Tue, 30 Oct 2012 10:23:55 -0700
8000988: VM deadlock when running btree006 on windows-i586
Reviewed-by: johnc, jcoomes, ysr
1 /*
2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "memory/filemap.hpp"
29 #include "runtime/arguments.hpp"
30 #include "runtime/java.hpp"
31 #include "runtime/os.hpp"
32 #include "services/memTracker.hpp"
33 #include "utilities/defaultStream.hpp"
35 # include <sys/stat.h>
36 # include <errno.h>
38 #ifndef O_BINARY // if defined (Win32) use binary files.
39 #define O_BINARY 0 // otherwise do nothing.
40 #endif
43 extern address JVM_FunctionAtStart();
44 extern address JVM_FunctionAtEnd();
46 // Complain and stop. All error conditions occurring during the writing of
47 // an archive file should stop the process. Unrecoverable errors during
48 // the reading of the archive file should stop the process.
50 static void fail(const char *msg, va_list ap) {
51 // This occurs very early during initialization: tty is not initialized.
52 jio_fprintf(defaultStream::error_stream(),
53 "An error has occurred while processing the"
54 " shared archive file.\n");
55 jio_vfprintf(defaultStream::error_stream(), msg, ap);
56 jio_fprintf(defaultStream::error_stream(), "\n");
57 vm_exit_during_initialization("Unable to use shared archive.", NULL);
58 }
61 void FileMapInfo::fail_stop(const char *msg, ...) {
62 va_list ap;
63 va_start(ap, msg);
64 fail(msg, ap); // Never returns.
65 va_end(ap); // for completeness.
66 }
69 // Complain and continue. Recoverable errors during the reading of the
70 // archive file may continue (with sharing disabled).
71 //
72 // If we continue, then disable shared spaces and close the file.
74 void FileMapInfo::fail_continue(const char *msg, ...) {
75 va_list ap;
76 va_start(ap, msg);
77 if (RequireSharedSpaces) {
78 fail(msg, ap);
79 }
80 va_end(ap);
81 UseSharedSpaces = false;
82 close();
83 }
86 // Fill in the fileMapInfo structure with data about this VM instance.
88 void FileMapInfo::populate_header(size_t alignment) {
89 _header._magic = 0xf00baba2;
90 _header._version = _current_version;
91 _header._alignment = alignment;
93 // The following fields are for sanity checks for whether this archive
94 // will function correctly with this JVM and the bootclasspath it's
95 // invoked with.
97 // JVM version string ... changes on each build.
98 const char *vm_version = VM_Version::internal_vm_info_string();
99 if (strlen(vm_version) < (JVM_IDENT_MAX-1)) {
100 strcpy(_header._jvm_ident, vm_version);
101 } else {
102 fail_stop("JVM Ident field for shared archive is too long"
103 " - truncated to <%s>", _header._jvm_ident);
104 }
106 // Build checks on classpath and jar files
107 _header._num_jars = 0;
108 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
109 for ( ; cpe != NULL; cpe = cpe->next()) {
111 if (cpe->is_jar_file()) {
112 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
113 fail_stop("Too many jar files to share.", NULL);
114 }
116 // Jar file - record timestamp and file size.
117 struct stat st;
118 const char *path = cpe->name();
119 if (os::stat(path, &st) != 0) {
120 // If we can't access a jar file in the boot path, then we can't
121 // make assumptions about where classes get loaded from.
122 fail_stop("Unable to open jar file %s.", path);
123 }
124 _header._jar[_header._num_jars]._timestamp = st.st_mtime;
125 _header._jar[_header._num_jars]._filesize = st.st_size;
126 _header._num_jars++;
127 } else {
129 // If directories appear in boot classpath, they must be empty to
130 // avoid having to verify each individual class file.
131 const char* name = ((ClassPathDirEntry*)cpe)->name();
132 if (!os::dir_is_empty(name)) {
133 fail_stop("Boot classpath directory %s is not empty.", name);
134 }
135 }
136 }
137 }
140 // Read the FileMapInfo information from the file.
142 bool FileMapInfo::init_from_file(int fd) {
144 size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
145 if (n != sizeof(struct FileMapHeader)) {
146 fail_continue("Unable to read the file header.");
147 return false;
148 }
149 if (_header._version != current_version()) {
150 fail_continue("The shared archive file has the wrong version.");
151 return false;
152 }
153 _file_offset = (long)n;
154 return true;
155 }
158 // Read the FileMapInfo information from the file.
159 bool FileMapInfo::open_for_read() {
160 _full_path = Arguments::GetSharedArchivePath();
161 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
162 if (fd < 0) {
163 if (errno == ENOENT) {
164 // Not locating the shared archive is ok.
165 fail_continue("Specified shared archive not found.");
166 } else {
167 fail_continue("Failed to open shared archive file (%s).",
168 strerror(errno));
169 }
170 return false;
171 }
173 _fd = fd;
174 _file_open = true;
175 return true;
176 }
179 // Write the FileMapInfo information to the file.
181 void FileMapInfo::open_for_write() {
182 _full_path = Arguments::GetSharedArchivePath();
183 if (PrintSharedSpaces) {
184 tty->print_cr("Dumping shared data to file: ");
185 tty->print_cr(" %s", _full_path);
186 }
188 // Remove the existing file in case another process has it open.
189 remove(_full_path);
190 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
191 if (fd < 0) {
192 fail_stop("Unable to create shared archive file %s.", _full_path);
193 }
194 _fd = fd;
195 _file_offset = 0;
196 _file_open = true;
197 }
200 // Write the header to the file, seek to the next allocation boundary.
202 void FileMapInfo::write_header() {
203 write_bytes_aligned(&_header, sizeof(FileMapHeader));
204 }
207 // Dump shared spaces to file.
209 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
210 align_file_position();
211 size_t used = space->used_words(Metaspace::NonClassType) * BytesPerWord;
212 size_t capacity = space->capacity_words(Metaspace::NonClassType) * BytesPerWord;
213 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
214 write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
215 }
218 // Dump region to file.
220 void FileMapInfo::write_region(int region, char* base, size_t size,
221 size_t capacity, bool read_only,
222 bool allow_exec) {
223 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
225 if (_file_open) {
226 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
227 if (PrintSharedSpaces) {
228 tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT
229 " file offset 0x%6x", region, size, base, _file_offset);
230 }
231 } else {
232 si->_file_offset = _file_offset;
233 }
234 si->_base = base;
235 si->_used = size;
236 si->_capacity = capacity;
237 si->_read_only = read_only;
238 si->_allow_exec = allow_exec;
239 write_bytes_aligned(base, (int)size);
240 }
243 // Dump bytes to file -- at the current file position.
245 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
246 if (_file_open) {
247 int n = ::write(_fd, buffer, nbytes);
248 if (n != nbytes) {
249 // It is dangerous to leave the corrupted shared archive file around,
250 // close and remove the file. See bug 6372906.
251 close();
252 remove(_full_path);
253 fail_stop("Unable to write to shared archive file.", NULL);
254 }
255 }
256 _file_offset += nbytes;
257 }
260 // Align file position to an allocation unit boundary.
262 void FileMapInfo::align_file_position() {
263 long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity());
264 if (new_file_offset != _file_offset) {
265 _file_offset = new_file_offset;
266 if (_file_open) {
267 // Seek one byte back from the target and write a byte to insure
268 // that the written file is the correct length.
269 _file_offset -= 1;
270 if (lseek(_fd, _file_offset, SEEK_SET) < 0) {
271 fail_stop("Unable to seek.", NULL);
272 }
273 char zero = 0;
274 write_bytes(&zero, 1);
275 }
276 }
277 }
280 // Dump bytes to file -- at the current file position.
282 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
283 align_file_position();
284 write_bytes(buffer, nbytes);
285 align_file_position();
286 }
289 // Close the shared archive file. This does NOT unmap mapped regions.
291 void FileMapInfo::close() {
292 if (_file_open) {
293 if (::close(_fd) < 0) {
294 fail_stop("Unable to close the shared archive file.");
295 }
296 _file_open = false;
297 _fd = -1;
298 }
299 }
302 // JVM/TI RedefineClasses() support:
303 // Remap the shared readonly space to shared readwrite, private.
304 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
305 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
306 if (!si->_read_only) {
307 // the space is already readwrite so we are done
308 return true;
309 }
310 size_t used = si->_used;
311 size_t size = align_size_up(used, os::vm_allocation_granularity());
312 if (!open_for_read()) {
313 return false;
314 }
315 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
316 si->_base, size, false /* !read_only */,
317 si->_allow_exec);
318 close();
319 if (base == NULL) {
320 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
321 return false;
322 }
323 if (base != si->_base) {
324 fail_continue("Unable to remap shared readonly space at required address.");
325 return false;
326 }
327 si->_read_only = false;
328 return true;
329 }
331 // Map the whole region at once, assumed to be allocated contiguously.
332 ReservedSpace FileMapInfo::reserve_shared_memory() {
333 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
334 char* requested_addr = si->_base;
335 size_t alignment = os::vm_allocation_granularity();
337 size_t size = align_size_up(SharedReadOnlySize + SharedReadWriteSize +
338 SharedMiscDataSize + SharedMiscCodeSize,
339 alignment);
341 // Reserve the space first, then map otherwise map will go right over some
342 // other reserved memory (like the code cache).
343 ReservedSpace rs(size, alignment, false, requested_addr);
344 if (!rs.is_reserved()) {
345 fail_continue(err_msg("Unable to reserved shared space at required address " INTPTR_FORMAT, requested_addr));
346 return rs;
347 }
348 // the reserved virtual memory is for mapping class data sharing archive
349 if (MemTracker::is_on()) {
350 MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared);
351 }
352 return rs;
353 }
355 // Memory map a region in the address space.
356 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode"};
358 char* FileMapInfo::map_region(int i) {
359 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
360 size_t used = si->_used;
361 size_t alignment = os::vm_allocation_granularity();
362 size_t size = align_size_up(used, alignment);
363 char *requested_addr = si->_base;
365 // map the contents of the CDS archive in this memory
366 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
367 requested_addr, size, si->_read_only,
368 si->_allow_exec);
369 if (base == NULL || base != si->_base) {
370 fail_continue(err_msg("Unable to map %s shared space at required address.", shared_region_name[i]));
371 return NULL;
372 }
373 return base;
374 }
377 // Unmap a memory region in the address space.
379 void FileMapInfo::unmap_region(int i) {
380 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
381 size_t used = si->_used;
382 size_t size = align_size_up(used, os::vm_allocation_granularity());
383 if (!os::unmap_memory(si->_base, size)) {
384 fail_stop("Unable to unmap shared space.");
385 }
386 }
389 void FileMapInfo::assert_mark(bool check) {
390 if (!check) {
391 fail_stop("Mark mismatch while restoring from shared file.", NULL);
392 }
393 }
396 FileMapInfo* FileMapInfo::_current_info = NULL;
399 // Open the shared archive file, read and validate the header
400 // information (version, boot classpath, etc.). If initialization
401 // fails, shared spaces are disabled and the file is closed. [See
402 // fail_continue.]
403 bool FileMapInfo::initialize() {
404 assert(UseSharedSpaces, "UseSharedSpaces expected.");
406 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
407 fail_continue("Tool agent requires sharing to be disabled.");
408 return false;
409 }
411 if (!open_for_read()) {
412 return false;
413 }
415 init_from_file(_fd);
416 if (!validate()) {
417 return false;
418 }
420 SharedReadOnlySize = _header._space[0]._capacity;
421 SharedReadWriteSize = _header._space[1]._capacity;
422 SharedMiscDataSize = _header._space[2]._capacity;
423 SharedMiscCodeSize = _header._space[3]._capacity;
424 return true;
425 }
428 bool FileMapInfo::validate() {
429 if (_header._version != current_version()) {
430 fail_continue("The shared archive file is the wrong version.");
431 return false;
432 }
433 if (_header._magic != (int)0xf00baba2) {
434 fail_continue("The shared archive file has a bad magic number.");
435 return false;
436 }
437 if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(),
438 JVM_IDENT_MAX-1) != 0) {
439 fail_continue("The shared archive file was created by a different"
440 " version or build of HotSpot.");
441 return false;
442 }
444 // Cannot verify interpreter yet, as it can only be created after the GC
445 // heap has been initialized.
447 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
448 fail_continue("Too many jar files to share.");
449 return false;
450 }
452 // Build checks on classpath and jar files
453 int num_jars_now = 0;
454 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
455 for ( ; cpe != NULL; cpe = cpe->next()) {
457 if (cpe->is_jar_file()) {
458 if (num_jars_now < _header._num_jars) {
460 // Jar file - verify timestamp and file size.
461 struct stat st;
462 const char *path = cpe->name();
463 if (os::stat(path, &st) != 0) {
464 fail_continue("Unable to open jar file %s.", path);
465 return false;
466 }
467 if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
468 _header._jar[num_jars_now]._filesize != st.st_size) {
469 fail_continue("A jar file is not the one used while building"
470 " the shared archive file.");
471 return false;
472 }
473 }
474 ++num_jars_now;
475 } else {
477 // If directories appear in boot classpath, they must be empty to
478 // avoid having to verify each individual class file.
479 const char* name = ((ClassPathDirEntry*)cpe)->name();
480 if (!os::dir_is_empty(name)) {
481 fail_continue("Boot classpath directory %s is not empty.", name);
482 return false;
483 }
484 }
485 }
486 if (num_jars_now < _header._num_jars) {
487 fail_continue("The number of jar files in the boot classpath is"
488 " less than the number the shared archive was created with.");
489 return false;
490 }
492 return true;
493 }
495 // The following method is provided to see whether a given pointer
496 // falls in the mapped shared space.
497 // Param:
498 // p, The given pointer
499 // Return:
500 // True if the p is within the mapped shared space, otherwise, false.
501 bool FileMapInfo::is_in_shared_space(const void* p) {
502 for (int i = 0; i < MetaspaceShared::n_regions; i++) {
503 if (p >= _header._space[i]._base &&
504 p < _header._space[i]._base + _header._space[i]._used) {
505 return true;
506 }
507 }
509 return false;
510 }