1 /* 2 * Copyright (c) 1997, 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 "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(THREAD, 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 // Load java dll 540 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 541 "java")) { 542 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 543 } 544 if (_native_java_library == NULL) { 545 vm_exit_during_initialization("Unable to load native library", ebuf); 546 } 547 548 #if defined(__OpenBSD__) 549 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 550 // ignore errors 551 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 552 "net")) { 553 dll_load(buffer, ebuf, sizeof(ebuf)); 554 } 555 #endif 556 } 557 return _native_java_library; 558 } 559 560 /* 561 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists. 562 * If check_lib == true then we are looking for an 563 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if 564 * this library is statically linked into the image. 565 * If check_lib == false then we will look for the appropriate symbol in the 566 * executable if agent_lib->is_static_lib() == true or in the shared library 567 * referenced by 'handle'. 568 */ 569 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib, 570 const char *syms[], size_t syms_len) { 571 assert(agent_lib != NULL, "sanity check"); 572 const char *lib_name; 573 void *handle = agent_lib->os_lib(); 574 void *entryName = NULL; 575 char *agent_function_name; 576 size_t i; 577 578 // If checking then use the agent name otherwise test is_static_lib() to 579 // see how to process this lookup 580 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL); 581 for (i = 0; i < syms_len; i++) { 582 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path()); 583 if (agent_function_name == NULL) { 584 break; 585 } 586 entryName = dll_lookup(handle, agent_function_name); 587 FREE_C_HEAP_ARRAY(char, agent_function_name); 588 if (entryName != NULL) { 589 break; 590 } 591 } 592 return entryName; 593 } 594 595 // See if the passed in agent is statically linked into the VM image. 596 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 597 size_t syms_len) { 598 void *ret; 599 void *proc_handle; 600 void *save_handle; 601 602 assert(agent_lib != NULL, "sanity check"); 603 if (agent_lib->name() == NULL) { 604 return false; 605 } 606 proc_handle = get_default_process_handle(); 607 // Check for Agent_OnLoad/Attach_lib_name function 608 save_handle = agent_lib->os_lib(); 609 // We want to look in this process' symbol table. 610 agent_lib->set_os_lib(proc_handle); 611 ret = find_agent_function(agent_lib, true, syms, syms_len); 612 if (ret != NULL) { 613 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent 614 agent_lib->set_valid(); 615 agent_lib->set_static_lib(true); 616 return true; 617 } 618 agent_lib->set_os_lib(save_handle); 619 return false; 620 } 621 622 // --------------------- heap allocation utilities --------------------- 623 624 char *os::strdup(const char *str, MEMFLAGS flags) { 625 size_t size = strlen(str); 626 char *dup_str = (char *)malloc(size + 1, flags); 627 if (dup_str == NULL) return NULL; 628 strcpy(dup_str, str); 629 return dup_str; 630 } 631 632 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) { 633 char* p = os::strdup(str, flags); 634 if (p == NULL) { 635 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom"); 636 } 637 return p; 638 } 639 640 641 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 642 643 #ifdef ASSERT 644 645 static void verify_memory(void* ptr) { 646 GuardedMemory guarded(ptr); 647 if (!guarded.verify_guards()) { 648 LogTarget(Warning, malloc, free) lt; 649 ResourceMark rm; 650 LogStream ls(lt); 651 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 652 ls.print_cr("## memory stomp:"); 653 guarded.print_on(&ls); 654 fatal("memory stomping error"); 655 } 656 } 657 658 #endif 659 660 // 661 // This function supports testing of the malloc out of memory 662 // condition without really running the system out of memory. 663 // 664 static bool has_reached_max_malloc_test_peak(size_t alloc_size) { 665 if (MallocMaxTestWords > 0) { 666 size_t words = (alloc_size / BytesPerWord); 667 668 if ((cur_malloc_words + words) > MallocMaxTestWords) { 669 return true; 670 } 671 Atomic::add(&cur_malloc_words, words); 672 } 673 return false; 674 } 675 676 void* os::malloc(size_t size, MEMFLAGS flags) { 677 return os::malloc(size, flags, CALLER_PC); 678 } 679 680 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 681 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 682 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 683 684 // Since os::malloc can be called when the libjvm.{dll,so} is 685 // first loaded and we don't have a thread yet we must accept NULL also here. 686 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()), 687 "malloc() not allowed when crash protection is set"); 688 689 if (size == 0) { 690 // return a valid pointer if size is zero 691 // if NULL is returned the calling functions assume out of memory. 692 size = 1; 693 } 694 695 // NMT support 696 NMT_TrackingLevel level = MemTracker::tracking_level(); 697 size_t nmt_header_size = MemTracker::malloc_header_size(level); 698 699 #ifndef ASSERT 700 const size_t alloc_size = size + nmt_header_size; 701 #else 702 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size); 703 if (size + nmt_header_size > alloc_size) { // Check for rollover. 704 return NULL; 705 } 706 #endif 707 708 // For the test flag -XX:MallocMaxTestWords 709 if (has_reached_max_malloc_test_peak(size)) { 710 return NULL; 711 } 712 713 u_char* ptr; 714 ptr = (u_char*)::malloc(alloc_size); 715 716 #ifdef ASSERT 717 if (ptr == NULL) { 718 return NULL; 719 } 720 // Wrap memory with guard 721 GuardedMemory guarded(ptr, size + nmt_header_size); 722 ptr = guarded.get_user_ptr(); 723 724 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 725 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 726 breakpoint(); 727 } 728 if (paranoid) { 729 verify_memory(ptr); 730 } 731 #endif 732 733 // we do not track guard memory 734 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level); 735 } 736 737 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) { 738 return os::realloc(memblock, size, flags, CALLER_PC); 739 } 740 741 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 742 743 // For the test flag -XX:MallocMaxTestWords 744 if (has_reached_max_malloc_test_peak(size)) { 745 return NULL; 746 } 747 748 if (size == 0) { 749 // return a valid pointer if size is zero 750 // if NULL is returned the calling functions assume out of memory. 751 size = 1; 752 } 753 754 #ifndef ASSERT 755 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 756 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 757 // NMT support 758 NMT_TrackingLevel level = MemTracker::tracking_level(); 759 void* membase = MemTracker::record_free(memblock, level); 760 size_t nmt_header_size = MemTracker::malloc_header_size(level); 761 void* ptr = ::realloc(membase, size + nmt_header_size); 762 return MemTracker::record_malloc(ptr, size, memflags, stack, level); 763 #else 764 if (memblock == NULL) { 765 return os::malloc(size, memflags, stack); 766 } 767 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 768 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock)); 769 breakpoint(); 770 } 771 // NMT support 772 void* membase = MemTracker::malloc_base(memblock); 773 verify_memory(membase); 774 // always move the block 775 void* ptr = os::malloc(size, memflags, stack); 776 // Copy to new memory if malloc didn't fail 777 if (ptr != NULL ) { 778 GuardedMemory guarded(MemTracker::malloc_base(memblock)); 779 // Guard's user data contains NMT header 780 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock); 781 memcpy(ptr, memblock, MIN2(size, memblock_size)); 782 if (paranoid) { 783 verify_memory(MemTracker::malloc_base(ptr)); 784 } 785 os::free(memblock); 786 } 787 return ptr; 788 #endif 789 } 790 791 // handles NULL pointers 792 void os::free(void *memblock) { 793 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 794 #ifdef ASSERT 795 if (memblock == NULL) return; 796 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 797 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock)); 798 breakpoint(); 799 } 800 void* membase = MemTracker::record_free(memblock, MemTracker::tracking_level()); 801 verify_memory(membase); 802 803 GuardedMemory guarded(membase); 804 size_t size = guarded.get_user_size(); 805 inc_stat_counter(&free_bytes, size); 806 membase = guarded.release_for_freeing(); 807 ::free(membase); 808 #else 809 void* membase = MemTracker::record_free(memblock, MemTracker::tracking_level()); 810 ::free(membase); 811 #endif 812 } 813 814 void os::init_random(unsigned int initval) { 815 _rand_seed = initval; 816 } 817 818 819 static int random_helper(unsigned int rand_seed) { 820 /* standard, well-known linear congruential random generator with 821 * next_rand = (16807*seed) mod (2**31-1) 822 * see 823 * (1) "Random Number Generators: Good Ones Are Hard to Find", 824 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 825 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 826 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 827 */ 828 const unsigned int a = 16807; 829 const unsigned int m = 2147483647; 830 const int q = m / a; assert(q == 127773, "weird math"); 831 const int r = m % a; assert(r == 2836, "weird math"); 832 833 // compute az=2^31p+q 834 unsigned int lo = a * (rand_seed & 0xFFFF); 835 unsigned int hi = a * (rand_seed >> 16); 836 lo += (hi & 0x7FFF) << 16; 837 838 // if q overflowed, ignore the overflow and increment q 839 if (lo > m) { 840 lo &= m; 841 ++lo; 842 } 843 lo += hi >> 15; 844 845 // if (p+q) overflowed, ignore the overflow and increment (p+q) 846 if (lo > m) { 847 lo &= m; 848 ++lo; 849 } 850 return lo; 851 } 852 853 int os::random() { 854 // Make updating the random seed thread safe. 855 while (true) { 856 unsigned int seed = _rand_seed; 857 unsigned int rand = random_helper(seed); 858 if (Atomic::cmpxchg(&_rand_seed, seed, rand) == seed) { 859 return static_cast<int>(rand); 860 } 861 } 862 } 863 864 // The INITIALIZED state is distinguished from the SUSPENDED state because the 865 // conditions in which a thread is first started are different from those in which 866 // a suspension is resumed. These differences make it hard for us to apply the 867 // tougher checks when starting threads that we want to do when resuming them. 868 // However, when start_thread is called as a result of Thread.start, on a Java 869 // thread, the operation is synchronized on the Java Thread object. So there 870 // cannot be a race to start the thread and hence for the thread to exit while 871 // we are working on it. Non-Java threads that start Java threads either have 872 // to do so in a context in which races are impossible, or should do appropriate 873 // locking. 874 875 void os::start_thread(Thread* thread) { 876 // guard suspend/resume 877 MutexLocker ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 878 OSThread* osthread = thread->osthread(); 879 osthread->set_state(RUNNABLE); 880 pd_start_thread(thread); 881 } 882 883 void os::abort(bool dump_core) { 884 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL); 885 } 886 887 //--------------------------------------------------------------------------- 888 // Helper functions for fatal error handler 889 890 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 891 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 892 893 start = align_down(start, unitsize); 894 895 int cols = 0; 896 int cols_per_line = 0; 897 switch (unitsize) { 898 case 1: cols_per_line = 16; break; 899 case 2: cols_per_line = 8; break; 900 case 4: cols_per_line = 4; break; 901 case 8: cols_per_line = 2; break; 902 default: return; 903 } 904 905 address p = start; 906 st->print(PTR_FORMAT ": ", p2i(start)); 907 while (p < end) { 908 if (is_readable_pointer(p)) { 909 switch (unitsize) { 910 case 1: st->print("%02x", *(u1*)p); break; 911 case 2: st->print("%04x", *(u2*)p); break; 912 case 4: st->print("%08x", *(u4*)p); break; 913 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 914 } 915 } else { 916 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????"); 917 } 918 p += unitsize; 919 cols++; 920 if (cols >= cols_per_line && p < end) { 921 cols = 0; 922 st->cr(); 923 st->print(PTR_FORMAT ": ", p2i(p)); 924 } else { 925 st->print(" "); 926 } 927 } 928 st->cr(); 929 } 930 931 void os::print_dhm(outputStream* st, const char* startStr, long sec) { 932 long days = sec/86400; 933 long hours = (sec/3600) - (days * 24); 934 long minutes = (sec/60) - (days * 1440) - (hours * 60); 935 if (startStr == NULL) startStr = ""; 936 st->print_cr("%s %ld days %ld:%02ld hours", startStr, days, hours, minutes); 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: a crash using printf("%f",...) on Linux was historically noted here. 1020 int eltime = (int)t; // elapsed time in seconds 1021 int eltimeFraction = (int) ((t - eltime) * 1000000); 1022 1023 // print elapsed time in a human-readable format: 1024 int eldays = eltime / secs_per_day; 1025 int day_secs = eldays * secs_per_day; 1026 int elhours = (eltime - day_secs) / secs_per_hour; 1027 int hour_secs = elhours * secs_per_hour; 1028 int elmins = (eltime - day_secs - hour_secs) / secs_per_min; 1029 int minute_secs = elmins * secs_per_min; 1030 int elsecs = (eltime - day_secs - hour_secs - minute_secs); 1031 st->print_cr(" elapsed time: %d.%06d seconds (%dd %dh %dm %ds)", eltime, eltimeFraction, eldays, elhours, elmins, elsecs); 1032 } 1033 1034 1035 // Check if pointer can be read from (4-byte read access). 1036 // Helps to prove validity of a not-NULL pointer. 1037 // Returns true in very early stages of VM life when stub is not yet generated. 1038 #define SAFEFETCH_DEFAULT true 1039 bool os::is_readable_pointer(const void* p) { 1040 if (!CanUseSafeFetch32()) { 1041 return SAFEFETCH_DEFAULT; 1042 } 1043 int* const aligned = (int*) align_down((intptr_t)p, 4); 1044 int cafebabe = 0xcafebabe; // tester value 1 1045 int deadbeef = 0xdeadbeef; // tester value 2 1046 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef); 1047 } 1048 1049 bool os::is_readable_range(const void* from, const void* to) { 1050 if ((uintptr_t)from >= (uintptr_t)to) return false; 1051 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) { 1052 if (!is_readable_pointer((const void*)p)) { 1053 return false; 1054 } 1055 } 1056 return true; 1057 } 1058 1059 1060 // moved from debug.cpp (used to be find()) but still called from there 1061 // The verbose parameter is only set by the debug code in one case 1062 void os::print_location(outputStream* st, intptr_t x, bool verbose) { 1063 address addr = (address)x; 1064 // Handle NULL first, so later checks don't need to protect against it. 1065 if (addr == NULL) { 1066 st->print_cr("0x0 is NULL"); 1067 return; 1068 } 1069 1070 // Check if addr points into a code blob. 1071 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 1072 if (b != NULL) { 1073 b->dump_for_addr(addr, st, verbose); 1074 return; 1075 } 1076 1077 // Check if addr points into Java heap. 1078 if (Universe::heap()->print_location(st, addr)) { 1079 return; 1080 } 1081 1082 bool accessible = is_readable_pointer(addr); 1083 1084 // Check if addr is a JNI handle. 1085 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) { 1086 if (JNIHandles::is_global_handle((jobject) addr)) { 1087 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr)); 1088 return; 1089 } 1090 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 1091 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr)); 1092 return; 1093 } 1094 #ifndef PRODUCT 1095 // we don't keep the block list in product mode 1096 if (JNIHandles::is_local_handle((jobject) addr)) { 1097 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr)); 1098 return; 1099 } 1100 #endif 1101 } 1102 1103 // Check if addr belongs to a Java thread. 1104 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 1105 // If the addr is a java thread print information about that. 1106 if (addr == (address)thread) { 1107 if (verbose) { 1108 thread->print_on(st); 1109 } else { 1110 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr)); 1111 } 1112 return; 1113 } 1114 // If the addr is in the stack region for this thread then report that 1115 // and print thread info 1116 if (thread->is_in_full_stack(addr)) { 1117 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 1118 INTPTR_FORMAT, p2i(addr), p2i(thread)); 1119 if (verbose) thread->print_on(st); 1120 return; 1121 } 1122 } 1123 1124 // Check if in metaspace and print types that have vptrs 1125 if (Metaspace::contains(addr)) { 1126 if (Klass::is_valid((Klass*)addr)) { 1127 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr)); 1128 ((Klass*)addr)->print_on(st); 1129 } else if (Method::is_valid_method((const Method*)addr)) { 1130 ((Method*)addr)->print_value_on(st); 1131 st->cr(); 1132 } else { 1133 // Use addr->print() from the debugger instead (not here) 1134 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr)); 1135 } 1136 return; 1137 } 1138 1139 // Compressed klass needs to be decoded first. 1140 #ifdef _LP64 1141 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) { 1142 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr; 1143 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass); 1144 1145 if (Klass::is_valid(k)) { 1146 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k)); 1147 k->print_on(st); 1148 return; 1149 } 1150 } 1151 #endif 1152 1153 // Try an OS specific find 1154 if (os::find(addr, st)) { 1155 return; 1156 } 1157 1158 if (accessible) { 1159 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr)); 1160 if (is_aligned(addr, sizeof(intptr_t))) { 1161 st->print(" " PTR_FORMAT " |", *(intptr_t*)addr); 1162 } 1163 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) { 1164 st->print(" %02x", *(u1*)p); 1165 } 1166 st->cr(); 1167 return; 1168 } 1169 1170 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr)); 1171 } 1172 1173 // Looks like all platforms can use the same function to check if C 1174 // stack is walkable beyond current frame. The check for fp() is not 1175 // necessary on Sparc, but it's harmless. 1176 bool os::is_first_C_frame(frame* fr) { 1177 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 1178 // Check usp first, because if that's bad the other accessors may fault 1179 // on some architectures. Ditto ufp second, etc. 1180 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 1181 // sp on amd can be 32 bit aligned. 1182 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 1183 1184 uintptr_t usp = (uintptr_t)fr->sp(); 1185 if ((usp & sp_align_mask) != 0) return true; 1186 1187 uintptr_t ufp = (uintptr_t)fr->fp(); 1188 if ((ufp & fp_align_mask) != 0) return true; 1189 1190 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 1191 if ((old_sp & sp_align_mask) != 0) return true; 1192 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 1193 1194 uintptr_t old_fp = (uintptr_t)fr->link(); 1195 if ((old_fp & fp_align_mask) != 0) return true; 1196 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1197 1198 // stack grows downwards; if old_fp is below current fp or if the stack 1199 // frame is too large, either the stack is corrupted or fp is not saved 1200 // on stack (i.e. on x86, ebp may be used as general register). The stack 1201 // is not walkable beyond current frame. 1202 if (old_fp < ufp) return true; 1203 if (old_fp - ufp > 64 * K) return true; 1204 1205 return false; 1206 } 1207 1208 1209 // Set up the boot classpath. 1210 1211 char* os::format_boot_path(const char* format_string, 1212 const char* home, 1213 int home_len, 1214 char fileSep, 1215 char pathSep) { 1216 assert((fileSep == '/' && pathSep == ':') || 1217 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars"); 1218 1219 // Scan the format string to determine the length of the actual 1220 // boot classpath, and handle platform dependencies as well. 1221 int formatted_path_len = 0; 1222 const char* p; 1223 for (p = format_string; *p != 0; ++p) { 1224 if (*p == '%') formatted_path_len += home_len - 1; 1225 ++formatted_path_len; 1226 } 1227 1228 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1229 1230 // Create boot classpath from format, substituting separator chars and 1231 // java home directory. 1232 char* q = formatted_path; 1233 for (p = format_string; *p != 0; ++p) { 1234 switch (*p) { 1235 case '%': 1236 strcpy(q, home); 1237 q += home_len; 1238 break; 1239 case '/': 1240 *q++ = fileSep; 1241 break; 1242 case ':': 1243 *q++ = pathSep; 1244 break; 1245 default: 1246 *q++ = *p; 1247 } 1248 } 1249 *q = '\0'; 1250 1251 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1252 return formatted_path; 1253 } 1254 1255 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N') 1256 // that ensures automatic closing of the file on exec. If it can not find support in 1257 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic 1258 // closing of the file on exec. 1259 FILE* os::fopen(const char* path, const char* mode) { 1260 char modified_mode[20]; 1261 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer"); 1262 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode); 1263 FILE* file = ::fopen(path, modified_mode); 1264 1265 #if !(defined LINUX || defined BSD || defined _WINDOWS) 1266 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N' 1267 // is not supported as mode in fopen 1268 if (file != NULL) { 1269 int fd = fileno(file); 1270 if (fd != -1) { 1271 int fd_flags = fcntl(fd, F_GETFD); 1272 if (fd_flags != -1) { 1273 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC); 1274 } 1275 } 1276 } 1277 #endif 1278 1279 return file; 1280 } 1281 1282 bool os::set_boot_path(char fileSep, char pathSep) { 1283 const char* home = Arguments::get_java_home(); 1284 int home_len = (int)strlen(home); 1285 1286 struct stat st; 1287 1288 // modular image if "modules" jimage exists 1289 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep); 1290 if (jimage == NULL) return false; 1291 bool has_jimage = (os::stat(jimage, &st) == 0); 1292 if (has_jimage) { 1293 Arguments::set_sysclasspath(jimage, true); 1294 FREE_C_HEAP_ARRAY(char, jimage); 1295 return true; 1296 } 1297 FREE_C_HEAP_ARRAY(char, jimage); 1298 1299 // check if developer build with exploded modules 1300 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep); 1301 if (base_classes == NULL) return false; 1302 if (os::stat(base_classes, &st) == 0) { 1303 Arguments::set_sysclasspath(base_classes, false); 1304 FREE_C_HEAP_ARRAY(char, base_classes); 1305 return true; 1306 } 1307 FREE_C_HEAP_ARRAY(char, base_classes); 1308 1309 return false; 1310 } 1311 1312 // Splits a path, based on its separator, the number of 1313 // elements is returned back in "elements". 1314 // file_name_length is used as a modifier for each path's 1315 // length when compared to JVM_MAXPATHLEN. So if you know 1316 // each returned path will have something appended when 1317 // in use, you can pass the length of that in 1318 // file_name_length, to ensure we detect if any path 1319 // exceeds the maximum path length once prepended onto 1320 // the sub-path/file name. 1321 // It is the callers responsibility to: 1322 // a> check the value of "elements", which may be 0. 1323 // b> ignore any empty path elements 1324 // c> free up the data. 1325 char** os::split_path(const char* path, size_t* elements, size_t file_name_length) { 1326 *elements = (size_t)0; 1327 if (path == NULL || strlen(path) == 0 || file_name_length == (size_t)NULL) { 1328 return NULL; 1329 } 1330 const char psepchar = *os::path_separator(); 1331 char* inpath = NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1332 strcpy(inpath, path); 1333 size_t count = 1; 1334 char* p = strchr(inpath, psepchar); 1335 // Get a count of elements to allocate memory 1336 while (p != NULL) { 1337 count++; 1338 p++; 1339 p = strchr(p, psepchar); 1340 } 1341 1342 char** opath = NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1343 1344 // do the actual splitting 1345 p = inpath; 1346 for (size_t i = 0 ; i < count ; i++) { 1347 size_t len = strcspn(p, os::path_separator()); 1348 if (len + file_name_length > JVM_MAXPATHLEN) { 1349 // release allocated storage before exiting the vm 1350 free_array_of_char_arrays(opath, i++); 1351 vm_exit_during_initialization("The VM tried to use a path that exceeds the maximum path length for " 1352 "this system. Review path-containing parameters and properties, such as " 1353 "sun.boot.library.path, to identify potential sources for this path."); 1354 } 1355 // allocate the string and add terminator storage 1356 char* s = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 1357 strncpy(s, p, len); 1358 s[len] = '\0'; 1359 opath[i] = s; 1360 p += len + 1; 1361 } 1362 FREE_C_HEAP_ARRAY(char, inpath); 1363 *elements = count; 1364 return opath; 1365 } 1366 1367 // Returns true if the current stack pointer is above the stack shadow 1368 // pages, false otherwise. 1369 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) { 1370 if (!thread->is_Java_thread()) return false; 1371 // Check if we have StackShadowPages above the yellow zone. This parameter 1372 // is dependent on the depth of the maximum VM call stack possible from 1373 // the handler for stack overflow. 'instanceof' in the stack overflow 1374 // handler or a println uses at least 8k stack of VM and native code 1375 // respectively. 1376 const int framesize_in_bytes = 1377 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1378 1379 address limit = ((JavaThread*)thread)->stack_end() + 1380 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size()); 1381 1382 return sp > (limit + framesize_in_bytes); 1383 } 1384 1385 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) { 1386 assert(min_pages > 0, "sanity"); 1387 if (UseLargePages) { 1388 const size_t max_page_size = region_size / min_pages; 1389 1390 for (size_t i = 0; _page_sizes[i] != 0; ++i) { 1391 const size_t page_size = _page_sizes[i]; 1392 if (page_size <= max_page_size) { 1393 if (!must_be_aligned || is_aligned(region_size, page_size)) { 1394 return page_size; 1395 } 1396 } 1397 } 1398 } 1399 1400 return vm_page_size(); 1401 } 1402 1403 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) { 1404 return page_size_for_region(region_size, min_pages, true); 1405 } 1406 1407 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) { 1408 return page_size_for_region(region_size, min_pages, false); 1409 } 1410 1411 static const char* errno_to_string (int e, bool short_text) { 1412 #define ALL_SHARED_ENUMS(X) \ 1413 X(E2BIG, "Argument list too long") \ 1414 X(EACCES, "Permission denied") \ 1415 X(EADDRINUSE, "Address in use") \ 1416 X(EADDRNOTAVAIL, "Address not available") \ 1417 X(EAFNOSUPPORT, "Address family not supported") \ 1418 X(EAGAIN, "Resource unavailable, try again") \ 1419 X(EALREADY, "Connection already in progress") \ 1420 X(EBADF, "Bad file descriptor") \ 1421 X(EBADMSG, "Bad message") \ 1422 X(EBUSY, "Device or resource busy") \ 1423 X(ECANCELED, "Operation canceled") \ 1424 X(ECHILD, "No child processes") \ 1425 X(ECONNABORTED, "Connection aborted") \ 1426 X(ECONNREFUSED, "Connection refused") \ 1427 X(ECONNRESET, "Connection reset") \ 1428 X(EDEADLK, "Resource deadlock would occur") \ 1429 X(EDESTADDRREQ, "Destination address required") \ 1430 X(EDOM, "Mathematics argument out of domain of function") \ 1431 X(EEXIST, "File exists") \ 1432 X(EFAULT, "Bad address") \ 1433 X(EFBIG, "File too large") \ 1434 X(EHOSTUNREACH, "Host is unreachable") \ 1435 X(EIDRM, "Identifier removed") \ 1436 X(EILSEQ, "Illegal byte sequence") \ 1437 X(EINPROGRESS, "Operation in progress") \ 1438 X(EINTR, "Interrupted function") \ 1439 X(EINVAL, "Invalid argument") \ 1440 X(EIO, "I/O error") \ 1441 X(EISCONN, "Socket is connected") \ 1442 X(EISDIR, "Is a directory") \ 1443 X(ELOOP, "Too many levels of symbolic links") \ 1444 X(EMFILE, "Too many open files") \ 1445 X(EMLINK, "Too many links") \ 1446 X(EMSGSIZE, "Message too large") \ 1447 X(ENAMETOOLONG, "Filename too long") \ 1448 X(ENETDOWN, "Network is down") \ 1449 X(ENETRESET, "Connection aborted by network") \ 1450 X(ENETUNREACH, "Network unreachable") \ 1451 X(ENFILE, "Too many files open in system") \ 1452 X(ENOBUFS, "No buffer space available") \ 1453 X(ENODATA, "No message is available on the STREAM head read queue") \ 1454 X(ENODEV, "No such device") \ 1455 X(ENOENT, "No such file or directory") \ 1456 X(ENOEXEC, "Executable file format error") \ 1457 X(ENOLCK, "No locks available") \ 1458 X(ENOLINK, "Reserved") \ 1459 X(ENOMEM, "Not enough space") \ 1460 X(ENOMSG, "No message of the desired type") \ 1461 X(ENOPROTOOPT, "Protocol not available") \ 1462 X(ENOSPC, "No space left on device") \ 1463 X(ENOSR, "No STREAM resources") \ 1464 X(ENOSTR, "Not a STREAM") \ 1465 X(ENOSYS, "Function not supported") \ 1466 X(ENOTCONN, "The socket is not connected") \ 1467 X(ENOTDIR, "Not a directory") \ 1468 X(ENOTEMPTY, "Directory not empty") \ 1469 X(ENOTSOCK, "Not a socket") \ 1470 X(ENOTSUP, "Not supported") \ 1471 X(ENOTTY, "Inappropriate I/O control operation") \ 1472 X(ENXIO, "No such device or address") \ 1473 X(EOPNOTSUPP, "Operation not supported on socket") \ 1474 X(EOVERFLOW, "Value too large to be stored in data type") \ 1475 X(EPERM, "Operation not permitted") \ 1476 X(EPIPE, "Broken pipe") \ 1477 X(EPROTO, "Protocol error") \ 1478 X(EPROTONOSUPPORT, "Protocol not supported") \ 1479 X(EPROTOTYPE, "Protocol wrong type for socket") \ 1480 X(ERANGE, "Result too large") \ 1481 X(EROFS, "Read-only file system") \ 1482 X(ESPIPE, "Invalid seek") \ 1483 X(ESRCH, "No such process") \ 1484 X(ETIME, "Stream ioctl() timeout") \ 1485 X(ETIMEDOUT, "Connection timed out") \ 1486 X(ETXTBSY, "Text file busy") \ 1487 X(EWOULDBLOCK, "Operation would block") \ 1488 X(EXDEV, "Cross-device link") 1489 1490 #define DEFINE_ENTRY(e, text) { e, #e, text }, 1491 1492 static const struct { 1493 int v; 1494 const char* short_text; 1495 const char* long_text; 1496 } table [] = { 1497 1498 ALL_SHARED_ENUMS(DEFINE_ENTRY) 1499 1500 // The following enums are not defined on all platforms. 1501 #ifdef ESTALE 1502 DEFINE_ENTRY(ESTALE, "Reserved") 1503 #endif 1504 #ifdef EDQUOT 1505 DEFINE_ENTRY(EDQUOT, "Reserved") 1506 #endif 1507 #ifdef EMULTIHOP 1508 DEFINE_ENTRY(EMULTIHOP, "Reserved") 1509 #endif 1510 1511 // End marker. 1512 { -1, "Unknown errno", "Unknown error" } 1513 1514 }; 1515 1516 #undef DEFINE_ENTRY 1517 #undef ALL_FLAGS 1518 1519 int i = 0; 1520 while (table[i].v != -1 && table[i].v != e) { 1521 i ++; 1522 } 1523 1524 return short_text ? table[i].short_text : table[i].long_text; 1525 1526 } 1527 1528 const char* os::strerror(int e) { 1529 return errno_to_string(e, false); 1530 } 1531 1532 const char* os::errno_name(int e) { 1533 return errno_to_string(e, true); 1534 } 1535 1536 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) { 1537 LogTarget(Info, pagesize) log; 1538 if (log.is_enabled()) { 1539 LogStream out(log); 1540 1541 out.print("%s: ", str); 1542 for (int i = 0; i < count; ++i) { 1543 out.print(" " SIZE_FORMAT, page_sizes[i]); 1544 } 1545 out.cr(); 1546 } 1547 } 1548 1549 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size) 1550 1551 void os::trace_page_sizes(const char* str, 1552 const size_t region_min_size, 1553 const size_t region_max_size, 1554 const size_t page_size, 1555 const char* base, 1556 const size_t size) { 1557 1558 log_info(pagesize)("%s: " 1559 " min=" SIZE_FORMAT "%s" 1560 " max=" SIZE_FORMAT "%s" 1561 " base=" PTR_FORMAT 1562 " page_size=" SIZE_FORMAT "%s" 1563 " size=" SIZE_FORMAT "%s", 1564 str, 1565 trace_page_size_params(region_min_size), 1566 trace_page_size_params(region_max_size), 1567 p2i(base), 1568 trace_page_size_params(page_size), 1569 trace_page_size_params(size)); 1570 } 1571 1572 void os::trace_page_sizes_for_requested_size(const char* str, 1573 const size_t requested_size, 1574 const size_t page_size, 1575 const size_t alignment, 1576 const char* base, 1577 const size_t size) { 1578 1579 log_info(pagesize)("%s:" 1580 " req_size=" SIZE_FORMAT "%s" 1581 " base=" PTR_FORMAT 1582 " page_size=" SIZE_FORMAT "%s" 1583 " alignment=" SIZE_FORMAT "%s" 1584 " size=" SIZE_FORMAT "%s", 1585 str, 1586 trace_page_size_params(requested_size), 1587 p2i(base), 1588 trace_page_size_params(page_size), 1589 trace_page_size_params(alignment), 1590 trace_page_size_params(size)); 1591 } 1592 1593 1594 // This is the working definition of a server class machine: 1595 // >= 2 physical CPU's and >=2GB of memory, with some fuzz 1596 // because the graphics memory (?) sometimes masks physical memory. 1597 // If you want to change the definition of a server class machine 1598 // on some OS or platform, e.g., >=4GB on Windows platforms, 1599 // then you'll have to parameterize this method based on that state, 1600 // as was done for logical processors here, or replicate and 1601 // specialize this method for each platform. (Or fix os to have 1602 // some inheritance structure and use subclassing. Sigh.) 1603 // If you want some platform to always or never behave as a server 1604 // class machine, change the setting of AlwaysActAsServerClassMachine 1605 // and NeverActAsServerClassMachine in globals*.hpp. 1606 bool os::is_server_class_machine() { 1607 // First check for the early returns 1608 if (NeverActAsServerClassMachine) { 1609 return false; 1610 } 1611 if (AlwaysActAsServerClassMachine) { 1612 return true; 1613 } 1614 // Then actually look at the machine 1615 bool result = false; 1616 const unsigned int server_processors = 2; 1617 const julong server_memory = 2UL * G; 1618 // We seem not to get our full complement of memory. 1619 // We allow some part (1/8?) of the memory to be "missing", 1620 // based on the sizes of DIMMs, and maybe graphics cards. 1621 const julong missing_memory = 256UL * M; 1622 1623 /* Is this a server class machine? */ 1624 if ((os::active_processor_count() >= (int)server_processors) && 1625 (os::physical_memory() >= (server_memory - missing_memory))) { 1626 const unsigned int logical_processors = 1627 VM_Version::logical_processors_per_package(); 1628 if (logical_processors > 1) { 1629 const unsigned int physical_packages = 1630 os::active_processor_count() / logical_processors; 1631 if (physical_packages >= server_processors) { 1632 result = true; 1633 } 1634 } else { 1635 result = true; 1636 } 1637 } 1638 return result; 1639 } 1640 1641 void os::initialize_initial_active_processor_count() { 1642 assert(_initial_active_processor_count == 0, "Initial active processor count already set."); 1643 _initial_active_processor_count = active_processor_count(); 1644 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count); 1645 } 1646 1647 void os::SuspendedThreadTask::run() { 1648 internal_do_task(); 1649 _done = true; 1650 } 1651 1652 bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1653 return os::pd_create_stack_guard_pages(addr, bytes); 1654 } 1655 1656 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) { 1657 char* result = NULL; 1658 1659 if (file_desc != -1) { 1660 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(), 1661 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file. 1662 result = os::map_memory_to_file(addr, bytes, file_desc); 1663 if (result != NULL) { 1664 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1665 } 1666 } else { 1667 result = pd_reserve_memory(bytes, addr, alignment_hint); 1668 if (result != NULL) { 1669 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1670 } 1671 } 1672 1673 return result; 1674 } 1675 1676 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, 1677 MEMFLAGS flags) { 1678 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1679 if (result != NULL) { 1680 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1681 MemTracker::record_virtual_memory_type((address)result, flags); 1682 } 1683 1684 return result; 1685 } 1686 1687 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) { 1688 char* result = NULL; 1689 if (file_desc != -1) { 1690 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc); 1691 if (result != NULL) { 1692 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1693 } 1694 } else { 1695 result = pd_attempt_reserve_memory_at(bytes, addr); 1696 if (result != NULL) { 1697 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1698 } 1699 } 1700 return result; 1701 } 1702 1703 bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1704 bool res = pd_commit_memory(addr, bytes, executable); 1705 if (res) { 1706 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1707 } 1708 return res; 1709 } 1710 1711 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1712 bool executable) { 1713 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1714 if (res) { 1715 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1716 } 1717 return res; 1718 } 1719 1720 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable, 1721 const char* mesg) { 1722 pd_commit_memory_or_exit(addr, bytes, executable, mesg); 1723 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1724 } 1725 1726 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, 1727 bool executable, const char* mesg) { 1728 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg); 1729 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1730 } 1731 1732 bool os::uncommit_memory(char* addr, size_t bytes) { 1733 bool res; 1734 if (MemTracker::tracking_level() > NMT_minimal) { 1735 Tracker tkr(Tracker::uncommit); 1736 res = pd_uncommit_memory(addr, bytes); 1737 if (res) { 1738 tkr.record((address)addr, bytes); 1739 } 1740 } else { 1741 res = pd_uncommit_memory(addr, bytes); 1742 } 1743 return res; 1744 } 1745 1746 bool os::release_memory(char* addr, size_t bytes) { 1747 bool res; 1748 if (MemTracker::tracking_level() > NMT_minimal) { 1749 // Note: Tracker contains a ThreadCritical. 1750 Tracker tkr(Tracker::release); 1751 res = pd_release_memory(addr, bytes); 1752 if (res) { 1753 tkr.record((address)addr, bytes); 1754 } 1755 } else { 1756 res = pd_release_memory(addr, bytes); 1757 } 1758 return res; 1759 } 1760 1761 void os::pretouch_memory(void* start, void* end, size_t page_size) { 1762 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) { 1763 *p = 0; 1764 } 1765 } 1766 1767 char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1768 char *addr, size_t bytes, bool read_only, 1769 bool allow_exec, MEMFLAGS flags) { 1770 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1771 if (result != NULL) { 1772 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC, flags); 1773 } 1774 return result; 1775 } 1776 1777 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1778 char *addr, size_t bytes, bool read_only, 1779 bool allow_exec) { 1780 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1781 read_only, allow_exec); 1782 } 1783 1784 bool os::unmap_memory(char *addr, size_t bytes) { 1785 bool result; 1786 if (MemTracker::tracking_level() > NMT_minimal) { 1787 Tracker tkr(Tracker::release); 1788 result = pd_unmap_memory(addr, bytes); 1789 if (result) { 1790 tkr.record((address)addr, bytes); 1791 } 1792 } else { 1793 result = pd_unmap_memory(addr, bytes); 1794 } 1795 return result; 1796 } 1797 1798 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1799 pd_free_memory(addr, bytes, alignment_hint); 1800 } 1801 1802 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1803 pd_realign_memory(addr, bytes, alignment_hint); 1804 } 1805 1806 char* os::reserve_memory_special(size_t size, size_t alignment, 1807 char* addr, bool executable) { 1808 1809 assert(is_aligned(addr, alignment), "Unaligned request address"); 1810 1811 char* result = pd_reserve_memory_special(size, alignment, addr, executable); 1812 if (result != NULL) { 1813 // The memory is committed 1814 MemTracker::record_virtual_memory_reserve_and_commit((address)result, size, CALLER_PC); 1815 } 1816 1817 return result; 1818 } 1819 1820 bool os::release_memory_special(char* addr, size_t bytes) { 1821 bool res; 1822 if (MemTracker::tracking_level() > NMT_minimal) { 1823 // Note: Tracker contains a ThreadCritical. 1824 Tracker tkr(Tracker::release); 1825 res = pd_release_memory_special(addr, bytes); 1826 if (res) { 1827 tkr.record((address)addr, bytes); 1828 } 1829 } else { 1830 res = pd_release_memory_special(addr, bytes); 1831 } 1832 return res; 1833 } 1834 1835 #ifndef _WINDOWS 1836 /* try to switch state from state "from" to state "to" 1837 * returns the state set after the method is complete 1838 */ 1839 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from, 1840 os::SuspendResume::State to) 1841 { 1842 os::SuspendResume::State result = Atomic::cmpxchg(&_state, from, to); 1843 if (result == from) { 1844 // success 1845 return to; 1846 } 1847 return result; 1848 } 1849 #endif 1850 1851 // Convenience wrapper around naked_short_sleep to allow for longer sleep 1852 // times. Only for use by non-JavaThreads. 1853 void os::naked_sleep(jlong millis) { 1854 assert(!Thread::current()->is_Java_thread(), "not for use by JavaThreads"); 1855 const jlong limit = 999; 1856 while (millis > limit) { 1857 naked_short_sleep(limit); 1858 millis -= limit; 1859 } 1860 naked_short_sleep(millis); 1861 }