 fail_continue("The shared archive file has the wrong version.");
755 return false;
756 }
757
758 if (_header->_header_size != sz) {
759 log_info(cds)("_header_size expected: " SIZE_FORMAT, sz);
760 log_info(cds)(" actual: " SIZE_FORMAT, _header->_header_size);
761 FileMapInfo::fail_continue("The shared archive file has an incorrect header size.");
762 return false;
763 }
764
765 if (_header->_jvm_ident[JVM_IDENT_MAX-1] != 0) {
766 FileMapInfo::fail_continue("JVM version identifier is corrupted.");
767 return false;
768 }
769
770 char header_version[JVM_IDENT_MAX];
771 get_header_version(header_version);
772 if (strncmp(_header->_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) {
773 log_info(cds)("_jvm_ident expected: %s", header_version);
774 log_info(cds)(" actual: %s", _header->_jvm_ident);
775 FileMapInfo::fail_continue("The shared archive file was created by a different"
776 " version or build of HotSpot");
777 return false;
778 }
779
780 if (VerifySharedSpaces) {
781 int expected_crc = _header->compute_crc();
782 if (expected_crc != _header->_crc) {
783 log_info(cds)("_crc expected: %d", expected_crc);
784 log_info(cds)(" actual: %d", _header->_crc);
785 FileMapInfo::fail_continue("Header checksum verification failed.");
786 return false;
787 }
788 }
789
790 _file_offset = n;
791
792 size_t info_size = _header->_paths_misc_info_size;
793 _paths_misc_info = NEW_C_HEAP_ARRAY(char, info_size, mtClass);
794 n = os::read(fd, _paths_misc_info, (unsigned int)info_size);
795 if (n != info_size) {
796 fail_continue("Unable to read the shared path info header.");
797 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
798 _paths_misc_info = NULL;
799 return false;
800 }
801 _file_offset += n + _header->_base_archive_name_size; // accounts for the size of _base_archive_name
802
803 if (is_static) {
804 // just checking the last region is sufficient since the archive is written
805 // in sequential order
806 size_t len = lseek(fd, 0, SEEK_END);
807 CDSFileMapRegion* si = space_at(MetaspaceShared::last_valid_region);
808 // The last space might be empty
809 if (si->_file_offset > len || len - si->_file_offset < si->_used) {
810 fail_continue("The shared archive file has been truncated.");
811 return false;
812 }
813
814 SharedBaseAddress = _header->_shared_base_address;
815 }
816
817 return true;
818 }
819
820
821 // Read the FileMapInfo information from the file.
822 bool FileMapInfo::open_for_read(const char* path) {
823 if (_file_open) {
824 return true;
825 }
826 if (path == NULL) {
827 _full_path = Arguments::GetSharedArchivePath();
828 } else {
829 _full_path = path;
830 }
831 int fd = os::open(_full_path, O_RDONLY | O_BINARY, 0);
832 if (fd < 0) {
833 if (errno == ENOENT) {
834 // Not locating the shared archive is ok.
835 fail_continue("Specified shared archive not found (%s).", _full_path);
836 } else {
837 fail_continue("Failed to open shared archive file (%s).",
838 os::strerror(errno));
839 }
840 return false;
841 }
842
843 _fd = fd;
844 _file_open = true;
845 return true;
846 }
847
848 // Write the FileMapInfo information to the file.
849
850 void FileMapInfo::open_for_write(const char* path) {
851 if (path == NULL) {
852 _full_path = Arguments::GetSharedArchivePath();
853 } else {
854 _full_path = path;
855 }
856 LogMessage(cds) msg;
857 if (msg.is_info()) {
858 msg.info("Dumping shared data to file: ");
859 msg.info(" %s", _full_path);
860 }
861
862 #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file.
863 chmod(_full_path, _S_IREAD | _S_IWRITE);
864 #endif
865
866 // Use remove() to delete the existing file because, on Unix, this will
867 // allow processes that have it open continued access to the file.
868 remove(_full_path);
869 int fd = os::open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
870 if (fd < 0) {
871 fail_stop("Unable to create shared archive file %s: (%s).", _full_path,
872 os::strerror(errno));
873 }
874 _fd = fd;
875 _file_offset = 0;
876 _file_open = true;
877 }
878
879
880 // Write the header to the file, seek to the next allocation boundary.
881
882 void FileMapInfo::write_header() {
883 int info_size = ClassLoader::get_shared_paths_misc_info_size();
884
885 _header->_paths_misc_info_size = info_size;
886
887 char* base_archive_name = NULL;
888 if (_header->_magic == CDS_DYNAMIC_ARCHIVE_MAGIC) {
889 base_archive_name = (char*)Arguments::GetSharedArchivePath();
890 _header->_base_archive_name_size = (int)strlen(base_archive_name) + 1;
891 _header->_base_archive_is_default = FLAG_IS_DEFAULT(SharedArchiveFile);
892 }
893
894 assert(is_file_position_aligned(), "must be");
895 write_bytes(_header, _header->_header_size);
896 write_bytes(ClassLoader::get_shared_paths_misc_info(), (size_t)info_size);
897 if (base_archive_name != NULL) {
898 write_bytes(base_archive_name, (size_t)_header->_base_archive_name_size);
899 }
900 align_file_position();
901 }
902
903 // Dump region to file.
904 // This is called twice for each region during archiving, once before
905 // the archive file is open (_file_open is false) and once after.
906 void FileMapInfo::write_region(int region, char* base, size_t size,
907 bool read_only, bool allow_exec) {
908 assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "Dump time only");
909
910 CDSFileMapRegion* si = space_at(region);
911 char* target_base = base;
912 if (DynamicDumpSharedSpaces) {
913 target_base = DynamicArchive::buffer_to_target(base);
914 }
915
916 if (_file_open) {
917 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
918 log_info(cds)("Shared file region %d: " SIZE_FORMAT_HEX_W(08)
919 " bytes, addr " INTPTR_FORMAT " file offset " SIZE_FORMAT_HEX_W(08),
920 region, size, p2i(target_base), _file_offset);
921 } else {
922 si->_file_offset = _file_offset;
923 }
924
925 if (HeapShared::is_heap_region(region)) {
926 assert((target_base - (char*)CompressedKlassPointers::base()) % HeapWordSize == 0, "Sanity");
927 if (target_base != NULL) {
928 si->_addr._offset = (intx)CompressedOops::encode_not_null((oop)target_base);
929 } else {
930 si->_addr._offset = 0;
931 }
932 } else {
933 si->_addr._base = target_base;
934 }
935 si->_used = size;
936 si->_read_only = read_only;
937 si->_allow_exec = allow_exec;
938
939 // Use the current 'base' when computing the CRC value and writing out data
940 si->_crc = ClassLoader::crc32(0, base, (jint)size);
941 if (base != NULL) {
942 write_bytes_aligned(base, size);
943 }
944 }
945
946 // Write out the given archive heap memory regions. GC code combines multiple
947 // consecutive archive GC regions into one MemRegion whenever possible and
948 // produces the 'heap_mem' array.
949 //
950 // If the archive heap memory size is smaller than a single dump time GC region
951 // size, there is only one MemRegion in the array.
952 //
953 // If the archive heap memory size is bigger than one dump time GC region size,
954 // the 'heap_mem' array may contain more than one consolidated MemRegions. When
955 // the first/bottom archive GC region is a partial GC region (with the empty
956 // portion at the higher address within the region), one MemRegion is used for
957 // the bottom partial archive GC region. The rest of the consecutive archive
958 // GC regions are combined into another MemRegion.
959 //
960 // Here's the mapping from (archive heap GC regions) -> (GrowableArray<MemRegion> *regions).
961 // + We have 1 or more archive heap regions: ah0, ah1, ah2 ..... ahn
962 // + We have 1 or 2 consolidated heap memory regions: r0 and r1
963 //
964 // If there's a single archive GC region (ah0), then r0 == ah0, and r1 is empty.
965 // Otherwise:
966 //
967 // "X" represented space that's occupied by heap objects.
968 // "_" represented unused spaced in the heap region.
969 //
970 //
971 // |ah0 | ah1 | ah2| ...... | ahn|
972 // |XXXXXX|__ |XXXXX|XXXX|XXXXXXXX|XXXX|
973 // |<-r0->| |<- r1 ----------------->|
974 // ^^^
975 // |
976 // +-- gap
977 size_t FileMapInfo::write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,
978 GrowableArray<ArchiveHeapOopmapInfo> *oopmaps,
979 int first_region_id, int max_num_regions,
980 bool print_log) {
981 assert(max_num_regions <= 2, "Only support maximum 2 memory regions");
982
983 int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
984 if(arr_len > max_num_regions) {
985 fail_stop("Unable to write archive heap memory regions: "
986 "number of memory regions exceeds maximum due to fragmentation. "
987 "Please increase java heap size "
988 "(current MaxHeapSize is " SIZE_FORMAT ", InitialHeapSize is " SIZE_FORMAT ").",
989 MaxHeapSize, InitialHeapSize);
990 }
991
992 size_t total_size = 0;
993 for (int i = first_region_id, arr_idx = 0;
994 i < first_region_id + max_num_regions;
995 i++, arr_idx++) {
996 char* start = NULL;
997 size_t size = 0;
998 if (arr_idx < arr_len) {
999 start = (char*)heap_mem->at(arr_idx).start();
1000 size = heap_mem->at(arr_idx).byte_size();
1001 total_size += size;
1002 }
1003
1004 if (print_log) {
1005 log_info(cds)("Archive heap region %d " INTPTR_FORMAT " - " INTPTR_FORMAT " = " SIZE_FORMAT_W(8) " bytes",
1006 i, p2i(start), p2i(start + size), size);
1007 }
1008 write_region(i, start, size, false, false);
1009 if (size > 0) {
1010 space_at(i)->_oopmap = oopmaps->at(arr_idx)._oopmap;
1011 space_at(i)->_oopmap_size_in_bits = oopmaps->at(arr_idx)._oopmap_size_in_bits;
1012 }
1013 }
1014 return total_size;
1015 }
1016
1017 // Dump bytes to file -- at the current file position.
1018
1019 void FileMapInfo::write_bytes(const void* buffer, size_t nbytes) {
1020 if (_file_open) {
1021 size_t n = os::write(_fd, buffer, (unsigned int)nbytes);
1022 if (n != nbytes) {
1023 // If the shared archive is corrupted, close it and remove it.
1024 close();
1025 remove(_full_path);
1026 fail_stop("Unable to write to shared archive file.");
1027 }
1028 }
1029 _file_offset += nbytes;
1030 }
1031
1032 bool FileMapInfo::is_file_position_aligned() const {
1033 return _file_offset == align_up(_file_offset,
1034 os::vm_allocation_granularity());
1035 }
1036
1037 // Align file position to an allocation unit boundary.
1038
1039 void FileMapInfo::align_file_position() {
1040 size_t new_file_offset = align_up(_file_offset,
1041 os::vm_allocation_granularity());
1042 if (new_file_offset != _file_offset) {
1043 _file_offset = new_file_offset;
1044 if (_file_open) {
1045 // Seek one byte back from the target and write a byte to insure
1046 // that the written file is the correct length.
1047 _file_offset -= 1;
1048 if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {
1049 fail_stop("Unable to seek.");
1050 }
1051 char zero = 0;
1052 write_bytes(&zero, 1);
1053 }
1054 }
1055 }
1056
1057
1058 // Dump bytes to file -- at the current file position.
1059
1060 void FileMapInfo::write_bytes_aligned(const void* buffer, size_t nbytes) {
1061 align_file_position();
1062 write_bytes(buffer, nbytes);
1063 align_file_position();
1064 }
1065
1066
1067 // Close the shared archive file. This does NOT unmap mapped regions.
1068
1069 void FileMapInfo::close() {
1070 if (_file_open) {
1071 if (::close(_fd) < 0) {
1072 fail_stop("Unable to close the shared archive file.");
1073 }
1074 _file_open = false;
1075 _fd = -1;
1076 }
1077 }
1078
1079
1080 // JVM/TI RedefineClasses() support:
1081 // Remap the shared readonly space to shared readwrite, private.
1082 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
1083 int idx = MetaspaceShared::ro;
1084 CDSFileMapRegion* si = space_at(idx);
1085 if (!si->_read_only) {
1086 // the space is already readwrite so we are done
1087 return true;
1088 }
1089 size_t used = si->_used;
1090 size_t size = align_up(used, os::vm_allocation_granularity());
1091 if (!open_for_read()) {
1092 return false;
1093 }
1094 char *addr = region_addr(idx);
1095 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
1096 addr, size, false /* !read_only */,
1097 si->_allow_exec);
1098 close();
1099 // These have to be errors because the shared region is now unmapped.
1100 if (base == NULL) {
1101 log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1102 vm_exit(1);
1103 }
1104 if (base != addr) {
1105 log_error(cds)("Unable to remap shared readonly space (errno=%d).", errno);
1106 vm_exit(1);
1107 }
1108 si->_read_only = false;
1109 return true;
1110 }
1111
1112 // Map the whole region at once, assumed to be allocated contiguously.
1113 ReservedSpace FileMapInfo::reserve_shared_memory() {
1114 char* requested_addr = region_addr(0);
1115 size_t size = FileMapInfo::core_spaces_size();
1116
1117 // Reserve the space first, then map otherwise map will go right over some
1118 // other reserved memory (like the code cache).
1119 ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr);
1120 if (!rs.is_reserved()) {
1121 fail_continue("Unable to reserve shared space at required address "
1122 INTPTR_FORMAT, p2i(requested_addr));
1123 return rs;
1124 }
1125 // the reserved virtual memory is for mapping class data sharing archive
1126 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
1127
1128 return rs;
1129 }
1130
1131 // Memory map a region in the address space.
1132 static const char* shared_region_name[] = { "MiscData", "ReadWrite", "ReadOnly", "MiscCode",
1133 "String1", "String2", "OpenArchive1", "OpenArchive2" };
1134
1135 char* FileMapInfo::map_regions(int regions[], char* saved_base[], size_t len) {
1136 char* prev_top = NULL;
1137 char* curr_base;
1138 char* curr_top;
1139 int i = 0;
1140 for (i = 0; i < (int)len; i++) {
1141 curr_base = map_region(regions[i], &curr_top);
1142 if (curr_base == NULL) {
1143 return NULL;
1144 }
1145 if (i > 0) {
1146 // We require that mc->rw->ro->md to be laid out consecutively, with no
1147 // gaps between them. That way, we can ensure that the OS won't be able to
1148 // allocate any new memory spaces inside _shared_metaspace_{base,top}, which
1149 // would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace().
1150 assert(curr_base == prev_top, "must be");
1151 }
1152 log_info(cds)("Mapped region #%d at base %p top %p", regions[i], curr_base, curr_top);
1153 saved_base[i] = curr_base;
1154 prev_top = curr_top;
1155 }
1156 return curr_top;
1157 }
1158
1159 char* FileMapInfo::map_region(int i, char** top_ret) {
1160 assert(!HeapShared::is_heap_region(i), "sanity");
1161 CDSFileMapRegion* si = space_at(i);
1162 size_t used = si->_used;
1163 size_t alignment = os::vm_allocation_granularity();
1164 size_t size = align_up(used, alignment);
1165 char *requested_addr = region_addr(i);
1166
1167 #ifdef _WINDOWS
1168 // Windows cannot remap read-only shared memory to read-write when required for
1169 // RedefineClasses, which is also used by JFR. Always map windows regions as RW.
1170 si->_read_only = false;
1171 #else
1172 // If a tool agent is in use (debugging enabled), or JFR, we must map the address space RW
1173 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space() ||
1174 Arguments::has_jfr_option()) {
1175 si->_read_only = false;
1176 }
1177 #endif // _WINDOWS
1178
1179 // map the contents of the CDS archive in this memory
1180 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
1181 requested_addr, size, si->_read_only,
1182 si->_allow_exec);
1183 if (base == NULL || base != requested_addr) {
1184 fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]);
1185 _memory_mapping_failed = true;
1186 return NULL;
1187 }
1188 #ifdef _WINDOWS
1189 // This call is Windows-only because the memory_type gets recorded for the other platforms
1190 // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows.
1191 MemTracker::record_virtual_memory_type((address)base, mtClassShared);
1192 #endif
1193
1194 if (VerifySharedSpaces && !verify_region_checksum(i)) {
1195 return NULL;
1196 }
1197
1198 *top_ret = base + size;
1199 return base;
1200 }
1201
1202 size_t FileMapInfo::read_bytes(void* buffer, size_t count) {
1203 assert(_file_open, "Archive file is not open");
1204 size_t n = os::read(_fd, buffer, (unsigned int)count);
1205 if (n != count) {
1206 // Close the file if there's a problem reading it.
1207 close();
1208 return 0;
1209 }
1210 _file_offset += count;
1211 return count;
1212 }
1213
1214 address FileMapInfo::decode_start_address(CDSFileMapRegion* spc, bool with_current_oop_encoding_mode) {
1215 if (with_current_oop_encoding_mode) {
1216 return (address)CompressedOops::decode_not_null(offset_of_space(spc));
1217 } else {
1218 return (address)HeapShared::decode_from_archive(offset_of_space(spc));
1219 }
1220 }
1221
1222 static MemRegion *closed_archive_heap_ranges = NULL;
1223 static MemRegion *open_archive_heap_ranges = NULL;
1224 static int num_closed_archive_heap_ranges = 0;
1225 static int num_open_archive_heap_ranges = 0;
1226
1227 #if INCLUDE_CDS_JAVA_HEAP
1228 bool FileMapInfo::has_heap_regions() {
1229 return (_header->_space[MetaspaceShared::first_closed_archive_heap_region]._used > 0);
1230 }
1231
1232 // Returns the address range of the archived heap regions computed using the
1233 // current oop encoding mode. This range may be different than the one seen at
1234 // dump time due to encoding mode differences. The result is used in determining
1235 // if/how these regions should be relocated at run time.
1236 MemRegion FileMapInfo::get_heap_regions_range_with_current_oop_encoding_mode() {
1237 address start = (address) max_uintx;
1238 address end = NULL;
1239
1240 for (int i = MetaspaceShared::first_closed_archive_heap_region;
1241 i <= MetaspaceShared::last_valid_region;
1242 i++) {
1243 CDSFileMapRegion* si = space_at(i);
1244 size_t size = si->_used;
1245 if (size > 0) {
1246 address s = start_address_as_decoded_with_current_oop_encoding_mode(si);
1247 address e = s + size;
1248 if (start > s) {
1249 start = s;
1250 }
1251 if (end < e) {
1252 end = e;
1253 }
1254 }
1255 }
1256 assert(end != NULL, "must have at least one used heap region");
1257 return MemRegion((HeapWord*)start, (HeapWord*)end);
1258 }
1259
1260 //
1261 // Map the closed and open archive heap objects to the runtime java heap.
1262 //
1263 // The shared objects are mapped at (or close to ) the java heap top in
1264 // closed archive regions. The mapped objects contain no out-going
1265 // references to any other java heap regions. GC does not write into the
1266 // mapped closed archive heap region.
1267 //
1268 // The open archive heap objects are mapped below the shared objects in
1269 // the runtime java heap. The mapped open archive heap data only contains
1270 // references to the shared objects and open archive objects initially.
1271 // During runtime execution, out-going references to any other java heap
1272 // regions may be added. GC may mark and update references in the mapped
1273 // open archive objects.
1274 void FileMapInfo::map_heap_regions_impl() {
1275 if (!HeapShared::is_heap_object_archiving_allowed()) {
1276 log_info(cds)("CDS heap data is being ignored. UseG1GC, "
1277 "UseCompressedOops and UseCompressedClassPointers are required.");
1278 return;
1279 }
1280
1281 if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
1282 ShouldNotReachHere(); // CDS should have been disabled.
1283 // The archived objects are mapped at JVM start-up, but we don't know if
1284 // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
1285 // which would make the archived String or mirror objects invalid. Let's be safe and not
1286 // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage.
1287 //
1288 // If JvmtiExport::has_early_class_hook_env() is false, the classes of some objects
1289 // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
1290 // because we won't install an archived object subgraph if the klass of any of the
1291 // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
1292 }
1293
1294 MemRegion heap_reserved = Universe::heap()->reserved_region();
1295
1296 log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
1297 max_heap_size()/M);
1298 log_info(cds)(" narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
1299 p2i(narrow_klass_base()), narrow_klass_shift());
1300 log_info(cds)(" narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
1301 narrow_oop_mode(), p2i(narrow_oop_base()), narrow_oop_shift());
1302
1303 log_info(cds)("The current max heap size = " SIZE_FORMAT "M, HeapRegion::GrainBytes = " SIZE_FORMAT,
1304 heap_reserved.byte_size()/M, HeapRegion::GrainBytes);
1305 log_info(cds)(" narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
1306 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
1307 log_info(cds)(" narrow_oop_mode = %d, narrow_oop_base = " PTR_FORMAT ", narrow_oop_shift = %d",
1308 CompressedOops::mode(), p2i(CompressedOops::base()), CompressedOops::shift());
1309
1310 if (narrow_klass_base() != CompressedKlassPointers::base() ||
1311 narrow_klass_shift() != CompressedKlassPointers::shift()) {
1312 log_info(cds)("CDS heap data cannot be used because the archive was created with an incompatible narrow klass encoding mode.");
1313 return;
1314 }
1315
1316 if (narrow_oop_mode() != CompressedOops::mode() ||
1317 narrow_oop_base() != CompressedOops::base() ||
1318 narrow_oop_shift() != CompressedOops::shift()) {
1319 log_info(cds)("CDS heap data need to be relocated because the archive was created with an incompatible oop encoding mode.");
1320 _heap_pointers_need_patching = true;
1321 } else {
1322 MemRegion range = get_heap_regions_range_with_current_oop_encoding_mode();
1323 if (!heap_reserved.contains(range)) {
1324 log_info(cds)("CDS heap data need to be relocated because");
1325 log_info(cds)("the desired range " PTR_FORMAT " - " PTR_FORMAT, p2i(range.start()), p2i(range.end()));
1326 log_info(cds)("is outside of the heap " PTR_FORMAT " - " PTR_FORMAT, p2i(heap_reserved.start()), p2i(heap_reserved.end()));
1327 _heap_pointers_need_patching = true;
1328 }
1329 }
1330
1331 ptrdiff_t delta = 0;
1332 if (_heap_pointers_need_patching) {
1333 // dumptime heap end ------------v
1334 // [ |archived heap regions| ] runtime heap end ------v
1335 // [ |archived heap regions| ]
1336 // |<-----delta-------------------->|
1337 //
1338 // At dump time, the archived heap regions were near the top of the heap.
1339 // At run time, they may not be inside the heap, so we move them so
1340 // that they are now near the top of the runtime time. This can be done by
1341 // the simple math of adding the delta as shown above.
1342 address dumptime_heap_end = (address)_header->_heap_reserved.end();
1343 address runtime_heap_end = (address)heap_reserved.end();
1344 delta = runtime_heap_end - dumptime_heap_end;
1345 }
1346
1347 log_info(cds)("CDS heap data relocation delta = " INTX_FORMAT " bytes", delta);
1348 HeapShared::init_narrow_oop_decoding(narrow_oop_base() + delta, narrow_oop_shift());
1349
1350 CDSFileMapRegion* si = space_at(MetaspaceShared::first_closed_archive_heap_region);
1351 address relocated_closed_heap_region_bottom = start_address_as_decoded_from_archive(si);
1352 if (!is_aligned(relocated_closed_heap_region_bottom, HeapRegion::GrainBytes)) {
1353 // Align the bottom of the closed archive heap regions at G1 region boundary.
1354 // This will avoid the situation where the highest open region and the lowest
1355 // closed region sharing the same G1 region. Otherwise we will fail to map the
1356 // open regions.
1357 size_t align = size_t(relocated_closed_heap_region_bottom) % HeapRegion::GrainBytes;
1358 delta -= align;
1359 log_info(cds)("CDS heap data need to be relocated lower by a further " SIZE_FORMAT
1360 " bytes to " INTX_FORMAT " to be aligned with HeapRegion::GrainBytes",
1361 align, delta);
1362 HeapShared::init_narrow_oop_decoding(narrow_oop_base() + delta, narrow_oop_shift());
1363 _heap_pointers_need_patching = true;
1364 relocated_closed_heap_region_bottom = start_address_as_decoded_from_archive(si);
1365 }
1366 assert(is_aligned(relocated_closed_heap_region_bottom, HeapRegion::GrainBytes),
1367 "must be");
1368
1369 // Map the closed_archive_heap regions, GC does not write into the regions.
1370 if (map_heap_data(&closed_archive_heap_ranges,
1371 MetaspaceShared::first_closed_archive_heap_region,
1372 MetaspaceShared::max_closed_archive_heap_region,
1373 &num_closed_archive_heap_ranges)) {
1374 HeapShared::set_closed_archive_heap_region_mapped();
1375
1376 // Now, map open_archive heap regions, GC can write into the regions.
1377 if (map_heap_data(&open_archive_heap_ranges,
1378 MetaspaceShared::first_open_archive_heap_region,
1379 MetaspaceShared::max_open_archive_heap_region,
1380 &num_open_archive_heap_ranges,
1381 true /* open */)) {
1382 HeapShared::set_open_archive_heap_region_mapped();
1383 }
1384 }
1385 }
1386
1387 void FileMapInfo::map_heap_regions() {
1388 if (has_heap_regions()) {
1389 map_heap_regions_impl();
1390 }
1391
1392 if (!HeapShared::closed_archive_heap_region_mapped()) {
1393 assert(closed_archive_heap_ranges == NULL &&
1394 num_closed_archive_heap_ranges == 0, "sanity");
1395 }
1396
1397 if (!HeapShared::open_archive_heap_region_mapped()) {
1398 assert(open_archive_heap_ranges == NULL && num_open_archive_heap_ranges == 0, "sanity");
1399 }
1400 }
1401
1402 bool FileMapInfo::map_heap_data(MemRegion **heap_mem, int first,
1403 int max, int* num, bool is_open_archive) {
1404 MemRegion * regions = new MemRegion[max];
1405 CDSFileMapRegion* si;
1406 int region_num = 0;
1407
1408 for (int i = first;
1409 i < first + max; i++) {
1410 si = space_at(i);
1411 size_t size = si->_used;
1412 if (size > 0) {
1413 HeapWord* start = (HeapWord*)start_address_as_decoded_from_archive(si);
1414 regions[region_num] = MemRegion(start, size / HeapWordSize);
1415 region_num ++;
1416 log_info(cds)("Trying to map heap data: region[%d] at " INTPTR_FORMAT ", size = " SIZE_FORMAT_W(8) " bytes",
1417 i, p2i(start), size);
1418 }
1419 }
1420
1421 if (region_num == 0) {
1422 return false; // no archived java heap data
1423 }
1424
1425 // Check that ranges are within the java heap
1426 if (!G1CollectedHeap::heap()->check_archive_addresses(regions, region_num)) {
1427 log_info(cds)("UseSharedSpaces: Unable to allocate region, range is not within java heap.");
1428 return false;
1429 }
1430
1431 // allocate from java heap
1432 if (!G1CollectedHeap::heap()->alloc_archive_regions(
1433 regions, region_num, is_open_archive)) {
1434 log_info(cds)("UseSharedSpaces: Unable to allocate region, java heap range is already in use.");
1435 return false;
1436 }
1437
1438 // Map the archived heap data. No need to call MemTracker::record_virtual_memory_type()
1439 // for mapped regions as they are part of the reserved java heap, which is
1440 // already recorded.
1441 for (int i = 0; i < region_num; i++) {
1442 si = space_at(first + i);
1443 char* addr = (char*)regions[i].start();
1444 char* base = os::map_memory(_fd, _full_path, si->_file_offset,
1445 addr, regions[i].byte_size(), si->_read_only,
1446 si->_allow_exec);
1447 if (base == NULL || base != addr) {
1448 // dealloc the regions from java heap
1449 dealloc_archive_heap_regions(regions, region_num, is_open_archive);
1450 log_info(cds)("UseSharedSpaces: Unable to map at required address in java heap. "
1451 INTPTR_FORMAT ", size = " SIZE_FORMAT " bytes",
1452 p2i(addr), regions[i].byte_size());
1453 return false;
1454 }
1455
1456 if (VerifySharedSpaces && !region_crc_check(addr, regions[i].byte_size(), si->_crc)) {
1457 // dealloc the regions from java heap
1458 dealloc_archive_heap_regions(regions, region_num, is_open_archive);
1459 log_info(cds)("UseSharedSpaces: mapped heap regions are corrupt");
1460 return false;
1461 }
1462 }
1463
1464 // the shared heap data is mapped successfully
1465 *heap_mem = regions;
1466 *num = region_num;
1467 return true;
1468 }
1469
1470 void FileMapInfo::patch_archived_heap_embedded_pointers() {
1471 if (!_heap_pointers_need_patching) {
1472 return;
1473 }
1474
1475 patch_archived_heap_embedded_pointers(closed_archive_heap_ranges,
1476 num_closed_archive_heap_ranges,
1477 MetaspaceShared::first_closed_archive_heap_region);
1478
1479 patch_archived_heap_embedded_pointers(open_archive_heap_ranges,
1480 num_open_archive_heap_ranges,
1481 MetaspaceShared::first_open_archive_heap_region);
1482 }
1483
1484 void FileMapInfo::patch_archived_heap_embedded_pointers(MemRegion* ranges, int num_ranges,
1485 int first_region_idx) {
1486 for (int i=0; i<num_ranges; i++) {
1487 CDSFileMapRegion* si = space_at(i + first_region_idx);
1488 HeapShared::patch_archived_heap_embedded_pointers(ranges[i], (address)si->_oopmap,
1489 si->_oopmap_size_in_bits);
1490 }
1491 }
1492
1493 // This internally allocates objects using SystemDictionary::Object_klass(), so it
1494 // must be called after the well-known classes are resolved.
1495 void FileMapInfo::fixup_mapped_heap_regions() {
1496 // If any closed regions were found, call the fill routine to make them parseable.
1497 // Note that closed_archive_heap_ranges may be non-NULL even if no ranges were found.
1498 if (num_closed_archive_heap_ranges != 0) {
1499 assert(closed_archive_heap_ranges != NULL,
1500 "Null closed_archive_heap_ranges array with non-zero count");
1501 G1CollectedHeap::heap()->fill_archive_regions(closed_archive_heap_ranges,
1502 num_closed_archive_heap_ranges);
1503 }
1504
1505 // do the same for mapped open archive heap regions
1506 if (num_open_archive_heap_ranges != 0) {
1507 assert(open_archive_heap_ranges != NULL, "NULL open_archive_heap_ranges array with non-zero count");
1508 G1CollectedHeap::heap()->fill_archive_regions(open_archive_heap_ranges,
1509 num_open_archive_heap_ranges);
1510 }
1511 }
1512
1513 // dealloc the archive regions from java heap
1514 void FileMapInfo::dealloc_archive_heap_regions(MemRegion* regions, int num, bool is_open) {
1515 if (num > 0) {
1516 assert(regions != NULL, "Null archive ranges array with non-zero count");
1517 G1CollectedHeap::heap()->dealloc_archive_regions(regions, num, is_open);
1518 }
1519 }
1520 #endif // INCLUDE_CDS_JAVA_HEAP
1521
1522 bool FileMapInfo::region_crc_check(char* buf, size_t size, int expected_crc) {
1523 int crc = ClassLoader::crc32(0, buf, (jint)size);
1524 if (crc != expected_crc) {
1525 fail_continue("Checksum verification failed.");
1526 return false;
1527 }
1528 return true;
1529 }
1530
1531 bool FileMapInfo::verify_region_checksum(int i) {
1532 assert(VerifySharedSpaces, "sanity");
1533
1534 size_t sz = space_at(i)->_used;
1535
1536 if (sz == 0) {
1537 return true; // no data
1538 }
1539
1540 return region_crc_check(region_addr(i), sz, space_at(i)->_crc);
1541 }
1542
1543 void FileMapInfo::unmap_regions(int regions[], char* saved_base[], size_t len) {
1544 for (int i = 0; i < (int)len; i++) {
1545 if (saved_base[i] != NULL) {
1546 unmap_region(regions[i]);
1547 }
1548 }
1549 }
1550
1551 // Unmap a memory region in the address space.
1552
1553 void FileMapInfo::unmap_region(int i) {
1554 assert(!HeapShared::is_heap_region(i), "sanity");
1555 CDSFileMapRegion* si = space_at(i);
1556 size_t used = si->_used;
1557 size_t size = align_up(used, os::vm_allocation_granularity());
1558
1559 if (used == 0) {
1560 return;
1561 }
1562
1563 char* addr = region_addr(i);
1564 if (!os::unmap_memory(addr, size)) {
1565 fail_stop("Unable to unmap shared space.");
1566 }
1567 }
1568
1569 void FileMapInfo::assert_mark(bool check) {
1570 if (!check) {
1571 fail_stop("Mark mismatch while restoring from shared file.");
1572 }
1573 }
1574
1575 void FileMapInfo::metaspace_pointers_do(MetaspaceClosure* it) {
1576 _shared_path_table.metaspace_pointers_do(it);
1577 }
1578
1579 FileMapInfo* FileMapInfo::_current_info = NULL;
1580 FileMapInfo* FileMapInfo::_dynamic_archive_info = NULL;
1581 bool FileMapInfo::_heap_pointers_need_patching = false;
1582 SharedPathTable FileMapInfo::_shared_path_table;
1583 bool FileMapInfo::_validating_shared_path_table = false;
1584 bool FileMapInfo::_memory_mapping_failed = false;
1585
1586 // Open the shared archive file, read and validate the header
1587 // information (version, boot classpath, etc.). If initialization
1588 // fails, shared spaces are disabled and the file is closed. [See
1589 // fail_continue.]
1590 //
1591 // Validation of the archive is done in two steps:
1592 //
1593 // [1] validate_header() - done here. This checks the header, including _paths_misc_info.
1594 // [2] validate_shared_path_table - this is done later, because the table is in the RW
1595 // region of the archive, which is not mapped yet.
1596 bool FileMapInfo::initialize(bool is_static) {
1597 assert(UseSharedSpaces, "UseSharedSpaces expected.");
1598
1599 if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::has_early_class_hook_env()) {
1600 // CDS assumes that no classes resolved in SystemDictionary::resolve_well_known_classes
1601 // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
1602 // during the JVMTI "early" stage, so we can still use CDS if
1603 // JvmtiExport::has_early_class_hook_env() is false.
1604 FileMapInfo::fail_continue("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
1605 return false;
1606 }
1607
1608 if (!open_for_read()) {
1609 return false;
1610 }
1611
1612 init_from_file(_fd, is_static);
1613 // UseSharedSpaces could be disabled if the checking of some of the header fields in
1614 // init_from_file has failed.
1615 if (!UseSharedSpaces || !validate_header(is_static)) {
1616 return false;
1617 }
1618 return true;
1619 }
1620
1621 char* FileMapInfo::region_addr(int idx) {
1622 CDSFileMapRegion* si = space_at(idx);
1623 if (HeapShared::is_heap_region(idx)) {
1624 assert(DumpSharedSpaces, "The following doesn't work at runtime");
1625 return si->_used > 0 ?
1626 (char*)start_address_as_decoded_with_current_oop_encoding_mode(si) : NULL;
1627 } else {
1628 return si->_addr._base;
1629 }
1630 }
1631
1632 int FileMapHeader::compute_crc() {
1633 char* start = (char*)this;
1634 // start computing from the field after _crc
1635 char* buf = (char*)&_crc + sizeof(_crc);
1636 size_t sz = _header_size - (buf - start);
1637 int crc = ClassLoader::crc32(0, buf, (jint)sz);
1638 return crc;
1639 }
1640
1641 // This function should only be called during run time with UseSharedSpaces enabled.
1642 bool FileMapHeader::validate() {
1643
1644 if (_obj_alignment != ObjectAlignmentInBytes) {
1645 FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
1646 " does not equal the current ObjectAlignmentInBytes of " INTX_FORMAT ".",
1647 _obj_alignment, ObjectAlignmentInBytes);
1648 return false;
1649 }
1650 if (_compact_strings != CompactStrings) {
1651 FileMapInfo::fail_continue("The shared archive file's CompactStrings setting (%s)"
1652 " does not equal the current CompactStrings setting (%s).",
1653 _compact_strings ? "enabled" : "disabled",
1654 CompactStrings ? "enabled" : "disabled");
1655 return false;
1656 }
1657
1658 // This must be done after header validation because it might change the
1659 // header data
1660 const char* prop = Arguments::get_property("java.system.class.loader");
1661 if (prop != NULL) {
1662 warning("Archived non-system classes are disabled because the "
1663 "java.system.class.loader property is specified (value = \"%s\"). "
1664 "To use archived non-system classes, this property must not be set", prop);
1665 _has_platform_or_app_classes = false;
1666 }
1667
1668 // For backwards compatibility, we don't check the verification setting
1669 // if the archive only contains system classes.
1670 if (_has_platform_or_app_classes &&
1671 ((!_verify_local && BytecodeVerificationLocal) ||
1672 (!_verify_remote && BytecodeVerificationRemote))) {
1673 FileMapInfo::fail_continue("The shared archive file was created with less restrictive "
1674 "verification setting than the current setting.");
1675 return false;
1676 }
1677
1678 // Java agents are allowed during run time. Therefore, the following condition is not
1679 // checked: (!_allow_archiving_with_java_agent && AllowArchivingWithJavaAgent)
1680 // Note: _allow_archiving_with_java_agent is set in the shared archive during dump time
1681 // while AllowArchivingWithJavaAgent is set during the current run.
1682 if (_allow_archiving_with_java_agent && !AllowArchivingWithJavaAgent) {
1683 FileMapInfo::fail_continue("The setting of the AllowArchivingWithJavaAgent is different "
1684 "from the setting in the shared archive.");
1685 return false;
1686 }
1687
1688 if (_allow_archiving_with_java_agent) {
1689 warning("This archive was created with AllowArchivingWithJavaAgent. It should be used "
1690 "for testing purposes only and should not be used in a production environment");
1691 }
1692
1693 return true;
1694 }
1695
1696 bool FileMapInfo::validate_header(bool is_static) {
1697 bool status = _header->validate();
1698
1699 if (status) {
1700 if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size, is_static)) {
1701 if (!PrintSharedArchiveAndExit) {
1702 fail_continue("shared class paths mismatch (hint: enable -Xlog:class+path=info to diagnose the failure)");
1703 status = false;
1704 }
1705 }
1706 }
1707
1708 if (_paths_misc_info != NULL) {
1709 FREE_C_HEAP_ARRAY(char, _paths_misc_info);
1710 _paths_misc_info = NULL;
1711 }
1712 return status;
1713 }
1714
1715 // Check if a given address is within one of the shared regions
1716 bool FileMapInfo::is_in_shared_region(const void* p, int idx) {
1717 assert(idx == MetaspaceShared::ro ||
1718 idx == MetaspaceShared::rw ||
1719 idx == MetaspaceShared::mc ||
1720 idx == MetaspaceShared::md, "invalid region index");
1721 char* base = region_addr(idx);
1722 if (p >= base && p < base + space_at(idx)->_used) {
1723 return true;
1724 }
1725 return false;
1726 }
1727
1728 // Unmap mapped regions of shared space.
1729 void FileMapInfo::stop_sharing_and_unmap(const char* msg) {
1730 MetaspaceShared::set_shared_metaspace_range(NULL, NULL);
1731
1732 FileMapInfo *map_info = FileMapInfo::current_info();
1733 if (map_info) {
1734 map_info->fail_continue("%s", msg);
1735 for (int i = 0; i < MetaspaceShared::num_non_heap_spaces; i++) {
1736 if (!HeapShared::is_heap_region(i)) {
1737 char *addr = map_info->region_addr(i);
1738 if (addr != NULL) {
1739 map_info->unmap_region(i);
1740 map_info->space_at(i)->_addr._base = NULL;
1741 }
1742 }
1743 }
1744 // Dealloc the archive heap regions only without unmapping. The regions are part
1745 // of the java heap. Unmapping of the heap regions are managed by GC.
1746 map_info->dealloc_archive_heap_regions(open_archive_heap_ranges,
1747 num_open_archive_heap_ranges,
1748 true);
1749 map_info->dealloc_archive_heap_regions(closed_archive_heap_ranges,
1750 num_closed_archive_heap_ranges,
1751 false);
1752 } else if (DumpSharedSpaces) {
1753 fail_stop("%s", msg);
1754 }
1755 }
1756
1757 #if INCLUDE_JVMTI
1758 ClassPathEntry** FileMapInfo::_classpath_entries_for_jvmti = NULL;
1759
1760 ClassPathEntry* FileMapInfo::get_classpath_entry_for_jvmti(int i, TRAPS) {
1761 ClassPathEntry* ent = _classpath_entries_for_jvmti[i];
1762 if (ent == NULL) {
1763 if (i == 0) {
1764 ent = ClassLoader:: get_jrt_entry();
1765 assert(ent != NULL, "must be");
1766 } else {
1767 SharedClassPathEntry* scpe = shared_path(i);
1768 assert(scpe->is_jar(), "must be"); // other types of scpe will not produce archived classes
1769
1770 const char* path = scpe->name();
1771 struct stat st;
1772 if (os::stat(path, &st) != 0) {
1773 char *msg = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, strlen(path) + 128); ;
1774 jio_snprintf(msg, strlen(path) + 127, "error in opening JAR file %s", path);
1775 THROW_MSG_(vmSymbols::java_io_IOException(), msg, NULL);
1776 } else {
1777 ent = ClassLoader::create_class_path_entry(path, &st, /*throw_exception=*/true, false, CHECK_NULL);
1778 }
1779 }
1780
1781 MutexLocker mu(CDSClassFileStream_lock, THREAD);
1782 if (_classpath_entries_for_jvmti[i] == NULL) {
1783 _classpath_entries_for_jvmti[i] = ent;
1784 } else {
1785 // Another thread has beat me to creating this entry
1786 delete ent;
1787 ent = _classpath_entries_for_jvmti[i];
1788 }
1789 }
1790
1791 return ent;
1792 }
1793
1794 ClassFileStream* FileMapInfo::open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS) {
1795 int path_index = ik->shared_classpath_index();
1796 assert(path_index >= 0, "should be called for shared built-in classes only");
1797 assert(path_index < (int)get_number_of_shared_paths(), "sanity");
1798
1799 ClassPathEntry* cpe = get_classpath_entry_for_jvmti(path_index, CHECK_NULL);
1800 assert(cpe != NULL, "must be");
1801
1802 Symbol* name = ik->name();
1803 const char* const class_name = name->as_C_string();
1804 const char* const file_name = ClassLoader::file_name_for_class_name(class_name,
1805 name->utf8_length());
1806 ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
1807 ClassFileStream* cfs = cpe->open_stream_for_loader(file_name, loader_data, THREAD);
1808 assert(cfs != NULL, "must be able to read the classfile data of shared classes for built-in loaders.");
1809 log_debug(cds, jvmti)("classfile data for %s [%d: %s] = %d bytes", class_name, path_index,
1810 cfs->source(), cfs->length());
1811 return cfs;
1812 }
1813
1814 #endif