1 /* 2 * Copyright (c) 1997, 2018, 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/vmGCOperations.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 #ifdef ASSERT 42 #include "memory/guardedMemory.hpp" 43 #endif 44 #include "memory/resourceArea.hpp" 45 #include "oops/oop.inline.hpp" 46 #include "prims/jvm_misc.hpp" 47 #include "prims/privilegedStack.hpp" 48 #include "runtime/arguments.hpp" 49 #include "runtime/atomic.hpp" 50 #include "runtime/frame.inline.hpp" 51 #include "runtime/interfaceSupport.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/stubRoutines.hpp" 57 #include "runtime/thread.inline.hpp" 58 #include "runtime/threadSMR.hpp" 59 #include "runtime/vm_version.hpp" 60 #include "services/attachListener.hpp" 61 #include "services/mallocTracker.hpp" 62 #include "services/memTracker.hpp" 63 #include "services/nmtCommon.hpp" 64 #include "services/threadService.hpp" 65 #include "utilities/align.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 69 # include <signal.h> 70 # include <errno.h> 71 72 OSThread* os::_starting_thread = NULL; 73 address os::_polling_page = NULL; 74 volatile int32_t* os::_mem_serialize_page = NULL; 75 uintptr_t os::_serialize_page_mask = 0; 76 volatile unsigned int os::_rand_seed = 1; 77 int os::_processor_count = 0; 78 int os::_initial_active_processor_count = 0; 79 size_t os::_page_sizes[os::page_sizes_max]; 80 81 #ifndef PRODUCT 82 julong os::num_mallocs = 0; // # of calls to malloc/realloc 83 julong os::alloc_bytes = 0; // # of bytes allocated 84 julong os::num_frees = 0; // # of calls to free 85 julong os::free_bytes = 0; // # of bytes freed 86 #endif 87 88 static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords 89 90 void os_init_globals() { 91 // Called from init_globals(). 92 // See Threads::create_vm() in thread.cpp, and init.cpp. 93 os::init_globals(); 94 } 95 96 static time_t get_timezone(const struct tm* time_struct) { 97 #if defined(_ALLBSD_SOURCE) 98 return time_struct->tm_gmtoff; 99 #elif defined(_WINDOWS) 100 long zone; 101 _get_timezone(&zone); 102 return static_cast<time_t>(zone); 103 #else 104 return timezone; 105 #endif 106 } 107 108 int os::snprintf(char* buf, size_t len, const char* fmt, ...) { 109 va_list args; 110 va_start(args, fmt); 111 int result = os::vsnprintf(buf, len, fmt, args); 112 va_end(args); 113 return result; 114 } 115 116 // Fill in buffer with current local time as an ISO-8601 string. 117 // E.g., yyyy-mm-ddThh:mm:ss-zzzz. 118 // Returns buffer, or NULL if it failed. 119 // This would mostly be a call to 120 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) 121 // except that on Windows the %z behaves badly, so we do it ourselves. 122 // Also, people wanted milliseconds on there, 123 // and strftime doesn't do milliseconds. 124 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) { 125 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" 126 // 1 2 127 // 12345678901234567890123456789 128 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d" 129 static const size_t needed_buffer = 29; 130 131 // Sanity check the arguments 132 if (buffer == NULL) { 133 assert(false, "NULL buffer"); 134 return NULL; 135 } 136 if (buffer_length < needed_buffer) { 137 assert(false, "buffer_length too small"); 138 return NULL; 139 } 140 // Get the current time 141 jlong milliseconds_since_19700101 = javaTimeMillis(); 142 const int milliseconds_per_microsecond = 1000; 143 const time_t seconds_since_19700101 = 144 milliseconds_since_19700101 / milliseconds_per_microsecond; 145 const int milliseconds_after_second = 146 milliseconds_since_19700101 % milliseconds_per_microsecond; 147 // Convert the time value to a tm and timezone variable 148 struct tm time_struct; 149 if (utc) { 150 if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 151 assert(false, "Failed gmtime_pd"); 152 return NULL; 153 } 154 } else { 155 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 156 assert(false, "Failed localtime_pd"); 157 return NULL; 158 } 159 } 160 const time_t zone = get_timezone(&time_struct); 161 162 // If daylight savings time is in effect, 163 // we are 1 hour East of our time zone 164 const time_t seconds_per_minute = 60; 165 const time_t minutes_per_hour = 60; 166 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; 167 time_t UTC_to_local = zone; 168 if (time_struct.tm_isdst > 0) { 169 UTC_to_local = UTC_to_local - seconds_per_hour; 170 } 171 172 // No offset when dealing with UTC 173 if (utc) { 174 UTC_to_local = 0; 175 } 176 177 // Compute the time zone offset. 178 // localtime_pd() sets timezone to the difference (in seconds) 179 // between UTC and and local time. 180 // ISO 8601 says we need the difference between local time and UTC, 181 // we change the sign of the localtime_pd() result. 182 const time_t local_to_UTC = -(UTC_to_local); 183 // Then we have to figure out if if we are ahead (+) or behind (-) UTC. 184 char sign_local_to_UTC = '+'; 185 time_t abs_local_to_UTC = local_to_UTC; 186 if (local_to_UTC < 0) { 187 sign_local_to_UTC = '-'; 188 abs_local_to_UTC = -(abs_local_to_UTC); 189 } 190 // Convert time zone offset seconds to hours and minutes. 191 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); 192 const time_t zone_min = 193 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); 194 195 // Print an ISO 8601 date and time stamp into the buffer 196 const int year = 1900 + time_struct.tm_year; 197 const int month = 1 + time_struct.tm_mon; 198 const int printed = jio_snprintf(buffer, buffer_length, 199 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d", 200 year, 201 month, 202 time_struct.tm_mday, 203 time_struct.tm_hour, 204 time_struct.tm_min, 205 time_struct.tm_sec, 206 milliseconds_after_second, 207 sign_local_to_UTC, 208 zone_hours, 209 zone_min); 210 if (printed == 0) { 211 assert(false, "Failed jio_printf"); 212 return NULL; 213 } 214 return buffer; 215 } 216 217 OSReturn os::set_priority(Thread* thread, ThreadPriority p) { 218 debug_only(Thread::check_for_dangling_thread_pointer(thread);) 219 220 if (p >= MinPriority && p <= MaxPriority) { 221 int priority = java_to_os_priority[p]; 222 return set_native_priority(thread, priority); 223 } else { 224 assert(false, "Should not happen"); 225 return OS_ERR; 226 } 227 } 228 229 // The mapping from OS priority back to Java priority may be inexact because 230 // Java priorities can map M:1 with native priorities. If you want the definite 231 // Java priority then use JavaThread::java_priority() 232 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { 233 int p; 234 int os_prio; 235 OSReturn ret = get_native_priority(thread, &os_prio); 236 if (ret != OS_OK) return ret; 237 238 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) { 239 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; 240 } else { 241 // niceness values are in reverse order 242 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ; 243 } 244 priority = (ThreadPriority)p; 245 return OS_OK; 246 } 247 248 bool os::dll_build_name(char* buffer, size_t size, const char* fname) { 249 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX); 250 return (n != -1); 251 } 252 253 // Helper for dll_locate_lib. 254 // Pass buffer and printbuffer as we already printed the path to buffer 255 // when we called get_current_directory. This way we avoid another buffer 256 // of size MAX_PATH. 257 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen, 258 const char* pname, char lastchar, const char* fname) { 259 260 // Concatenate path and file name, but don't print double path separators. 261 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ? 262 "" : os::file_separator(); 263 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname); 264 // Check whether file exists. 265 if (ret != -1) { 266 struct stat statbuf; 267 return os::stat(buffer, &statbuf) == 0; 268 } 269 return false; 270 } 271 272 bool os::dll_locate_lib(char *buffer, size_t buflen, 273 const char* pname, const char* fname) { 274 bool retval = false; 275 276 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX); 277 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal); 278 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) { 279 const size_t pnamelen = pname ? strlen(pname) : 0; 280 281 if (pnamelen == 0) { 282 // If no path given, use current working directory. 283 const char* p = get_current_directory(buffer, buflen); 284 if (p != NULL) { 285 const size_t plen = strlen(buffer); 286 const char lastchar = buffer[plen - 1]; 287 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen, 288 "", lastchar, fullfname); 289 } 290 } else if (strchr(pname, *os::path_separator()) != NULL) { 291 // A list of paths. Search for the path that contains the library. 292 int n; 293 char** pelements = split_path(pname, &n); 294 if (pelements != NULL) { 295 for (int i = 0; i < n; i++) { 296 char* path = pelements[i]; 297 // Really shouldn't be NULL, but check can't hurt. 298 size_t plen = (path == NULL) ? 0 : strlen(path); 299 if (plen == 0) { 300 continue; // Skip the empty path values. 301 } 302 const char lastchar = path[plen - 1]; 303 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname); 304 if (retval) break; 305 } 306 // Release the storage allocated by split_path. 307 for (int i = 0; i < n; i++) { 308 if (pelements[i] != NULL) { 309 FREE_C_HEAP_ARRAY(char, pelements[i]); 310 } 311 } 312 FREE_C_HEAP_ARRAY(char*, pelements); 313 } 314 } else { 315 // A definite path. 316 const char lastchar = pname[pnamelen-1]; 317 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname); 318 } 319 } 320 321 FREE_C_HEAP_ARRAY(char*, fullfname); 322 return retval; 323 } 324 325 // --------------------- sun.misc.Signal (optional) --------------------- 326 327 328 // SIGBREAK is sent by the keyboard to query the VM state 329 #ifndef SIGBREAK 330 #define SIGBREAK SIGQUIT 331 #endif 332 333 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. 334 335 336 static void signal_thread_entry(JavaThread* thread, TRAPS) { 337 os::set_priority(thread, NearMaxPriority); 338 while (true) { 339 int sig; 340 { 341 // FIXME : Currently we have not decided what should be the status 342 // for this java thread blocked here. Once we decide about 343 // that we should fix this. 344 sig = os::signal_wait(); 345 } 346 if (sig == os::sigexitnum_pd()) { 347 // Terminate the signal thread 348 return; 349 } 350 351 switch (sig) { 352 case SIGBREAK: { 353 // Check if the signal is a trigger to start the Attach Listener - in that 354 // case don't print stack traces. 355 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { 356 continue; 357 } 358 // Print stack traces 359 // Any SIGBREAK operations added here should make sure to flush 360 // the output stream (e.g. tty->flush()) after output. See 4803766. 361 // Each module also prints an extra carriage return after its output. 362 VM_PrintThreads op; 363 VMThread::execute(&op); 364 VM_PrintJNI jni_op; 365 VMThread::execute(&jni_op); 366 VM_FindDeadlocks op1(tty); 367 VMThread::execute(&op1); 368 Universe::print_heap_at_SIGBREAK(); 369 if (PrintClassHistogram) { 370 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */); 371 VMThread::execute(&op1); 372 } 373 if (JvmtiExport::should_post_data_dump()) { 374 JvmtiExport::post_data_dump(); 375 } 376 break; 377 } 378 default: { 379 // Dispatch the signal to java 380 HandleMark hm(THREAD); 381 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD); 382 if (klass != NULL) { 383 JavaValue result(T_VOID); 384 JavaCallArguments args; 385 args.push_int(sig); 386 JavaCalls::call_static( 387 &result, 388 klass, 389 vmSymbols::dispatch_name(), 390 vmSymbols::int_void_signature(), 391 &args, 392 THREAD 393 ); 394 } 395 if (HAS_PENDING_EXCEPTION) { 396 // tty is initialized early so we don't expect it to be null, but 397 // if it is we can't risk doing an initialization that might 398 // trigger additional out-of-memory conditions 399 if (tty != NULL) { 400 char klass_name[256]; 401 char tmp_sig_name[16]; 402 const char* sig_name = "UNKNOWN"; 403 InstanceKlass::cast(PENDING_EXCEPTION->klass())-> 404 name()->as_klass_external_name(klass_name, 256); 405 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) 406 sig_name = tmp_sig_name; 407 warning("Exception %s occurred dispatching signal %s to handler" 408 "- the VM may need to be forcibly terminated", 409 klass_name, sig_name ); 410 } 411 CLEAR_PENDING_EXCEPTION; 412 } 413 } 414 } 415 } 416 } 417 418 void os::init_before_ergo() { 419 initialize_initial_active_processor_count(); 420 // We need to initialize large page support here because ergonomics takes some 421 // decisions depending on large page support and the calculated large page size. 422 large_page_init(); 423 424 // We need to adapt the configured number of stack protection pages given 425 // in 4K pages to the actual os page size. We must do this before setting 426 // up minimal stack sizes etc. in os::init_2(). 427 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size())); 428 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size())); 429 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size())); 430 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size())); 431 432 // VM version initialization identifies some characteristics of the 433 // platform that are used during ergonomic decisions. 434 VM_Version::init_before_ergo(); 435 } 436 437 void os::signal_init(TRAPS) { 438 if (!ReduceSignalUsage) { 439 // Setup JavaThread for processing signals 440 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); 441 InstanceKlass* ik = InstanceKlass::cast(k); 442 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 443 444 const char thread_name[] = "Signal Dispatcher"; 445 Handle string = java_lang_String::create_from_str(thread_name, CHECK); 446 447 // Initialize thread_oop to put it into the system threadGroup 448 Handle thread_group (THREAD, Universe::system_thread_group()); 449 JavaValue result(T_VOID); 450 JavaCalls::call_special(&result, thread_oop, 451 ik, 452 vmSymbols::object_initializer_name(), 453 vmSymbols::threadgroup_string_void_signature(), 454 thread_group, 455 string, 456 CHECK); 457 458 Klass* group = SystemDictionary::ThreadGroup_klass(); 459 JavaCalls::call_special(&result, 460 thread_group, 461 group, 462 vmSymbols::add_method_name(), 463 vmSymbols::thread_void_signature(), 464 thread_oop, // ARG 1 465 CHECK); 466 467 os::signal_init_pd(); 468 469 { MutexLocker mu(Threads_lock); 470 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); 471 472 // At this point it may be possible that no osthread was created for the 473 // JavaThread due to lack of memory. We would have to throw an exception 474 // in that case. However, since this must work and we do not allow 475 // exceptions anyway, check and abort if this fails. 476 if (signal_thread == NULL || signal_thread->osthread() == NULL) { 477 vm_exit_during_initialization("java.lang.OutOfMemoryError", 478 os::native_thread_creation_failed_msg()); 479 } 480 481 java_lang_Thread::set_thread(thread_oop(), signal_thread); 482 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); 483 java_lang_Thread::set_daemon(thread_oop()); 484 485 signal_thread->set_threadObj(thread_oop()); 486 Threads::add(signal_thread); 487 Thread::start(signal_thread); 488 } 489 // Handle ^BREAK 490 os::signal(SIGBREAK, os::user_handler()); 491 } 492 } 493 494 495 void os::terminate_signal_thread() { 496 if (!ReduceSignalUsage) 497 signal_notify(sigexitnum_pd()); 498 } 499 500 501 // --------------------- loading libraries --------------------- 502 503 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); 504 extern struct JavaVM_ main_vm; 505 506 static void* _native_java_library = NULL; 507 508 void* os::native_java_library() { 509 if (_native_java_library == NULL) { 510 char buffer[JVM_MAXPATHLEN]; 511 char ebuf[1024]; 512 513 // Try to load verify dll first. In 1.3 java dll depends on it and is not 514 // always able to find it when the loading executable is outside the JDK. 515 // In order to keep working with 1.2 we ignore any loading errors. 516 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 517 "verify")) { 518 dll_load(buffer, ebuf, sizeof(ebuf)); 519 } 520 521 // Load java dll 522 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 523 "java")) { 524 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 525 } 526 if (_native_java_library == NULL) { 527 vm_exit_during_initialization("Unable to load native library", ebuf); 528 } 529 530 #if defined(__OpenBSD__) 531 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 532 // ignore errors 533 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 534 "net")) { 535 dll_load(buffer, ebuf, sizeof(ebuf)); 536 } 537 #endif 538 } 539 return _native_java_library; 540 } 541 542 /* 543 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists. 544 * If check_lib == true then we are looking for an 545 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if 546 * this library is statically linked into the image. 547 * If check_lib == false then we will look for the appropriate symbol in the 548 * executable if agent_lib->is_static_lib() == true or in the shared library 549 * referenced by 'handle'. 550 */ 551 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib, 552 const char *syms[], size_t syms_len) { 553 assert(agent_lib != NULL, "sanity check"); 554 const char *lib_name; 555 void *handle = agent_lib->os_lib(); 556 void *entryName = NULL; 557 char *agent_function_name; 558 size_t i; 559 560 // If checking then use the agent name otherwise test is_static_lib() to 561 // see how to process this lookup 562 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL); 563 for (i = 0; i < syms_len; i++) { 564 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path()); 565 if (agent_function_name == NULL) { 566 break; 567 } 568 entryName = dll_lookup(handle, agent_function_name); 569 FREE_C_HEAP_ARRAY(char, agent_function_name); 570 if (entryName != NULL) { 571 break; 572 } 573 } 574 return entryName; 575 } 576 577 // See if the passed in agent is statically linked into the VM image. 578 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 579 size_t syms_len) { 580 void *ret; 581 void *proc_handle; 582 void *save_handle; 583 584 assert(agent_lib != NULL, "sanity check"); 585 if (agent_lib->name() == NULL) { 586 return false; 587 } 588 proc_handle = get_default_process_handle(); 589 // Check for Agent_OnLoad/Attach_lib_name function 590 save_handle = agent_lib->os_lib(); 591 // We want to look in this process' symbol table. 592 agent_lib->set_os_lib(proc_handle); 593 ret = find_agent_function(agent_lib, true, syms, syms_len); 594 if (ret != NULL) { 595 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent 596 agent_lib->set_valid(); 597 agent_lib->set_static_lib(true); 598 return true; 599 } 600 agent_lib->set_os_lib(save_handle); 601 return false; 602 } 603 604 // --------------------- heap allocation utilities --------------------- 605 606 char *os::strdup(const char *str, MEMFLAGS flags) { 607 size_t size = strlen(str); 608 char *dup_str = (char *)malloc(size + 1, flags); 609 if (dup_str == NULL) return NULL; 610 strcpy(dup_str, str); 611 return dup_str; 612 } 613 614 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) { 615 char* p = os::strdup(str, flags); 616 if (p == NULL) { 617 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom"); 618 } 619 return p; 620 } 621 622 623 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 624 625 #ifdef ASSERT 626 627 static void verify_memory(void* ptr) { 628 GuardedMemory guarded(ptr); 629 if (!guarded.verify_guards()) { 630 LogTarget(Warning, malloc, free) lt; 631 ResourceMark rm; 632 LogStream ls(lt); 633 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 634 ls.print_cr("## memory stomp:"); 635 guarded.print_on(&ls); 636 fatal("memory stomping error"); 637 } 638 } 639 640 #endif 641 642 // 643 // This function supports testing of the malloc out of memory 644 // condition without really running the system out of memory. 645 // 646 static bool has_reached_max_malloc_test_peak(size_t alloc_size) { 647 if (MallocMaxTestWords > 0) { 648 size_t words = (alloc_size / BytesPerWord); 649 650 if ((cur_malloc_words + words) > MallocMaxTestWords) { 651 return true; 652 } 653 Atomic::add(words, &cur_malloc_words); 654 } 655 return false; 656 } 657 658 void* os::malloc(size_t size, MEMFLAGS flags) { 659 return os::malloc(size, flags, CALLER_PC); 660 } 661 662 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 663 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 664 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 665 666 // Since os::malloc can be called when the libjvm.{dll,so} is 667 // first loaded and we don't have a thread yet we must accept NULL also here. 668 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()), 669 "malloc() not allowed when crash protection is set"); 670 671 if (size == 0) { 672 // return a valid pointer if size is zero 673 // if NULL is returned the calling functions assume out of memory. 674 size = 1; 675 } 676 677 // NMT support 678 NMT_TrackingLevel level = MemTracker::tracking_level(); 679 size_t nmt_header_size = MemTracker::malloc_header_size(level); 680 681 #ifndef ASSERT 682 const size_t alloc_size = size + nmt_header_size; 683 #else 684 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size); 685 if (size + nmt_header_size > alloc_size) { // Check for rollover. 686 return NULL; 687 } 688 #endif 689 690 // For the test flag -XX:MallocMaxTestWords 691 if (has_reached_max_malloc_test_peak(size)) { 692 return NULL; 693 } 694 695 u_char* ptr; 696 ptr = (u_char*)::malloc(alloc_size); 697 698 #ifdef ASSERT 699 if (ptr == NULL) { 700 return NULL; 701 } 702 // Wrap memory with guard 703 GuardedMemory guarded(ptr, size + nmt_header_size); 704 ptr = guarded.get_user_ptr(); 705 #endif 706 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 707 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 708 breakpoint(); 709 } 710 debug_only(if (paranoid) verify_memory(ptr)); 711 712 // we do not track guard memory 713 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level); 714 } 715 716 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) { 717 return os::realloc(memblock, size, flags, CALLER_PC); 718 } 719 720 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 721 722 // For the test flag -XX:MallocMaxTestWords 723 if (has_reached_max_malloc_test_peak(size)) { 724 return NULL; 725 } 726 727 if (size == 0) { 728 // return a valid pointer if size is zero 729 // if NULL is returned the calling functions assume out of memory. 730 size = 1; 731 } 732 733 #ifndef ASSERT 734 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 735 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 736 // NMT support 737 void* membase = MemTracker::record_free(memblock); 738 NMT_TrackingLevel level = MemTracker::tracking_level(); 739 size_t nmt_header_size = MemTracker::malloc_header_size(level); 740 void* ptr = ::realloc(membase, size + nmt_header_size); 741 return MemTracker::record_malloc(ptr, size, memflags, stack, level); 742 #else 743 if (memblock == NULL) { 744 return os::malloc(size, memflags, stack); 745 } 746 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 747 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock)); 748 breakpoint(); 749 } 750 // NMT support 751 void* membase = MemTracker::malloc_base(memblock); 752 verify_memory(membase); 753 // always move the block 754 void* ptr = os::malloc(size, memflags, stack); 755 // Copy to new memory if malloc didn't fail 756 if (ptr != NULL ) { 757 GuardedMemory guarded(MemTracker::malloc_base(memblock)); 758 // Guard's user data contains NMT header 759 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock); 760 memcpy(ptr, memblock, MIN2(size, memblock_size)); 761 if (paranoid) verify_memory(MemTracker::malloc_base(ptr)); 762 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 763 log_warning(malloc, free)("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 764 breakpoint(); 765 } 766 os::free(memblock); 767 } 768 return ptr; 769 #endif 770 } 771 772 773 void os::free(void *memblock) { 774 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 775 #ifdef ASSERT 776 if (memblock == NULL) return; 777 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 778 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock)); 779 breakpoint(); 780 } 781 void* membase = MemTracker::record_free(memblock); 782 verify_memory(membase); 783 784 GuardedMemory guarded(membase); 785 size_t size = guarded.get_user_size(); 786 inc_stat_counter(&free_bytes, size); 787 membase = guarded.release_for_freeing(); 788 ::free(membase); 789 #else 790 void* membase = MemTracker::record_free(memblock); 791 ::free(membase); 792 #endif 793 } 794 795 void os::init_random(unsigned int initval) { 796 _rand_seed = initval; 797 } 798 799 800 static int random_helper(unsigned int rand_seed) { 801 /* standard, well-known linear congruential random generator with 802 * next_rand = (16807*seed) mod (2**31-1) 803 * see 804 * (1) "Random Number Generators: Good Ones Are Hard to Find", 805 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 806 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 807 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 808 */ 809 const unsigned int a = 16807; 810 const unsigned int m = 2147483647; 811 const int q = m / a; assert(q == 127773, "weird math"); 812 const int r = m % a; assert(r == 2836, "weird math"); 813 814 // compute az=2^31p+q 815 unsigned int lo = a * (rand_seed & 0xFFFF); 816 unsigned int hi = a * (rand_seed >> 16); 817 lo += (hi & 0x7FFF) << 16; 818 819 // if q overflowed, ignore the overflow and increment q 820 if (lo > m) { 821 lo &= m; 822 ++lo; 823 } 824 lo += hi >> 15; 825 826 // if (p+q) overflowed, ignore the overflow and increment (p+q) 827 if (lo > m) { 828 lo &= m; 829 ++lo; 830 } 831 return lo; 832 } 833 834 int os::random() { 835 // Make updating the random seed thread safe. 836 while (true) { 837 unsigned int seed = _rand_seed; 838 unsigned int rand = random_helper(seed); 839 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) { 840 return static_cast<int>(rand); 841 } 842 } 843 } 844 845 // The INITIALIZED state is distinguished from the SUSPENDED state because the 846 // conditions in which a thread is first started are different from those in which 847 // a suspension is resumed. These differences make it hard for us to apply the 848 // tougher checks when starting threads that we want to do when resuming them. 849 // However, when start_thread is called as a result of Thread.start, on a Java 850 // thread, the operation is synchronized on the Java Thread object. So there 851 // cannot be a race to start the thread and hence for the thread to exit while 852 // we are working on it. Non-Java threads that start Java threads either have 853 // to do so in a context in which races are impossible, or should do appropriate 854 // locking. 855 856 void os::start_thread(Thread* thread) { 857 // guard suspend/resume 858 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 859 OSThread* osthread = thread->osthread(); 860 osthread->set_state(RUNNABLE); 861 pd_start_thread(thread); 862 } 863 864 void os::abort(bool dump_core) { 865 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL); 866 } 867 868 //--------------------------------------------------------------------------- 869 // Helper functions for fatal error handler 870 871 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 872 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 873 874 int cols = 0; 875 int cols_per_line = 0; 876 switch (unitsize) { 877 case 1: cols_per_line = 16; break; 878 case 2: cols_per_line = 8; break; 879 case 4: cols_per_line = 4; break; 880 case 8: cols_per_line = 2; break; 881 default: return; 882 } 883 884 address p = start; 885 st->print(PTR_FORMAT ": ", p2i(start)); 886 while (p < end) { 887 switch (unitsize) { 888 case 1: st->print("%02x", *(u1*)p); break; 889 case 2: st->print("%04x", *(u2*)p); break; 890 case 4: st->print("%08x", *(u4*)p); break; 891 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 892 } 893 p += unitsize; 894 cols++; 895 if (cols >= cols_per_line && p < end) { 896 cols = 0; 897 st->cr(); 898 st->print(PTR_FORMAT ": ", p2i(p)); 899 } else { 900 st->print(" "); 901 } 902 } 903 st->cr(); 904 } 905 906 void os::print_environment_variables(outputStream* st, const char** env_list) { 907 if (env_list) { 908 st->print_cr("Environment Variables:"); 909 910 for (int i = 0; env_list[i] != NULL; i++) { 911 char *envvar = ::getenv(env_list[i]); 912 if (envvar != NULL) { 913 st->print("%s", env_list[i]); 914 st->print("="); 915 st->print_cr("%s", envvar); 916 } 917 } 918 } 919 } 920 921 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) { 922 // cpu 923 st->print("CPU:"); 924 st->print("total %d", os::processor_count()); 925 // It's not safe to query number of active processors after crash 926 // st->print("(active %d)", os::active_processor_count()); but we can 927 // print the initial number of active processors. 928 // We access the raw value here because the assert in the accessor will 929 // fail if the crash occurs before initialization of this value. 930 st->print(" (initial active %d)", _initial_active_processor_count); 931 st->print(" %s", VM_Version::features_string()); 932 st->cr(); 933 pd_print_cpu_info(st, buf, buflen); 934 } 935 936 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version 937 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) { 938 st->print("Host: "); 939 #ifndef PRODUCT 940 if (get_host_name(buf, buflen)) { 941 st->print("%s, ", buf); 942 } 943 #endif // PRODUCT 944 get_summary_cpu_info(buf, buflen); 945 st->print("%s, ", buf); 946 size_t mem = physical_memory()/G; 947 if (mem == 0) { // for low memory systems 948 mem = physical_memory()/M; 949 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem); 950 } else { 951 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem); 952 } 953 get_summary_os_info(buf, buflen); 954 st->print_raw(buf); 955 st->cr(); 956 } 957 958 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) { 959 const int secs_per_day = 86400; 960 const int secs_per_hour = 3600; 961 const int secs_per_min = 60; 962 963 time_t tloc; 964 (void)time(&tloc); 965 char* timestring = ctime(&tloc); // ctime adds newline. 966 // edit out the newline 967 char* nl = strchr(timestring, '\n'); 968 if (nl != NULL) { 969 *nl = '\0'; 970 } 971 972 struct tm tz; 973 if (localtime_pd(&tloc, &tz) != NULL) { 974 ::strftime(buf, buflen, "%Z", &tz); 975 st->print("Time: %s %s", timestring, buf); 976 } else { 977 st->print("Time: %s", timestring); 978 } 979 980 double t = os::elapsedTime(); 981 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in 982 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int 983 // before printf. We lost some precision, but who cares? 984 int eltime = (int)t; // elapsed time in seconds 985 986 // print elapsed time in a human-readable format: 987 int eldays = eltime / secs_per_day; 988 int day_secs = eldays * secs_per_day; 989 int elhours = (eltime - day_secs) / secs_per_hour; 990 int hour_secs = elhours * secs_per_hour; 991 int elmins = (eltime - day_secs - hour_secs) / secs_per_min; 992 int minute_secs = elmins * secs_per_min; 993 int elsecs = (eltime - day_secs - hour_secs - minute_secs); 994 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs); 995 } 996 997 // moved from debug.cpp (used to be find()) but still called from there 998 // The verbose parameter is only set by the debug code in one case 999 void os::print_location(outputStream* st, intptr_t x, bool verbose) { 1000 address addr = (address)x; 1001 // Handle NULL first, so later checks don't need to protect against it. 1002 if (addr == NULL) { 1003 st->print_cr("0x0 is NULL"); 1004 return; 1005 } 1006 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 1007 if (b != NULL) { 1008 if (b->is_buffer_blob()) { 1009 // the interpreter is generated into a buffer blob 1010 InterpreterCodelet* i = Interpreter::codelet_containing(addr); 1011 if (i != NULL) { 1012 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin())); 1013 i->print_on(st); 1014 return; 1015 } 1016 if (Interpreter::contains(addr)) { 1017 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code" 1018 " (not bytecode specific)", p2i(addr)); 1019 return; 1020 } 1021 // 1022 if (AdapterHandlerLibrary::contains(b)) { 1023 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin())); 1024 AdapterHandlerLibrary::print_handler_on(st, b); 1025 } 1026 // the stubroutines are generated into a buffer blob 1027 StubCodeDesc* d = StubCodeDesc::desc_for(addr); 1028 if (d != NULL) { 1029 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin())); 1030 d->print_on(st); 1031 st->cr(); 1032 return; 1033 } 1034 if (StubRoutines::contains(addr)) { 1035 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr)); 1036 return; 1037 } 1038 // the InlineCacheBuffer is using stubs generated into a buffer blob 1039 if (InlineCacheBuffer::contains(addr)) { 1040 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr)); 1041 return; 1042 } 1043 VtableStub* v = VtableStubs::stub_containing(addr); 1044 if (v != NULL) { 1045 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point())); 1046 v->print_on(st); 1047 st->cr(); 1048 return; 1049 } 1050 } 1051 nmethod* nm = b->as_nmethod_or_null(); 1052 if (nm != NULL) { 1053 ResourceMark rm; 1054 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT, 1055 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm)); 1056 if (verbose) { 1057 st->print(" for "); 1058 nm->method()->print_value_on(st); 1059 } 1060 st->cr(); 1061 nm->print_nmethod(verbose); 1062 return; 1063 } 1064 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin())); 1065 b->print_on(st); 1066 return; 1067 } 1068 1069 if (Universe::heap()->is_in(addr)) { 1070 HeapWord* p = Universe::heap()->block_start(addr); 1071 bool print = false; 1072 // If we couldn't find it it just may mean that heap wasn't parsable 1073 // See if we were just given an oop directly 1074 if (p != NULL && Universe::heap()->block_is_obj(p)) { 1075 print = true; 1076 } else if (p == NULL && oopDesc::is_oop(oop(addr))) { 1077 p = (HeapWord*) addr; 1078 print = true; 1079 } 1080 if (print) { 1081 if (p == (HeapWord*) addr) { 1082 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr)); 1083 } else { 1084 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p)); 1085 } 1086 oop(p)->print_on(st); 1087 return; 1088 } 1089 } else { 1090 if (Universe::heap()->is_in_reserved(addr)) { 1091 st->print_cr(INTPTR_FORMAT " is an unallocated location " 1092 "in the heap", p2i(addr)); 1093 return; 1094 } 1095 } 1096 if (JNIHandles::is_global_handle((jobject) addr)) { 1097 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr)); 1098 return; 1099 } 1100 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 1101 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr)); 1102 return; 1103 } 1104 #ifndef PRODUCT 1105 // we don't keep the block list in product mode 1106 if (JNIHandles::is_local_handle((jobject) addr)) { 1107 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr)); 1108 return; 1109 } 1110 #endif 1111 1112 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 1113 // Check for privilege stack 1114 if (thread->privileged_stack_top() != NULL && 1115 thread->privileged_stack_top()->contains(addr)) { 1116 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack " 1117 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread)); 1118 if (verbose) thread->print_on(st); 1119 return; 1120 } 1121 // If the addr is a java thread print information about that. 1122 if (addr == (address)thread) { 1123 if (verbose) { 1124 thread->print_on(st); 1125 } else { 1126 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr)); 1127 } 1128 return; 1129 } 1130 // If the addr is in the stack region for this thread then report that 1131 // and print thread info 1132 if (thread->on_local_stack(addr)) { 1133 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 1134 INTPTR_FORMAT, p2i(addr), p2i(thread)); 1135 if (verbose) thread->print_on(st); 1136 return; 1137 } 1138 } 1139 1140 // Check if in metaspace and print types that have vptrs (only method now) 1141 if (Metaspace::contains(addr)) { 1142 if (Method::has_method_vptr((const void*)addr)) { 1143 ((Method*)addr)->print_value_on(st); 1144 st->cr(); 1145 } else { 1146 // Use addr->print() from the debugger instead (not here) 1147 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr)); 1148 } 1149 return; 1150 } 1151 1152 // Try an OS specific find 1153 if (os::find(addr, st)) { 1154 return; 1155 } 1156 1157 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr)); 1158 } 1159 1160 // Looks like all platforms except IA64 can use the same function to check 1161 // if C stack is walkable beyond current frame. The check for fp() is not 1162 // necessary on Sparc, but it's harmless. 1163 bool os::is_first_C_frame(frame* fr) { 1164 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32) 1165 // On IA64 we have to check if the callers bsp is still valid 1166 // (i.e. within the register stack bounds). 1167 // Notice: this only works for threads created by the VM and only if 1168 // we walk the current stack!!! If we want to be able to walk 1169 // arbitrary other threads, we'll have to somehow store the thread 1170 // object in the frame. 1171 Thread *thread = Thread::current(); 1172 if ((address)fr->fp() <= 1173 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) { 1174 // This check is a little hacky, because on Linux the first C 1175 // frame's ('start_thread') register stack frame starts at 1176 // "register_stack_base + 0x48" while on HPUX, the first C frame's 1177 // ('__pthread_bound_body') register stack frame seems to really 1178 // start at "register_stack_base". 1179 return true; 1180 } else { 1181 return false; 1182 } 1183 #elif defined(IA64) && defined(_WIN32) 1184 return true; 1185 #else 1186 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 1187 // Check usp first, because if that's bad the other accessors may fault 1188 // on some architectures. Ditto ufp second, etc. 1189 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 1190 // sp on amd can be 32 bit aligned. 1191 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 1192 1193 uintptr_t usp = (uintptr_t)fr->sp(); 1194 if ((usp & sp_align_mask) != 0) return true; 1195 1196 uintptr_t ufp = (uintptr_t)fr->fp(); 1197 if ((ufp & fp_align_mask) != 0) return true; 1198 1199 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 1200 if ((old_sp & sp_align_mask) != 0) return true; 1201 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 1202 1203 uintptr_t old_fp = (uintptr_t)fr->link(); 1204 if ((old_fp & fp_align_mask) != 0) return true; 1205 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1206 1207 // stack grows downwards; if old_fp is below current fp or if the stack 1208 // frame is too large, either the stack is corrupted or fp is not saved 1209 // on stack (i.e. on x86, ebp may be used as general register). The stack 1210 // is not walkable beyond current frame. 1211 if (old_fp < ufp) return true; 1212 if (old_fp - ufp > 64 * K) return true; 1213 1214 return false; 1215 #endif 1216 } 1217 1218 1219 // Set up the boot classpath. 1220 1221 char* os::format_boot_path(const char* format_string, 1222 const char* home, 1223 int home_len, 1224 char fileSep, 1225 char pathSep) { 1226 assert((fileSep == '/' && pathSep == ':') || 1227 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars"); 1228 1229 // Scan the format string to determine the length of the actual 1230 // boot classpath, and handle platform dependencies as well. 1231 int formatted_path_len = 0; 1232 const char* p; 1233 for (p = format_string; *p != 0; ++p) { 1234 if (*p == '%') formatted_path_len += home_len - 1; 1235 ++formatted_path_len; 1236 } 1237 1238 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1239 if (formatted_path == NULL) { 1240 return NULL; 1241 } 1242 1243 // Create boot classpath from format, substituting separator chars and 1244 // java home directory. 1245 char* q = formatted_path; 1246 for (p = format_string; *p != 0; ++p) { 1247 switch (*p) { 1248 case '%': 1249 strcpy(q, home); 1250 q += home_len; 1251 break; 1252 case '/': 1253 *q++ = fileSep; 1254 break; 1255 case ':': 1256 *q++ = pathSep; 1257 break; 1258 default: 1259 *q++ = *p; 1260 } 1261 } 1262 *q = '\0'; 1263 1264 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1265 return formatted_path; 1266 } 1267 1268 bool os::set_boot_path(char fileSep, char pathSep) { 1269 const char* home = Arguments::get_java_home(); 1270 int home_len = (int)strlen(home); 1271 1272 struct stat st; 1273 1274 // modular image if "modules" jimage exists 1275 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep); 1276 if (jimage == NULL) return false; 1277 bool has_jimage = (os::stat(jimage, &st) == 0); 1278 if (has_jimage) { 1279 Arguments::set_sysclasspath(jimage, true); 1280 FREE_C_HEAP_ARRAY(char, jimage); 1281 return true; 1282 } 1283 FREE_C_HEAP_ARRAY(char, jimage); 1284 1285 // check if developer build with exploded modules 1286 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep); 1287 if (base_classes == NULL) return false; 1288 if (os::stat(base_classes, &st) == 0) { 1289 Arguments::set_sysclasspath(base_classes, false); 1290 FREE_C_HEAP_ARRAY(char, base_classes); 1291 return true; 1292 } 1293 FREE_C_HEAP_ARRAY(char, base_classes); 1294 1295 return false; 1296 } 1297 1298 /* 1299 * Splits a path, based on its separator, the number of 1300 * elements is returned back in n. 1301 * It is the callers responsibility to: 1302 * a> check the value of n, and n may be 0. 1303 * b> ignore any empty path elements 1304 * c> free up the data. 1305 */ 1306 char** os::split_path(const char* path, int* n) { 1307 *n = 0; 1308 if (path == NULL || strlen(path) == 0) { 1309 return NULL; 1310 } 1311 const char psepchar = *os::path_separator(); 1312 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1313 if (inpath == NULL) { 1314 return NULL; 1315 } 1316 strcpy(inpath, path); 1317 int count = 1; 1318 char* p = strchr(inpath, psepchar); 1319 // Get a count of elements to allocate memory 1320 while (p != NULL) { 1321 count++; 1322 p++; 1323 p = strchr(p, psepchar); 1324 } 1325 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1326 if (opath == NULL) { 1327 return NULL; 1328 } 1329 1330 // do the actual splitting 1331 p = inpath; 1332 for (int i = 0 ; i < count ; i++) { 1333 size_t len = strcspn(p, os::path_separator()); 1334 if (len > JVM_MAXPATHLEN) { 1335 return NULL; 1336 } 1337 // allocate the string and add terminator storage 1338 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 1339 if (s == NULL) { 1340 return NULL; 1341 } 1342 strncpy(s, p, len); 1343 s[len] = '\0'; 1344 opath[i] = s; 1345 p += len + 1; 1346 } 1347 FREE_C_HEAP_ARRAY(char, inpath); 1348 *n = count; 1349 return opath; 1350 } 1351 1352 void os::set_memory_serialize_page(address page) { 1353 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); 1354 _mem_serialize_page = (volatile int32_t *)page; 1355 // We initialize the serialization page shift count here 1356 // We assume a cache line size of 64 bytes 1357 assert(SerializePageShiftCount == count, "JavaThread size changed; " 1358 "SerializePageShiftCount constant should be %d", count); 1359 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); 1360 } 1361 1362 static volatile intptr_t SerializePageLock = 0; 1363 1364 // This method is called from signal handler when SIGSEGV occurs while the current 1365 // thread tries to store to the "read-only" memory serialize page during state 1366 // transition. 1367 void os::block_on_serialize_page_trap() { 1368 log_debug(safepoint)("Block until the serialize page permission restored"); 1369 1370 // When VMThread is holding the SerializePageLock during modifying the 1371 // access permission of the memory serialize page, the following call 1372 // will block until the permission of that page is restored to rw. 1373 // Generally, it is unsafe to manipulate locks in signal handlers, but in 1374 // this case, it's OK as the signal is synchronous and we know precisely when 1375 // it can occur. 1376 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); 1377 Thread::muxRelease(&SerializePageLock); 1378 } 1379 1380 // Serialize all thread state variables 1381 void os::serialize_thread_states() { 1382 // On some platforms such as Solaris & Linux, the time duration of the page 1383 // permission restoration is observed to be much longer than expected due to 1384 // scheduler starvation problem etc. To avoid the long synchronization 1385 // time and expensive page trap spinning, 'SerializePageLock' is used to block 1386 // the mutator thread if such case is encountered. See bug 6546278 for details. 1387 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); 1388 os::protect_memory((char *)os::get_memory_serialize_page(), 1389 os::vm_page_size(), MEM_PROT_READ); 1390 os::protect_memory((char *)os::get_memory_serialize_page(), 1391 os::vm_page_size(), MEM_PROT_RW); 1392 Thread::muxRelease(&SerializePageLock); 1393 } 1394 1395 // Returns true if the current stack pointer is above the stack shadow 1396 // pages, false otherwise. 1397 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) { 1398 if (!thread->is_Java_thread()) return false; 1399 // Check if we have StackShadowPages above the yellow zone. This parameter 1400 // is dependent on the depth of the maximum VM call stack possible from 1401 // the handler for stack overflow. 'instanceof' in the stack overflow 1402 // handler or a println uses at least 8k stack of VM and native code 1403 // respectively. 1404 const int framesize_in_bytes = 1405 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1406 1407 address limit = ((JavaThread*)thread)->stack_end() + 1408 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size()); 1409 1410 return sp > (limit + framesize_in_bytes); 1411 } 1412 1413 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) { 1414 assert(min_pages > 0, "sanity"); 1415 if (UseLargePages) { 1416 const size_t max_page_size = region_size / min_pages; 1417 1418 for (size_t i = 0; _page_sizes[i] != 0; ++i) { 1419 const size_t page_size = _page_sizes[i]; 1420 if (page_size <= max_page_size) { 1421 if (!must_be_aligned || is_aligned(region_size, page_size)) { 1422 return page_size; 1423 } 1424 } 1425 } 1426 } 1427 1428 return vm_page_size(); 1429 } 1430 1431 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) { 1432 return page_size_for_region(region_size, min_pages, true); 1433 } 1434 1435 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) { 1436 return page_size_for_region(region_size, min_pages, false); 1437 } 1438 1439 static const char* errno_to_string (int e, bool short_text) { 1440 #define ALL_SHARED_ENUMS(X) \ 1441 X(E2BIG, "Argument list too long") \ 1442 X(EACCES, "Permission denied") \ 1443 X(EADDRINUSE, "Address in use") \ 1444 X(EADDRNOTAVAIL, "Address not available") \ 1445 X(EAFNOSUPPORT, "Address family not supported") \ 1446 X(EAGAIN, "Resource unavailable, try again") \ 1447 X(EALREADY, "Connection already in progress") \ 1448 X(EBADF, "Bad file descriptor") \ 1449 X(EBADMSG, "Bad message") \ 1450 X(EBUSY, "Device or resource busy") \ 1451 X(ECANCELED, "Operation canceled") \ 1452 X(ECHILD, "No child processes") \ 1453 X(ECONNABORTED, "Connection aborted") \ 1454 X(ECONNREFUSED, "Connection refused") \ 1455 X(ECONNRESET, "Connection reset") \ 1456 X(EDEADLK, "Resource deadlock would occur") \ 1457 X(EDESTADDRREQ, "Destination address required") \ 1458 X(EDOM, "Mathematics argument out of domain of function") \ 1459 X(EEXIST, "File exists") \ 1460 X(EFAULT, "Bad address") \ 1461 X(EFBIG, "File too large") \ 1462 X(EHOSTUNREACH, "Host is unreachable") \ 1463 X(EIDRM, "Identifier removed") \ 1464 X(EILSEQ, "Illegal byte sequence") \ 1465 X(EINPROGRESS, "Operation in progress") \ 1466 X(EINTR, "Interrupted function") \ 1467 X(EINVAL, "Invalid argument") \ 1468 X(EIO, "I/O error") \ 1469 X(EISCONN, "Socket is connected") \ 1470 X(EISDIR, "Is a directory") \ 1471 X(ELOOP, "Too many levels of symbolic links") \ 1472 X(EMFILE, "Too many open files") \ 1473 X(EMLINK, "Too many links") \ 1474 X(EMSGSIZE, "Message too large") \ 1475 X(ENAMETOOLONG, "Filename too long") \ 1476 X(ENETDOWN, "Network is down") \ 1477 X(ENETRESET, "Connection aborted by network") \ 1478 X(ENETUNREACH, "Network unreachable") \ 1479 X(ENFILE, "Too many files open in system") \ 1480 X(ENOBUFS, "No buffer space available") \ 1481 X(ENODATA, "No message is available on the STREAM head read queue") \ 1482 X(ENODEV, "No such device") \ 1483 X(ENOENT, "No such file or directory") \ 1484 X(ENOEXEC, "Executable file format error") \ 1485 X(ENOLCK, "No locks available") \ 1486 X(ENOLINK, "Reserved") \ 1487 X(ENOMEM, "Not enough space") \ 1488 X(ENOMSG, "No message of the desired type") \ 1489 X(ENOPROTOOPT, "Protocol not available") \ 1490 X(ENOSPC, "No space left on device") \ 1491 X(ENOSR, "No STREAM resources") \ 1492 X(ENOSTR, "Not a STREAM") \ 1493 X(ENOSYS, "Function not supported") \ 1494 X(ENOTCONN, "The socket is not connected") \ 1495 X(ENOTDIR, "Not a directory") \ 1496 X(ENOTEMPTY, "Directory not empty") \ 1497 X(ENOTSOCK, "Not a socket") \ 1498 X(ENOTSUP, "Not supported") \ 1499 X(ENOTTY, "Inappropriate I/O control operation") \ 1500 X(ENXIO, "No such device or address") \ 1501 X(EOPNOTSUPP, "Operation not supported on socket") \ 1502 X(EOVERFLOW, "Value too large to be stored in data type") \ 1503 X(EPERM, "Operation not permitted") \ 1504 X(EPIPE, "Broken pipe") \ 1505 X(EPROTO, "Protocol error") \ 1506 X(EPROTONOSUPPORT, "Protocol not supported") \ 1507 X(EPROTOTYPE, "Protocol wrong type for socket") \ 1508 X(ERANGE, "Result too large") \ 1509 X(EROFS, "Read-only file system") \ 1510 X(ESPIPE, "Invalid seek") \ 1511 X(ESRCH, "No such process") \ 1512 X(ETIME, "Stream ioctl() timeout") \ 1513 X(ETIMEDOUT, "Connection timed out") \ 1514 X(ETXTBSY, "Text file busy") \ 1515 X(EWOULDBLOCK, "Operation would block") \ 1516 X(EXDEV, "Cross-device link") 1517 1518 #define DEFINE_ENTRY(e, text) { e, #e, text }, 1519 1520 static const struct { 1521 int v; 1522 const char* short_text; 1523 const char* long_text; 1524 } table [] = { 1525 1526 ALL_SHARED_ENUMS(DEFINE_ENTRY) 1527 1528 // The following enums are not defined on all platforms. 1529 #ifdef ESTALE 1530 DEFINE_ENTRY(ESTALE, "Reserved") 1531 #endif 1532 #ifdef EDQUOT 1533 DEFINE_ENTRY(EDQUOT, "Reserved") 1534 #endif 1535 #ifdef EMULTIHOP 1536 DEFINE_ENTRY(EMULTIHOP, "Reserved") 1537 #endif 1538 1539 // End marker. 1540 { -1, "Unknown errno", "Unknown error" } 1541 1542 }; 1543 1544 #undef DEFINE_ENTRY 1545 #undef ALL_FLAGS 1546 1547 int i = 0; 1548 while (table[i].v != -1 && table[i].v != e) { 1549 i ++; 1550 } 1551 1552 return short_text ? table[i].short_text : table[i].long_text; 1553 1554 } 1555 1556 const char* os::strerror(int e) { 1557 return errno_to_string(e, false); 1558 } 1559 1560 const char* os::errno_name(int e) { 1561 return errno_to_string(e, true); 1562 } 1563 1564 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) { 1565 LogTarget(Info, pagesize) log; 1566 if (log.is_enabled()) { 1567 LogStream out(log); 1568 1569 out.print("%s: ", str); 1570 for (int i = 0; i < count; ++i) { 1571 out.print(" " SIZE_FORMAT, page_sizes[i]); 1572 } 1573 out.cr(); 1574 } 1575 } 1576 1577 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size) 1578 1579 void os::trace_page_sizes(const char* str, 1580 const size_t region_min_size, 1581 const size_t region_max_size, 1582 const size_t page_size, 1583 const char* base, 1584 const size_t size) { 1585 1586 log_info(pagesize)("%s: " 1587 " min=" SIZE_FORMAT "%s" 1588 " max=" SIZE_FORMAT "%s" 1589 " base=" PTR_FORMAT 1590 " page_size=" SIZE_FORMAT "%s" 1591 " size=" SIZE_FORMAT "%s", 1592 str, 1593 trace_page_size_params(region_min_size), 1594 trace_page_size_params(region_max_size), 1595 p2i(base), 1596 trace_page_size_params(page_size), 1597 trace_page_size_params(size)); 1598 } 1599 1600 void os::trace_page_sizes_for_requested_size(const char* str, 1601 const size_t requested_size, 1602 const size_t page_size, 1603 const size_t alignment, 1604 const char* base, 1605 const size_t size) { 1606 1607 log_info(pagesize)("%s:" 1608 " req_size=" SIZE_FORMAT "%s" 1609 " base=" PTR_FORMAT 1610 " page_size=" SIZE_FORMAT "%s" 1611 " alignment=" SIZE_FORMAT "%s" 1612 " size=" SIZE_FORMAT "%s", 1613 str, 1614 trace_page_size_params(requested_size), 1615 p2i(base), 1616 trace_page_size_params(page_size), 1617 trace_page_size_params(alignment), 1618 trace_page_size_params(size)); 1619 } 1620 1621 1622 // This is the working definition of a server class machine: 1623 // >= 2 physical CPU's and >=2GB of memory, with some fuzz 1624 // because the graphics memory (?) sometimes masks physical memory. 1625 // If you want to change the definition of a server class machine 1626 // on some OS or platform, e.g., >=4GB on Windows platforms, 1627 // then you'll have to parameterize this method based on that state, 1628 // as was done for logical processors here, or replicate and 1629 // specialize this method for each platform. (Or fix os to have 1630 // some inheritance structure and use subclassing. Sigh.) 1631 // If you want some platform to always or never behave as a server 1632 // class machine, change the setting of AlwaysActAsServerClassMachine 1633 // and NeverActAsServerClassMachine in globals*.hpp. 1634 bool os::is_server_class_machine() { 1635 // First check for the early returns 1636 if (NeverActAsServerClassMachine) { 1637 return false; 1638 } 1639 if (AlwaysActAsServerClassMachine) { 1640 return true; 1641 } 1642 // Then actually look at the machine 1643 bool result = false; 1644 const unsigned int server_processors = 2; 1645 const julong server_memory = 2UL * G; 1646 // We seem not to get our full complement of memory. 1647 // We allow some part (1/8?) of the memory to be "missing", 1648 // based on the sizes of DIMMs, and maybe graphics cards. 1649 const julong missing_memory = 256UL * M; 1650 1651 /* Is this a server class machine? */ 1652 if ((os::active_processor_count() >= (int)server_processors) && 1653 (os::physical_memory() >= (server_memory - missing_memory))) { 1654 const unsigned int logical_processors = 1655 VM_Version::logical_processors_per_package(); 1656 if (logical_processors > 1) { 1657 const unsigned int physical_packages = 1658 os::active_processor_count() / logical_processors; 1659 if (physical_packages >= server_processors) { 1660 result = true; 1661 } 1662 } else { 1663 result = true; 1664 } 1665 } 1666 return result; 1667 } 1668 1669 void os::initialize_initial_active_processor_count() { 1670 assert(_initial_active_processor_count == 0, "Initial active processor count already set."); 1671 _initial_active_processor_count = active_processor_count(); 1672 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count); 1673 } 1674 1675 void os::SuspendedThreadTask::run() { 1676 internal_do_task(); 1677 _done = true; 1678 } 1679 1680 bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1681 return os::pd_create_stack_guard_pages(addr, bytes); 1682 } 1683 1684 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) { 1685 char* result = NULL; 1686 1687 if (file_desc != -1) { 1688 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(), 1689 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file. 1690 result = os::map_memory_to_file(addr, bytes, 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_reserve_memory(bytes, addr, alignment_hint); 1696 if (result != NULL) { 1697 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1698 } 1699 } 1700 1701 return result; 1702 } 1703 1704 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, 1705 MEMFLAGS flags) { 1706 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1707 if (result != NULL) { 1708 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1709 MemTracker::record_virtual_memory_type((address)result, flags); 1710 } 1711 1712 return result; 1713 } 1714 1715 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) { 1716 char* result = NULL; 1717 if (file_desc != -1) { 1718 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc); 1719 if (result != NULL) { 1720 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1721 } 1722 } else { 1723 result = pd_attempt_reserve_memory_at(bytes, addr); 1724 if (result != NULL) { 1725 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1726 } 1727 } 1728 return result; 1729 } 1730 1731 void os::split_reserved_memory(char *base, size_t size, 1732 size_t split, bool realloc) { 1733 pd_split_reserved_memory(base, size, split, realloc); 1734 } 1735 1736 bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1737 bool res = pd_commit_memory(addr, bytes, executable); 1738 if (res) { 1739 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1740 } 1741 return res; 1742 } 1743 1744 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1745 bool executable) { 1746 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1747 if (res) { 1748 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1749 } 1750 return res; 1751 } 1752 1753 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable, 1754 const char* mesg) { 1755 pd_commit_memory_or_exit(addr, bytes, executable, mesg); 1756 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1757 } 1758 1759 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, 1760 bool executable, const char* mesg) { 1761 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg); 1762 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1763 } 1764 1765 bool os::uncommit_memory(char* addr, size_t bytes) { 1766 bool res; 1767 if (MemTracker::tracking_level() > NMT_minimal) { 1768 Tracker tkr(Tracker::uncommit); 1769 res = pd_uncommit_memory(addr, bytes); 1770 if (res) { 1771 tkr.record((address)addr, bytes); 1772 } 1773 } else { 1774 res = pd_uncommit_memory(addr, bytes); 1775 } 1776 return res; 1777 } 1778 1779 bool os::release_memory(char* addr, size_t bytes) { 1780 bool res; 1781 if (MemTracker::tracking_level() > NMT_minimal) { 1782 Tracker tkr(Tracker::release); 1783 res = pd_release_memory(addr, bytes); 1784 if (res) { 1785 tkr.record((address)addr, bytes); 1786 } 1787 } else { 1788 res = pd_release_memory(addr, bytes); 1789 } 1790 return res; 1791 } 1792 1793 void os::pretouch_memory(void* start, void* end, size_t page_size) { 1794 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) { 1795 *p = 0; 1796 } 1797 } 1798 1799 char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1800 char *addr, size_t bytes, bool read_only, 1801 bool allow_exec) { 1802 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1803 if (result != NULL) { 1804 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1805 } 1806 return result; 1807 } 1808 1809 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1810 char *addr, size_t bytes, bool read_only, 1811 bool allow_exec) { 1812 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1813 read_only, allow_exec); 1814 } 1815 1816 bool os::unmap_memory(char *addr, size_t bytes) { 1817 bool result; 1818 if (MemTracker::tracking_level() > NMT_minimal) { 1819 Tracker tkr(Tracker::release); 1820 result = pd_unmap_memory(addr, bytes); 1821 if (result) { 1822 tkr.record((address)addr, bytes); 1823 } 1824 } else { 1825 result = pd_unmap_memory(addr, bytes); 1826 } 1827 return result; 1828 } 1829 1830 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1831 pd_free_memory(addr, bytes, alignment_hint); 1832 } 1833 1834 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1835 pd_realign_memory(addr, bytes, alignment_hint); 1836 } 1837 1838 #ifndef _WINDOWS 1839 /* try to switch state from state "from" to state "to" 1840 * returns the state set after the method is complete 1841 */ 1842 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from, 1843 os::SuspendResume::State to) 1844 { 1845 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from); 1846 if (result == from) { 1847 // success 1848 return to; 1849 } 1850 return result; 1851 } 1852 #endif