1 /* 2 * Copyright (c) 1997, 2012, 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 "classfile/classLoader.hpp" 27 #include "classfile/javaClasses.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/icBuffer.hpp" 31 #include "code/vtableStubs.hpp" 32 #include "gc_implementation/shared/vmGCOperations.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "memory/allocation.inline.hpp" 35 #include "oops/oop.inline.hpp" 36 #include "prims/jvm.h" 37 #include "prims/jvm_misc.hpp" 38 #include "prims/privilegedStack.hpp" 39 #include "runtime/arguments.hpp" 40 #include "runtime/frame.inline.hpp" 41 #include "runtime/interfaceSupport.hpp" 42 #include "runtime/java.hpp" 43 #include "runtime/javaCalls.hpp" 44 #include "runtime/mutexLocker.hpp" 45 #include "runtime/os.hpp" 46 #include "runtime/stubRoutines.hpp" 47 #include "services/attachListener.hpp" 48 #include "services/memTracker.hpp" 49 #include "services/threadService.hpp" 50 #include "utilities/defaultStream.hpp" 51 #include "utilities/events.hpp" 52 #ifdef TARGET_OS_FAMILY_linux 53 # include "os_linux.inline.hpp" 54 # include "thread_linux.inline.hpp" 55 #endif 56 #ifdef TARGET_OS_FAMILY_solaris 57 # include "os_solaris.inline.hpp" 58 # include "thread_solaris.inline.hpp" 59 #endif 60 #ifdef TARGET_OS_FAMILY_windows 61 # include "os_windows.inline.hpp" 62 # include "thread_windows.inline.hpp" 63 #endif 64 #ifdef TARGET_OS_FAMILY_bsd 65 # include "os_bsd.inline.hpp" 66 # include "thread_bsd.inline.hpp" 67 #endif 68 69 # include <signal.h> 70 71 OSThread* os::_starting_thread = NULL; 72 address os::_polling_page = NULL; 73 volatile int32_t* os::_mem_serialize_page = NULL; 74 uintptr_t os::_serialize_page_mask = 0; 75 long os::_rand_seed = 1; 76 int os::_processor_count = 0; 77 size_t os::_page_sizes[os::page_sizes_max]; 78 79 #ifndef PRODUCT 80 julong os::num_mallocs = 0; // # of calls to malloc/realloc 81 julong os::alloc_bytes = 0; // # of bytes allocated 82 julong os::num_frees = 0; // # of calls to free 83 julong os::free_bytes = 0; // # of bytes freed 84 #endif 85 86 void os_init_globals() { 87 // Called from init_globals(). 88 // See Threads::create_vm() in thread.cpp, and init.cpp. 89 os::init_globals(); 90 } 91 92 // Fill in buffer with current local time as an ISO-8601 string. 93 // E.g., yyyy-mm-ddThh:mm:ss-zzzz. 94 // Returns buffer, or NULL if it failed. 95 // This would mostly be a call to 96 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) 97 // except that on Windows the %z behaves badly, so we do it ourselves. 98 // Also, people wanted milliseconds on there, 99 // and strftime doesn't do milliseconds. 100 char* os::iso8601_time(char* buffer, size_t buffer_length) { 101 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" 102 // 1 2 103 // 12345678901234567890123456789 104 static const char* iso8601_format = 105 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"; 106 static const size_t needed_buffer = 29; 107 108 // Sanity check the arguments 109 if (buffer == NULL) { 110 assert(false, "NULL buffer"); 111 return NULL; 112 } 113 if (buffer_length < needed_buffer) { 114 assert(false, "buffer_length too small"); 115 return NULL; 116 } 117 // Get the current time 118 jlong milliseconds_since_19700101 = javaTimeMillis(); 119 const int milliseconds_per_microsecond = 1000; 120 const time_t seconds_since_19700101 = 121 milliseconds_since_19700101 / milliseconds_per_microsecond; 122 const int milliseconds_after_second = 123 milliseconds_since_19700101 % milliseconds_per_microsecond; 124 // Convert the time value to a tm and timezone variable 125 struct tm time_struct; 126 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 127 assert(false, "Failed localtime_pd"); 128 return NULL; 129 } 130 #if defined(_ALLBSD_SOURCE) 131 const time_t zone = (time_t) time_struct.tm_gmtoff; 132 #else 133 const time_t zone = timezone; 134 #endif 135 136 // If daylight savings time is in effect, 137 // we are 1 hour East of our time zone 138 const time_t seconds_per_minute = 60; 139 const time_t minutes_per_hour = 60; 140 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; 141 time_t UTC_to_local = zone; 142 if (time_struct.tm_isdst > 0) { 143 UTC_to_local = UTC_to_local - seconds_per_hour; 144 } 145 // Compute the time zone offset. 146 // localtime_pd() sets timezone to the difference (in seconds) 147 // between UTC and and local time. 148 // ISO 8601 says we need the difference between local time and UTC, 149 // we change the sign of the localtime_pd() result. 150 const time_t local_to_UTC = -(UTC_to_local); 151 // Then we have to figure out if if we are ahead (+) or behind (-) UTC. 152 char sign_local_to_UTC = '+'; 153 time_t abs_local_to_UTC = local_to_UTC; 154 if (local_to_UTC < 0) { 155 sign_local_to_UTC = '-'; 156 abs_local_to_UTC = -(abs_local_to_UTC); 157 } 158 // Convert time zone offset seconds to hours and minutes. 159 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); 160 const time_t zone_min = 161 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); 162 163 // Print an ISO 8601 date and time stamp into the buffer 164 const int year = 1900 + time_struct.tm_year; 165 const int month = 1 + time_struct.tm_mon; 166 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format, 167 year, 168 month, 169 time_struct.tm_mday, 170 time_struct.tm_hour, 171 time_struct.tm_min, 172 time_struct.tm_sec, 173 milliseconds_after_second, 174 sign_local_to_UTC, 175 zone_hours, 176 zone_min); 177 if (printed == 0) { 178 assert(false, "Failed jio_printf"); 179 return NULL; 180 } 181 return buffer; 182 } 183 184 OSReturn os::set_priority(Thread* thread, ThreadPriority p) { 185 #ifdef ASSERT 186 if (!(!thread->is_Java_thread() || 187 Thread::current() == thread || 188 Threads_lock->owned_by_self() 189 || thread->is_Compiler_thread() 190 )) { 191 assert(false, "possibility of dangling Thread pointer"); 192 } 193 #endif 194 195 if (p >= MinPriority && p <= MaxPriority) { 196 int priority = java_to_os_priority[p]; 197 return set_native_priority(thread, priority); 198 } else { 199 assert(false, "Should not happen"); 200 return OS_ERR; 201 } 202 } 203 204 205 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { 206 int p; 207 int os_prio; 208 OSReturn ret = get_native_priority(thread, &os_prio); 209 if (ret != OS_OK) return ret; 210 211 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; 212 priority = (ThreadPriority)p; 213 return OS_OK; 214 } 215 216 217 // --------------------- sun.misc.Signal (optional) --------------------- 218 219 220 // SIGBREAK is sent by the keyboard to query the VM state 221 #ifndef SIGBREAK 222 #define SIGBREAK SIGQUIT 223 #endif 224 225 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. 226 227 228 static void signal_thread_entry(JavaThread* thread, TRAPS) { 229 os::set_priority(thread, NearMaxPriority); 230 while (true) { 231 int sig; 232 { 233 // FIXME : Currently we have not decieded what should be the status 234 // for this java thread blocked here. Once we decide about 235 // that we should fix this. 236 sig = os::signal_wait(); 237 } 238 if (sig == os::sigexitnum_pd()) { 239 // Terminate the signal thread 240 return; 241 } 242 243 switch (sig) { 244 case SIGBREAK: { 245 // Check if the signal is a trigger to start the Attach Listener - in that 246 // case don't print stack traces. 247 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { 248 continue; 249 } 250 // Print stack traces 251 // Any SIGBREAK operations added here should make sure to flush 252 // the output stream (e.g. tty->flush()) after output. See 4803766. 253 // Each module also prints an extra carriage return after its output. 254 VM_PrintThreads op; 255 VMThread::execute(&op); 256 VM_PrintJNI jni_op; 257 VMThread::execute(&jni_op); 258 VM_FindDeadlocks op1(tty); 259 VMThread::execute(&op1); 260 Universe::print_heap_at_SIGBREAK(); 261 if (PrintClassHistogram) { 262 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */, 263 true /* need_prologue */); 264 VMThread::execute(&op1); 265 } 266 if (JvmtiExport::should_post_data_dump()) { 267 JvmtiExport::post_data_dump(); 268 } 269 break; 270 } 271 default: { 272 // Dispatch the signal to java 273 HandleMark hm(THREAD); 274 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD); 275 KlassHandle klass (THREAD, k); 276 if (klass.not_null()) { 277 JavaValue result(T_VOID); 278 JavaCallArguments args; 279 args.push_int(sig); 280 JavaCalls::call_static( 281 &result, 282 klass, 283 vmSymbols::dispatch_name(), 284 vmSymbols::int_void_signature(), 285 &args, 286 THREAD 287 ); 288 } 289 if (HAS_PENDING_EXCEPTION) { 290 // tty is initialized early so we don't expect it to be null, but 291 // if it is we can't risk doing an initialization that might 292 // trigger additional out-of-memory conditions 293 if (tty != NULL) { 294 char klass_name[256]; 295 char tmp_sig_name[16]; 296 const char* sig_name = "UNKNOWN"; 297 InstanceKlass::cast(PENDING_EXCEPTION->klass())-> 298 name()->as_klass_external_name(klass_name, 256); 299 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) 300 sig_name = tmp_sig_name; 301 warning("Exception %s occurred dispatching signal %s to handler" 302 "- the VM may need to be forcibly terminated", 303 klass_name, sig_name ); 304 } 305 CLEAR_PENDING_EXCEPTION; 306 } 307 } 308 } 309 } 310 } 311 312 313 void os::signal_init() { 314 if (!ReduceSignalUsage) { 315 // Setup JavaThread for processing signals 316 EXCEPTION_MARK; 317 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); 318 instanceKlassHandle klass (THREAD, k); 319 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); 320 321 const char thread_name[] = "Signal Dispatcher"; 322 Handle string = java_lang_String::create_from_str(thread_name, CHECK); 323 324 // Initialize thread_oop to put it into the system threadGroup 325 Handle thread_group (THREAD, Universe::system_thread_group()); 326 JavaValue result(T_VOID); 327 JavaCalls::call_special(&result, thread_oop, 328 klass, 329 vmSymbols::object_initializer_name(), 330 vmSymbols::threadgroup_string_void_signature(), 331 thread_group, 332 string, 333 CHECK); 334 335 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass()); 336 JavaCalls::call_special(&result, 337 thread_group, 338 group, 339 vmSymbols::add_method_name(), 340 vmSymbols::thread_void_signature(), 341 thread_oop, // ARG 1 342 CHECK); 343 344 os::signal_init_pd(); 345 346 { MutexLocker mu(Threads_lock); 347 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); 348 349 // At this point it may be possible that no osthread was created for the 350 // JavaThread due to lack of memory. We would have to throw an exception 351 // in that case. However, since this must work and we do not allow 352 // exceptions anyway, check and abort if this fails. 353 if (signal_thread == NULL || signal_thread->osthread() == NULL) { 354 vm_exit_during_initialization("java.lang.OutOfMemoryError", 355 "unable to create new native thread"); 356 } 357 358 java_lang_Thread::set_thread(thread_oop(), signal_thread); 359 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); 360 java_lang_Thread::set_daemon(thread_oop()); 361 362 signal_thread->set_threadObj(thread_oop()); 363 Threads::add(signal_thread); 364 Thread::start(signal_thread); 365 } 366 // Handle ^BREAK 367 os::signal(SIGBREAK, os::user_handler()); 368 } 369 } 370 371 372 void os::terminate_signal_thread() { 373 if (!ReduceSignalUsage) 374 signal_notify(sigexitnum_pd()); 375 } 376 377 378 // --------------------- loading libraries --------------------- 379 380 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); 381 extern struct JavaVM_ main_vm; 382 383 static void* _native_java_library = NULL; 384 385 void* os::native_java_library() { 386 if (_native_java_library == NULL) { 387 char buffer[JVM_MAXPATHLEN]; 388 char ebuf[1024]; 389 390 // Try to load verify dll first. In 1.3 java dll depends on it and is not 391 // always able to find it when the loading executable is outside the JDK. 392 // In order to keep working with 1.2 we ignore any loading errors. 393 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify"); 394 dll_load(buffer, ebuf, sizeof(ebuf)); 395 396 // Load java dll 397 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java"); 398 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 399 if (_native_java_library == NULL) { 400 vm_exit_during_initialization("Unable to load native library", ebuf); 401 } 402 403 #if defined(__OpenBSD__) 404 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 405 // ignore errors 406 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net"); 407 dll_load(buffer, ebuf, sizeof(ebuf)); 408 #endif 409 } 410 static jboolean onLoaded = JNI_FALSE; 411 if (onLoaded) { 412 // We may have to wait to fire OnLoad until TLS is initialized. 413 if (ThreadLocalStorage::is_initialized()) { 414 // The JNI_OnLoad handling is normally done by method load in 415 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library 416 // explicitly so we have to check for JNI_OnLoad as well 417 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS; 418 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR( 419 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0])); 420 if (JNI_OnLoad != NULL) { 421 JavaThread* thread = JavaThread::current(); 422 ThreadToNativeFromVM ttn(thread); 423 HandleMark hm(thread); 424 jint ver = (*JNI_OnLoad)(&main_vm, NULL); 425 onLoaded = JNI_TRUE; 426 if (!Threads::is_supported_jni_version_including_1_1(ver)) { 427 vm_exit_during_initialization("Unsupported JNI version"); 428 } 429 } 430 } 431 } 432 return _native_java_library; 433 } 434 435 // --------------------- heap allocation utilities --------------------- 436 437 char *os::strdup(const char *str, MEMFLAGS flags) { 438 size_t size = strlen(str); 439 char *dup_str = (char *)malloc(size + 1, flags); 440 if (dup_str == NULL) return NULL; 441 strcpy(dup_str, str); 442 return dup_str; 443 } 444 445 446 447 #ifdef ASSERT 448 #define space_before (MallocCushion + sizeof(double)) 449 #define space_after MallocCushion 450 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t)) 451 #define size_addr_from_obj(p) ((size_t*)p - 1) 452 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly 453 // NB: cannot be debug variable, because these aren't set from the command line until 454 // *after* the first few allocs already happened 455 #define MallocCushion 16 456 #else 457 #define space_before 0 458 #define space_after 0 459 #define size_addr_from_base(p) should not use w/o ASSERT 460 #define size_addr_from_obj(p) should not use w/o ASSERT 461 #define MallocCushion 0 462 #endif 463 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 464 465 #ifdef ASSERT 466 inline size_t get_size(void* obj) { 467 size_t size = *size_addr_from_obj(obj); 468 if (size < 0) { 469 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten (" 470 SIZE_FORMAT ")", obj, size)); 471 } 472 return size; 473 } 474 475 u_char* find_cushion_backwards(u_char* start) { 476 u_char* p = start; 477 while (p[ 0] != badResourceValue || p[-1] != badResourceValue || 478 p[-2] != badResourceValue || p[-3] != badResourceValue) p--; 479 // ok, we have four consecutive marker bytes; find start 480 u_char* q = p - 4; 481 while (*q == badResourceValue) q--; 482 return q + 1; 483 } 484 485 u_char* find_cushion_forwards(u_char* start) { 486 u_char* p = start; 487 while (p[0] != badResourceValue || p[1] != badResourceValue || 488 p[2] != badResourceValue || p[3] != badResourceValue) p++; 489 // ok, we have four consecutive marker bytes; find end of cushion 490 u_char* q = p + 4; 491 while (*q == badResourceValue) q++; 492 return q - MallocCushion; 493 } 494 495 void print_neighbor_blocks(void* ptr) { 496 // find block allocated before ptr (not entirely crash-proof) 497 if (MallocCushion < 4) { 498 tty->print_cr("### cannot find previous block (MallocCushion < 4)"); 499 return; 500 } 501 u_char* start_of_this_block = (u_char*)ptr - space_before; 502 u_char* end_of_prev_block_data = start_of_this_block - space_after -1; 503 // look for cushion in front of prev. block 504 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data); 505 ptrdiff_t size = *size_addr_from_base(start_of_prev_block); 506 u_char* obj = start_of_prev_block + space_before; 507 if (size <= 0 ) { 508 // start is bad; mayhave been confused by OS data inbetween objects 509 // search one more backwards 510 start_of_prev_block = find_cushion_backwards(start_of_prev_block); 511 size = *size_addr_from_base(start_of_prev_block); 512 obj = start_of_prev_block + space_before; 513 } 514 515 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) { 516 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size); 517 } else { 518 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size); 519 } 520 521 // now find successor block 522 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after; 523 start_of_next_block = find_cushion_forwards(start_of_next_block); 524 u_char* next_obj = start_of_next_block + space_before; 525 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block); 526 if (start_of_next_block[0] == badResourceValue && 527 start_of_next_block[1] == badResourceValue && 528 start_of_next_block[2] == badResourceValue && 529 start_of_next_block[3] == badResourceValue) { 530 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size); 531 } else { 532 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size); 533 } 534 } 535 536 537 void report_heap_error(void* memblock, void* bad, const char* where) { 538 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 539 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock); 540 print_neighbor_blocks(memblock); 541 fatal("memory stomping error"); 542 } 543 544 void verify_block(void* memblock) { 545 size_t size = get_size(memblock); 546 if (MallocCushion) { 547 u_char* ptr = (u_char*)memblock - space_before; 548 for (int i = 0; i < MallocCushion; i++) { 549 if (ptr[i] != badResourceValue) { 550 report_heap_error(memblock, ptr+i, "in front of"); 551 } 552 } 553 u_char* end = (u_char*)memblock + size + space_after; 554 for (int j = -MallocCushion; j < 0; j++) { 555 if (end[j] != badResourceValue) { 556 report_heap_error(memblock, end+j, "after"); 557 } 558 } 559 } 560 } 561 #endif 562 563 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) { 564 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 565 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 566 567 if (size == 0) { 568 // return a valid pointer if size is zero 569 // if NULL is returned the calling functions assume out of memory. 570 size = 1; 571 } 572 573 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 574 u_char* ptr = (u_char*)::malloc(size + space_before + space_after); 575 576 #ifdef ASSERT 577 if (ptr == NULL) return NULL; 578 if (MallocCushion) { 579 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue; 580 u_char* end = ptr + space_before + size; 581 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad; 582 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue; 583 } 584 // put size just before data 585 *size_addr_from_base(ptr) = size; 586 #endif 587 u_char* memblock = ptr + space_before; 588 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 589 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock); 590 breakpoint(); 591 } 592 debug_only(if (paranoid) verify_block(memblock)); 593 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock); 594 595 // we do not track MallocCushion memory 596 if (MemTracker::is_on()) { 597 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller); 598 } 599 600 return memblock; 601 } 602 603 604 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) { 605 #ifndef ASSERT 606 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 607 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 608 void* ptr = ::realloc(memblock, size); 609 if (ptr != NULL && MemTracker::is_on()) { 610 MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags, 611 caller == 0 ? CALLER_PC : caller); 612 } 613 return ptr; 614 #else 615 if (memblock == NULL) { 616 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller)); 617 } 618 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 619 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock); 620 breakpoint(); 621 } 622 verify_block(memblock); 623 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 624 if (size == 0) return NULL; 625 // always move the block 626 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller); 627 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr); 628 // Copy to new memory if malloc didn't fail 629 if ( ptr != NULL ) { 630 memcpy(ptr, memblock, MIN2(size, get_size(memblock))); 631 if (paranoid) verify_block(ptr); 632 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 633 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr); 634 breakpoint(); 635 } 636 free(memblock); 637 } 638 return ptr; 639 #endif 640 } 641 642 643 void os::free(void *memblock, MEMFLAGS memflags) { 644 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 645 #ifdef ASSERT 646 if (memblock == NULL) return; 647 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 648 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock); 649 breakpoint(); 650 } 651 verify_block(memblock); 652 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 653 // Added by detlefs. 654 if (MallocCushion) { 655 u_char* ptr = (u_char*)memblock - space_before; 656 for (u_char* p = ptr; p < ptr + MallocCushion; p++) { 657 guarantee(*p == badResourceValue, 658 "Thing freed should be malloc result."); 659 *p = (u_char)freeBlockPad; 660 } 661 size_t size = get_size(memblock); 662 inc_stat_counter(&free_bytes, size); 663 u_char* end = ptr + space_before + size; 664 for (u_char* q = end; q < end + MallocCushion; q++) { 665 guarantee(*q == badResourceValue, 666 "Thing freed should be malloc result."); 667 *q = (u_char)freeBlockPad; 668 } 669 if (PrintMalloc && tty != NULL) 670 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock); 671 } else if (PrintMalloc && tty != NULL) { 672 // tty->print_cr("os::free %p", memblock); 673 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock); 674 } 675 #endif 676 MemTracker::record_free((address)memblock, memflags); 677 678 ::free((char*)memblock - space_before); 679 } 680 681 void os::init_random(long initval) { 682 _rand_seed = initval; 683 } 684 685 686 long os::random() { 687 /* standard, well-known linear congruential random generator with 688 * next_rand = (16807*seed) mod (2**31-1) 689 * see 690 * (1) "Random Number Generators: Good Ones Are Hard to Find", 691 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 692 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 693 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 694 */ 695 const long a = 16807; 696 const unsigned long m = 2147483647; 697 const long q = m / a; assert(q == 127773, "weird math"); 698 const long r = m % a; assert(r == 2836, "weird math"); 699 700 // compute az=2^31p+q 701 unsigned long lo = a * (long)(_rand_seed & 0xFFFF); 702 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16); 703 lo += (hi & 0x7FFF) << 16; 704 705 // if q overflowed, ignore the overflow and increment q 706 if (lo > m) { 707 lo &= m; 708 ++lo; 709 } 710 lo += hi >> 15; 711 712 // if (p+q) overflowed, ignore the overflow and increment (p+q) 713 if (lo > m) { 714 lo &= m; 715 ++lo; 716 } 717 return (_rand_seed = lo); 718 } 719 720 // The INITIALIZED state is distinguished from the SUSPENDED state because the 721 // conditions in which a thread is first started are different from those in which 722 // a suspension is resumed. These differences make it hard for us to apply the 723 // tougher checks when starting threads that we want to do when resuming them. 724 // However, when start_thread is called as a result of Thread.start, on a Java 725 // thread, the operation is synchronized on the Java Thread object. So there 726 // cannot be a race to start the thread and hence for the thread to exit while 727 // we are working on it. Non-Java threads that start Java threads either have 728 // to do so in a context in which races are impossible, or should do appropriate 729 // locking. 730 731 void os::start_thread(Thread* thread) { 732 // guard suspend/resume 733 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 734 OSThread* osthread = thread->osthread(); 735 osthread->set_state(RUNNABLE); 736 pd_start_thread(thread); 737 } 738 739 //--------------------------------------------------------------------------- 740 // Helper functions for fatal error handler 741 742 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 743 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 744 745 int cols = 0; 746 int cols_per_line = 0; 747 switch (unitsize) { 748 case 1: cols_per_line = 16; break; 749 case 2: cols_per_line = 8; break; 750 case 4: cols_per_line = 4; break; 751 case 8: cols_per_line = 2; break; 752 default: return; 753 } 754 755 address p = start; 756 st->print(PTR_FORMAT ": ", start); 757 while (p < end) { 758 switch (unitsize) { 759 case 1: st->print("%02x", *(u1*)p); break; 760 case 2: st->print("%04x", *(u2*)p); break; 761 case 4: st->print("%08x", *(u4*)p); break; 762 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 763 } 764 p += unitsize; 765 cols++; 766 if (cols >= cols_per_line && p < end) { 767 cols = 0; 768 st->cr(); 769 st->print(PTR_FORMAT ": ", p); 770 } else { 771 st->print(" "); 772 } 773 } 774 st->cr(); 775 } 776 777 void os::print_environment_variables(outputStream* st, const char** env_list, 778 char* buffer, int len) { 779 if (env_list) { 780 st->print_cr("Environment Variables:"); 781 782 for (int i = 0; env_list[i] != NULL; i++) { 783 if (getenv(env_list[i], buffer, len)) { 784 st->print(env_list[i]); 785 st->print("="); 786 st->print_cr(buffer); 787 } 788 } 789 } 790 } 791 792 void os::print_cpu_info(outputStream* st) { 793 // cpu 794 st->print("CPU:"); 795 st->print("total %d", os::processor_count()); 796 // It's not safe to query number of active processors after crash 797 // st->print("(active %d)", os::active_processor_count()); 798 st->print(" %s", VM_Version::cpu_features()); 799 st->cr(); 800 pd_print_cpu_info(st); 801 } 802 803 void os::print_date_and_time(outputStream *st) { 804 time_t tloc; 805 (void)time(&tloc); 806 st->print("time: %s", ctime(&tloc)); // ctime adds newline. 807 808 double t = os::elapsedTime(); 809 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in 810 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int 811 // before printf. We lost some precision, but who cares? 812 st->print_cr("elapsed time: %d seconds", (int)t); 813 } 814 815 // moved from debug.cpp (used to be find()) but still called from there 816 // The verbose parameter is only set by the debug code in one case 817 void os::print_location(outputStream* st, intptr_t x, bool verbose) { 818 address addr = (address)x; 819 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 820 if (b != NULL) { 821 if (b->is_buffer_blob()) { 822 // the interpreter is generated into a buffer blob 823 InterpreterCodelet* i = Interpreter::codelet_containing(addr); 824 if (i != NULL) { 825 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin())); 826 i->print_on(st); 827 return; 828 } 829 if (Interpreter::contains(addr)) { 830 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code" 831 " (not bytecode specific)", addr); 832 return; 833 } 834 // 835 if (AdapterHandlerLibrary::contains(b)) { 836 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin())); 837 AdapterHandlerLibrary::print_handler_on(st, b); 838 } 839 // the stubroutines are generated into a buffer blob 840 StubCodeDesc* d = StubCodeDesc::desc_for(addr); 841 if (d != NULL) { 842 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin())); 843 d->print_on(st); 844 st->cr(); 845 return; 846 } 847 if (StubRoutines::contains(addr)) { 848 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) " 849 "stub routine", addr); 850 return; 851 } 852 // the InlineCacheBuffer is using stubs generated into a buffer blob 853 if (InlineCacheBuffer::contains(addr)) { 854 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr); 855 return; 856 } 857 VtableStub* v = VtableStubs::stub_containing(addr); 858 if (v != NULL) { 859 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point())); 860 v->print_on(st); 861 st->cr(); 862 return; 863 } 864 } 865 nmethod* nm = b->as_nmethod_or_null(); 866 if (nm != NULL) { 867 ResourceMark rm; 868 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT, 869 addr, (int)(addr - nm->entry_point()), nm); 870 if (verbose) { 871 st->print(" for "); 872 nm->method()->print_value_on(st); 873 } 874 nm->print_nmethod(verbose); 875 return; 876 } 877 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin())); 878 b->print_on(st); 879 return; 880 } 881 882 if (Universe::heap()->is_in(addr)) { 883 HeapWord* p = Universe::heap()->block_start(addr); 884 bool print = false; 885 // If we couldn't find it it just may mean that heap wasn't parseable 886 // See if we were just given an oop directly 887 if (p != NULL && Universe::heap()->block_is_obj(p)) { 888 print = true; 889 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) { 890 p = (HeapWord*) addr; 891 print = true; 892 } 893 if (print) { 894 st->print_cr(INTPTR_FORMAT " is an oop", addr); 895 oop(p)->print_on(st); 896 return; 897 } 898 } else { 899 if (Universe::heap()->is_in_reserved(addr)) { 900 st->print_cr(INTPTR_FORMAT " is an unallocated location " 901 "in the heap", addr); 902 return; 903 } 904 } 905 if (JNIHandles::is_global_handle((jobject) addr)) { 906 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr); 907 return; 908 } 909 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 910 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr); 911 return; 912 } 913 #ifndef PRODUCT 914 // we don't keep the block list in product mode 915 if (JNIHandleBlock::any_contains((jobject) addr)) { 916 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr); 917 return; 918 } 919 #endif 920 921 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) { 922 // Check for privilege stack 923 if (thread->privileged_stack_top() != NULL && 924 thread->privileged_stack_top()->contains(addr)) { 925 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack " 926 "for thread: " INTPTR_FORMAT, addr, thread); 927 if (verbose) thread->print_on(st); 928 return; 929 } 930 // If the addr is a java thread print information about that. 931 if (addr == (address)thread) { 932 if (verbose) { 933 thread->print_on(st); 934 } else { 935 st->print_cr(INTPTR_FORMAT " is a thread", addr); 936 } 937 return; 938 } 939 // If the addr is in the stack region for this thread then report that 940 // and print thread info 941 if (thread->stack_base() >= addr && 942 addr > (thread->stack_base() - thread->stack_size())) { 943 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 944 INTPTR_FORMAT, addr, thread); 945 if (verbose) thread->print_on(st); 946 return; 947 } 948 949 } 950 951 #ifndef PRODUCT 952 // Check if in metaspace. 953 if (ClassLoaderDataGraph::contains((address)addr)) { 954 // Use addr->print() from the debugger instead (not here) 955 st->print_cr(INTPTR_FORMAT 956 " is pointing into metadata", addr); 957 return; 958 } 959 #endif 960 961 // Try an OS specific find 962 if (os::find(addr, st)) { 963 return; 964 } 965 966 st->print_cr(INTPTR_FORMAT " is an unknown value", addr); 967 } 968 969 // Looks like all platforms except IA64 can use the same function to check 970 // if C stack is walkable beyond current frame. The check for fp() is not 971 // necessary on Sparc, but it's harmless. 972 bool os::is_first_C_frame(frame* fr) { 973 #ifdef IA64 974 // In order to walk native frames on Itanium, we need to access the unwind 975 // table, which is inside ELF. We don't want to parse ELF after fatal error, 976 // so return true for IA64. If we need to support C stack walking on IA64, 977 // this function needs to be moved to CPU specific files, as fp() on IA64 978 // is register stack, which grows towards higher memory address. 979 return true; 980 #endif 981 982 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 983 // Check usp first, because if that's bad the other accessors may fault 984 // on some architectures. Ditto ufp second, etc. 985 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 986 // sp on amd can be 32 bit aligned. 987 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 988 989 uintptr_t usp = (uintptr_t)fr->sp(); 990 if ((usp & sp_align_mask) != 0) return true; 991 992 uintptr_t ufp = (uintptr_t)fr->fp(); 993 if ((ufp & fp_align_mask) != 0) return true; 994 995 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 996 if ((old_sp & sp_align_mask) != 0) return true; 997 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 998 999 uintptr_t old_fp = (uintptr_t)fr->link(); 1000 if ((old_fp & fp_align_mask) != 0) return true; 1001 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1002 1003 // stack grows downwards; if old_fp is below current fp or if the stack 1004 // frame is too large, either the stack is corrupted or fp is not saved 1005 // on stack (i.e. on x86, ebp may be used as general register). The stack 1006 // is not walkable beyond current frame. 1007 if (old_fp < ufp) return true; 1008 if (old_fp - ufp > 64 * K) return true; 1009 1010 return false; 1011 } 1012 1013 #ifdef ASSERT 1014 extern "C" void test_random() { 1015 const double m = 2147483647; 1016 double mean = 0.0, variance = 0.0, t; 1017 long reps = 10000; 1018 unsigned long seed = 1; 1019 1020 tty->print_cr("seed %ld for %ld repeats...", seed, reps); 1021 os::init_random(seed); 1022 long num; 1023 for (int k = 0; k < reps; k++) { 1024 num = os::random(); 1025 double u = (double)num / m; 1026 assert(u >= 0.0 && u <= 1.0, "bad random number!"); 1027 1028 // calculate mean and variance of the random sequence 1029 mean += u; 1030 variance += (u*u); 1031 } 1032 mean /= reps; 1033 variance /= (reps - 1); 1034 1035 assert(num == 1043618065, "bad seed"); 1036 tty->print_cr("mean of the 1st 10000 numbers: %f", mean); 1037 tty->print_cr("variance of the 1st 10000 numbers: %f", variance); 1038 const double eps = 0.0001; 1039 t = fabsd(mean - 0.5018); 1040 assert(t < eps, "bad mean"); 1041 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355; 1042 assert(t < eps, "bad variance"); 1043 } 1044 #endif 1045 1046 1047 // Set up the boot classpath. 1048 1049 char* os::format_boot_path(const char* format_string, 1050 const char* home, 1051 int home_len, 1052 char fileSep, 1053 char pathSep) { 1054 assert((fileSep == '/' && pathSep == ':') || 1055 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars"); 1056 1057 // Scan the format string to determine the length of the actual 1058 // boot classpath, and handle platform dependencies as well. 1059 int formatted_path_len = 0; 1060 const char* p; 1061 for (p = format_string; *p != 0; ++p) { 1062 if (*p == '%') formatted_path_len += home_len - 1; 1063 ++formatted_path_len; 1064 } 1065 1066 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1067 if (formatted_path == NULL) { 1068 return NULL; 1069 } 1070 1071 // Create boot classpath from format, substituting separator chars and 1072 // java home directory. 1073 char* q = formatted_path; 1074 for (p = format_string; *p != 0; ++p) { 1075 switch (*p) { 1076 case '%': 1077 strcpy(q, home); 1078 q += home_len; 1079 break; 1080 case '/': 1081 *q++ = fileSep; 1082 break; 1083 case ':': 1084 *q++ = pathSep; 1085 break; 1086 default: 1087 *q++ = *p; 1088 } 1089 } 1090 *q = '\0'; 1091 1092 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1093 return formatted_path; 1094 } 1095 1096 1097 bool os::set_boot_path(char fileSep, char pathSep) { 1098 const char* home = Arguments::get_java_home(); 1099 int home_len = (int)strlen(home); 1100 1101 static const char* meta_index_dir_format = "%/lib/"; 1102 static const char* meta_index_format = "%/lib/meta-index"; 1103 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep); 1104 if (meta_index == NULL) return false; 1105 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep); 1106 if (meta_index_dir == NULL) return false; 1107 Arguments::set_meta_index_path(meta_index, meta_index_dir); 1108 1109 // Any modification to the JAR-file list, for the boot classpath must be 1110 // aligned with install/install/make/common/Pack.gmk. Note: boot class 1111 // path class JARs, are stripped for StackMapTable to reduce download size. 1112 static const char classpath_format[] = 1113 "%/lib/resources.jar:" 1114 "%/lib/rt.jar:" 1115 "%/lib/sunrsasign.jar:" 1116 "%/lib/jsse.jar:" 1117 "%/lib/jce.jar:" 1118 "%/lib/charsets.jar:" 1119 "%/lib/jfr.jar:" 1120 #ifdef __APPLE__ 1121 "%/lib/JObjC.jar:" 1122 #endif 1123 "%/classes"; 1124 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep); 1125 if (sysclasspath == NULL) return false; 1126 Arguments::set_sysclasspath(sysclasspath); 1127 1128 return true; 1129 } 1130 1131 /* 1132 * Splits a path, based on its separator, the number of 1133 * elements is returned back in n. 1134 * It is the callers responsibility to: 1135 * a> check the value of n, and n may be 0. 1136 * b> ignore any empty path elements 1137 * c> free up the data. 1138 */ 1139 char** os::split_path(const char* path, int* n) { 1140 *n = 0; 1141 if (path == NULL || strlen(path) == 0) { 1142 return NULL; 1143 } 1144 const char psepchar = *os::path_separator(); 1145 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1146 if (inpath == NULL) { 1147 return NULL; 1148 } 1149 strncpy(inpath, path, strlen(path)); 1150 int count = 1; 1151 char* p = strchr(inpath, psepchar); 1152 // Get a count of elements to allocate memory 1153 while (p != NULL) { 1154 count++; 1155 p++; 1156 p = strchr(p, psepchar); 1157 } 1158 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1159 if (opath == NULL) { 1160 return NULL; 1161 } 1162 1163 // do the actual splitting 1164 p = inpath; 1165 for (int i = 0 ; i < count ; i++) { 1166 size_t len = strcspn(p, os::path_separator()); 1167 if (len > JVM_MAXPATHLEN) { 1168 return NULL; 1169 } 1170 // allocate the string and add terminator storage 1171 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 1172 if (s == NULL) { 1173 return NULL; 1174 } 1175 strncpy(s, p, len); 1176 s[len] = '\0'; 1177 opath[i] = s; 1178 p += len + 1; 1179 } 1180 FREE_C_HEAP_ARRAY(char, inpath, mtInternal); 1181 *n = count; 1182 return opath; 1183 } 1184 1185 void os::set_memory_serialize_page(address page) { 1186 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); 1187 _mem_serialize_page = (volatile int32_t *)page; 1188 // We initialize the serialization page shift count here 1189 // We assume a cache line size of 64 bytes 1190 assert(SerializePageShiftCount == count, 1191 "thread size changed, fix SerializePageShiftCount constant"); 1192 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); 1193 } 1194 1195 static volatile intptr_t SerializePageLock = 0; 1196 1197 // This method is called from signal handler when SIGSEGV occurs while the current 1198 // thread tries to store to the "read-only" memory serialize page during state 1199 // transition. 1200 void os::block_on_serialize_page_trap() { 1201 if (TraceSafepoint) { 1202 tty->print_cr("Block until the serialize page permission restored"); 1203 } 1204 // When VMThread is holding the SerializePageLock during modifying the 1205 // access permission of the memory serialize page, the following call 1206 // will block until the permission of that page is restored to rw. 1207 // Generally, it is unsafe to manipulate locks in signal handlers, but in 1208 // this case, it's OK as the signal is synchronous and we know precisely when 1209 // it can occur. 1210 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); 1211 Thread::muxRelease(&SerializePageLock); 1212 } 1213 1214 // Serialize all thread state variables 1215 void os::serialize_thread_states() { 1216 // On some platforms such as Solaris & Linux, the time duration of the page 1217 // permission restoration is observed to be much longer than expected due to 1218 // scheduler starvation problem etc. To avoid the long synchronization 1219 // time and expensive page trap spinning, 'SerializePageLock' is used to block 1220 // the mutator thread if such case is encountered. See bug 6546278 for details. 1221 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); 1222 os::protect_memory((char *)os::get_memory_serialize_page(), 1223 os::vm_page_size(), MEM_PROT_READ); 1224 os::protect_memory((char *)os::get_memory_serialize_page(), 1225 os::vm_page_size(), MEM_PROT_RW); 1226 Thread::muxRelease(&SerializePageLock); 1227 } 1228 1229 // Returns true if the current stack pointer is above the stack shadow 1230 // pages, false otherwise. 1231 1232 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) { 1233 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check"); 1234 address sp = current_stack_pointer(); 1235 // Check if we have StackShadowPages above the yellow zone. This parameter 1236 // is dependent on the depth of the maximum VM call stack possible from 1237 // the handler for stack overflow. 'instanceof' in the stack overflow 1238 // handler or a println uses at least 8k stack of VM and native code 1239 // respectively. 1240 const int framesize_in_bytes = 1241 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1242 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages) 1243 * vm_page_size()) + framesize_in_bytes; 1244 // The very lower end of the stack 1245 address stack_limit = thread->stack_base() - thread->stack_size(); 1246 return (sp > (stack_limit + reserved_area)); 1247 } 1248 1249 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size, 1250 uint min_pages) 1251 { 1252 assert(min_pages > 0, "sanity"); 1253 if (UseLargePages) { 1254 const size_t max_page_size = region_max_size / min_pages; 1255 1256 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) { 1257 const size_t sz = _page_sizes[i]; 1258 const size_t mask = sz - 1; 1259 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) { 1260 // The largest page size with no fragmentation. 1261 return sz; 1262 } 1263 1264 if (sz <= max_page_size) { 1265 // The largest page size that satisfies the min_pages requirement. 1266 return sz; 1267 } 1268 } 1269 } 1270 1271 return vm_page_size(); 1272 } 1273 1274 #ifndef PRODUCT 1275 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) 1276 { 1277 if (TracePageSizes) { 1278 tty->print("%s: ", str); 1279 for (int i = 0; i < count; ++i) { 1280 tty->print(" " SIZE_FORMAT, page_sizes[i]); 1281 } 1282 tty->cr(); 1283 } 1284 } 1285 1286 void os::trace_page_sizes(const char* str, const size_t region_min_size, 1287 const size_t region_max_size, const size_t page_size, 1288 const char* base, const size_t size) 1289 { 1290 if (TracePageSizes) { 1291 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT 1292 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT 1293 " size=" SIZE_FORMAT, 1294 str, region_min_size, region_max_size, 1295 page_size, base, size); 1296 } 1297 } 1298 #endif // #ifndef PRODUCT 1299 1300 // This is the working definition of a server class machine: 1301 // >= 2 physical CPU's and >=2GB of memory, with some fuzz 1302 // because the graphics memory (?) sometimes masks physical memory. 1303 // If you want to change the definition of a server class machine 1304 // on some OS or platform, e.g., >=4GB on Windohs platforms, 1305 // then you'll have to parameterize this method based on that state, 1306 // as was done for logical processors here, or replicate and 1307 // specialize this method for each platform. (Or fix os to have 1308 // some inheritance structure and use subclassing. Sigh.) 1309 // If you want some platform to always or never behave as a server 1310 // class machine, change the setting of AlwaysActAsServerClassMachine 1311 // and NeverActAsServerClassMachine in globals*.hpp. 1312 bool os::is_server_class_machine() { 1313 // First check for the early returns 1314 if (NeverActAsServerClassMachine) { 1315 return false; 1316 } 1317 if (AlwaysActAsServerClassMachine) { 1318 return true; 1319 } 1320 // Then actually look at the machine 1321 bool result = false; 1322 const unsigned int server_processors = 2; 1323 const julong server_memory = 2UL * G; 1324 // We seem not to get our full complement of memory. 1325 // We allow some part (1/8?) of the memory to be "missing", 1326 // based on the sizes of DIMMs, and maybe graphics cards. 1327 const julong missing_memory = 256UL * M; 1328 1329 /* Is this a server class machine? */ 1330 if ((os::active_processor_count() >= (int)server_processors) && 1331 (os::physical_memory() >= (server_memory - missing_memory))) { 1332 const unsigned int logical_processors = 1333 VM_Version::logical_processors_per_package(); 1334 if (logical_processors > 1) { 1335 const unsigned int physical_packages = 1336 os::active_processor_count() / logical_processors; 1337 if (physical_packages > server_processors) { 1338 result = true; 1339 } 1340 } else { 1341 result = true; 1342 } 1343 } 1344 return result; 1345 } 1346 1347 // Read file line by line, if line is longer than bsize, 1348 // skip rest of line. 1349 int os::get_line_chars(int fd, char* buf, const size_t bsize){ 1350 size_t sz, i = 0; 1351 1352 // read until EOF, EOL or buf is full 1353 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') { 1354 ++i; 1355 } 1356 1357 if (buf[i] == '\n') { 1358 // EOL reached so ignore EOL character and return 1359 1360 buf[i] = 0; 1361 return (int) i; 1362 } 1363 1364 buf[i+1] = 0; 1365 1366 if (sz != 1) { 1367 // EOF reached. if we read chars before EOF return them and 1368 // return EOF on next call otherwise return EOF 1369 1370 return (i == 0) ? -1 : (int) i; 1371 } 1372 1373 // line is longer than size of buf, skip to EOL 1374 char ch; 1375 while (read(fd, &ch, 1) == 1 && ch != '\n') { 1376 // Do nothing 1377 } 1378 1379 // return initial part of line that fits in buf. 1380 // If we reached EOF, it will be returned on next call. 1381 1382 return (int) i; 1383 } 1384 1385 bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1386 return os::pd_create_stack_guard_pages(addr, bytes); 1387 } 1388 1389 1390 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) { 1391 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1392 if (result != NULL && MemTracker::is_on()) { 1393 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1394 } 1395 1396 return result; 1397 } 1398 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) { 1399 char* result = pd_attempt_reserve_memory_at(bytes, addr); 1400 if (result != NULL && MemTracker::is_on()) { 1401 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1402 } 1403 return result; 1404 } 1405 1406 void os::split_reserved_memory(char *base, size_t size, 1407 size_t split, bool realloc) { 1408 pd_split_reserved_memory(base, size, split, realloc); 1409 } 1410 1411 bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1412 bool res = pd_commit_memory(addr, bytes, executable); 1413 if (res && MemTracker::is_on()) { 1414 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1415 } 1416 return res; 1417 } 1418 1419 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1420 bool executable) { 1421 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1422 if (res && MemTracker::is_on()) { 1423 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1424 } 1425 return res; 1426 } 1427 1428 bool os::uncommit_memory(char* addr, size_t bytes) { 1429 bool res = pd_uncommit_memory(addr, bytes); 1430 if (res) { 1431 MemTracker::record_virtual_memory_uncommit((address)addr, bytes); 1432 } 1433 return res; 1434 } 1435 1436 bool os::release_memory(char* addr, size_t bytes) { 1437 bool res = pd_release_memory(addr, bytes); 1438 if (res) { 1439 MemTracker::record_virtual_memory_release((address)addr, bytes); 1440 } 1441 return res; 1442 } 1443 1444 1445 char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1446 char *addr, size_t bytes, bool read_only, 1447 bool allow_exec) { 1448 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1449 if (result != NULL && MemTracker::is_on()) { 1450 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1451 } 1452 return result; 1453 } 1454 1455 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1456 char *addr, size_t bytes, bool read_only, 1457 bool allow_exec) { 1458 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1459 read_only, allow_exec); 1460 } 1461 1462 bool os::unmap_memory(char *addr, size_t bytes) { 1463 bool result = pd_unmap_memory(addr, bytes); 1464 if (result) { 1465 MemTracker::record_virtual_memory_release((address)addr, bytes); 1466 } 1467 return result; 1468 } 1469 1470 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1471 pd_free_memory(addr, bytes, alignment_hint); 1472 } 1473 1474 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1475 pd_realign_memory(addr, bytes, alignment_hint); 1476 } 1477