1 /* 2 * Copyright (c) 1997, 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/classLoader.hpp" 28 #include "classfile/javaClasses.hpp" 29 #include "classfile/moduleEntry.hpp" 30 #include "classfile/systemDictionary.hpp" 31 #include "classfile/vmSymbols.hpp" 32 #include "code/codeCache.hpp" 33 #include "code/icBuffer.hpp" 34 #include "code/vtableStubs.hpp" 35 #include "gc/shared/gcVMOperations.hpp" 36 #include "logging/log.hpp" 37 #include "interpreter/interpreter.hpp" 38 #include "logging/log.hpp" 39 #include "logging/logStream.hpp" 40 #include "memory/allocation.inline.hpp" 41 #include "memory/guardedMemory.hpp" 42 #include "memory/resourceArea.hpp" 43 #include "memory/universe.hpp" 44 #include "oops/compressedOops.inline.hpp" 45 #include "oops/oop.inline.hpp" 46 #include "prims/jvm_misc.hpp" 47 #include "runtime/arguments.hpp" 48 #include "runtime/atomic.hpp" 49 #include "runtime/frame.inline.hpp" 50 #include "runtime/handles.inline.hpp" 51 #include "runtime/interfaceSupport.inline.hpp" 52 #include "runtime/java.hpp" 53 #include "runtime/javaCalls.hpp" 54 #include "runtime/mutexLocker.hpp" 55 #include "runtime/os.inline.hpp" 56 #include "runtime/sharedRuntime.hpp" 57 #include "runtime/stubRoutines.hpp" 58 #include "runtime/thread.inline.hpp" 59 #include "runtime/threadSMR.hpp" 60 #include "runtime/vm_version.hpp" 61 #include "services/attachListener.hpp" 62 #include "services/mallocTracker.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/nmtCommon.hpp" 65 #include "services/threadService.hpp" 66 #include "utilities/align.hpp" 67 #include "utilities/defaultStream.hpp" 68 #include "utilities/events.hpp" 69 70 # include <signal.h> 71 # include <errno.h> 72 73 OSThread* os::_starting_thread = NULL; 74 address os::_polling_page = NULL; 75 volatile unsigned int os::_rand_seed = 1; 76 int os::_processor_count = 0; 77 int os::_initial_active_processor_count = 0; 78 size_t os::_page_sizes[os::page_sizes_max]; 79 80 #ifndef PRODUCT 81 julong os::num_mallocs = 0; // # of calls to malloc/realloc 82 julong os::alloc_bytes = 0; // # of bytes allocated 83 julong os::num_frees = 0; // # of calls to free 84 julong os::free_bytes = 0; // # of bytes freed 85 #endif 86 87 static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords 88 89 DEBUG_ONLY(bool os::_mutex_init_done = false;) 90 91 static time_t get_timezone(const struct tm* time_struct) { 92 #if defined(_ALLBSD_SOURCE) 93 return time_struct->tm_gmtoff; 94 #elif defined(_WINDOWS) 95 long zone; 96 _get_timezone(&zone); 97 return static_cast<time_t>(zone); 98 #else 99 return timezone; 100 #endif 101 } 102 103 int os::snprintf(char* buf, size_t len, const char* fmt, ...) { 104 va_list args; 105 va_start(args, fmt); 106 int result = os::vsnprintf(buf, len, fmt, args); 107 va_end(args); 108 return result; 109 } 110 111 // Fill in buffer with current local time as an ISO-8601 string. 112 // E.g., yyyy-mm-ddThh:mm:ss-zzzz. 113 // Returns buffer, or NULL if it failed. 114 // This would mostly be a call to 115 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) 116 // except that on Windows the %z behaves badly, so we do it ourselves. 117 // Also, people wanted milliseconds on there, 118 // and strftime doesn't do milliseconds. 119 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) { 120 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" 121 // 1 2 122 // 12345678901234567890123456789 123 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d" 124 static const size_t needed_buffer = 29; 125 126 // Sanity check the arguments 127 if (buffer == NULL) { 128 assert(false, "NULL buffer"); 129 return NULL; 130 } 131 if (buffer_length < needed_buffer) { 132 assert(false, "buffer_length too small"); 133 return NULL; 134 } 135 // Get the current time 136 jlong milliseconds_since_19700101 = javaTimeMillis(); 137 const int milliseconds_per_microsecond = 1000; 138 const time_t seconds_since_19700101 = 139 milliseconds_since_19700101 / milliseconds_per_microsecond; 140 const int milliseconds_after_second = 141 milliseconds_since_19700101 % milliseconds_per_microsecond; 142 // Convert the time value to a tm and timezone variable 143 struct tm time_struct; 144 if (utc) { 145 if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 146 assert(false, "Failed gmtime_pd"); 147 return NULL; 148 } 149 } else { 150 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 151 assert(false, "Failed localtime_pd"); 152 return NULL; 153 } 154 } 155 const time_t zone = get_timezone(&time_struct); 156 157 // If daylight savings time is in effect, 158 // we are 1 hour East of our time zone 159 const time_t seconds_per_minute = 60; 160 const time_t minutes_per_hour = 60; 161 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; 162 time_t UTC_to_local = zone; 163 if (time_struct.tm_isdst > 0) { 164 UTC_to_local = UTC_to_local - seconds_per_hour; 165 } 166 167 // No offset when dealing with UTC 168 if (utc) { 169 UTC_to_local = 0; 170 } 171 172 // Compute the time zone offset. 173 // localtime_pd() sets timezone to the difference (in seconds) 174 // between UTC and and local time. 175 // ISO 8601 says we need the difference between local time and UTC, 176 // we change the sign of the localtime_pd() result. 177 const time_t local_to_UTC = -(UTC_to_local); 178 // Then we have to figure out if if we are ahead (+) or behind (-) UTC. 179 char sign_local_to_UTC = '+'; 180 time_t abs_local_to_UTC = local_to_UTC; 181 if (local_to_UTC < 0) { 182 sign_local_to_UTC = '-'; 183 abs_local_to_UTC = -(abs_local_to_UTC); 184 } 185 // Convert time zone offset seconds to hours and minutes. 186 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); 187 const time_t zone_min = 188 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); 189 190 // Print an ISO 8601 date and time stamp into the buffer 191 const int year = 1900 + time_struct.tm_year; 192 const int month = 1 + time_struct.tm_mon; 193 const int printed = jio_snprintf(buffer, buffer_length, 194 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d", 195 year, 196 month, 197 time_struct.tm_mday, 198 time_struct.tm_hour, 199 time_struct.tm_min, 200 time_struct.tm_sec, 201 milliseconds_after_second, 202 sign_local_to_UTC, 203 zone_hours, 204 zone_min); 205 if (printed == 0) { 206 assert(false, "Failed jio_printf"); 207 return NULL; 208 } 209 return buffer; 210 } 211 212 OSReturn os::set_priority(Thread* thread, ThreadPriority p) { 213 debug_only(Thread::check_for_dangling_thread_pointer(thread);) 214 215 if ((p >= MinPriority && p <= MaxPriority) || 216 (p == CriticalPriority && thread->is_ConcurrentGC_thread())) { 217 int priority = java_to_os_priority[p]; 218 return set_native_priority(thread, priority); 219 } else { 220 assert(false, "Should not happen"); 221 return OS_ERR; 222 } 223 } 224 225 // The mapping from OS priority back to Java priority may be inexact because 226 // Java priorities can map M:1 with native priorities. If you want the definite 227 // Java priority then use JavaThread::java_priority() 228 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { 229 int p; 230 int os_prio; 231 OSReturn ret = get_native_priority(thread, &os_prio); 232 if (ret != OS_OK) return ret; 233 234 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) { 235 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; 236 } else { 237 // niceness values are in reverse order 238 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ; 239 } 240 priority = (ThreadPriority)p; 241 return OS_OK; 242 } 243 244 bool os::dll_build_name(char* buffer, size_t size, const char* fname) { 245 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX); 246 return (n != -1); 247 } 248 249 #if !defined(LINUX) && !defined(_WINDOWS) 250 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) { 251 committed_start = start; 252 committed_size = size; 253 return true; 254 } 255 #endif 256 257 // Helper for dll_locate_lib. 258 // Pass buffer and printbuffer as we already printed the path to buffer 259 // when we called get_current_directory. This way we avoid another buffer 260 // of size MAX_PATH. 261 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen, 262 const char* pname, char lastchar, const char* fname) { 263 264 // Concatenate path and file name, but don't print double path separators. 265 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ? 266 "" : os::file_separator(); 267 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname); 268 // Check whether file exists. 269 if (ret != -1) { 270 struct stat statbuf; 271 return os::stat(buffer, &statbuf) == 0; 272 } 273 return false; 274 } 275 276 // Frees all memory allocated on the heap for the 277 // supplied array of arrays of chars (a), where n 278 // is the number of elements in the array. 279 static void free_array_of_char_arrays(char** a, size_t n) { 280 while (n > 0) { 281 n--; 282 if (a[n] != NULL) { 283 FREE_C_HEAP_ARRAY(char, a[n]); 284 } 285 } 286 FREE_C_HEAP_ARRAY(char*, a); 287 } 288 289 bool os::dll_locate_lib(char *buffer, size_t buflen, 290 const char* pname, const char* fname) { 291 bool retval = false; 292 293 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX); 294 char* fullfname = NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal); 295 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) { 296 const size_t pnamelen = pname ? strlen(pname) : 0; 297 298 if (pnamelen == 0) { 299 // If no path given, use current working directory. 300 const char* p = get_current_directory(buffer, buflen); 301 if (p != NULL) { 302 const size_t plen = strlen(buffer); 303 const char lastchar = buffer[plen - 1]; 304 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen, 305 "", lastchar, fullfname); 306 } 307 } else if (strchr(pname, *os::path_separator()) != NULL) { 308 // A list of paths. Search for the path that contains the library. 309 size_t n; 310 char** pelements = split_path(pname, &n, fullfnamelen); 311 if (pelements != NULL) { 312 for (size_t i = 0; i < n; i++) { 313 char* path = pelements[i]; 314 // Really shouldn't be NULL, but check can't hurt. 315 size_t plen = (path == NULL) ? 0 : strlen(path); 316 if (plen == 0) { 317 continue; // Skip the empty path values. 318 } 319 const char lastchar = path[plen - 1]; 320 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname); 321 if (retval) break; 322 } 323 // Release the storage allocated by split_path. 324 free_array_of_char_arrays(pelements, n); 325 } 326 } else { 327 // A definite path. 328 const char lastchar = pname[pnamelen-1]; 329 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname); 330 } 331 } 332 333 FREE_C_HEAP_ARRAY(char*, fullfname); 334 return retval; 335 } 336 337 // --------------------- sun.misc.Signal (optional) --------------------- 338 339 340 // SIGBREAK is sent by the keyboard to query the VM state 341 #ifndef SIGBREAK 342 #define SIGBREAK SIGQUIT 343 #endif 344 345 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. 346 347 348 static void signal_thread_entry(JavaThread* thread, TRAPS) { 349 os::set_priority(thread, NearMaxPriority); 350 while (true) { 351 int sig; 352 { 353 // FIXME : Currently we have not decided what should be the status 354 // for this java thread blocked here. Once we decide about 355 // that we should fix this. 356 sig = os::signal_wait(); 357 } 358 if (sig == os::sigexitnum_pd()) { 359 // Terminate the signal thread 360 return; 361 } 362 363 switch (sig) { 364 case SIGBREAK: { 365 #if INCLUDE_SERVICES 366 // Check if the signal is a trigger to start the Attach Listener - in that 367 // case don't print stack traces. 368 if (!DisableAttachMechanism) { 369 // Attempt to transit state to AL_INITIALIZING. 370 AttachListenerState cur_state = AttachListener::transit_state(AL_INITIALIZING, AL_NOT_INITIALIZED); 371 if (cur_state == AL_INITIALIZING) { 372 // Attach Listener has been started to initialize. Ignore this signal. 373 continue; 374 } else if (cur_state == AL_NOT_INITIALIZED) { 375 // Start to initialize. 376 if (AttachListener::is_init_trigger()) { 377 // Attach Listener has been initialized. 378 // Accept subsequent request. 379 continue; 380 } else { 381 // Attach Listener could not be started. 382 // So we need to transit the state to AL_NOT_INITIALIZED. 383 AttachListener::set_state(AL_NOT_INITIALIZED); 384 } 385 } else if (AttachListener::check_socket_file()) { 386 // Attach Listener has been started, but unix domain socket file 387 // does not exist. So restart Attach Listener. 388 continue; 389 } 390 } 391 #endif 392 // Print stack traces 393 // Any SIGBREAK operations added here should make sure to flush 394 // the output stream (e.g. tty->flush()) after output. See 4803766. 395 // Each module also prints an extra carriage return after its output. 396 VM_PrintThreads op; 397 VMThread::execute(&op); 398 VM_PrintJNI jni_op; 399 VMThread::execute(&jni_op); 400 VM_FindDeadlocks op1(tty); 401 VMThread::execute(&op1); 402 Universe::print_heap_at_SIGBREAK(); 403 if (PrintClassHistogram) { 404 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */); 405 VMThread::execute(&op1); 406 } 407 if (JvmtiExport::should_post_data_dump()) { 408 JvmtiExport::post_data_dump(); 409 } 410 break; 411 } 412 default: { 413 // Dispatch the signal to java 414 HandleMark hm(THREAD); 415 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD); 416 if (klass != NULL) { 417 JavaValue result(T_VOID); 418 JavaCallArguments args; 419 args.push_int(sig); 420 JavaCalls::call_static( 421 &result, 422 klass, 423 vmSymbols::dispatch_name(), 424 vmSymbols::int_void_signature(), 425 &args, 426 THREAD 427 ); 428 } 429 if (HAS_PENDING_EXCEPTION) { 430 // tty is initialized early so we don't expect it to be null, but 431 // if it is we can't risk doing an initialization that might 432 // trigger additional out-of-memory conditions 433 if (tty != NULL) { 434 char klass_name[256]; 435 char tmp_sig_name[16]; 436 const char* sig_name = "UNKNOWN"; 437 InstanceKlass::cast(PENDING_EXCEPTION->klass())-> 438 name()->as_klass_external_name(klass_name, 256); 439 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) 440 sig_name = tmp_sig_name; 441 warning("Exception %s occurred dispatching signal %s to handler" 442 "- the VM may need to be forcibly terminated", 443 klass_name, sig_name ); 444 } 445 CLEAR_PENDING_EXCEPTION; 446 } 447 } 448 } 449 } 450 } 451 452 void os::init_before_ergo() { 453 initialize_initial_active_processor_count(); 454 // We need to initialize large page support here because ergonomics takes some 455 // decisions depending on large page support and the calculated large page size. 456 large_page_init(); 457 458 // We need to adapt the configured number of stack protection pages given 459 // in 4K pages to the actual os page size. We must do this before setting 460 // up minimal stack sizes etc. in os::init_2(). 461 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size())); 462 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size())); 463 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size())); 464 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size())); 465 466 // VM version initialization identifies some characteristics of the 467 // platform that are used during ergonomic decisions. 468 VM_Version::init_before_ergo(); 469 } 470 471 void os::initialize_jdk_signal_support(TRAPS) { 472 if (!ReduceSignalUsage) { 473 // Setup JavaThread for processing signals 474 const char thread_name[] = "Signal Dispatcher"; 475 Handle string = java_lang_String::create_from_str(thread_name, CHECK); 476 477 // Initialize thread_oop to put it into the system threadGroup 478 Handle thread_group (THREAD, Universe::system_thread_group()); 479 Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(), 480 vmSymbols::threadgroup_string_void_signature(), 481 thread_group, 482 string, 483 CHECK); 484 485 Klass* group = SystemDictionary::ThreadGroup_klass(); 486 JavaValue result(T_VOID); 487 JavaCalls::call_special(&result, 488 thread_group, 489 group, 490 vmSymbols::add_method_name(), 491 vmSymbols::thread_void_signature(), 492 thread_oop, 493 CHECK); 494 495 { MutexLocker mu(Threads_lock); 496 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); 497 498 // At this point it may be possible that no osthread was created for the 499 // JavaThread due to lack of memory. We would have to throw an exception 500 // in that case. However, since this must work and we do not allow 501 // exceptions anyway, check and abort if this fails. 502 if (signal_thread == NULL || signal_thread->osthread() == NULL) { 503 vm_exit_during_initialization("java.lang.OutOfMemoryError", 504 os::native_thread_creation_failed_msg()); 505 } 506 507 java_lang_Thread::set_thread(thread_oop(), signal_thread); 508 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); 509 java_lang_Thread::set_daemon(thread_oop()); 510 511 signal_thread->set_threadObj(thread_oop()); 512 Threads::add(signal_thread); 513 Thread::start(signal_thread); 514 } 515 // Handle ^BREAK 516 os::signal(SIGBREAK, os::user_handler()); 517 } 518 } 519 520 521 void os::terminate_signal_thread() { 522 if (!ReduceSignalUsage) 523 signal_notify(sigexitnum_pd()); 524 } 525 526 527 // --------------------- loading libraries --------------------- 528 529 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); 530 extern struct JavaVM_ main_vm; 531 532 static void* _native_java_library = NULL; 533 534 void* os::native_java_library() { 535 if (_native_java_library == NULL) { 536 char buffer[JVM_MAXPATHLEN]; 537 char ebuf[1024]; 538 539 // Try to load verify dll first. In 1.3 java dll depends on it and is not 540 // always able to find it when the loading executable is outside the JDK. 541 // In order to keep working with 1.2 we ignore any loading errors. 542 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 543 "verify")) { 544 dll_load(buffer, ebuf, sizeof(ebuf)); 545 } 546 547 // Load java dll 548 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 549 "java")) { 550 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 551 } 552 if (_native_java_library == NULL) { 553 vm_exit_during_initialization("Unable to load native library", ebuf); 554 } 555 556 #if defined(__OpenBSD__) 557 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 558 // ignore errors 559 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 560 "net")) { 561 dll_load(buffer, ebuf, sizeof(ebuf)); 562 } 563 #endif 564 } 565 return _native_java_library; 566 } 567 568 /* 569 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists. 570 * If check_lib == true then we are looking for an 571 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if 572 * this library is statically linked into the image. 573 * If check_lib == false then we will look for the appropriate symbol in the 574 * executable if agent_lib->is_static_lib() == true or in the shared library 575 * referenced by 'handle'. 576 */ 577 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib, 578 const char *syms[], size_t syms_len) { 579 assert(agent_lib != NULL, "sanity check"); 580 const char *lib_name; 581 void *handle = agent_lib->os_lib(); 582 void *entryName = NULL; 583 char *agent_function_name; 584 size_t i; 585 586 // If checking then use the agent name otherwise test is_static_lib() to 587 // see how to process this lookup 588 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL); 589 for (i = 0; i < syms_len; i++) { 590 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path()); 591 if (agent_function_name == NULL) { 592 break; 593 } 594 entryName = dll_lookup(handle, agent_function_name); 595 FREE_C_HEAP_ARRAY(char, agent_function_name); 596 if (entryName != NULL) { 597 break; 598 } 599 } 600 return entryName; 601 } 602 603 // See if the passed in agent is statically linked into the VM image. 604 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 605 size_t syms_len) { 606 void *ret; 607 void *proc_handle; 608 void *save_handle; 609 610 assert(agent_lib != NULL, "sanity check"); 611 if (agent_lib->name() == NULL) { 612 return false; 613 } 614 proc_handle = get_default_process_handle(); 615 // Check for Agent_OnLoad/Attach_lib_name function 616 save_handle = agent_lib->os_lib(); 617 // We want to look in this process' symbol table. 618 agent_lib->set_os_lib(proc_handle); 619 ret = find_agent_function(agent_lib, true, syms, syms_len); 620 if (ret != NULL) { 621 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent 622 agent_lib->set_valid(); 623 agent_lib->set_static_lib(true); 624 return true; 625 } 626 agent_lib->set_os_lib(save_handle); 627 return false; 628 } 629 630 // --------------------- heap allocation utilities --------------------- 631 632 char *os::strdup(const char *str, MEMFLAGS flags) { 633 size_t size = strlen(str); 634 char *dup_str = (char *)malloc(size + 1, flags); 635 if (dup_str == NULL) return NULL; 636 strcpy(dup_str, str); 637 return dup_str; 638 } 639 640 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) { 641 char* p = os::strdup(str, flags); 642 if (p == NULL) { 643 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom"); 644 } 645 return p; 646 } 647 648 649 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 650 651 #ifdef ASSERT 652 653 static void verify_memory(void* ptr) { 654 GuardedMemory guarded(ptr); 655 if (!guarded.verify_guards()) { 656 LogTarget(Warning, malloc, free) lt; 657 ResourceMark rm; 658 LogStream ls(lt); 659 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 660 ls.print_cr("## memory stomp:"); 661 guarded.print_on(&ls); 662 fatal("memory stomping error"); 663 } 664 } 665 666 #endif 667 668 // 669 // This function supports testing of the malloc out of memory 670 // condition without really running the system out of memory. 671 // 672 static bool has_reached_max_malloc_test_peak(size_t alloc_size) { 673 if (MallocMaxTestWords > 0) { 674 size_t words = (alloc_size / BytesPerWord); 675 676 if ((cur_malloc_words + words) > MallocMaxTestWords) { 677 return true; 678 } 679 Atomic::add(words, &cur_malloc_words); 680 } 681 return false; 682 } 683 684 void* os::malloc(size_t size, MEMFLAGS flags) { 685 return os::malloc(size, flags, CALLER_PC); 686 } 687 688 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 689 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 690 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 691 692 // Since os::malloc can be called when the libjvm.{dll,so} is 693 // first loaded and we don't have a thread yet we must accept NULL also here. 694 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()), 695 "malloc() not allowed when crash protection is set"); 696 697 if (size == 0) { 698 // return a valid pointer if size is zero 699 // if NULL is returned the calling functions assume out of memory. 700 size = 1; 701 } 702 703 // NMT support 704 NMT_TrackingLevel level = MemTracker::tracking_level(); 705 size_t nmt_header_size = MemTracker::malloc_header_size(level); 706 707 #ifndef ASSERT 708 const size_t alloc_size = size + nmt_header_size; 709 #else 710 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size); 711 if (size + nmt_header_size > alloc_size) { // Check for rollover. 712 return NULL; 713 } 714 #endif 715 716 // For the test flag -XX:MallocMaxTestWords 717 if (has_reached_max_malloc_test_peak(size)) { 718 return NULL; 719 } 720 721 u_char* ptr; 722 ptr = (u_char*)::malloc(alloc_size); 723 724 #ifdef ASSERT 725 if (ptr == NULL) { 726 return NULL; 727 } 728 // Wrap memory with guard 729 GuardedMemory guarded(ptr, size + nmt_header_size); 730 ptr = guarded.get_user_ptr(); 731 732 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 733 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 734 breakpoint(); 735 } 736 if (paranoid) { 737 verify_memory(ptr); 738 } 739 #endif 740 741 // we do not track guard memory 742 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level); 743 } 744 745 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) { 746 return os::realloc(memblock, size, flags, CALLER_PC); 747 } 748 749 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 750 751 // For the test flag -XX:MallocMaxTestWords 752 if (has_reached_max_malloc_test_peak(size)) { 753 return NULL; 754 } 755 756 if (size == 0) { 757 // return a valid pointer if size is zero 758 // if NULL is returned the calling functions assume out of memory. 759 size = 1; 760 } 761 762 #ifndef ASSERT 763 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 764 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 765 // NMT support 766 void* membase = MemTracker::record_free(memblock); 767 NMT_TrackingLevel level = MemTracker::tracking_level(); 768 size_t nmt_header_size = MemTracker::malloc_header_size(level); 769 void* ptr = ::realloc(membase, size + nmt_header_size); 770 return MemTracker::record_malloc(ptr, size, memflags, stack, level); 771 #else 772 if (memblock == NULL) { 773 return os::malloc(size, memflags, stack); 774 } 775 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 776 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock)); 777 breakpoint(); 778 } 779 // NMT support 780 void* membase = MemTracker::malloc_base(memblock); 781 verify_memory(membase); 782 // always move the block 783 void* ptr = os::malloc(size, memflags, stack); 784 // Copy to new memory if malloc didn't fail 785 if (ptr != NULL ) { 786 GuardedMemory guarded(MemTracker::malloc_base(memblock)); 787 // Guard's user data contains NMT header 788 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock); 789 memcpy(ptr, memblock, MIN2(size, memblock_size)); 790 if (paranoid) { 791 verify_memory(MemTracker::malloc_base(ptr)); 792 } 793 os::free(memblock); 794 } 795 return ptr; 796 #endif 797 } 798 799 // handles NULL pointers 800 void os::free(void *memblock) { 801 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 802 #ifdef ASSERT 803 if (memblock == NULL) return; 804 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 805 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock)); 806 breakpoint(); 807 } 808 void* membase = MemTracker::record_free(memblock); 809 verify_memory(membase); 810 811 GuardedMemory guarded(membase); 812 size_t size = guarded.get_user_size(); 813 inc_stat_counter(&free_bytes, size); 814 membase = guarded.release_for_freeing(); 815 ::free(membase); 816 #else 817 void* membase = MemTracker::record_free(memblock); 818 ::free(membase); 819 #endif 820 } 821 822 void os::init_random(unsigned int initval) { 823 _rand_seed = initval; 824 } 825 826 827 static int random_helper(unsigned int rand_seed) { 828 /* standard, well-known linear congruential random generator with 829 * next_rand = (16807*seed) mod (2**31-1) 830 * see 831 * (1) "Random Number Generators: Good Ones Are Hard to Find", 832 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 833 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 834 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 835 */ 836 const unsigned int a = 16807; 837 const unsigned int m = 2147483647; 838 const int q = m / a; assert(q == 127773, "weird math"); 839 const int r = m % a; assert(r == 2836, "weird math"); 840 841 // compute az=2^31p+q 842 unsigned int lo = a * (rand_seed & 0xFFFF); 843 unsigned int hi = a * (rand_seed >> 16); 844 lo += (hi & 0x7FFF) << 16; 845 846 // if q overflowed, ignore the overflow and increment q 847 if (lo > m) { 848 lo &= m; 849 ++lo; 850 } 851 lo += hi >> 15; 852 853 // if (p+q) overflowed, ignore the overflow and increment (p+q) 854 if (lo > m) { 855 lo &= m; 856 ++lo; 857 } 858 return lo; 859 } 860 861 int os::random() { 862 // Make updating the random seed thread safe. 863 while (true) { 864 unsigned int seed = _rand_seed; 865 unsigned int rand = random_helper(seed); 866 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) { 867 return static_cast<int>(rand); 868 } 869 } 870 } 871 872 // The INITIALIZED state is distinguished from the SUSPENDED state because the 873 // conditions in which a thread is first started are different from those in which 874 // a suspension is resumed. These differences make it hard for us to apply the 875 // tougher checks when starting threads that we want to do when resuming them. 876 // However, when start_thread is called as a result of Thread.start, on a Java 877 // thread, the operation is synchronized on the Java Thread object. So there 878 // cannot be a race to start the thread and hence for the thread to exit while 879 // we are working on it. Non-Java threads that start Java threads either have 880 // to do so in a context in which races are impossible, or should do appropriate 881 // locking. 882 883 void os::start_thread(Thread* thread) { 884 // guard suspend/resume 885 MutexLocker ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 886 OSThread* osthread = thread->osthread(); 887 osthread->set_state(RUNNABLE); 888 pd_start_thread(thread); 889 } 890 891 void os::abort(bool dump_core) { 892 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL); 893 } 894 895 //--------------------------------------------------------------------------- 896 // Helper functions for fatal error handler 897 898 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 899 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 900 901 start = align_down(start, unitsize); 902 903 int cols = 0; 904 int cols_per_line = 0; 905 switch (unitsize) { 906 case 1: cols_per_line = 16; break; 907 case 2: cols_per_line = 8; break; 908 case 4: cols_per_line = 4; break; 909 case 8: cols_per_line = 2; break; 910 default: return; 911 } 912 913 address p = start; 914 st->print(PTR_FORMAT ": ", p2i(start)); 915 while (p < end) { 916 if (is_readable_pointer(p)) { 917 switch (unitsize) { 918 case 1: st->print("%02x", *(u1*)p); break; 919 case 2: st->print("%04x", *(u2*)p); break; 920 case 4: st->print("%08x", *(u4*)p); break; 921 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 922 } 923 } else { 924 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????"); 925 } 926 p += unitsize; 927 cols++; 928 if (cols >= cols_per_line && p < end) { 929 cols = 0; 930 st->cr(); 931 st->print(PTR_FORMAT ": ", p2i(p)); 932 } else { 933 st->print(" "); 934 } 935 } 936 st->cr(); 937 } 938 939 void os::print_instructions(outputStream* st, address pc, int unitsize) { 940 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc)); 941 print_hex_dump(st, pc - 256, pc + 256, unitsize); 942 } 943 944 void os::print_environment_variables(outputStream* st, const char** env_list) { 945 if (env_list) { 946 st->print_cr("Environment Variables:"); 947 948 for (int i = 0; env_list[i] != NULL; i++) { 949 char *envvar = ::getenv(env_list[i]); 950 if (envvar != NULL) { 951 st->print("%s", env_list[i]); 952 st->print("="); 953 st->print_cr("%s", envvar); 954 } 955 } 956 } 957 } 958 959 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) { 960 // cpu 961 st->print("CPU:"); 962 st->print("total %d", os::processor_count()); 963 // It's not safe to query number of active processors after crash 964 // st->print("(active %d)", os::active_processor_count()); but we can 965 // print the initial number of active processors. 966 // We access the raw value here because the assert in the accessor will 967 // fail if the crash occurs before initialization of this value. 968 st->print(" (initial active %d)", _initial_active_processor_count); 969 st->print(" %s", VM_Version::features_string()); 970 st->cr(); 971 pd_print_cpu_info(st, buf, buflen); 972 } 973 974 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version 975 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) { 976 st->print("Host: "); 977 #ifndef PRODUCT 978 if (get_host_name(buf, buflen)) { 979 st->print("%s, ", buf); 980 } 981 #endif // PRODUCT 982 get_summary_cpu_info(buf, buflen); 983 st->print("%s, ", buf); 984 size_t mem = physical_memory()/G; 985 if (mem == 0) { // for low memory systems 986 mem = physical_memory()/M; 987 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem); 988 } else { 989 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem); 990 } 991 get_summary_os_info(buf, buflen); 992 st->print_raw(buf); 993 st->cr(); 994 } 995 996 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) { 997 const int secs_per_day = 86400; 998 const int secs_per_hour = 3600; 999 const int secs_per_min = 60; 1000 1001 time_t tloc; 1002 (void)time(&tloc); 1003 char* timestring = ctime(&tloc); // ctime adds newline. 1004 // edit out the newline 1005 char* nl = strchr(timestring, '\n'); 1006 if (nl != NULL) { 1007 *nl = '\0'; 1008 } 1009 1010 struct tm tz; 1011 if (localtime_pd(&tloc, &tz) != NULL) { 1012 ::strftime(buf, buflen, "%Z", &tz); 1013 st->print("Time: %s %s", timestring, buf); 1014 } else { 1015 st->print("Time: %s", timestring); 1016 } 1017 1018 double t = os::elapsedTime(); 1019 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in 1020 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int 1021 // before printf. We lost some precision, but who cares? 1022 int eltime = (int)t; // elapsed time in seconds 1023 1024 // print elapsed time in a human-readable format: 1025 int eldays = eltime / secs_per_day; 1026 int day_secs = eldays * secs_per_day; 1027 int elhours = (eltime - day_secs) / secs_per_hour; 1028 int hour_secs = elhours * secs_per_hour; 1029 int elmins = (eltime - day_secs - hour_secs) / secs_per_min; 1030 int minute_secs = elmins * secs_per_min; 1031 int elsecs = (eltime - day_secs - hour_secs - minute_secs); 1032 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs); 1033 } 1034 1035 1036 // Check if pointer can be read from (4-byte read access). 1037 // Helps to prove validity of a not-NULL pointer. 1038 // Returns true in very early stages of VM life when stub is not yet generated. 1039 #define SAFEFETCH_DEFAULT true 1040 bool os::is_readable_pointer(const void* p) { 1041 if (!CanUseSafeFetch32()) { 1042 return SAFEFETCH_DEFAULT; 1043 } 1044 int* const aligned = (int*) align_down((intptr_t)p, 4); 1045 int cafebabe = 0xcafebabe; // tester value 1 1046 int deadbeef = 0xdeadbeef; // tester value 2 1047 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef); 1048 } 1049 1050 bool os::is_readable_range(const void* from, const void* to) { 1051 if ((uintptr_t)from >= (uintptr_t)to) return false; 1052 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) { 1053 if (!is_readable_pointer((const void*)p)) { 1054 return false; 1055 } 1056 } 1057 return true; 1058 } 1059 1060 1061 // moved from debug.cpp (used to be find()) but still called from there 1062 // The verbose parameter is only set by the debug code in one case 1063 void os::print_location(outputStream* st, intptr_t x, bool verbose) { 1064 address addr = (address)x; 1065 // Handle NULL first, so later checks don't need to protect against it. 1066 if (addr == NULL) { 1067 st->print_cr("0x0 is NULL"); 1068 return; 1069 } 1070 1071 // Check if addr points into a code blob. 1072 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 1073 if (b != NULL) { 1074 b->dump_for_addr(addr, st, verbose); 1075 return; 1076 } 1077 1078 // Check if addr points into Java heap. 1079 if (Universe::heap()->print_location(st, addr)) { 1080 return; 1081 } 1082 1083 bool accessible = is_readable_pointer(addr); 1084 1085 // Check if addr is a JNI handle. 1086 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) { 1087 if (JNIHandles::is_global_handle((jobject) addr)) { 1088 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr)); 1089 return; 1090 } 1091 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 1092 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr)); 1093 return; 1094 } 1095 #ifndef PRODUCT 1096 // we don't keep the block list in product mode 1097 if (JNIHandles::is_local_handle((jobject) addr)) { 1098 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr)); 1099 return; 1100 } 1101 #endif 1102 } 1103 1104 // Check if addr belongs to a Java thread. 1105 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 1106 // If the addr is a java thread print information about that. 1107 if (addr == (address)thread) { 1108 if (verbose) { 1109 thread->print_on(st); 1110 } else { 1111 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr)); 1112 } 1113 return; 1114 } 1115 // If the addr is in the stack region for this thread then report that 1116 // and print thread info 1117 if (thread->on_local_stack(addr)) { 1118 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 1119 INTPTR_FORMAT, p2i(addr), p2i(thread)); 1120 if (verbose) thread->print_on(st); 1121 return; 1122 } 1123 } 1124 1125 // Check if in metaspace and print types that have vptrs 1126 if (Metaspace::contains(addr)) { 1127 if (Klass::is_valid((Klass*)addr)) { 1128 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr)); 1129 ((Klass*)addr)->print_on(st); 1130 } else if (Method::is_valid_method((const Method*)addr)) { 1131 ((Method*)addr)->print_value_on(st); 1132 st->cr(); 1133 } else { 1134 // Use addr->print() from the debugger instead (not here) 1135 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr)); 1136 } 1137 return; 1138 } 1139 1140 // Compressed klass needs to be decoded first. 1141 #ifdef _LP64 1142 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) { 1143 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr; 1144 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass); 1145 1146 if (Klass::is_valid(k)) { 1147 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k)); 1148 k->print_on(st); 1149 return; 1150 } 1151 } 1152 #endif 1153 1154 // Try an OS specific find 1155 if (os::find(addr, st)) { 1156 return; 1157 } 1158 1159 if (accessible) { 1160 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr)); 1161 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) { 1162 st->print(" %02x", *(u1*)p); 1163 } 1164 st->cr(); 1165 return; 1166 } 1167 1168 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr)); 1169 } 1170 1171 // Looks like all platforms can use the same function to check if C 1172 // stack is walkable beyond current frame. The check for fp() is not 1173 // necessary on Sparc, but it's harmless. 1174 bool os::is_first_C_frame(frame* fr) { 1175 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 1176 // Check usp first, because if that's bad the other accessors may fault 1177 // on some architectures. Ditto ufp second, etc. 1178 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 1179 // sp on amd can be 32 bit aligned. 1180 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 1181 1182 uintptr_t usp = (uintptr_t)fr->sp(); 1183 if ((usp & sp_align_mask) != 0) return true; 1184 1185 uintptr_t ufp = (uintptr_t)fr->fp(); 1186 if ((ufp & fp_align_mask) != 0) return true; 1187 1188 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 1189 if ((old_sp & sp_align_mask) != 0) return true; 1190 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 1191 1192 uintptr_t old_fp = (uintptr_t)fr->link(); 1193 if ((old_fp & fp_align_mask) != 0) return true; 1194 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1195 1196 // stack grows downwards; if old_fp is below current fp or if the stack 1197 // frame is too large, either the stack is corrupted or fp is not saved 1198 // on stack (i.e. on x86, ebp may be used as general register). The stack 1199 // is not walkable beyond current frame. 1200 if (old_fp < ufp) return true; 1201 if (old_fp - ufp > 64 * K) return true; 1202 1203 return false; 1204 } 1205 1206 1207 // Set up the boot classpath. 1208 1209 char* os::format_boot_path(const char* format_string, 1210 const char* home, 1211 int home_len, 1212 char fileSep, 1213 char pathSep) { 1214 assert((fileSep == '/' && pathSep == ':') || 1215 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars"); 1216 1217 // Scan the format string to determine the length of the actual 1218 // boot classpath, and handle platform dependencies as well. 1219 int formatted_path_len = 0; 1220 const char* p; 1221 for (p = format_string; *p != 0; ++p) { 1222 if (*p == '%') formatted_path_len += home_len - 1; 1223 ++formatted_path_len; 1224 } 1225 1226 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1227 if (formatted_path == NULL) { 1228 return NULL; 1229 } 1230 1231 // Create boot classpath from format, substituting separator chars and 1232 // java home directory. 1233 char* q = formatted_path; 1234 for (p = format_string; *p != 0; ++p) { 1235 switch (*p) { 1236 case '%': 1237 strcpy(q, home); 1238 q += home_len; 1239 break; 1240 case '/': 1241 *q++ = fileSep; 1242 break; 1243 case ':': 1244 *q++ = pathSep; 1245 break; 1246 default: 1247 *q++ = *p; 1248 } 1249 } 1250 *q = '\0'; 1251 1252 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1253 return formatted_path; 1254 } 1255 1256 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N') 1257 // that ensures automatic closing of the file on exec. If it can not find support in 1258 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic 1259 // closing of the file on exec. 1260 FILE* os::fopen(const char* path, const char* mode) { 1261 char modified_mode[20]; 1262 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer"); 1263 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode); 1264 FILE* file = ::fopen(path, modified_mode); 1265 1266 #if !(defined LINUX || defined BSD || defined _WINDOWS) 1267 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N' 1268 // is not supported as mode in fopen 1269 if (file != NULL) { 1270 int fd = fileno(file); 1271 if (fd != -1) { 1272 int fd_flags = fcntl(fd, F_GETFD); 1273 if (fd_flags != -1) { 1274 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC); 1275 } 1276 } 1277 } 1278 #endif 1279 1280 return file; 1281 } 1282 1283 bool os::set_boot_path(char fileSep, char pathSep) { 1284 const char* home = Arguments::get_java_home(); 1285 int home_len = (int)strlen(home); 1286 1287 struct stat st; 1288 1289 // modular image if "modules" jimage exists 1290 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep); 1291 if (jimage == NULL) return false; 1292 bool has_jimage = (os::stat(jimage, &st) == 0); 1293 if (has_jimage) { 1294 Arguments::set_sysclasspath(jimage, true); 1295 FREE_C_HEAP_ARRAY(char, jimage); 1296 return true; 1297 } 1298 FREE_C_HEAP_ARRAY(char, jimage); 1299 1300 // check if developer build with exploded modules 1301 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep); 1302 if (base_classes == NULL) return false; 1303 if (os::stat(base_classes, &st) == 0) { 1304 Arguments::set_sysclasspath(base_classes, false); 1305 FREE_C_HEAP_ARRAY(char, base_classes); 1306 return true; 1307 } 1308 FREE_C_HEAP_ARRAY(char, base_classes); 1309 1310 return false; 1311 } 1312 1313 // Splits a path, based on its separator, the number of 1314 // elements is returned back in "elements". 1315 // file_name_length is used as a modifier for each path's 1316 // length when compared to JVM_MAXPATHLEN. So if you know 1317 // each returned path will have something appended when 1318 // in use, you can pass the length of that in 1319 // file_name_length, to ensure we detect if any path 1320 // exceeds the maximum path length once prepended onto 1321 // the sub-path/file name. 1322 // It is the callers responsibility to: 1323 // a> check the value of "elements", which may be 0. 1324 // b> ignore any empty path elements 1325 // c> free up the data. 1326 char** os::split_path(const char* path, size_t* elements, size_t file_name_length) { 1327 *elements = (size_t)0; 1328 if (path == NULL || strlen(path) == 0 || file_name_length == (size_t)NULL) { 1329 return NULL; 1330 } 1331 const char psepchar = *os::path_separator(); 1332 char* inpath = NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1333 if (inpath == NULL) { 1334 return NULL; 1335 } 1336 strcpy(inpath, path); 1337 size_t count = 1; 1338 char* p = strchr(inpath, psepchar); 1339 // Get a count of elements to allocate memory 1340 while (p != NULL) { 1341 count++; 1342 p++; 1343 p = strchr(p, psepchar); 1344 } 1345 1346 char** opath = NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1347 1348 // do the actual splitting 1349 p = inpath; 1350 for (size_t i = 0 ; i < count ; i++) { 1351 size_t len = strcspn(p, os::path_separator()); 1352 if (len + file_name_length > JVM_MAXPATHLEN) { 1353 // release allocated storage before exiting the vm 1354 free_array_of_char_arrays(opath, i++); 1355 vm_exit_during_initialization("The VM tried to use a path that exceeds the maximum path length for " 1356 "this system. Review path-containing parameters and properties, such as " 1357 "sun.boot.library.path, to identify potential sources for this path."); 1358 } 1359 // allocate the string and add terminator storage 1360 char* s = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal); 1361 1362 if (s == NULL) { 1363 // release allocated storage before returning null 1364 free_array_of_char_arrays(opath, i++); 1365 return NULL; 1366 } 1367 strncpy(s, p, len); 1368 s[len] = '\0'; 1369 opath[i] = s; 1370 p += len + 1; 1371 } 1372 FREE_C_HEAP_ARRAY(char, inpath); 1373 *elements = count; 1374 return opath; 1375 } 1376 1377 // Returns true if the current stack pointer is above the stack shadow 1378 // pages, false otherwise. 1379 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) { 1380 if (!thread->is_Java_thread()) return false; 1381 // Check if we have StackShadowPages above the yellow zone. This parameter 1382 // is dependent on the depth of the maximum VM call stack possible from 1383 // the handler for stack overflow. 'instanceof' in the stack overflow 1384 // handler or a println uses at least 8k stack of VM and native code 1385 // respectively. 1386 const int framesize_in_bytes = 1387 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1388 1389 address limit = ((JavaThread*)thread)->stack_end() + 1390 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size()); 1391 1392 return sp > (limit + framesize_in_bytes); 1393 } 1394 1395 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) { 1396 assert(min_pages > 0, "sanity"); 1397 if (UseLargePages) { 1398 const size_t max_page_size = region_size / min_pages; 1399 1400 for (size_t i = 0; _page_sizes[i] != 0; ++i) { 1401 const size_t page_size = _page_sizes[i]; 1402 if (page_size <= max_page_size) { 1403 if (!must_be_aligned || is_aligned(region_size, page_size)) { 1404 return page_size; 1405 } 1406 } 1407 } 1408 } 1409 1410 return vm_page_size(); 1411 } 1412 1413 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) { 1414 return page_size_for_region(region_size, min_pages, true); 1415 } 1416 1417 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) { 1418 return page_size_for_region(region_size, min_pages, false); 1419 } 1420 1421 static const char* errno_to_string (int e, bool short_text) { 1422 #define ALL_SHARED_ENUMS(X) \ 1423 X(E2BIG, "Argument list too long") \ 1424 X(EACCES, "Permission denied") \ 1425 X(EADDRINUSE, "Address in use") \ 1426 X(EADDRNOTAVAIL, "Address not available") \ 1427 X(EAFNOSUPPORT, "Address family not supported") \ 1428 X(EAGAIN, "Resource unavailable, try again") \ 1429 X(EALREADY, "Connection already in progress") \ 1430 X(EBADF, "Bad file descriptor") \ 1431 X(EBADMSG, "Bad message") \ 1432 X(EBUSY, "Device or resource busy") \ 1433 X(ECANCELED, "Operation canceled") \ 1434 X(ECHILD, "No child processes") \ 1435 X(ECONNABORTED, "Connection aborted") \ 1436 X(ECONNREFUSED, "Connection refused") \ 1437 X(ECONNRESET, "Connection reset") \ 1438 X(EDEADLK, "Resource deadlock would occur") \ 1439 X(EDESTADDRREQ, "Destination address required") \ 1440 X(EDOM, "Mathematics argument out of domain of function") \ 1441 X(EEXIST, "File exists") \ 1442 X(EFAULT, "Bad address") \ 1443 X(EFBIG, "File too large") \ 1444 X(EHOSTUNREACH, "Host is unreachable") \ 1445 X(EIDRM, "Identifier removed") \ 1446 X(EILSEQ, "Illegal byte sequence") \ 1447 X(EINPROGRESS, "Operation in progress") \ 1448 X(EINTR, "Interrupted function") \ 1449 X(EINVAL, "Invalid argument") \ 1450 X(EIO, "I/O error") \ 1451 X(EISCONN, "Socket is connected") \ 1452 X(EISDIR, "Is a directory") \ 1453 X(ELOOP, "Too many levels of symbolic links") \ 1454 X(EMFILE, "Too many open files") \ 1455 X(EMLINK, "Too many links") \ 1456 X(EMSGSIZE, "Message too large") \ 1457 X(ENAMETOOLONG, "Filename too long") \ 1458 X(ENETDOWN, "Network is down") \ 1459 X(ENETRESET, "Connection aborted by network") \ 1460 X(ENETUNREACH, "Network unreachable") \ 1461 X(ENFILE, "Too many files open in system") \ 1462 X(ENOBUFS, "No buffer space available") \ 1463 X(ENODATA, "No message is available on the STREAM head read queue") \ 1464 X(ENODEV, "No such device") \ 1465 X(ENOENT, "No such file or directory") \ 1466 X(ENOEXEC, "Executable file format error") \ 1467 X(ENOLCK, "No locks available") \ 1468 X(ENOLINK, "Reserved") \ 1469 X(ENOMEM, "Not enough space") \ 1470 X(ENOMSG, "No message of the desired type") \ 1471 X(ENOPROTOOPT, "Protocol not available") \ 1472 X(ENOSPC, "No space left on device") \ 1473 X(ENOSR, "No STREAM resources") \ 1474 X(ENOSTR, "Not a STREAM") \ 1475 X(ENOSYS, "Function not supported") \ 1476 X(ENOTCONN, "The socket is not connected") \ 1477 X(ENOTDIR, "Not a directory") \ 1478 X(ENOTEMPTY, "Directory not empty") \ 1479 X(ENOTSOCK, "Not a socket") \ 1480 X(ENOTSUP, "Not supported") \ 1481 X(ENOTTY, "Inappropriate I/O control operation") \ 1482 X(ENXIO, "No such device or address") \ 1483 X(EOPNOTSUPP, "Operation not supported on socket") \ 1484 X(EOVERFLOW, "Value too large to be stored in data type") \ 1485 X(EPERM, "Operation not permitted") \ 1486 X(EPIPE, "Broken pipe") \ 1487 X(EPROTO, "Protocol error") \ 1488 X(EPROTONOSUPPORT, "Protocol not supported") \ 1489 X(EPROTOTYPE, "Protocol wrong type for socket") \ 1490 X(ERANGE, "Result too large") \ 1491 X(EROFS, "Read-only file system") \ 1492 X(ESPIPE, "Invalid seek") \ 1493 X(ESRCH, "No such process") \ 1494 X(ETIME, "Stream ioctl() timeout") \ 1495 X(ETIMEDOUT, "Connection timed out") \ 1496 X(ETXTBSY, "Text file busy") \ 1497 X(EWOULDBLOCK, "Operation would block") \ 1498 X(EXDEV, "Cross-device link") 1499 1500 #define DEFINE_ENTRY(e, text) { e, #e, text }, 1501 1502 static const struct { 1503 int v; 1504 const char* short_text; 1505 const char* long_text; 1506 } table [] = { 1507 1508 ALL_SHARED_ENUMS(DEFINE_ENTRY) 1509 1510 // The following enums are not defined on all platforms. 1511 #ifdef ESTALE 1512 DEFINE_ENTRY(ESTALE, "Reserved") 1513 #endif 1514 #ifdef EDQUOT 1515 DEFINE_ENTRY(EDQUOT, "Reserved") 1516 #endif 1517 #ifdef EMULTIHOP 1518 DEFINE_ENTRY(EMULTIHOP, "Reserved") 1519 #endif 1520 1521 // End marker. 1522 { -1, "Unknown errno", "Unknown error" } 1523 1524 }; 1525 1526 #undef DEFINE_ENTRY 1527 #undef ALL_FLAGS 1528 1529 int i = 0; 1530 while (table[i].v != -1 && table[i].v != e) { 1531 i ++; 1532 } 1533 1534 return short_text ? table[i].short_text : table[i].long_text; 1535 1536 } 1537 1538 const char* os::strerror(int e) { 1539 return errno_to_string(e, false); 1540 } 1541 1542 const char* os::errno_name(int e) { 1543 return errno_to_string(e, true); 1544 } 1545 1546 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) { 1547 LogTarget(Info, pagesize) log; 1548 if (log.is_enabled()) { 1549 LogStream out(log); 1550 1551 out.print("%s: ", str); 1552 for (int i = 0; i < count; ++i) { 1553 out.print(" " SIZE_FORMAT, page_sizes[i]); 1554 } 1555 out.cr(); 1556 } 1557 } 1558 1559 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size) 1560 1561 void os::trace_page_sizes(const char* str, 1562 const size_t region_min_size, 1563 const size_t region_max_size, 1564 const size_t page_size, 1565 const char* base, 1566 const size_t size) { 1567 1568 log_info(pagesize)("%s: " 1569 " min=" SIZE_FORMAT "%s" 1570 " max=" SIZE_FORMAT "%s" 1571 " base=" PTR_FORMAT 1572 " page_size=" SIZE_FORMAT "%s" 1573 " size=" SIZE_FORMAT "%s", 1574 str, 1575 trace_page_size_params(region_min_size), 1576 trace_page_size_params(region_max_size), 1577 p2i(base), 1578 trace_page_size_params(page_size), 1579 trace_page_size_params(size)); 1580 } 1581 1582 void os::trace_page_sizes_for_requested_size(const char* str, 1583 const size_t requested_size, 1584 const size_t page_size, 1585 const size_t alignment, 1586 const char* base, 1587 const size_t size) { 1588 1589 log_info(pagesize)("%s:" 1590 " req_size=" SIZE_FORMAT "%s" 1591 " base=" PTR_FORMAT 1592 " page_size=" SIZE_FORMAT "%s" 1593 " alignment=" SIZE_FORMAT "%s" 1594 " size=" SIZE_FORMAT "%s", 1595 str, 1596 trace_page_size_params(requested_size), 1597 p2i(base), 1598 trace_page_size_params(page_size), 1599 trace_page_size_params(alignment), 1600 trace_page_size_params(size)); 1601 } 1602 1603 1604 // This is the working definition of a server class machine: 1605 // >= 2 physical CPU's and >=2GB of memory, with some fuzz 1606 // because the graphics memory (?) sometimes masks physical memory. 1607 // If you want to change the definition of a server class machine 1608 // on some OS or platform, e.g., >=4GB on Windows platforms, 1609 // then you'll have to parameterize this method based on that state, 1610 // as was done for logical processors here, or replicate and 1611 // specialize this method for each platform. (Or fix os to have 1612 // some inheritance structure and use subclassing. Sigh.) 1613 // If you want some platform to always or never behave as a server 1614 // class machine, change the setting of AlwaysActAsServerClassMachine 1615 // and NeverActAsServerClassMachine in globals*.hpp. 1616 bool os::is_server_class_machine() { 1617 // First check for the early returns 1618 if (NeverActAsServerClassMachine) { 1619 return false; 1620 } 1621 if (AlwaysActAsServerClassMachine) { 1622 return true; 1623 } 1624 // Then actually look at the machine 1625 bool result = false; 1626 const unsigned int server_processors = 2; 1627 const julong server_memory = 2UL * G; 1628 // We seem not to get our full complement of memory. 1629 // We allow some part (1/8?) of the memory to be "missing", 1630 // based on the sizes of DIMMs, and maybe graphics cards. 1631 const julong missing_memory = 256UL * M; 1632 1633 /* Is this a server class machine? */ 1634 if ((os::active_processor_count() >= (int)server_processors) && 1635 (os::physical_memory() >= (server_memory - missing_memory))) { 1636 const unsigned int logical_processors = 1637 VM_Version::logical_processors_per_package(); 1638 if (logical_processors > 1) { 1639 const unsigned int physical_packages = 1640 os::active_processor_count() / logical_processors; 1641 if (physical_packages >= server_processors) { 1642 result = true; 1643 } 1644 } else { 1645 result = true; 1646 } 1647 } 1648 return result; 1649 } 1650 1651 void os::initialize_initial_active_processor_count() { 1652 assert(_initial_active_processor_count == 0, "Initial active processor count already set."); 1653 _initial_active_processor_count = active_processor_count(); 1654 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count); 1655 } 1656 1657 void os::SuspendedThreadTask::run() { 1658 internal_do_task(); 1659 _done = true; 1660 } 1661 1662 bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1663 return os::pd_create_stack_guard_pages(addr, bytes); 1664 } 1665 1666 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) { 1667 char* result = NULL; 1668 1669 if (file_desc != -1) { 1670 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(), 1671 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file. 1672 result = os::map_memory_to_file(addr, bytes, file_desc); 1673 if (result != NULL) { 1674 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1675 } 1676 } else { 1677 result = pd_reserve_memory(bytes, addr, alignment_hint); 1678 if (result != NULL) { 1679 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1680 } 1681 } 1682 1683 return result; 1684 } 1685 1686 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, 1687 MEMFLAGS flags) { 1688 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1689 if (result != NULL) { 1690 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1691 MemTracker::record_virtual_memory_type((address)result, flags); 1692 } 1693 1694 return result; 1695 } 1696 1697 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) { 1698 char* result = NULL; 1699 if (file_desc != -1) { 1700 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc); 1701 if (result != NULL) { 1702 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1703 } 1704 } else { 1705 result = pd_attempt_reserve_memory_at(bytes, addr); 1706 if (result != NULL) { 1707 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1708 } 1709 } 1710 return result; 1711 } 1712 1713 void os::split_reserved_memory(char *base, size_t size, 1714 size_t split, bool realloc) { 1715 pd_split_reserved_memory(base, size, split, realloc); 1716 } 1717 1718 bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1719 bool res = pd_commit_memory(addr, bytes, executable); 1720 if (res) { 1721 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1722 } 1723 return res; 1724 } 1725 1726 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1727 bool executable) { 1728 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1729 if (res) { 1730 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1731 } 1732 return res; 1733 } 1734 1735 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable, 1736 const char* mesg) { 1737 pd_commit_memory_or_exit(addr, bytes, executable, mesg); 1738 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1739 } 1740 1741 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, 1742 bool executable, const char* mesg) { 1743 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg); 1744 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1745 } 1746 1747 bool os::uncommit_memory(char* addr, size_t bytes) { 1748 bool res; 1749 if (MemTracker::tracking_level() > NMT_minimal) { 1750 Tracker tkr(Tracker::uncommit); 1751 res = pd_uncommit_memory(addr, bytes); 1752 if (res) { 1753 tkr.record((address)addr, bytes); 1754 } 1755 } else { 1756 res = pd_uncommit_memory(addr, bytes); 1757 } 1758 return res; 1759 } 1760 1761 bool os::release_memory(char* addr, size_t bytes) { 1762 bool res; 1763 if (MemTracker::tracking_level() > NMT_minimal) { 1764 Tracker tkr(Tracker::release); 1765 res = pd_release_memory(addr, bytes); 1766 if (res) { 1767 tkr.record((address)addr, bytes); 1768 } 1769 } else { 1770 res = pd_release_memory(addr, bytes); 1771 } 1772 return res; 1773 } 1774 1775 void os::pretouch_memory(void* start, void* end, size_t page_size) { 1776 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) { 1777 *p = 0; 1778 } 1779 } 1780 1781 char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1782 char *addr, size_t bytes, bool read_only, 1783 bool allow_exec) { 1784 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1785 if (result != NULL) { 1786 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1787 } 1788 return result; 1789 } 1790 1791 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1792 char *addr, size_t bytes, bool read_only, 1793 bool allow_exec) { 1794 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1795 read_only, allow_exec); 1796 } 1797 1798 bool os::unmap_memory(char *addr, size_t bytes) { 1799 bool result; 1800 if (MemTracker::tracking_level() > NMT_minimal) { 1801 Tracker tkr(Tracker::release); 1802 result = pd_unmap_memory(addr, bytes); 1803 if (result) { 1804 tkr.record((address)addr, bytes); 1805 } 1806 } else { 1807 result = pd_unmap_memory(addr, bytes); 1808 } 1809 return result; 1810 } 1811 1812 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1813 pd_free_memory(addr, bytes, alignment_hint); 1814 } 1815 1816 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1817 pd_realign_memory(addr, bytes, alignment_hint); 1818 } 1819 1820 #ifndef _WINDOWS 1821 /* try to switch state from state "from" to state "to" 1822 * returns the state set after the method is complete 1823 */ 1824 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from, 1825 os::SuspendResume::State to) 1826 { 1827 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from); 1828 if (result == from) { 1829 // success 1830 return to; 1831 } 1832 return result; 1833 } 1834 #endif 1835 1836 // Convenience wrapper around naked_short_sleep to allow for longer sleep 1837 // times. Only for use by non-JavaThreads. 1838 void os::naked_sleep(jlong millis) { 1839 assert(!Thread::current()->is_Java_thread(), "not for use by JavaThreads"); 1840 const jlong limit = 999; 1841 while (millis > limit) { 1842 naked_short_sleep(limit); 1843 millis -= limit; 1844 } 1845 naked_short_sleep(millis); 1846 } 1847 1848 int os::sleep(JavaThread* thread, jlong millis) { 1849 assert(thread == Thread::current(), "thread consistency check"); 1850 1851 ParkEvent * const slp = thread->_SleepEvent; 1852 // Because there can be races with thread interruption sending an unpark() 1853 // to the event, we explicitly reset it here to avoid an immediate return. 1854 // The actual interrupt state will be checked before we park(). 1855 slp->reset(); 1856 // Thread interruption establishes a happens-before ordering in the 1857 // Java Memory Model, so we need to ensure we synchronize with the 1858 // interrupt state. 1859 OrderAccess::fence(); 1860 1861 jlong prevtime = javaTimeNanos(); 1862 1863 for (;;) { 1864 // interruption has precedence over timing out 1865 if (os::is_interrupted(thread, true)) { 1866 return OS_INTRPT; 1867 } 1868 1869 jlong newtime = javaTimeNanos(); 1870 1871 if (newtime - prevtime < 0) { 1872 // time moving backwards, should only happen if no monotonic clock 1873 // not a guarantee() because JVM should not abort on kernel/glibc bugs 1874 assert(!os::supports_monotonic_clock(), 1875 "unexpected time moving backwards detected in os::sleep()"); 1876 } else { 1877 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 1878 } 1879 1880 if (millis <= 0) { 1881 return OS_OK; 1882 } 1883 1884 prevtime = newtime; 1885 1886 { 1887 ThreadBlockInVM tbivm(thread); 1888 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 1889 1890 thread->set_suspend_equivalent(); 1891 // cleared by handle_special_suspend_equivalent_condition() or 1892 // java_suspend_self() via check_and_wait_while_suspended() 1893 1894 slp->park(millis); 1895 1896 // were we externally suspended while we were waiting? 1897 thread->check_and_wait_while_suspended(); 1898 } 1899 } 1900 }