1 /* 2 * Copyright (c) 2012, 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 "jfr/jfrEvents.hpp" 27 #include "jfr/jni/jfrJavaSupport.hpp" 28 #include "jfr/leakprofiler/leakProfiler.hpp" 29 #include "jfr/recorder/repository/jfrEmergencyDump.hpp" 30 #include "jfr/recorder/service/jfrPostBox.hpp" 31 #include "jfr/recorder/service/jfrRecorderService.hpp" 32 #include "jfr/utilities/jfrTypes.hpp" 33 #include "logging/log.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "runtime/atomic.hpp" 36 #include "runtime/handles.inline.hpp" 37 #include "runtime/globals.hpp" 38 #include "runtime/mutexLocker.hpp" 39 #include "runtime/os.hpp" 40 #include "runtime/thread.inline.hpp" 41 #include "utilities/growableArray.hpp" 42 43 static const char vm_error_filename_fmt[] = "hs_err_pid%p.jfr"; 44 static const char vm_oom_filename_fmt[] = "hs_oom_pid%p.jfr"; 45 static const char vm_soe_filename_fmt[] = "hs_soe_pid%p.jfr"; 46 static const char chunk_file_jfr_ext[] = ".jfr"; 47 static const size_t iso8601_len = 19; // "YYYY-MM-DDTHH:MM:SS" 48 49 static fio_fd open_exclusivly(const char* path) { 50 return os::open(path, O_CREAT | O_RDWR, S_IREAD | S_IWRITE); 51 } 52 53 static int file_sort(const char** const file1, const char** file2) { 54 assert(NULL != *file1 && NULL != *file2, "invariant"); 55 int cmp = strncmp(*file1, *file2, iso8601_len); 56 if (0 == cmp) { 57 const char* const dot1 = strchr(*file1, '.'); 58 assert(NULL != dot1, "invariant"); 59 const char* const dot2 = strchr(*file2, '.'); 60 assert(NULL != dot2, "invariant"); 61 ptrdiff_t file1_len = dot1 - *file1; 62 ptrdiff_t file2_len = dot2 - *file2; 63 if (file1_len < file2_len) { 64 return -1; 65 } 66 if (file1_len > file2_len) { 67 return 1; 68 } 69 assert(file1_len == file2_len, "invariant"); 70 cmp = strncmp(*file1, *file2, file1_len); 71 } 72 assert(cmp != 0, "invariant"); 92 static void date_time(char* buffer, size_t buffer_len) { 93 assert(buffer != NULL, "invariant"); 94 assert(buffer_len >= iso8601_len, "buffer too small"); 95 os::iso8601_time(buffer, buffer_len); 96 assert(strlen(buffer) >= iso8601_len + 1, "invariant"); 97 // "YYYY-MM-DDTHH:MM:SS" 98 buffer[iso8601_len] = '\0'; 99 iso8601_to_date_time(buffer); 100 } 101 102 static int64_t file_size(fio_fd fd) { 103 assert(fd != invalid_fd, "invariant"); 104 const int64_t current_offset = os::current_file_offset(fd); 105 const int64_t size = os::lseek(fd, 0, SEEK_END); 106 os::seek_to_file_offset(fd, current_offset); 107 return size; 108 } 109 110 class RepositoryIterator : public StackObj { 111 private: 112 const char* const _repo; 113 const size_t _repository_len; 114 GrowableArray<const char*>* _files; 115 const char* const fully_qualified(const char* entry) const; 116 mutable int _iterator; 117 118 public: 119 RepositoryIterator(const char* repository, size_t repository_len); 120 ~RepositoryIterator() {} 121 const char* const filter(const char* entry) const; 122 bool has_next() const; 123 const char* const next() const; 124 }; 125 126 const char* const RepositoryIterator::fully_qualified(const char* entry) const { 127 assert(NULL != entry, "invariant"); 128 char* file_path_entry = NULL; 129 // only use files that have content, not placeholders 130 const char* const file_separator = os::file_separator(); 131 if (NULL != file_separator) { 132 const size_t entry_len = strlen(entry); 133 const size_t file_separator_length = strlen(file_separator); 134 const size_t file_path_entry_length = _repository_len + file_separator_length + entry_len; 135 file_path_entry = NEW_RESOURCE_ARRAY_RETURN_NULL(char, file_path_entry_length + 1); 136 if (NULL == file_path_entry) { 137 return NULL; 138 } 139 int position = 0; 140 position += jio_snprintf(&file_path_entry[position], _repository_len + 1, "%s", _repo); 141 position += jio_snprintf(&file_path_entry[position], file_separator_length + 1, "%s", os::file_separator()); 142 position += jio_snprintf(&file_path_entry[position], entry_len + 1, "%s", entry); 143 file_path_entry[position] = '\0'; 144 assert((size_t)position == file_path_entry_length, "invariant"); 145 assert(strlen(file_path_entry) == (size_t)position, "invariant"); 146 } 147 return file_path_entry; 148 } 149 150 const char* const RepositoryIterator::filter(const char* entry) const { 151 if (entry == NULL) { 152 return NULL; 153 } 154 const size_t entry_len = strlen(entry); 155 if (entry_len <= 2) { 156 // for "." and ".." 157 return NULL; 158 } 159 char* entry_name = NEW_RESOURCE_ARRAY_RETURN_NULL(char, entry_len + 1); 160 if (entry_name == NULL) { 161 return NULL; 162 } 163 strncpy(entry_name, entry, entry_len + 1); 164 const char* const fully_qualified_path_entry = fully_qualified(entry_name); 165 if (NULL == fully_qualified_path_entry) { 166 return NULL; 167 } 168 const fio_fd entry_fd = open_exclusivly(fully_qualified_path_entry); 169 if (invalid_fd == entry_fd) { 170 return NULL; 171 } 172 const int64_t entry_size = file_size(entry_fd); 173 os::close(entry_fd); 174 if (0 == entry_size) { 175 return NULL; 176 } 177 return entry_name; 178 } 179 180 RepositoryIterator::RepositoryIterator(const char* repository, size_t repository_len) : 181 _repo(repository), 182 _repository_len(repository_len), 183 _files(NULL), 184 _iterator(0) { 185 if (NULL != _repo) { 186 assert(strlen(_repo) == _repository_len, "invariant"); 187 _files = new GrowableArray<const char*>(10); 188 DIR* dirp = os::opendir(_repo); 189 if (dirp == NULL) { 190 log_error(jfr, system)("Unable to open repository %s", _repo); 191 return; 192 } 193 struct dirent* dentry; 194 while ((dentry = os::readdir(dirp)) != NULL) { 195 const char* const entry_path = filter(dentry->d_name); 196 if (NULL != entry_path) { 197 _files->append(entry_path); 198 } 199 } 200 os::closedir(dirp); 201 if (_files->length() > 1) { 202 _files->sort(file_sort); 203 } 204 } 205 } 206 207 bool RepositoryIterator::has_next() const { 208 return (_files != NULL && _iterator < _files->length()); 209 } 210 211 const char* const RepositoryIterator::next() const { 212 return _iterator >= _files->length() ? NULL : fully_qualified(_files->at(_iterator++)); 213 } 214 215 static void write_emergency_file(fio_fd emergency_fd, const RepositoryIterator& iterator) { 216 assert(emergency_fd != invalid_fd, "invariant"); 217 const size_t size_of_file_copy_block = 1 * M; // 1 mb 218 jbyte* const file_copy_block = NEW_RESOURCE_ARRAY_RETURN_NULL(jbyte, size_of_file_copy_block); 219 if (file_copy_block == NULL) { 220 return; 221 } 222 while (iterator.has_next()) { 223 fio_fd current_fd = invalid_fd; 224 const char* const fqn = iterator.next(); 225 if (fqn != NULL) { 226 current_fd = open_exclusivly(fqn); 227 if (current_fd != invalid_fd) { 228 const int64_t current_filesize = file_size(current_fd); 229 assert(current_filesize > 0, "invariant"); 230 int64_t bytes_read = 0; 231 int64_t bytes_written = 0; 232 while (bytes_read < current_filesize) { 233 const ssize_t read_result = os::read_at(current_fd, file_copy_block, size_of_file_copy_block, bytes_read); 234 if (-1 == read_result) { 235 log_info(jfr)( // For user, should not be "jfr, system" 236 "Unable to recover JFR data"); 237 break; 238 } 239 bytes_read += (int64_t)read_result; 240 assert(bytes_read - bytes_written <= (int64_t)size_of_file_copy_block, "invariant"); 241 bytes_written += (int64_t)os::write(emergency_fd, file_copy_block, bytes_read - bytes_written); 242 assert(bytes_read == bytes_written, "invariant"); 243 } 244 os::close(current_fd); 245 } 246 } 247 } 248 } 249 250 static const char* create_emergency_dump_path() { 251 char* buffer = NEW_RESOURCE_ARRAY_RETURN_NULL(char, JVM_MAXPATHLEN); 252 if (NULL == buffer) { 253 return NULL; 254 } 255 const char* const cwd = os::get_current_directory(buffer, JVM_MAXPATHLEN); 256 if (NULL == cwd) { 257 return NULL; 258 } 259 size_t pos = strlen(cwd); 260 const int fsep_len = jio_snprintf(&buffer[pos], JVM_MAXPATHLEN - pos, "%s", os::file_separator()); 261 const char* filename_fmt = NULL; 262 // fetch specific error cause 263 switch (JfrJavaSupport::cause()) { 264 case JfrJavaSupport::OUT_OF_MEMORY: 265 filename_fmt = vm_oom_filename_fmt; 266 break; 267 case JfrJavaSupport::STACK_OVERFLOW: 268 filename_fmt = vm_soe_filename_fmt; 269 break; 270 default: 271 filename_fmt = vm_error_filename_fmt; 272 } 273 char* emergency_dump_path = NULL; 274 pos += fsep_len; 275 if (Arguments::copy_expand_pid(filename_fmt, strlen(filename_fmt), &buffer[pos], JVM_MAXPATHLEN - pos)) { 276 const size_t emergency_filename_length = strlen(buffer); 277 emergency_dump_path = NEW_RESOURCE_ARRAY_RETURN_NULL(char, emergency_filename_length + 1); 278 if (NULL == emergency_dump_path) { 279 return NULL; 280 } 281 strncpy(emergency_dump_path, buffer, emergency_filename_length + 1); 282 } 283 if (emergency_dump_path != NULL) { 284 log_info(jfr)( // For user, should not be "jfr, system" 285 "Attempting to recover JFR data, emergency jfr file: %s", emergency_dump_path); 286 } 287 return emergency_dump_path; 288 } 289 290 // Caller needs ResourceMark 291 static const char* create_emergency_chunk_path(const char* repository_path) { 292 assert(repository_path != NULL, "invariant"); 293 const size_t repository_path_len = strlen(repository_path); 294 // date time 295 char date_time_buffer[32] = { 0 }; 296 date_time(date_time_buffer, sizeof(date_time_buffer)); 297 size_t date_time_len = strlen(date_time_buffer); 298 size_t chunkname_max_len = repository_path_len // repository_base_path 299 + 1 // "/" 300 + date_time_len // date_time 301 + strlen(chunk_file_jfr_ext) // .jfr 302 + 1; 303 char* chunk_path = NEW_RESOURCE_ARRAY_RETURN_NULL(char, chunkname_max_len); 304 if (chunk_path == NULL) { 305 return NULL; 306 } 307 // append the individual substrings 308 jio_snprintf(chunk_path, chunkname_max_len, "%s%s%s%s", repository_path, os::file_separator(), date_time_buffer, chunk_file_jfr_ext); 309 return chunk_path; 310 } 311 312 static fio_fd emergency_dump_file_descriptor() { 313 ResourceMark rm; 314 const char* const emergency_dump_path = create_emergency_dump_path(); 315 return emergency_dump_path != NULL ? open_exclusivly(emergency_dump_path) : invalid_fd; 316 } 317 318 const char* JfrEmergencyDump::build_dump_path(const char* repository_path) { 319 return repository_path == NULL ? create_emergency_dump_path() : create_emergency_chunk_path(repository_path); 320 } 321 322 void JfrEmergencyDump::on_vm_error(const char* repository_path) { 323 assert(repository_path != NULL, "invariant"); 324 ResourceMark rm; 325 const fio_fd emergency_fd = emergency_dump_file_descriptor(); 326 if (emergency_fd != invalid_fd) { 327 RepositoryIterator iterator(repository_path, strlen(repository_path)); 328 write_emergency_file(emergency_fd, iterator); 329 os::close(emergency_fd); 330 } 331 } 332 333 /* 334 * We are just about to exit the VM, so we will be very aggressive 335 * at this point in order to increase overall success of dumping jfr data. 336 * 337 * If we end up deadlocking in the attempt of dumping out jfr data, 338 * we rely on the WatcherThread task "is_error_reported()", 339 * to exit the VM after a hard-coded timeout (disallow WatcherThread to emergency dump). 340 * This "safety net" somewhat explains the aggressiveness in this attempt. 341 * 342 */ 343 static bool prepare_for_emergency_dump(Thread* thread) { 344 assert(thread != NULL, "invariant"); 345 346 if (thread->is_Watcher_thread()) { 347 // need WatcherThread as a safeguard against potential deadlocks 348 return false; 349 } 350 if (JfrStream_lock->owned_by_self()) { 426 JavaThread* const _jt; 427 JavaThreadState _original_state; 428 public: 429 430 JavaThreadInVM(Thread* t) : _jt(t->is_Java_thread() ? (JavaThread*)t : NULL), 431 _original_state(_thread_max_state) { 432 if ((_jt != NULL) && (_jt->thread_state() != _thread_in_vm)) { 433 _original_state = _jt->thread_state(); 434 _jt->set_thread_state(_thread_in_vm); 435 } 436 } 437 438 ~JavaThreadInVM() { 439 if (_original_state != _thread_max_state) { 440 _jt->set_thread_state(_original_state); 441 } 442 } 443 444 }; 445 446 void JfrEmergencyDump::on_vm_shutdown(bool exception_handler) { 447 if (!guard_reentrancy()) { 448 return; 449 } 450 451 Thread* thread = Thread::current_or_null_safe(); 452 if (thread == NULL) { 453 return; 454 } 455 // Ensure a JavaThread is _thread_in_vm when we make this call 456 JavaThreadInVM jtivm(thread); 457 if (!prepare_for_emergency_dump(thread)) { 458 return; 459 } 460 461 EventDumpReason event; 462 if (event.should_commit()) { 463 event.set_reason(exception_handler ? "Crash" : "Out of Memory"); 464 event.set_recordingId(-1); 465 event.commit(); 466 } 467 if (!exception_handler) { 468 // OOM 469 LeakProfiler::emit_events(max_jlong, false); 470 } 471 const int messages = MSGBIT(MSG_VM_ERROR); 472 JfrRecorderService service; 473 service.rotate(messages); 474 } | 1 /* 2 * Copyright (c) 2012, 2020, 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 "jfr/jfrEvents.hpp" 27 #include "jfr/jni/jfrJavaSupport.hpp" 28 #include "jfr/leakprofiler/leakProfiler.hpp" 29 #include "jfr/recorder/repository/jfrEmergencyDump.hpp" 30 #include "jfr/recorder/service/jfrPostBox.hpp" 31 #include "jfr/recorder/service/jfrRecorderService.hpp" 32 #include "jfr/utilities/jfrTypes.hpp" 33 #include "logging/log.hpp" 34 #include "runtime/atomic.hpp" 35 #include "runtime/globals.hpp" 36 #include "runtime/mutexLocker.hpp" 37 #include "runtime/os.hpp" 38 #include "runtime/thread.inline.hpp" 39 #include "utilities/growableArray.hpp" 40 #include "utilities/ostream.hpp" 41 42 static const char vm_error_filename_fmt[] = "hs_err_pid%p.jfr"; 43 static const char vm_oom_filename_fmt[] = "hs_oom_pid%p.jfr"; 44 static const char vm_soe_filename_fmt[] = "hs_soe_pid%p.jfr"; 45 static const char chunk_file_jfr_ext[] = ".jfr"; 46 static const size_t iso8601_len = 19; // "YYYY-MM-DDTHH:MM:SS" 47 static fio_fd emergency_fd = invalid_fd; 48 static const int64_t chunk_file_header_size = 68; 49 static const size_t chunk_file_extension_length = sizeof chunk_file_jfr_ext - 1; 50 51 /* 52 * The emergency dump logic is restrictive when it comes to 53 * using internal VM constructs such as ResourceArea / Handle / Arena. 54 * The reason being that the thread context is unknown. 55 * 56 * A single static buffer of size JVM_MAXPATHLEN is used for building paths. 57 * os::malloc / os::free are used in a few places. 58 */ 59 60 static const size_t _max_path_buffer_size = JVM_MAXPATHLEN; 61 static char _path_buffer[_max_path_buffer_size] = { 0 }; 62 63 static bool is_empty(const char* path) { 64 assert(path != NULL, "invariant"); 65 return path[0] == '\0'; 66 } 67 68 static bool is_path_empty() { 69 return is_empty(_path_buffer); 70 } 71 72 static size_t append(char* path, int path_len, size_t pos, const char* str) { 73 assert(path_len - pos > 0, "invariant"); 74 const int result = jio_snprintf(path + pos, path_len - pos, "%s", str); 75 return result == -1 ? 0 : pos + (size_t)result; 76 } 77 78 // returns with an appended file separator (if successful) 79 static size_t get_current_directory(char* path, int path_len) { 80 assert(path != NULL, "invariant"); 81 if (os::get_current_directory(path, path_len) == NULL) { 82 return 0; 83 } 84 return append(path, path_len, strlen(path), os::file_separator()); 85 } 86 87 static fio_fd open_exclusivly(const char* path) { 88 assert(path != NULL, "invariant"); 89 assert(!is_empty(path), "invariant"); 90 return os::open(path, O_CREAT | O_RDWR, S_IREAD | S_IWRITE); 91 } 92 93 static bool is_emergency_dump_file_open() { 94 return emergency_fd != invalid_fd; 95 } 96 97 static bool open_emergency_dump_fd(const char* path) { 98 if (path == NULL) { 99 return false; 100 } 101 assert(emergency_fd == invalid_fd, "invariant"); 102 emergency_fd = open_exclusivly(path); 103 return emergency_fd != invalid_fd; 104 } 105 106 static void close_emergency_dump_file() { 107 if (is_emergency_dump_file_open()) { 108 os::close(emergency_fd); 109 } 110 } 111 112 static const char* create_emergency_dump_path() { 113 assert(is_path_empty(), "invariant"); 114 115 char* const path = _path_buffer; 116 const size_t path_len = get_current_directory(path, _max_path_buffer_size); 117 if (path_len == 0) { 118 return NULL; 119 } 120 const char* filename_fmt = NULL; 121 // fetch specific error cause 122 switch (JfrJavaSupport::cause()) { 123 case JfrJavaSupport::OUT_OF_MEMORY: 124 filename_fmt = vm_oom_filename_fmt; 125 break; 126 case JfrJavaSupport::STACK_OVERFLOW: 127 filename_fmt = vm_soe_filename_fmt; 128 break; 129 default: 130 filename_fmt = vm_error_filename_fmt; 131 } 132 const bool result = Arguments::copy_expand_pid(filename_fmt, strlen(filename_fmt), path + path_len, _max_path_buffer_size - path_len); 133 return result ? path : NULL; 134 } 135 136 static bool open_emergency_dump_file() { 137 if (is_emergency_dump_file_open()) { 138 // opened already 139 return true; 140 } 141 return open_emergency_dump_fd(create_emergency_dump_path()); 142 } 143 144 static void report(outputStream* st, bool emergency_file_opened, const char* repository_path) { 145 assert(st != NULL, "invariant"); 146 if (emergency_file_opened) { 147 st->print_raw("# JFR recording file will be written. Location: "); 148 st->print_raw_cr(_path_buffer); 149 st->print_raw_cr("#"); 150 } else if (repository_path != NULL) { 151 st->print_raw("# The JFR repository may contain useful JFR files. Location: "); 152 st->print_raw_cr(repository_path); 153 st->print_raw_cr("#"); 154 } else if (!is_path_empty()) { 155 st->print_raw("# Unable to create a JFR recording file at location: "); 156 st->print_raw_cr(_path_buffer); 157 st->print_raw_cr("#"); 158 } 159 } 160 161 void JfrEmergencyDump::on_vm_error_report(outputStream* st, const char* repository_path) { 162 assert(st != NULL, "invariant"); 163 Thread* thread = Thread::current_or_null_safe(); 164 if (thread != NULL) { 165 report(st, open_emergency_dump_file(), repository_path); 166 } else if (repository_path != NULL) { 167 // a non-attached thread will not be able to write anything later 168 report(st, false, repository_path); 169 } 170 } 171 172 static int file_sort(const char** const file1, const char** file2) { 173 assert(NULL != *file1 && NULL != *file2, "invariant"); 174 int cmp = strncmp(*file1, *file2, iso8601_len); 175 if (0 == cmp) { 176 const char* const dot1 = strchr(*file1, '.'); 177 assert(NULL != dot1, "invariant"); 178 const char* const dot2 = strchr(*file2, '.'); 179 assert(NULL != dot2, "invariant"); 180 ptrdiff_t file1_len = dot1 - *file1; 181 ptrdiff_t file2_len = dot2 - *file2; 182 if (file1_len < file2_len) { 183 return -1; 184 } 185 if (file1_len > file2_len) { 186 return 1; 187 } 188 assert(file1_len == file2_len, "invariant"); 189 cmp = strncmp(*file1, *file2, file1_len); 190 } 191 assert(cmp != 0, "invariant"); 211 static void date_time(char* buffer, size_t buffer_len) { 212 assert(buffer != NULL, "invariant"); 213 assert(buffer_len >= iso8601_len, "buffer too small"); 214 os::iso8601_time(buffer, buffer_len); 215 assert(strlen(buffer) >= iso8601_len + 1, "invariant"); 216 // "YYYY-MM-DDTHH:MM:SS" 217 buffer[iso8601_len] = '\0'; 218 iso8601_to_date_time(buffer); 219 } 220 221 static int64_t file_size(fio_fd fd) { 222 assert(fd != invalid_fd, "invariant"); 223 const int64_t current_offset = os::current_file_offset(fd); 224 const int64_t size = os::lseek(fd, 0, SEEK_END); 225 os::seek_to_file_offset(fd, current_offset); 226 return size; 227 } 228 229 class RepositoryIterator : public StackObj { 230 private: 231 GrowableArray<const char*>* _file_names; 232 size_t _path_buffer_file_name_offset; 233 mutable int _iterator; 234 const char* fully_qualified(const char* file_name) const; 235 const char* filter(const char* file_name) const; 236 public: 237 RepositoryIterator(const char* repository_path); 238 ~RepositoryIterator(); 239 bool has_next() const; 240 const char* next() const; 241 }; 242 243 // append the file_name at the _path_buffer_file_name_offset position 244 const char* RepositoryIterator::fully_qualified(const char* file_name) const { 245 assert(NULL != file_name, "invariant"); 246 char* const path = _path_buffer; 247 assert(!is_empty(path), "invariant"); 248 assert(_path_buffer_file_name_offset != 0, "invariant"); 249 return append(path, _max_path_buffer_size, _path_buffer_file_name_offset, file_name) != 0 ? path : NULL; 250 } 251 252 // caller responsible for deallocation 253 const char* RepositoryIterator::filter(const char* file_name) const { 254 if (file_name == NULL) { 255 return NULL; 256 } 257 const size_t len = strlen(file_name); 258 if ((len < chunk_file_extension_length) || 259 (strncmp(&file_name[len - chunk_file_extension_length], 260 chunk_file_jfr_ext, 261 chunk_file_extension_length) != 0)) { 262 // not a .jfr file 263 return NULL; 264 } 265 const char* fqn = fully_qualified(file_name); 266 if (fqn == NULL) { 267 return NULL; 268 } 269 const fio_fd fd = open_exclusivly(fqn); 270 if (invalid_fd == fd) { 271 return NULL; 272 } 273 const int64_t size = file_size(fd); 274 os::close(fd); 275 if (size <= chunk_file_header_size) { 276 return NULL; 277 } 278 char* const file_name_copy = (char*)os::malloc(len + 1, mtTracing); 279 if (file_name_copy == NULL) { 280 log_error(jfr, system)("Unable to malloc memory during jfr emergency dump"); 281 return NULL; 282 } 283 strncpy(file_name_copy, file_name, len + 1); 284 return file_name_copy; 285 } 286 287 RepositoryIterator::RepositoryIterator(const char* repository_path) : 288 _file_names(NULL), 289 _path_buffer_file_name_offset(0), 290 _iterator(0) { 291 DIR* dirp = os::opendir(repository_path); 292 if (dirp == NULL) { 293 log_error(jfr, system)("Unable to open repository %s", repository_path); 294 return; 295 } 296 char* const path = _path_buffer; 297 // store repository path in the path buffer 298 size_t result = append(path, _max_path_buffer_size, 0, repository_path); 299 if (result == 0) { 300 return; 301 } 302 // append a file separator and save that position 303 _path_buffer_file_name_offset = append(path, _max_path_buffer_size, result, os::file_separator()); 304 if (_path_buffer_file_name_offset == 0) { 305 return; 306 } 307 _file_names = new (ResourceObj::C_HEAP, mtTracing) GrowableArray<const char*>(10, true, mtTracing); 308 if (_file_names == NULL) { 309 log_error(jfr, system)("Unable to malloc memory during jfr emergency dump"); 310 return; 311 } 312 // iterate files in the repository and append filtered file names to the files array 313 struct dirent* dentry; 314 while ((dentry = os::readdir(dirp)) != NULL) { 315 const char* file_name = filter(dentry->d_name); 316 if (file_name != NULL) { 317 _file_names->append(file_name); 318 } 319 } 320 os::closedir(dirp); 321 if (_file_names->length() > 1) { 322 _file_names->sort(file_sort); 323 } 324 } 325 326 RepositoryIterator::~RepositoryIterator() { 327 if (_file_names != NULL) { 328 for (int i = 0; i < _file_names->length(); ++i) { 329 os::free(const_cast<char*>(_file_names->at(i))); 330 } 331 delete _file_names; 332 } 333 } 334 335 bool RepositoryIterator::has_next() const { 336 return _file_names != NULL && _iterator < _file_names->length(); 337 } 338 339 const char* RepositoryIterator::next() const { 340 return _iterator >= _file_names->length() ? NULL : fully_qualified(_file_names->at(_iterator++)); 341 } 342 343 static void write_repository_files(const RepositoryIterator& iterator, char* const copy_block, size_t block_size) { 344 assert(is_emergency_dump_file_open(), "invariant"); 345 while (iterator.has_next()) { 346 fio_fd current_fd = invalid_fd; 347 const char* const fqn = iterator.next(); 348 assert(fqn != NULL, "invariant"); 349 current_fd = open_exclusivly(fqn); 350 if (current_fd != invalid_fd) { 351 const int64_t size = file_size(current_fd); 352 assert(size > 0, "invariant"); 353 int64_t bytes_read = 0; 354 int64_t bytes_written = 0; 355 while (bytes_read < size) { 356 const ssize_t read_result = os::read_at(current_fd, copy_block, (int)block_size, bytes_read); 357 if (-1 == read_result) { 358 log_info(jfr)( // For user, should not be "jfr, system" 359 "Unable to recover JFR data"); 360 break; 361 } 362 bytes_read += (int64_t)read_result; 363 assert(bytes_read - bytes_written <= (int64_t)block_size, "invariant"); 364 bytes_written += (int64_t)os::write(emergency_fd, copy_block, bytes_read - bytes_written); 365 assert(bytes_read == bytes_written, "invariant"); 366 } 367 os::close(current_fd); 368 } 369 } 370 } 371 372 static void write_emergency_dump_file(const RepositoryIterator& iterator) { 373 static const size_t block_size = 1 * M; // 1 mb 374 char* const copy_block = (char*)os::malloc(block_size, mtTracing); 375 if (copy_block == NULL) { 376 log_error(jfr, system)("Unable to malloc memory during jfr emergency dump"); 377 log_error(jfr, system)("Unable to write jfr emergency dump file"); 378 } 379 write_repository_files(iterator, copy_block, block_size); 380 os::free(copy_block); 381 } 382 383 void JfrEmergencyDump::on_vm_error(const char* repository_path) { 384 assert(repository_path != NULL, "invariant"); 385 if (open_emergency_dump_file()) { 386 RepositoryIterator iterator(repository_path); 387 write_emergency_dump_file(iterator); 388 close_emergency_dump_file(); 389 } 390 } 391 392 static const char* create_emergency_chunk_path(const char* repository_path) { 393 const size_t repository_path_len = strlen(repository_path); 394 char date_time_buffer[32] = { 0 }; 395 date_time(date_time_buffer, sizeof(date_time_buffer)); 396 char* const path = _path_buffer; 397 // append the individual substrings 398 const int result = jio_snprintf(path, 399 _max_path_buffer_size, 400 "%s%s%s%s", 401 repository_path, 402 os::file_separator(), 403 date_time_buffer, 404 chunk_file_jfr_ext); 405 return result == -1 ? NULL : path; 406 } 407 408 const char* JfrEmergencyDump::chunk_path(const char* repository_path) { 409 if (repository_path == NULL) { 410 if (!open_emergency_dump_file()) { 411 return NULL; 412 } 413 // We can directly use the emergency dump file name as the chunk. 414 // The chunk writer will open its own fd so we close this descriptor. 415 close_emergency_dump_file(); 416 assert(!is_path_empty(), "invariant"); 417 return _path_buffer; 418 } 419 return create_emergency_chunk_path(repository_path); 420 } 421 422 /* 423 * We are just about to exit the VM, so we will be very aggressive 424 * at this point in order to increase overall success of dumping jfr data. 425 * 426 * If we end up deadlocking in the attempt of dumping out jfr data, 427 * we rely on the WatcherThread task "is_error_reported()", 428 * to exit the VM after a hard-coded timeout (disallow WatcherThread to emergency dump). 429 * This "safety net" somewhat explains the aggressiveness in this attempt. 430 * 431 */ 432 static bool prepare_for_emergency_dump(Thread* thread) { 433 assert(thread != NULL, "invariant"); 434 435 if (thread->is_Watcher_thread()) { 436 // need WatcherThread as a safeguard against potential deadlocks 437 return false; 438 } 439 if (JfrStream_lock->owned_by_self()) { 515 JavaThread* const _jt; 516 JavaThreadState _original_state; 517 public: 518 519 JavaThreadInVM(Thread* t) : _jt(t->is_Java_thread() ? (JavaThread*)t : NULL), 520 _original_state(_thread_max_state) { 521 if ((_jt != NULL) && (_jt->thread_state() != _thread_in_vm)) { 522 _original_state = _jt->thread_state(); 523 _jt->set_thread_state(_thread_in_vm); 524 } 525 } 526 527 ~JavaThreadInVM() { 528 if (_original_state != _thread_max_state) { 529 _jt->set_thread_state(_original_state); 530 } 531 } 532 533 }; 534 535 static void post_events(bool exception_handler) { 536 if (exception_handler) { 537 EventShutdown e; 538 e.set_reason("VM Error"); 539 e.commit(); 540 } else { 541 // OOM 542 LeakProfiler::emit_events(max_jlong, false); 543 } 544 EventDumpReason event; 545 event.set_reason(exception_handler ? "Crash" : "Out of Memory"); 546 event.set_recordingId(-1); 547 event.commit(); 548 } 549 550 void JfrEmergencyDump::on_vm_shutdown(bool exception_handler) { 551 if (!guard_reentrancy()) { 552 return; 553 } 554 Thread* thread = Thread::current_or_null_safe(); 555 if (thread == NULL) { 556 return; 557 } 558 // Ensure a JavaThread is _thread_in_vm when we make this call 559 JavaThreadInVM jtivm(thread); 560 if (!prepare_for_emergency_dump(thread)) { 561 return; 562 } 563 post_events(exception_handler); 564 const int messages = MSGBIT(MSG_VM_ERROR); 565 JfrRecorderService service; 566 service.rotate(messages); 567 } |