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 #if !defined(LINUX) && !defined(_WINDOWS) 254 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) { 255 committed_start = start; 256 committed_size = size; 257 return true; 258 } 259 #endif 260 261 // Helper for dll_locate_lib. 262 // Pass buffer and printbuffer as we already printed the path to buffer 263 // when we called get_current_directory. This way we avoid another buffer 264 // of size MAX_PATH. 265 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen, 266 const char* pname, char lastchar, const char* fname) { 267 268 // Concatenate path and file name, but don't print double path separators. 269 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ? 270 "" : os::file_separator(); 271 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname); 272 // Check whether file exists. 273 if (ret != -1) { 274 struct stat statbuf; 275 return os::stat(buffer, &statbuf) == 0; 276 } 277 return false; 278 } 279 280 bool os::dll_locate_lib(char *buffer, size_t buflen, 281 const char* pname, const char* fname) { 282 bool retval = false; 283 284 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX); 285 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal); 286 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) { 287 const size_t pnamelen = pname ? strlen(pname) : 0; 288 289 if (pnamelen == 0) { 290 // If no path given, use current working directory. 291 const char* p = get_current_directory(buffer, buflen); 292 if (p != NULL) { 293 const size_t plen = strlen(buffer); 294 const char lastchar = buffer[plen - 1]; 295 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen, 296 "", lastchar, fullfname); 297 } 298 } else if (strchr(pname, *os::path_separator()) != NULL) { 299 // A list of paths. Search for the path that contains the library. 300 int n; 301 char** pelements = split_path(pname, &n); 302 if (pelements != NULL) { 303 for (int i = 0; i < n; i++) { 304 char* path = pelements[i]; 305 // Really shouldn't be NULL, but check can't hurt. 306 size_t plen = (path == NULL) ? 0 : strlen(path); 307 if (plen == 0) { 308 continue; // Skip the empty path values. 309 } 310 const char lastchar = path[plen - 1]; 311 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname); 312 if (retval) break; 313 } 314 // Release the storage allocated by split_path. 315 for (int i = 0; i < n; i++) { 316 if (pelements[i] != NULL) { 317 FREE_C_HEAP_ARRAY(char, pelements[i]); 318 } 319 } 320 FREE_C_HEAP_ARRAY(char*, pelements); 321 } 322 } else { 323 // A definite path. 324 const char lastchar = pname[pnamelen-1]; 325 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname); 326 } 327 } 328 329 FREE_C_HEAP_ARRAY(char*, fullfname); 330 return retval; 331 } 332 333 // --------------------- sun.misc.Signal (optional) --------------------- 334 335 336 // SIGBREAK is sent by the keyboard to query the VM state 337 #ifndef SIGBREAK 338 #define SIGBREAK SIGQUIT 339 #endif 340 341 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. 342 343 344 static void signal_thread_entry(JavaThread* thread, TRAPS) { 345 os::set_priority(thread, NearMaxPriority); 346 while (true) { 347 int sig; 348 { 349 // FIXME : Currently we have not decided what should be the status 350 // for this java thread blocked here. Once we decide about 351 // that we should fix this. 352 sig = os::signal_wait(); 353 } 354 if (sig == os::sigexitnum_pd()) { 355 // Terminate the signal thread 356 return; 357 } 358 359 switch (sig) { 360 case SIGBREAK: { 361 // Check if the signal is a trigger to start the Attach Listener - in that 362 // case don't print stack traces. 363 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { 364 continue; 365 } 366 // Print stack traces 367 // Any SIGBREAK operations added here should make sure to flush 368 // the output stream (e.g. tty->flush()) after output. See 4803766. 369 // Each module also prints an extra carriage return after its output. 370 VM_PrintThreads op; 371 VMThread::execute(&op); 372 VM_PrintJNI jni_op; 373 VMThread::execute(&jni_op); 374 VM_FindDeadlocks op1(tty); 375 VMThread::execute(&op1); 376 Universe::print_heap_at_SIGBREAK(); 377 if (PrintClassHistogram) { 378 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */); 379 VMThread::execute(&op1); 380 } 381 if (JvmtiExport::should_post_data_dump()) { 382 JvmtiExport::post_data_dump(); 383 } 384 break; 385 } 386 default: { 387 // Dispatch the signal to java 388 HandleMark hm(THREAD); 389 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD); 390 if (klass != NULL) { 391 JavaValue result(T_VOID); 392 JavaCallArguments args; 393 args.push_int(sig); 394 JavaCalls::call_static( 395 &result, 396 klass, 397 vmSymbols::dispatch_name(), 398 vmSymbols::int_void_signature(), 399 &args, 400 THREAD 401 ); 402 } 403 if (HAS_PENDING_EXCEPTION) { 404 // tty is initialized early so we don't expect it to be null, but 405 // if it is we can't risk doing an initialization that might 406 // trigger additional out-of-memory conditions 407 if (tty != NULL) { 408 char klass_name[256]; 409 char tmp_sig_name[16]; 410 const char* sig_name = "UNKNOWN"; 411 InstanceKlass::cast(PENDING_EXCEPTION->klass())-> 412 name()->as_klass_external_name(klass_name, 256); 413 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) 414 sig_name = tmp_sig_name; 415 warning("Exception %s occurred dispatching signal %s to handler" 416 "- the VM may need to be forcibly terminated", 417 klass_name, sig_name ); 418 } 419 CLEAR_PENDING_EXCEPTION; 420 } 421 } 422 } 423 } 424 } 425 426 void os::init_before_ergo() { 427 initialize_initial_active_processor_count(); 428 // We need to initialize large page support here because ergonomics takes some 429 // decisions depending on large page support and the calculated large page size. 430 large_page_init(); 431 432 // We need to adapt the configured number of stack protection pages given 433 // in 4K pages to the actual os page size. We must do this before setting 434 // up minimal stack sizes etc. in os::init_2(). 435 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size())); 436 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size())); 437 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size())); 438 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size())); 439 440 // VM version initialization identifies some characteristics of the 441 // platform that are used during ergonomic decisions. 442 VM_Version::init_before_ergo(); 443 } 444 445 void os::signal_init(TRAPS) { 446 if (!ReduceSignalUsage) { 447 // Setup JavaThread for processing signals 448 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); 449 InstanceKlass* ik = InstanceKlass::cast(k); 450 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 451 452 const char thread_name[] = "Signal Dispatcher"; 453 Handle string = java_lang_String::create_from_str(thread_name, CHECK); 454 455 // Initialize thread_oop to put it into the system threadGroup 456 Handle thread_group (THREAD, Universe::system_thread_group()); 457 JavaValue result(T_VOID); 458 JavaCalls::call_special(&result, thread_oop, 459 ik, 460 vmSymbols::object_initializer_name(), 461 vmSymbols::threadgroup_string_void_signature(), 462 thread_group, 463 string, 464 CHECK); 465 466 Klass* group = SystemDictionary::ThreadGroup_klass(); 467 JavaCalls::call_special(&result, 468 thread_group, 469 group, 470 vmSymbols::add_method_name(), 471 vmSymbols::thread_void_signature(), 472 thread_oop, // ARG 1 473 CHECK); 474 475 os::signal_init_pd(); 476 477 { MutexLocker mu(Threads_lock); 478 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); 479 480 // At this point it may be possible that no osthread was created for the 481 // JavaThread due to lack of memory. We would have to throw an exception 482 // in that case. However, since this must work and we do not allow 483 // exceptions anyway, check and abort if this fails. 484 if (signal_thread == NULL || signal_thread->osthread() == NULL) { 485 vm_exit_during_initialization("java.lang.OutOfMemoryError", 486 os::native_thread_creation_failed_msg()); 487 } 488 489 java_lang_Thread::set_thread(thread_oop(), signal_thread); 490 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); 491 java_lang_Thread::set_daemon(thread_oop()); 492 493 signal_thread->set_threadObj(thread_oop()); 494 Threads::add(signal_thread); 495 Thread::start(signal_thread); 496 } 497 // Handle ^BREAK 498 os::signal(SIGBREAK, os::user_handler()); 499 } 500 } 501 502 503 void os::terminate_signal_thread() { 504 if (!ReduceSignalUsage) 505 signal_notify(sigexitnum_pd()); 506 } 507 508 509 // --------------------- loading libraries --------------------- 510 511 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); 512 extern struct JavaVM_ main_vm; 513 514 static void* _native_java_library = NULL; 515 516 void* os::native_java_library() { 517 if (_native_java_library == NULL) { 518 char buffer[JVM_MAXPATHLEN]; 519 char ebuf[1024]; 520 521 // Try to load verify dll first. In 1.3 java dll depends on it and is not 522 // always able to find it when the loading executable is outside the JDK. 523 // In order to keep working with 1.2 we ignore any loading errors. 524 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 525 "verify")) { 526 dll_load(buffer, ebuf, sizeof(ebuf)); 527 } 528 529 // Load java dll 530 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 531 "java")) { 532 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 533 } 534 if (_native_java_library == NULL) { 535 vm_exit_during_initialization("Unable to load native library", ebuf); 536 } 537 538 #if defined(__OpenBSD__) 539 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 540 // ignore errors 541 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 542 "net")) { 543 dll_load(buffer, ebuf, sizeof(ebuf)); 544 } 545 #endif 546 } 547 return _native_java_library; 548 } 549 550 /* 551 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists. 552 * If check_lib == true then we are looking for an 553 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if 554 * this library is statically linked into the image. 555 * If check_lib == false then we will look for the appropriate symbol in the 556 * executable if agent_lib->is_static_lib() == true or in the shared library 557 * referenced by 'handle'. 558 */ 559 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib, 560 const char *syms[], size_t syms_len) { 561 assert(agent_lib != NULL, "sanity check"); 562 const char *lib_name; 563 void *handle = agent_lib->os_lib(); 564 void *entryName = NULL; 565 char *agent_function_name; 566 size_t i; 567 568 // If checking then use the agent name otherwise test is_static_lib() to 569 // see how to process this lookup 570 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL); 571 for (i = 0; i < syms_len; i++) { 572 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path()); 573 if (agent_function_name == NULL) { 574 break; 575 } 576 entryName = dll_lookup(handle, agent_function_name); 577 FREE_C_HEAP_ARRAY(char, agent_function_name); 578 if (entryName != NULL) { 579 break; 580 } 581 } 582 return entryName; 583 } 584 585 // See if the passed in agent is statically linked into the VM image. 586 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 587 size_t syms_len) { 588 void *ret; 589 void *proc_handle; 590 void *save_handle; 591 592 assert(agent_lib != NULL, "sanity check"); 593 if (agent_lib->name() == NULL) { 594 return false; 595 } 596 proc_handle = get_default_process_handle(); 597 // Check for Agent_OnLoad/Attach_lib_name function 598 save_handle = agent_lib->os_lib(); 599 // We want to look in this process' symbol table. 600 agent_lib->set_os_lib(proc_handle); 601 ret = find_agent_function(agent_lib, true, syms, syms_len); 602 if (ret != NULL) { 603 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent 604 agent_lib->set_valid(); 605 agent_lib->set_static_lib(true); 606 return true; 607 } 608 agent_lib->set_os_lib(save_handle); 609 return false; 610 } 611 612 // --------------------- heap allocation utilities --------------------- 613 614 char *os::strdup(const char *str, MEMFLAGS flags) { 615 size_t size = strlen(str); 616 char *dup_str = (char *)malloc(size + 1, flags); 617 if (dup_str == NULL) return NULL; 618 strcpy(dup_str, str); 619 return dup_str; 620 } 621 622 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) { 623 char* p = os::strdup(str, flags); 624 if (p == NULL) { 625 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom"); 626 } 627 return p; 628 } 629 630 631 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 632 633 #ifdef ASSERT 634 635 static void verify_memory(void* ptr) { 636 GuardedMemory guarded(ptr); 637 if (!guarded.verify_guards()) { 638 LogTarget(Warning, malloc, free) lt; 639 ResourceMark rm; 640 LogStream ls(lt); 641 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 642 ls.print_cr("## memory stomp:"); 643 guarded.print_on(&ls); 644 fatal("memory stomping error"); 645 } 646 } 647 648 #endif 649 650 // 651 // This function supports testing of the malloc out of memory 652 // condition without really running the system out of memory. 653 // 654 static bool has_reached_max_malloc_test_peak(size_t alloc_size) { 655 if (MallocMaxTestWords > 0) { 656 size_t words = (alloc_size / BytesPerWord); 657 658 if ((cur_malloc_words + words) > MallocMaxTestWords) { 659 return true; 660 } 661 Atomic::add(words, &cur_malloc_words); 662 } 663 return false; 664 } 665 666 void* os::malloc(size_t size, MEMFLAGS flags) { 667 return os::malloc(size, flags, CALLER_PC); 668 } 669 670 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 671 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 672 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 673 674 // Since os::malloc can be called when the libjvm.{dll,so} is 675 // first loaded and we don't have a thread yet we must accept NULL also here. 676 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()), 677 "malloc() not allowed when crash protection is set"); 678 679 if (size == 0) { 680 // return a valid pointer if size is zero 681 // if NULL is returned the calling functions assume out of memory. 682 size = 1; 683 } 684 685 // NMT support 686 NMT_TrackingLevel level = MemTracker::tracking_level(); 687 size_t nmt_header_size = MemTracker::malloc_header_size(level); 688 689 #ifndef ASSERT 690 const size_t alloc_size = size + nmt_header_size; 691 #else 692 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size); 693 if (size + nmt_header_size > alloc_size) { // Check for rollover. 694 return NULL; 695 } 696 #endif 697 698 // For the test flag -XX:MallocMaxTestWords 699 if (has_reached_max_malloc_test_peak(size)) { 700 return NULL; 701 } 702 703 u_char* ptr; 704 ptr = (u_char*)::malloc(alloc_size); 705 706 #ifdef ASSERT 707 if (ptr == NULL) { 708 return NULL; 709 } 710 // Wrap memory with guard 711 GuardedMemory guarded(ptr, size + nmt_header_size); 712 ptr = guarded.get_user_ptr(); 713 #endif 714 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 715 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 716 breakpoint(); 717 } 718 debug_only(if (paranoid) verify_memory(ptr)); 719 720 // we do not track guard memory 721 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level); 722 } 723 724 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) { 725 return os::realloc(memblock, size, flags, CALLER_PC); 726 } 727 728 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { 729 730 // For the test flag -XX:MallocMaxTestWords 731 if (has_reached_max_malloc_test_peak(size)) { 732 return NULL; 733 } 734 735 if (size == 0) { 736 // return a valid pointer if size is zero 737 // if NULL is returned the calling functions assume out of memory. 738 size = 1; 739 } 740 741 #ifndef ASSERT 742 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 743 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 744 // NMT support 745 void* membase = MemTracker::record_free(memblock); 746 NMT_TrackingLevel level = MemTracker::tracking_level(); 747 size_t nmt_header_size = MemTracker::malloc_header_size(level); 748 void* ptr = ::realloc(membase, size + nmt_header_size); 749 return MemTracker::record_malloc(ptr, size, memflags, stack, level); 750 #else 751 if (memblock == NULL) { 752 return os::malloc(size, memflags, stack); 753 } 754 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 755 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock)); 756 breakpoint(); 757 } 758 // NMT support 759 void* membase = MemTracker::malloc_base(memblock); 760 verify_memory(membase); 761 // always move the block 762 void* ptr = os::malloc(size, memflags, stack); 763 // Copy to new memory if malloc didn't fail 764 if (ptr != NULL ) { 765 GuardedMemory guarded(MemTracker::malloc_base(memblock)); 766 // Guard's user data contains NMT header 767 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock); 768 memcpy(ptr, memblock, MIN2(size, memblock_size)); 769 if (paranoid) verify_memory(MemTracker::malloc_base(ptr)); 770 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 771 log_warning(malloc, free)("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr)); 772 breakpoint(); 773 } 774 os::free(memblock); 775 } 776 return ptr; 777 #endif 778 } 779 780 781 void os::free(void *memblock) { 782 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 783 #ifdef ASSERT 784 if (memblock == NULL) return; 785 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 786 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock)); 787 breakpoint(); 788 } 789 void* membase = MemTracker::record_free(memblock); 790 verify_memory(membase); 791 792 GuardedMemory guarded(membase); 793 size_t size = guarded.get_user_size(); 794 inc_stat_counter(&free_bytes, size); 795 membase = guarded.release_for_freeing(); 796 ::free(membase); 797 #else 798 void* membase = MemTracker::record_free(memblock); 799 ::free(membase); 800 #endif 801 } 802 803 void os::init_random(unsigned int initval) { 804 _rand_seed = initval; 805 } 806 807 808 static int random_helper(unsigned int rand_seed) { 809 /* standard, well-known linear congruential random generator with 810 * next_rand = (16807*seed) mod (2**31-1) 811 * see 812 * (1) "Random Number Generators: Good Ones Are Hard to Find", 813 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 814 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 815 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 816 */ 817 const unsigned int a = 16807; 818 const unsigned int m = 2147483647; 819 const int q = m / a; assert(q == 127773, "weird math"); 820 const int r = m % a; assert(r == 2836, "weird math"); 821 822 // compute az=2^31p+q 823 unsigned int lo = a * (rand_seed & 0xFFFF); 824 unsigned int hi = a * (rand_seed >> 16); 825 lo += (hi & 0x7FFF) << 16; 826 827 // if q overflowed, ignore the overflow and increment q 828 if (lo > m) { 829 lo &= m; 830 ++lo; 831 } 832 lo += hi >> 15; 833 834 // if (p+q) overflowed, ignore the overflow and increment (p+q) 835 if (lo > m) { 836 lo &= m; 837 ++lo; 838 } 839 return lo; 840 } 841 842 int os::random() { 843 // Make updating the random seed thread safe. 844 while (true) { 845 unsigned int seed = _rand_seed; 846 unsigned int rand = random_helper(seed); 847 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) { 848 return static_cast<int>(rand); 849 } 850 } 851 } 852 853 // The INITIALIZED state is distinguished from the SUSPENDED state because the 854 // conditions in which a thread is first started are different from those in which 855 // a suspension is resumed. These differences make it hard for us to apply the 856 // tougher checks when starting threads that we want to do when resuming them. 857 // However, when start_thread is called as a result of Thread.start, on a Java 858 // thread, the operation is synchronized on the Java Thread object. So there 859 // cannot be a race to start the thread and hence for the thread to exit while 860 // we are working on it. Non-Java threads that start Java threads either have 861 // to do so in a context in which races are impossible, or should do appropriate 862 // locking. 863 864 void os::start_thread(Thread* thread) { 865 // guard suspend/resume 866 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 867 OSThread* osthread = thread->osthread(); 868 osthread->set_state(RUNNABLE); 869 pd_start_thread(thread); 870 } 871 872 void os::abort(bool dump_core) { 873 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL); 874 } 875 876 //--------------------------------------------------------------------------- 877 // Helper functions for fatal error handler 878 879 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 880 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 881 882 int cols = 0; 883 int cols_per_line = 0; 884 switch (unitsize) { 885 case 1: cols_per_line = 16; break; 886 case 2: cols_per_line = 8; break; 887 case 4: cols_per_line = 4; break; 888 case 8: cols_per_line = 2; break; 889 default: return; 890 } 891 892 address p = start; 893 st->print(PTR_FORMAT ": ", p2i(start)); 894 while (p < end) { 895 switch (unitsize) { 896 case 1: st->print("%02x", *(u1*)p); break; 897 case 2: st->print("%04x", *(u2*)p); break; 898 case 4: st->print("%08x", *(u4*)p); break; 899 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 900 } 901 p += unitsize; 902 cols++; 903 if (cols >= cols_per_line && p < end) { 904 cols = 0; 905 st->cr(); 906 st->print(PTR_FORMAT ": ", p2i(p)); 907 } else { 908 st->print(" "); 909 } 910 } 911 st->cr(); 912 } 913 914 void os::print_environment_variables(outputStream* st, const char** env_list) { 915 if (env_list) { 916 st->print_cr("Environment Variables:"); 917 918 for (int i = 0; env_list[i] != NULL; i++) { 919 char *envvar = ::getenv(env_list[i]); 920 if (envvar != NULL) { 921 st->print("%s", env_list[i]); 922 st->print("="); 923 st->print_cr("%s", envvar); 924 } 925 } 926 } 927 } 928 929 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) { 930 // cpu 931 st->print("CPU:"); 932 st->print("total %d", os::processor_count()); 933 // It's not safe to query number of active processors after crash 934 // st->print("(active %d)", os::active_processor_count()); but we can 935 // print the initial number of active processors. 936 // We access the raw value here because the assert in the accessor will 937 // fail if the crash occurs before initialization of this value. 938 st->print(" (initial active %d)", _initial_active_processor_count); 939 st->print(" %s", VM_Version::features_string()); 940 st->cr(); 941 pd_print_cpu_info(st, buf, buflen); 942 } 943 944 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version 945 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) { 946 st->print("Host: "); 947 #ifndef PRODUCT 948 if (get_host_name(buf, buflen)) { 949 st->print("%s, ", buf); 950 } 951 #endif // PRODUCT 952 get_summary_cpu_info(buf, buflen); 953 st->print("%s, ", buf); 954 size_t mem = physical_memory()/G; 955 if (mem == 0) { // for low memory systems 956 mem = physical_memory()/M; 957 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem); 958 } else { 959 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem); 960 } 961 get_summary_os_info(buf, buflen); 962 st->print_raw(buf); 963 st->cr(); 964 } 965 966 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) { 967 const int secs_per_day = 86400; 968 const int secs_per_hour = 3600; 969 const int secs_per_min = 60; 970 971 time_t tloc; 972 (void)time(&tloc); 973 char* timestring = ctime(&tloc); // ctime adds newline. 974 // edit out the newline 975 char* nl = strchr(timestring, '\n'); 976 if (nl != NULL) { 977 *nl = '\0'; 978 } 979 980 struct tm tz; 981 if (localtime_pd(&tloc, &tz) != NULL) { 982 ::strftime(buf, buflen, "%Z", &tz); 983 st->print("Time: %s %s", timestring, buf); 984 } else { 985 st->print("Time: %s", timestring); 986 } 987 988 double t = os::elapsedTime(); 989 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in 990 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int 991 // before printf. We lost some precision, but who cares? 992 int eltime = (int)t; // elapsed time in seconds 993 994 // print elapsed time in a human-readable format: 995 int eldays = eltime / secs_per_day; 996 int day_secs = eldays * secs_per_day; 997 int elhours = (eltime - day_secs) / secs_per_hour; 998 int hour_secs = elhours * secs_per_hour; 999 int elmins = (eltime - day_secs - hour_secs) / secs_per_min; 1000 int minute_secs = elmins * secs_per_min; 1001 int elsecs = (eltime - day_secs - hour_secs - minute_secs); 1002 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs); 1003 } 1004 1005 // moved from debug.cpp (used to be find()) but still called from there 1006 // The verbose parameter is only set by the debug code in one case 1007 void os::print_location(outputStream* st, intptr_t x, bool verbose) { 1008 address addr = (address)x; 1009 // Handle NULL first, so later checks don't need to protect against it. 1010 if (addr == NULL) { 1011 st->print_cr("0x0 is NULL"); 1012 return; 1013 } 1014 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 1015 if (b != NULL) { 1016 if (b->is_buffer_blob()) { 1017 // the interpreter is generated into a buffer blob 1018 InterpreterCodelet* i = Interpreter::codelet_containing(addr); 1019 if (i != NULL) { 1020 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin())); 1021 i->print_on(st); 1022 return; 1023 } 1024 if (Interpreter::contains(addr)) { 1025 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code" 1026 " (not bytecode specific)", p2i(addr)); 1027 return; 1028 } 1029 // 1030 if (AdapterHandlerLibrary::contains(b)) { 1031 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin())); 1032 AdapterHandlerLibrary::print_handler_on(st, b); 1033 } 1034 // the stubroutines are generated into a buffer blob 1035 StubCodeDesc* d = StubCodeDesc::desc_for(addr); 1036 if (d != NULL) { 1037 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin())); 1038 d->print_on(st); 1039 st->cr(); 1040 return; 1041 } 1042 if (StubRoutines::contains(addr)) { 1043 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr)); 1044 return; 1045 } 1046 // the InlineCacheBuffer is using stubs generated into a buffer blob 1047 if (InlineCacheBuffer::contains(addr)) { 1048 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr)); 1049 return; 1050 } 1051 VtableStub* v = VtableStubs::stub_containing(addr); 1052 if (v != NULL) { 1053 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point())); 1054 v->print_on(st); 1055 st->cr(); 1056 return; 1057 } 1058 } 1059 nmethod* nm = b->as_nmethod_or_null(); 1060 if (nm != NULL) { 1061 ResourceMark rm; 1062 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT, 1063 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm)); 1064 if (verbose) { 1065 st->print(" for "); 1066 nm->method()->print_value_on(st); 1067 } 1068 st->cr(); 1069 nm->print_nmethod(verbose); 1070 return; 1071 } 1072 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin())); 1073 b->print_on(st); 1074 return; 1075 } 1076 1077 if (Universe::heap()->is_in(addr)) { 1078 HeapWord* p = Universe::heap()->block_start(addr); 1079 bool print = false; 1080 // If we couldn't find it it just may mean that heap wasn't parsable 1081 // See if we were just given an oop directly 1082 if (p != NULL && Universe::heap()->block_is_obj(p)) { 1083 print = true; 1084 } else if (p == NULL && oopDesc::is_oop(oop(addr))) { 1085 p = (HeapWord*) addr; 1086 print = true; 1087 } 1088 if (print) { 1089 if (p == (HeapWord*) addr) { 1090 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr)); 1091 } else { 1092 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p)); 1093 } 1094 oop(p)->print_on(st); 1095 return; 1096 } 1097 } else { 1098 if (Universe::heap()->is_in_reserved(addr)) { 1099 st->print_cr(INTPTR_FORMAT " is an unallocated location " 1100 "in the heap", p2i(addr)); 1101 return; 1102 } 1103 } 1104 if (JNIHandles::is_global_handle((jobject) addr)) { 1105 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr)); 1106 return; 1107 } 1108 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 1109 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr)); 1110 return; 1111 } 1112 #ifndef PRODUCT 1113 // we don't keep the block list in product mode 1114 if (JNIHandles::is_local_handle((jobject) addr)) { 1115 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr)); 1116 return; 1117 } 1118 #endif 1119 1120 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 1121 // Check for privilege stack 1122 if (thread->privileged_stack_top() != NULL && 1123 thread->privileged_stack_top()->contains(addr)) { 1124 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack " 1125 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread)); 1126 if (verbose) thread->print_on(st); 1127 return; 1128 } 1129 // If the addr is a java thread print information about that. 1130 if (addr == (address)thread) { 1131 if (verbose) { 1132 thread->print_on(st); 1133 } else { 1134 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr)); 1135 } 1136 return; 1137 } 1138 // If the addr is in the stack region for this thread then report that 1139 // and print thread info 1140 if (thread->on_local_stack(addr)) { 1141 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 1142 INTPTR_FORMAT, p2i(addr), p2i(thread)); 1143 if (verbose) thread->print_on(st); 1144 return; 1145 } 1146 } 1147 1148 // Check if in metaspace and print types that have vptrs (only method now) 1149 if (Metaspace::contains(addr)) { 1150 if (Method::has_method_vptr((const void*)addr)) { 1151 ((Method*)addr)->print_value_on(st); 1152 st->cr(); 1153 } else { 1154 // Use addr->print() from the debugger instead (not here) 1155 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr)); 1156 } 1157 return; 1158 } 1159 1160 // Try an OS specific find 1161 if (os::find(addr, st)) { 1162 return; 1163 } 1164 1165 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr)); 1166 } 1167 1168 // Looks like all platforms except IA64 can use the same function to check 1169 // if C stack is walkable beyond current frame. The check for fp() is not 1170 // necessary on Sparc, but it's harmless. 1171 bool os::is_first_C_frame(frame* fr) { 1172 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32) 1173 // On IA64 we have to check if the callers bsp is still valid 1174 // (i.e. within the register stack bounds). 1175 // Notice: this only works for threads created by the VM and only if 1176 // we walk the current stack!!! If we want to be able to walk 1177 // arbitrary other threads, we'll have to somehow store the thread 1178 // object in the frame. 1179 Thread *thread = Thread::current(); 1180 if ((address)fr->fp() <= 1181 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) { 1182 // This check is a little hacky, because on Linux the first C 1183 // frame's ('start_thread') register stack frame starts at 1184 // "register_stack_base + 0x48" while on HPUX, the first C frame's 1185 // ('__pthread_bound_body') register stack frame seems to really 1186 // start at "register_stack_base". 1187 return true; 1188 } else { 1189 return false; 1190 } 1191 #elif defined(IA64) && defined(_WIN32) 1192 return true; 1193 #else 1194 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 1195 // Check usp first, because if that's bad the other accessors may fault 1196 // on some architectures. Ditto ufp second, etc. 1197 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 1198 // sp on amd can be 32 bit aligned. 1199 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 1200 1201 uintptr_t usp = (uintptr_t)fr->sp(); 1202 if ((usp & sp_align_mask) != 0) return true; 1203 1204 uintptr_t ufp = (uintptr_t)fr->fp(); 1205 if ((ufp & fp_align_mask) != 0) return true; 1206 1207 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 1208 if ((old_sp & sp_align_mask) != 0) return true; 1209 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 1210 1211 uintptr_t old_fp = (uintptr_t)fr->link(); 1212 if ((old_fp & fp_align_mask) != 0) return true; 1213 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1214 1215 // stack grows downwards; if old_fp is below current fp or if the stack 1216 // frame is too large, either the stack is corrupted or fp is not saved 1217 // on stack (i.e. on x86, ebp may be used as general register). The stack 1218 // is not walkable beyond current frame. 1219 if (old_fp < ufp) return true; 1220 if (old_fp - ufp > 64 * K) return true; 1221 1222 return false; 1223 #endif 1224 } 1225 1226 1227 // Set up the boot classpath. 1228 1229 char* os::format_boot_path(const char* format_string, 1230 const char* home, 1231 int home_len, 1232 char fileSep, 1233 char pathSep) { 1234 assert((fileSep == '/' && pathSep == ':') || 1235 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars"); 1236 1237 // Scan the format string to determine the length of the actual 1238 // boot classpath, and handle platform dependencies as well. 1239 int formatted_path_len = 0; 1240 const char* p; 1241 for (p = format_string; *p != 0; ++p) { 1242 if (*p == '%') formatted_path_len += home_len - 1; 1243 ++formatted_path_len; 1244 } 1245 1246 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1247 if (formatted_path == NULL) { 1248 return NULL; 1249 } 1250 1251 // Create boot classpath from format, substituting separator chars and 1252 // java home directory. 1253 char* q = formatted_path; 1254 for (p = format_string; *p != 0; ++p) { 1255 switch (*p) { 1256 case '%': 1257 strcpy(q, home); 1258 q += home_len; 1259 break; 1260 case '/': 1261 *q++ = fileSep; 1262 break; 1263 case ':': 1264 *q++ = pathSep; 1265 break; 1266 default: 1267 *q++ = *p; 1268 } 1269 } 1270 *q = '\0'; 1271 1272 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1273 return formatted_path; 1274 } 1275 1276 bool os::set_boot_path(char fileSep, char pathSep) { 1277 const char* home = Arguments::get_java_home(); 1278 int home_len = (int)strlen(home); 1279 1280 struct stat st; 1281 1282 // modular image if "modules" jimage exists 1283 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep); 1284 if (jimage == NULL) return false; 1285 bool has_jimage = (os::stat(jimage, &st) == 0); 1286 if (has_jimage) { 1287 Arguments::set_sysclasspath(jimage, true); 1288 FREE_C_HEAP_ARRAY(char, jimage); 1289 return true; 1290 } 1291 FREE_C_HEAP_ARRAY(char, jimage); 1292 1293 // check if developer build with exploded modules 1294 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep); 1295 if (base_classes == NULL) return false; 1296 if (os::stat(base_classes, &st) == 0) { 1297 Arguments::set_sysclasspath(base_classes, false); 1298 FREE_C_HEAP_ARRAY(char, base_classes); 1299 return true; 1300 } 1301 FREE_C_HEAP_ARRAY(char, base_classes); 1302 1303 return false; 1304 } 1305 1306 /* 1307 * Splits a path, based on its separator, the number of 1308 * elements is returned back in n. 1309 * It is the callers responsibility to: 1310 * a> check the value of n, and n may be 0. 1311 * b> ignore any empty path elements 1312 * c> free up the data. 1313 */ 1314 char** os::split_path(const char* path, int* n) { 1315 *n = 0; 1316 if (path == NULL || strlen(path) == 0) { 1317 return NULL; 1318 } 1319 const char psepchar = *os::path_separator(); 1320 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1321 if (inpath == NULL) { 1322 return NULL; 1323 } 1324 strcpy(inpath, path); 1325 int count = 1; 1326 char* p = strchr(inpath, psepchar); 1327 // Get a count of elements to allocate memory 1328 while (p != NULL) { 1329 count++; 1330 p++; 1331 p = strchr(p, psepchar); 1332 } 1333 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1334 if (opath == NULL) { 1335 return NULL; 1336 } 1337 1338 // do the actual splitting 1339 p = inpath; 1340 for (int i = 0 ; i < count ; i++) { 1341 size_t len = strcspn(p, os::path_separator()); 1342 if (len > JVM_MAXPATHLEN) { 1343 return NULL; 1344 } 1345 // allocate the string and add terminator storage 1346 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 1347 if (s == NULL) { 1348 return NULL; 1349 } 1350 strncpy(s, p, len); 1351 s[len] = '\0'; 1352 opath[i] = s; 1353 p += len + 1; 1354 } 1355 FREE_C_HEAP_ARRAY(char, inpath); 1356 *n = count; 1357 return opath; 1358 } 1359 1360 void os::set_memory_serialize_page(address page) { 1361 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); 1362 _mem_serialize_page = (volatile int32_t *)page; 1363 // We initialize the serialization page shift count here 1364 // We assume a cache line size of 64 bytes 1365 assert(SerializePageShiftCount == count, "JavaThread size changed; " 1366 "SerializePageShiftCount constant should be %d", count); 1367 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); 1368 } 1369 1370 static volatile intptr_t SerializePageLock = 0; 1371 1372 // This method is called from signal handler when SIGSEGV occurs while the current 1373 // thread tries to store to the "read-only" memory serialize page during state 1374 // transition. 1375 void os::block_on_serialize_page_trap() { 1376 log_debug(safepoint)("Block until the serialize page permission restored"); 1377 1378 // When VMThread is holding the SerializePageLock during modifying the 1379 // access permission of the memory serialize page, the following call 1380 // will block until the permission of that page is restored to rw. 1381 // Generally, it is unsafe to manipulate locks in signal handlers, but in 1382 // this case, it's OK as the signal is synchronous and we know precisely when 1383 // it can occur. 1384 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); 1385 Thread::muxRelease(&SerializePageLock); 1386 } 1387 1388 // Serialize all thread state variables 1389 void os::serialize_thread_states() { 1390 // On some platforms such as Solaris & Linux, the time duration of the page 1391 // permission restoration is observed to be much longer than expected due to 1392 // scheduler starvation problem etc. To avoid the long synchronization 1393 // time and expensive page trap spinning, 'SerializePageLock' is used to block 1394 // the mutator thread if such case is encountered. See bug 6546278 for details. 1395 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); 1396 os::protect_memory((char *)os::get_memory_serialize_page(), 1397 os::vm_page_size(), MEM_PROT_READ); 1398 os::protect_memory((char *)os::get_memory_serialize_page(), 1399 os::vm_page_size(), MEM_PROT_RW); 1400 Thread::muxRelease(&SerializePageLock); 1401 } 1402 1403 // Returns true if the current stack pointer is above the stack shadow 1404 // pages, false otherwise. 1405 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) { 1406 if (!thread->is_Java_thread()) return false; 1407 // Check if we have StackShadowPages above the yellow zone. This parameter 1408 // is dependent on the depth of the maximum VM call stack possible from 1409 // the handler for stack overflow. 'instanceof' in the stack overflow 1410 // handler or a println uses at least 8k stack of VM and native code 1411 // respectively. 1412 const int framesize_in_bytes = 1413 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1414 1415 address limit = ((JavaThread*)thread)->stack_end() + 1416 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size()); 1417 1418 return sp > (limit + framesize_in_bytes); 1419 } 1420 1421 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) { 1422 assert(min_pages > 0, "sanity"); 1423 if (UseLargePages) { 1424 const size_t max_page_size = region_size / min_pages; 1425 1426 for (size_t i = 0; _page_sizes[i] != 0; ++i) { 1427 const size_t page_size = _page_sizes[i]; 1428 if (page_size <= max_page_size) { 1429 if (!must_be_aligned || is_aligned(region_size, page_size)) { 1430 return page_size; 1431 } 1432 } 1433 } 1434 } 1435 1436 return vm_page_size(); 1437 } 1438 1439 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) { 1440 return page_size_for_region(region_size, min_pages, true); 1441 } 1442 1443 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) { 1444 return page_size_for_region(region_size, min_pages, false); 1445 } 1446 1447 static const char* errno_to_string (int e, bool short_text) { 1448 #define ALL_SHARED_ENUMS(X) \ 1449 X(E2BIG, "Argument list too long") \ 1450 X(EACCES, "Permission denied") \ 1451 X(EADDRINUSE, "Address in use") \ 1452 X(EADDRNOTAVAIL, "Address not available") \ 1453 X(EAFNOSUPPORT, "Address family not supported") \ 1454 X(EAGAIN, "Resource unavailable, try again") \ 1455 X(EALREADY, "Connection already in progress") \ 1456 X(EBADF, "Bad file descriptor") \ 1457 X(EBADMSG, "Bad message") \ 1458 X(EBUSY, "Device or resource busy") \ 1459 X(ECANCELED, "Operation canceled") \ 1460 X(ECHILD, "No child processes") \ 1461 X(ECONNABORTED, "Connection aborted") \ 1462 X(ECONNREFUSED, "Connection refused") \ 1463 X(ECONNRESET, "Connection reset") \ 1464 X(EDEADLK, "Resource deadlock would occur") \ 1465 X(EDESTADDRREQ, "Destination address required") \ 1466 X(EDOM, "Mathematics argument out of domain of function") \ 1467 X(EEXIST, "File exists") \ 1468 X(EFAULT, "Bad address") \ 1469 X(EFBIG, "File too large") \ 1470 X(EHOSTUNREACH, "Host is unreachable") \ 1471 X(EIDRM, "Identifier removed") \ 1472 X(EILSEQ, "Illegal byte sequence") \ 1473 X(EINPROGRESS, "Operation in progress") \ 1474 X(EINTR, "Interrupted function") \ 1475 X(EINVAL, "Invalid argument") \ 1476 X(EIO, "I/O error") \ 1477 X(EISCONN, "Socket is connected") \ 1478 X(EISDIR, "Is a directory") \ 1479 X(ELOOP, "Too many levels of symbolic links") \ 1480 X(EMFILE, "Too many open files") \ 1481 X(EMLINK, "Too many links") \ 1482 X(EMSGSIZE, "Message too large") \ 1483 X(ENAMETOOLONG, "Filename too long") \ 1484 X(ENETDOWN, "Network is down") \ 1485 X(ENETRESET, "Connection aborted by network") \ 1486 X(ENETUNREACH, "Network unreachable") \ 1487 X(ENFILE, "Too many files open in system") \ 1488 X(ENOBUFS, "No buffer space available") \ 1489 X(ENODATA, "No message is available on the STREAM head read queue") \ 1490 X(ENODEV, "No such device") \ 1491 X(ENOENT, "No such file or directory") \ 1492 X(ENOEXEC, "Executable file format error") \ 1493 X(ENOLCK, "No locks available") \ 1494 X(ENOLINK, "Reserved") \ 1495 X(ENOMEM, "Not enough space") \ 1496 X(ENOMSG, "No message of the desired type") \ 1497 X(ENOPROTOOPT, "Protocol not available") \ 1498 X(ENOSPC, "No space left on device") \ 1499 X(ENOSR, "No STREAM resources") \ 1500 X(ENOSTR, "Not a STREAM") \ 1501 X(ENOSYS, "Function not supported") \ 1502 X(ENOTCONN, "The socket is not connected") \ 1503 X(ENOTDIR, "Not a directory") \ 1504 X(ENOTEMPTY, "Directory not empty") \ 1505 X(ENOTSOCK, "Not a socket") \ 1506 X(ENOTSUP, "Not supported") \ 1507 X(ENOTTY, "Inappropriate I/O control operation") \ 1508 X(ENXIO, "No such device or address") \ 1509 X(EOPNOTSUPP, "Operation not supported on socket") \ 1510 X(EOVERFLOW, "Value too large to be stored in data type") \ 1511 X(EPERM, "Operation not permitted") \ 1512 X(EPIPE, "Broken pipe") \ 1513 X(EPROTO, "Protocol error") \ 1514 X(EPROTONOSUPPORT, "Protocol not supported") \ 1515 X(EPROTOTYPE, "Protocol wrong type for socket") \ 1516 X(ERANGE, "Result too large") \ 1517 X(EROFS, "Read-only file system") \ 1518 X(ESPIPE, "Invalid seek") \ 1519 X(ESRCH, "No such process") \ 1520 X(ETIME, "Stream ioctl() timeout") \ 1521 X(ETIMEDOUT, "Connection timed out") \ 1522 X(ETXTBSY, "Text file busy") \ 1523 X(EWOULDBLOCK, "Operation would block") \ 1524 X(EXDEV, "Cross-device link") 1525 1526 #define DEFINE_ENTRY(e, text) { e, #e, text }, 1527 1528 static const struct { 1529 int v; 1530 const char* short_text; 1531 const char* long_text; 1532 } table [] = { 1533 1534 ALL_SHARED_ENUMS(DEFINE_ENTRY) 1535 1536 // The following enums are not defined on all platforms. 1537 #ifdef ESTALE 1538 DEFINE_ENTRY(ESTALE, "Reserved") 1539 #endif 1540 #ifdef EDQUOT 1541 DEFINE_ENTRY(EDQUOT, "Reserved") 1542 #endif 1543 #ifdef EMULTIHOP 1544 DEFINE_ENTRY(EMULTIHOP, "Reserved") 1545 #endif 1546 1547 // End marker. 1548 { -1, "Unknown errno", "Unknown error" } 1549 1550 }; 1551 1552 #undef DEFINE_ENTRY 1553 #undef ALL_FLAGS 1554 1555 int i = 0; 1556 while (table[i].v != -1 && table[i].v != e) { 1557 i ++; 1558 } 1559 1560 return short_text ? table[i].short_text : table[i].long_text; 1561 1562 } 1563 1564 const char* os::strerror(int e) { 1565 return errno_to_string(e, false); 1566 } 1567 1568 const char* os::errno_name(int e) { 1569 return errno_to_string(e, true); 1570 } 1571 1572 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) { 1573 LogTarget(Info, pagesize) log; 1574 if (log.is_enabled()) { 1575 LogStream out(log); 1576 1577 out.print("%s: ", str); 1578 for (int i = 0; i < count; ++i) { 1579 out.print(" " SIZE_FORMAT, page_sizes[i]); 1580 } 1581 out.cr(); 1582 } 1583 } 1584 1585 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size) 1586 1587 void os::trace_page_sizes(const char* str, 1588 const size_t region_min_size, 1589 const size_t region_max_size, 1590 const size_t page_size, 1591 const char* base, 1592 const size_t size) { 1593 1594 log_info(pagesize)("%s: " 1595 " min=" SIZE_FORMAT "%s" 1596 " max=" SIZE_FORMAT "%s" 1597 " base=" PTR_FORMAT 1598 " page_size=" SIZE_FORMAT "%s" 1599 " size=" SIZE_FORMAT "%s", 1600 str, 1601 trace_page_size_params(region_min_size), 1602 trace_page_size_params(region_max_size), 1603 p2i(base), 1604 trace_page_size_params(page_size), 1605 trace_page_size_params(size)); 1606 } 1607 1608 void os::trace_page_sizes_for_requested_size(const char* str, 1609 const size_t requested_size, 1610 const size_t page_size, 1611 const size_t alignment, 1612 const char* base, 1613 const size_t size) { 1614 1615 log_info(pagesize)("%s:" 1616 " req_size=" SIZE_FORMAT "%s" 1617 " base=" PTR_FORMAT 1618 " page_size=" SIZE_FORMAT "%s" 1619 " alignment=" SIZE_FORMAT "%s" 1620 " size=" SIZE_FORMAT "%s", 1621 str, 1622 trace_page_size_params(requested_size), 1623 p2i(base), 1624 trace_page_size_params(page_size), 1625 trace_page_size_params(alignment), 1626 trace_page_size_params(size)); 1627 } 1628 1629 1630 // This is the working definition of a server class machine: 1631 // >= 2 physical CPU's and >=2GB of memory, with some fuzz 1632 // because the graphics memory (?) sometimes masks physical memory. 1633 // If you want to change the definition of a server class machine 1634 // on some OS or platform, e.g., >=4GB on Windows platforms, 1635 // then you'll have to parameterize this method based on that state, 1636 // as was done for logical processors here, or replicate and 1637 // specialize this method for each platform. (Or fix os to have 1638 // some inheritance structure and use subclassing. Sigh.) 1639 // If you want some platform to always or never behave as a server 1640 // class machine, change the setting of AlwaysActAsServerClassMachine 1641 // and NeverActAsServerClassMachine in globals*.hpp. 1642 bool os::is_server_class_machine() { 1643 // First check for the early returns 1644 if (NeverActAsServerClassMachine) { 1645 return false; 1646 } 1647 if (AlwaysActAsServerClassMachine) { 1648 return true; 1649 } 1650 // Then actually look at the machine 1651 bool result = false; 1652 const unsigned int server_processors = 2; 1653 const julong server_memory = 2UL * G; 1654 // We seem not to get our full complement of memory. 1655 // We allow some part (1/8?) of the memory to be "missing", 1656 // based on the sizes of DIMMs, and maybe graphics cards. 1657 const julong missing_memory = 256UL * M; 1658 1659 /* Is this a server class machine? */ 1660 if ((os::active_processor_count() >= (int)server_processors) && 1661 (os::physical_memory() >= (server_memory - missing_memory))) { 1662 const unsigned int logical_processors = 1663 VM_Version::logical_processors_per_package(); 1664 if (logical_processors > 1) { 1665 const unsigned int physical_packages = 1666 os::active_processor_count() / logical_processors; 1667 if (physical_packages >= server_processors) { 1668 result = true; 1669 } 1670 } else { 1671 result = true; 1672 } 1673 } 1674 return result; 1675 } 1676 1677 void os::initialize_initial_active_processor_count() { 1678 assert(_initial_active_processor_count == 0, "Initial active processor count already set."); 1679 _initial_active_processor_count = active_processor_count(); 1680 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count); 1681 } 1682 1683 void os::SuspendedThreadTask::run() { 1684 internal_do_task(); 1685 _done = true; 1686 } 1687 1688 bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1689 return os::pd_create_stack_guard_pages(addr, bytes); 1690 } 1691 1692 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) { 1693 char* result = NULL; 1694 1695 if (file_desc != -1) { 1696 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(), 1697 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file. 1698 result = os::map_memory_to_file(addr, bytes, file_desc); 1699 if (result != NULL) { 1700 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1701 } 1702 } else { 1703 result = pd_reserve_memory(bytes, addr, alignment_hint); 1704 if (result != NULL) { 1705 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1706 } 1707 } 1708 1709 return result; 1710 } 1711 1712 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, 1713 MEMFLAGS flags) { 1714 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1715 if (result != NULL) { 1716 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1717 MemTracker::record_virtual_memory_type((address)result, flags); 1718 } 1719 1720 return result; 1721 } 1722 1723 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) { 1724 char* result = NULL; 1725 if (file_desc != -1) { 1726 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc); 1727 if (result != NULL) { 1728 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1729 } 1730 } else { 1731 result = pd_attempt_reserve_memory_at(bytes, addr); 1732 if (result != NULL) { 1733 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1734 } 1735 } 1736 return result; 1737 } 1738 1739 void os::split_reserved_memory(char *base, size_t size, 1740 size_t split, bool realloc) { 1741 pd_split_reserved_memory(base, size, split, realloc); 1742 } 1743 1744 bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1745 bool res = pd_commit_memory(addr, bytes, executable); 1746 if (res) { 1747 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1748 } 1749 return res; 1750 } 1751 1752 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1753 bool executable) { 1754 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1755 if (res) { 1756 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1757 } 1758 return res; 1759 } 1760 1761 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable, 1762 const char* mesg) { 1763 pd_commit_memory_or_exit(addr, bytes, executable, mesg); 1764 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1765 } 1766 1767 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, 1768 bool executable, const char* mesg) { 1769 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg); 1770 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1771 } 1772 1773 bool os::uncommit_memory(char* addr, size_t bytes) { 1774 bool res; 1775 if (MemTracker::tracking_level() > NMT_minimal) { 1776 Tracker tkr(Tracker::uncommit); 1777 res = pd_uncommit_memory(addr, bytes); 1778 if (res) { 1779 tkr.record((address)addr, bytes); 1780 } 1781 } else { 1782 res = pd_uncommit_memory(addr, bytes); 1783 } 1784 return res; 1785 } 1786 1787 bool os::release_memory(char* addr, size_t bytes) { 1788 bool res; 1789 if (MemTracker::tracking_level() > NMT_minimal) { 1790 Tracker tkr(Tracker::release); 1791 res = pd_release_memory(addr, bytes); 1792 if (res) { 1793 tkr.record((address)addr, bytes); 1794 } 1795 } else { 1796 res = pd_release_memory(addr, bytes); 1797 } 1798 return res; 1799 } 1800 1801 void os::pretouch_memory(void* start, void* end, size_t page_size) { 1802 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) { 1803 *p = 0; 1804 } 1805 } 1806 1807 char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1808 char *addr, size_t bytes, bool read_only, 1809 bool allow_exec) { 1810 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1811 if (result != NULL) { 1812 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); 1813 } 1814 return result; 1815 } 1816 1817 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1818 char *addr, size_t bytes, bool read_only, 1819 bool allow_exec) { 1820 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1821 read_only, allow_exec); 1822 } 1823 1824 bool os::unmap_memory(char *addr, size_t bytes) { 1825 bool result; 1826 if (MemTracker::tracking_level() > NMT_minimal) { 1827 Tracker tkr(Tracker::release); 1828 result = pd_unmap_memory(addr, bytes); 1829 if (result) { 1830 tkr.record((address)addr, bytes); 1831 } 1832 } else { 1833 result = pd_unmap_memory(addr, bytes); 1834 } 1835 return result; 1836 } 1837 1838 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1839 pd_free_memory(addr, bytes, alignment_hint); 1840 } 1841 1842 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1843 pd_realign_memory(addr, bytes, alignment_hint); 1844 } 1845 1846 #ifndef _WINDOWS 1847 /* try to switch state from state "from" to state "to" 1848 * returns the state set after the method is complete 1849 */ 1850 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from, 1851 os::SuspendResume::State to) 1852 { 1853 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from); 1854 if (result == from) { 1855 // success 1856 return to; 1857 } 1858 return result; 1859 } 1860 #endif