Wed, 15 Feb 2012 10:12:55 -0800
7145537: minor tweaks to LogEvents
Reviewed-by: kvn, twisti
1 /*
2 * Copyright (c) 2003, 2010, 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 "utilities/defaultStream.hpp"
34 # include <sys/stat.h>
35 # include <errno.h>
37 #ifndef O_BINARY // if defined (Win32) use binary files.
38 #define O_BINARY 0 // otherwise do nothing.
39 #endif
42 extern address JVM_FunctionAtStart();
43 extern address JVM_FunctionAtEnd();
45 // Complain and stop. All error conditions occurring during the writing of
46 // an archive file should stop the process. Unrecoverable errors during
47 // the reading of the archive file should stop the process.
49 static void fail(const char *msg, va_list ap) {
50 // This occurs very early during initialization: tty is not initialized.
51 jio_fprintf(defaultStream::error_stream(),
52 "An error has occurred while processing the"
53 " shared archive file.\n");
54 jio_vfprintf(defaultStream::error_stream(), msg, ap);
55 jio_fprintf(defaultStream::error_stream(), "\n");
56 vm_exit_during_initialization("Unable to use shared archive.", NULL);
57 }
60 void FileMapInfo::fail_stop(const char *msg, ...) {
61 va_list ap;
62 va_start(ap, msg);
63 fail(msg, ap); // Never returns.
64 va_end(ap); // for completeness.
65 }
68 // Complain and continue. Recoverable errors during the reading of the
69 // archive file may continue (with sharing disabled).
70 //
71 // If we continue, then disable shared spaces and close the file.
73 void FileMapInfo::fail_continue(const char *msg, ...) {
74 va_list ap;
75 va_start(ap, msg);
76 if (RequireSharedSpaces) {
77 fail(msg, ap);
78 }
79 va_end(ap);
80 UseSharedSpaces = false;
81 close();
82 }
85 // Fill in the fileMapInfo structure with data about this VM instance.
87 void FileMapInfo::populate_header(size_t alignment) {
88 _header._magic = 0xf00baba2;
89 _header._version = _current_version;
90 _header._alignment = alignment;
92 // The following fields are for sanity checks for whether this archive
93 // will function correctly with this JVM and the bootclasspath it's
94 // invoked with.
96 // JVM version string ... changes on each build.
97 const char *vm_version = VM_Version::internal_vm_info_string();
98 if (strlen(vm_version) < (JVM_IDENT_MAX-1)) {
99 strcpy(_header._jvm_ident, vm_version);
100 } else {
101 fail_stop("JVM Ident field for shared archive is too long"
102 " - truncated to <%s>", _header._jvm_ident);
103 }
105 // Build checks on classpath and jar files
106 _header._num_jars = 0;
107 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
108 for ( ; cpe != NULL; cpe = cpe->next()) {
110 if (cpe->is_jar_file()) {
111 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
112 fail_stop("Too many jar files to share.", NULL);
113 }
115 // Jar file - record timestamp and file size.
116 struct stat st;
117 const char *path = cpe->name();
118 if (os::stat(path, &st) != 0) {
119 // If we can't access a jar file in the boot path, then we can't
120 // make assumptions about where classes get loaded from.
121 fail_stop("Unable to open jar file %s.", path);
122 }
123 _header._jar[_header._num_jars]._timestamp = st.st_mtime;
124 _header._jar[_header._num_jars]._filesize = st.st_size;
125 _header._num_jars++;
126 } else {
128 // If directories appear in boot classpath, they must be empty to
129 // avoid having to verify each individual class file.
130 const char* name = ((ClassPathDirEntry*)cpe)->name();
131 if (!os::dir_is_empty(name)) {
132 fail_stop("Boot classpath directory %s is not empty.", name);
133 }
134 }
135 }
136 }
139 // Read the FileMapInfo information from the file.
141 bool FileMapInfo::init_from_file(int fd) {
143 size_t n = read(fd, &_header, sizeof(struct FileMapHeader));
144 if (n != sizeof(struct FileMapHeader)) {
145 fail_continue("Unable to read the file header.");
146 return false;
147 }
148 if (_header._version != current_version()) {
149 fail_continue("The shared archive file has the wrong version.");
150 return false;
151 }
152 _file_offset = (long)n;
153 return true;
154 }
157 // Read the FileMapInfo information from the file.
158 bool FileMapInfo::open_for_read() {
159 _full_path = Arguments::GetSharedArchivePath();
160 int fd = open(_full_path, O_RDONLY | O_BINARY, 0);
161 if (fd < 0) {
162 if (errno == ENOENT) {
163 // Not locating the shared archive is ok.
164 fail_continue("Specified shared archive not found.");
165 } else {
166 fail_continue("Failed to open shared archive file (%s).",
167 strerror(errno));
168 }
169 return false;
170 }
172 _fd = fd;
173 _file_open = true;
174 return true;
175 }
178 // Write the FileMapInfo information to the file.
180 void FileMapInfo::open_for_write() {
181 _full_path = Arguments::GetSharedArchivePath();
182 if (PrintSharedSpaces) {
183 tty->print_cr("Dumping shared data to file: ");
184 tty->print_cr(" %s", _full_path);
185 }
187 // Remove the existing file in case another process has it open.
188 remove(_full_path);
189 int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);
190 if (fd < 0) {
191 fail_stop("Unable to create shared archive file %s.", _full_path);
192 }
193 _fd = fd;
194 _file_offset = 0;
195 _file_open = true;
196 }
199 // Write the header to the file, seek to the next allocation boundary.
201 void FileMapInfo::write_header() {
202 write_bytes_aligned(&_header, sizeof(FileMapHeader));
203 }
206 // Dump shared spaces to file.
208 void FileMapInfo::write_space(int i, CompactibleSpace* space, bool read_only) {
209 align_file_position();
210 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
211 write_region(i, (char*)space->bottom(), space->used(),
212 space->capacity(), read_only, false);
213 }
216 // Dump region to file.
218 void FileMapInfo::write_region(int region, char* base, size_t size,
219 size_t capacity, bool read_only,
220 bool allow_exec) {
221 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[region];
223 if (_file_open) {
224 guarantee(si->_file_offset == _file_offset, "file offset mismatch.");
225 if (PrintSharedSpaces) {
226 tty->print_cr("Shared file region %d: 0x%x bytes, addr 0x%x,"
227 " file offset 0x%x", region, size, base, _file_offset);
228 }
229 } else {
230 si->_file_offset = _file_offset;
231 }
232 si->_base = base;
233 si->_used = size;
234 si->_capacity = capacity;
235 si->_read_only = read_only;
236 si->_allow_exec = allow_exec;
237 write_bytes_aligned(base, (int)size);
238 }
241 // Dump bytes to file -- at the current file position.
243 void FileMapInfo::write_bytes(const void* buffer, int nbytes) {
244 if (_file_open) {
245 int n = ::write(_fd, buffer, nbytes);
246 if (n != nbytes) {
247 // It is dangerous to leave the corrupted shared archive file around,
248 // close and remove the file. See bug 6372906.
249 close();
250 remove(_full_path);
251 fail_stop("Unable to write to shared archive file.", NULL);
252 }
253 }
254 _file_offset += nbytes;
255 }
258 // Align file position to an allocation unit boundary.
260 void FileMapInfo::align_file_position() {
261 long new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity());
262 if (new_file_offset != _file_offset) {
263 _file_offset = new_file_offset;
264 if (_file_open) {
265 // Seek one byte back from the target and write a byte to insure
266 // that the written file is the correct length.
267 _file_offset -= 1;
268 if (lseek(_fd, _file_offset, SEEK_SET) < 0) {
269 fail_stop("Unable to seek.", NULL);
270 }
271 char zero = 0;
272 write_bytes(&zero, 1);
273 }
274 }
275 }
278 // Dump bytes to file -- at the current file position.
280 void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {
281 align_file_position();
282 write_bytes(buffer, nbytes);
283 align_file_position();
284 }
287 // Close the shared archive file. This does NOT unmap mapped regions.
289 void FileMapInfo::close() {
290 if (_file_open) {
291 if (::close(_fd) < 0) {
292 fail_stop("Unable to close the shared archive file.");
293 }
294 _file_open = false;
295 _fd = -1;
296 }
297 }
300 // Memory map a shared space from the archive file.
302 bool FileMapInfo::map_space(int i, ReservedSpace rs, ContiguousSpace* space) {
303 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
304 if (space != NULL) {
305 if (si->_base != (char*)space->bottom() ||
306 si->_capacity != space->capacity()) {
307 fail_continue("Shared space base address does not match.");
308 return false;
309 }
310 }
311 bool result = (map_region(i, rs) != NULL);
312 if (space != NULL && result) {
313 space->set_top((HeapWord*)(si->_base + si->_used));
314 space->set_saved_mark();
315 }
316 return result;
317 }
320 // JVM/TI RedefineClasses() support:
321 // Remap the shared readonly space to shared readwrite, private.
322 bool FileMapInfo::remap_shared_readonly_as_readwrite() {
323 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[0];
324 if (!si->_read_only) {
325 // the space is already readwrite so we are done
326 return true;
327 }
328 size_t used = si->_used;
329 size_t size = align_size_up(used, os::vm_allocation_granularity());
330 if (!open_for_read()) {
331 return false;
332 }
333 char *base = os::remap_memory(_fd, _full_path, si->_file_offset,
334 si->_base, size, false /* !read_only */,
335 si->_allow_exec);
336 close();
337 if (base == NULL) {
338 fail_continue("Unable to remap shared readonly space (errno=%d).", errno);
339 return false;
340 }
341 if (base != si->_base) {
342 fail_continue("Unable to remap shared readonly space at required address.");
343 return false;
344 }
345 si->_read_only = false;
346 return true;
347 }
350 // Memory map a region in the address space.
352 char* FileMapInfo::map_region(int i, ReservedSpace rs) {
353 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
354 size_t used = si->_used;
355 size_t size = align_size_up(used, os::vm_allocation_granularity());
357 ReservedSpace mapped_rs = rs.first_part(size, true, true);
358 ReservedSpace unmapped_rs = rs.last_part(size);
359 mapped_rs.release();
361 return map_region(i, true);
362 }
365 // Memory map a region in the address space.
367 char* FileMapInfo::map_region(int i, bool address_must_match) {
368 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
369 size_t used = si->_used;
370 size_t size = align_size_up(used, os::vm_allocation_granularity());
371 char *requested_addr = 0;
372 if (address_must_match) {
373 requested_addr = si->_base;
374 }
375 char *base = os::map_memory(_fd, _full_path, si->_file_offset,
376 requested_addr, size, si->_read_only,
377 si->_allow_exec);
378 if (base == NULL) {
379 fail_continue("Unable to map shared space.");
380 return NULL;
381 }
382 if (address_must_match) {
383 if (base != si->_base) {
384 fail_continue("Unable to map shared space at required address.");
385 return NULL;
386 }
387 } else {
388 si->_base = base; // save mapped address for unmapping.
389 }
390 return base;
391 }
394 // Unmap a memory region in the address space.
396 void FileMapInfo::unmap_region(int i) {
397 struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
398 size_t used = si->_used;
399 size_t size = align_size_up(used, os::vm_allocation_granularity());
400 if (!os::unmap_memory(si->_base, size)) {
401 fail_stop("Unable to unmap shared space.");
402 }
403 }
406 void FileMapInfo::assert_mark(bool check) {
407 if (!check) {
408 fail_stop("Mark mismatch while restoring from shared file.", NULL);
409 }
410 }
413 FileMapInfo* FileMapInfo::_current_info = NULL;
416 // Open the shared archive file, read and validate the header
417 // information (version, boot classpath, etc.). If initialization
418 // fails, shared spaces are disabled and the file is closed. [See
419 // fail_continue.]
422 bool FileMapInfo::initialize() {
423 assert(UseSharedSpaces, "UseSharedSpaces expected.");
425 if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) {
426 fail_continue("Tool agent requires sharing to be disabled.");
427 return false;
428 }
430 if (!open_for_read()) {
431 return false;
432 }
434 init_from_file(_fd);
435 if (!validate()) {
436 return false;
437 }
439 SharedReadOnlySize = _header._space[0]._capacity;
440 SharedReadWriteSize = _header._space[1]._capacity;
441 SharedMiscDataSize = _header._space[2]._capacity;
442 SharedMiscCodeSize = _header._space[3]._capacity;
443 return true;
444 }
447 bool FileMapInfo::validate() {
448 if (_header._version != current_version()) {
449 fail_continue("The shared archive file is the wrong version.");
450 return false;
451 }
452 if (_header._magic != (int)0xf00baba2) {
453 fail_continue("The shared archive file has a bad magic number.");
454 return false;
455 }
456 if (strncmp(_header._jvm_ident, VM_Version::internal_vm_info_string(),
457 JVM_IDENT_MAX-1) != 0) {
458 fail_continue("The shared archive file was created by a different"
459 " version or build of HotSpot.");
460 return false;
461 }
463 // Cannot verify interpreter yet, as it can only be created after the GC
464 // heap has been initialized.
466 if (_header._num_jars >= JVM_SHARED_JARS_MAX) {
467 fail_continue("Too many jar files to share.");
468 return false;
469 }
471 // Build checks on classpath and jar files
472 int num_jars_now = 0;
473 ClassPathEntry *cpe = ClassLoader::classpath_entry(0);
474 for ( ; cpe != NULL; cpe = cpe->next()) {
476 if (cpe->is_jar_file()) {
477 if (num_jars_now < _header._num_jars) {
479 // Jar file - verify timestamp and file size.
480 struct stat st;
481 const char *path = cpe->name();
482 if (os::stat(path, &st) != 0) {
483 fail_continue("Unable to open jar file %s.", path);
484 return false;
485 }
486 if (_header._jar[num_jars_now]._timestamp != st.st_mtime ||
487 _header._jar[num_jars_now]._filesize != st.st_size) {
488 fail_continue("A jar file is not the one used while building"
489 " the shared archive file.");
490 return false;
491 }
492 }
493 ++num_jars_now;
494 } else {
496 // If directories appear in boot classpath, they must be empty to
497 // avoid having to verify each individual class file.
498 const char* name = ((ClassPathDirEntry*)cpe)->name();
499 if (!os::dir_is_empty(name)) {
500 fail_continue("Boot classpath directory %s is not empty.", name);
501 return false;
502 }
503 }
504 }
505 if (num_jars_now < _header._num_jars) {
506 fail_continue("The number of jar files in the boot classpath is"
507 " less than the number the shared archive was created with.");
508 return false;
509 }
511 return true;
512 }
514 // The following method is provided to see whether a given pointer
515 // falls in the mapped shared space.
516 // Param:
517 // p, The given pointer
518 // Return:
519 // True if the p is within the mapped shared space, otherwise, false.
520 bool FileMapInfo::is_in_shared_space(const void* p) {
521 for (int i = 0; i < CompactingPermGenGen::n_regions; i++) {
522 if (p >= _header._space[i]._base &&
523 p < _header._space[i]._base + _header._space[i]._used) {
524 return true;
525 }
526 }
528 return false;
529 }