1 /*
   2  * Copyright (c) 1997, 2013, 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 "runtime/thread.inline.hpp"
  48 #include "services/attachListener.hpp"
  49 #include "services/memTracker.hpp"
  50 #include "services/threadService.hpp"
  51 #include "utilities/defaultStream.hpp"
  52 #include "utilities/events.hpp"
  53 #ifdef TARGET_OS_FAMILY_linux
  54 # include "os_linux.inline.hpp"
  55 #endif
  56 #ifdef TARGET_OS_FAMILY_solaris
  57 # include "os_solaris.inline.hpp"
  58 #endif
  59 #ifdef TARGET_OS_FAMILY_windows
  60 # include "os_windows.inline.hpp"
  61 #endif
  62 #ifdef TARGET_OS_FAMILY_bsd
  63 # include "os_bsd.inline.hpp"
  64 #endif
  65 
  66 # include <signal.h>
  67 
  68 OSThread*         os::_starting_thread    = NULL;
  69 address           os::_polling_page       = NULL;
  70 volatile int32_t* os::_mem_serialize_page = NULL;
  71 uintptr_t         os::_serialize_page_mask = 0;
  72 long              os::_rand_seed          = 1;
  73 int               os::_processor_count    = 0;
  74 size_t            os::_page_sizes[os::page_sizes_max];
  75 
  76 #ifndef PRODUCT
  77 julong os::num_mallocs = 0;         // # of calls to malloc/realloc
  78 julong os::alloc_bytes = 0;         // # of bytes allocated
  79 julong os::num_frees = 0;           // # of calls to free
  80 julong os::free_bytes = 0;          // # of bytes freed
  81 #endif
  82 
  83 static juint cur_malloc_words = 0;  // current size for MallocMaxTestWords
  84 
  85 void os_init_globals() {
  86   // Called from init_globals().
  87   // See Threads::create_vm() in thread.cpp, and init.cpp.
  88   os::init_globals();
  89 }
  90 
  91 // Fill in buffer with current local time as an ISO-8601 string.
  92 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
  93 // Returns buffer, or NULL if it failed.
  94 // This would mostly be a call to
  95 //     strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
  96 // except that on Windows the %z behaves badly, so we do it ourselves.
  97 // Also, people wanted milliseconds on there,
  98 // and strftime doesn't do milliseconds.
  99 char* os::iso8601_time(char* buffer, size_t buffer_length) {
 100   // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
 101   //                                      1         2
 102   //                             12345678901234567890123456789
 103   static const char* iso8601_format =
 104     "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
 105   static const size_t needed_buffer = 29;
 106 
 107   // Sanity check the arguments
 108   if (buffer == NULL) {
 109     assert(false, "NULL buffer");
 110     return NULL;
 111   }
 112   if (buffer_length < needed_buffer) {
 113     assert(false, "buffer_length too small");
 114     return NULL;
 115   }
 116   // Get the current time
 117   jlong milliseconds_since_19700101 = javaTimeMillis();
 118   const int milliseconds_per_microsecond = 1000;
 119   const time_t seconds_since_19700101 =
 120     milliseconds_since_19700101 / milliseconds_per_microsecond;
 121   const int milliseconds_after_second =
 122     milliseconds_since_19700101 % milliseconds_per_microsecond;
 123   // Convert the time value to a tm and timezone variable
 124   struct tm time_struct;
 125   if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
 126     assert(false, "Failed localtime_pd");
 127     return NULL;
 128   }
 129 #if defined(_ALLBSD_SOURCE)
 130   const time_t zone = (time_t) time_struct.tm_gmtoff;
 131 #else
 132   const time_t zone = timezone;
 133 #endif
 134 
 135   // If daylight savings time is in effect,
 136   // we are 1 hour East of our time zone
 137   const time_t seconds_per_minute = 60;
 138   const time_t minutes_per_hour = 60;
 139   const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
 140   time_t UTC_to_local = zone;
 141   if (time_struct.tm_isdst > 0) {
 142     UTC_to_local = UTC_to_local - seconds_per_hour;
 143   }
 144   // Compute the time zone offset.
 145   //    localtime_pd() sets timezone to the difference (in seconds)
 146   //    between UTC and and local time.
 147   //    ISO 8601 says we need the difference between local time and UTC,
 148   //    we change the sign of the localtime_pd() result.
 149   const time_t local_to_UTC = -(UTC_to_local);
 150   // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
 151   char sign_local_to_UTC = '+';
 152   time_t abs_local_to_UTC = local_to_UTC;
 153   if (local_to_UTC < 0) {
 154     sign_local_to_UTC = '-';
 155     abs_local_to_UTC = -(abs_local_to_UTC);
 156   }
 157   // Convert time zone offset seconds to hours and minutes.
 158   const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
 159   const time_t zone_min =
 160     ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
 161 
 162   // Print an ISO 8601 date and time stamp into the buffer
 163   const int year = 1900 + time_struct.tm_year;
 164   const int month = 1 + time_struct.tm_mon;
 165   const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
 166                                    year,
 167                                    month,
 168                                    time_struct.tm_mday,
 169                                    time_struct.tm_hour,
 170                                    time_struct.tm_min,
 171                                    time_struct.tm_sec,
 172                                    milliseconds_after_second,
 173                                    sign_local_to_UTC,
 174                                    zone_hours,
 175                                    zone_min);
 176   if (printed == 0) {
 177     assert(false, "Failed jio_printf");
 178     return NULL;
 179   }
 180   return buffer;
 181 }
 182 
 183 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
 184 #ifdef ASSERT
 185   if (!(!thread->is_Java_thread() ||
 186          Thread::current() == thread  ||
 187          Threads_lock->owned_by_self()
 188          || thread->is_Compiler_thread()
 189         )) {
 190     assert(false, "possibility of dangling Thread pointer");
 191   }
 192 #endif
 193 
 194   if (p >= MinPriority && p <= MaxPriority) {
 195     int priority = java_to_os_priority[p];
 196     return set_native_priority(thread, priority);
 197   } else {
 198     assert(false, "Should not happen");
 199     return OS_ERR;
 200   }
 201 }
 202 
 203 // The mapping from OS priority back to Java priority may be inexact because
 204 // Java priorities can map M:1 with native priorities. If you want the definite
 205 // Java priority then use JavaThread::java_priority()
 206 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
 207   int p;
 208   int os_prio;
 209   OSReturn ret = get_native_priority(thread, &os_prio);
 210   if (ret != OS_OK) return ret;
 211 
 212   if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
 213     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
 214   } else {
 215     // niceness values are in reverse order
 216     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
 217   }
 218   priority = (ThreadPriority)p;
 219   return OS_OK;
 220 }
 221 
 222 
 223 // --------------------- sun.misc.Signal (optional) ---------------------
 224 
 225 
 226 // SIGBREAK is sent by the keyboard to query the VM state
 227 #ifndef SIGBREAK
 228 #define SIGBREAK SIGQUIT
 229 #endif
 230 
 231 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
 232 
 233 
 234 static void signal_thread_entry(JavaThread* thread, TRAPS) {
 235   os::set_priority(thread, NearMaxPriority);
 236   while (true) {
 237     int sig;
 238     {
 239       // FIXME : Currently we have not decieded what should be the status
 240       //         for this java thread blocked here. Once we decide about
 241       //         that we should fix this.
 242       sig = os::signal_wait();
 243     }
 244     if (sig == os::sigexitnum_pd()) {
 245        // Terminate the signal thread
 246        return;
 247     }
 248 
 249     switch (sig) {
 250       case SIGBREAK: {
 251         // Check if the signal is a trigger to start the Attach Listener - in that
 252         // case don't print stack traces.
 253         if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
 254           continue;
 255         }
 256         // Print stack traces
 257         // Any SIGBREAK operations added here should make sure to flush
 258         // the output stream (e.g. tty->flush()) after output.  See 4803766.
 259         // Each module also prints an extra carriage return after its output.
 260         VM_PrintThreads op;
 261         VMThread::execute(&op);
 262         VM_PrintJNI jni_op;
 263         VMThread::execute(&jni_op);
 264         VM_FindDeadlocks op1(tty);
 265         VMThread::execute(&op1);
 266         Universe::print_heap_at_SIGBREAK();
 267         if (PrintClassHistogram) {
 268           VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
 269           VMThread::execute(&op1);
 270         }
 271         if (JvmtiExport::should_post_data_dump()) {
 272           JvmtiExport::post_data_dump();
 273         }
 274         break;
 275       }
 276       default: {
 277         // Dispatch the signal to java
 278         HandleMark hm(THREAD);
 279         Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
 280         KlassHandle klass (THREAD, k);
 281         if (klass.not_null()) {
 282           JavaValue result(T_VOID);
 283           JavaCallArguments args;
 284           args.push_int(sig);
 285           JavaCalls::call_static(
 286             &result,
 287             klass,
 288             vmSymbols::dispatch_name(),
 289             vmSymbols::int_void_signature(),
 290             &args,
 291             THREAD
 292           );
 293         }
 294         if (HAS_PENDING_EXCEPTION) {
 295           // tty is initialized early so we don't expect it to be null, but
 296           // if it is we can't risk doing an initialization that might
 297           // trigger additional out-of-memory conditions
 298           if (tty != NULL) {
 299             char klass_name[256];
 300             char tmp_sig_name[16];
 301             const char* sig_name = "UNKNOWN";
 302             InstanceKlass::cast(PENDING_EXCEPTION->klass())->
 303               name()->as_klass_external_name(klass_name, 256);
 304             if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
 305               sig_name = tmp_sig_name;
 306             warning("Exception %s occurred dispatching signal %s to handler"
 307                     "- the VM may need to be forcibly terminated",
 308                     klass_name, sig_name );
 309           }
 310           CLEAR_PENDING_EXCEPTION;
 311         }
 312       }
 313     }
 314   }
 315 }
 316 
 317 
 318 void os::signal_init() {
 319   if (!ReduceSignalUsage) {
 320     // Setup JavaThread for processing signals
 321     EXCEPTION_MARK;
 322     Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
 323     instanceKlassHandle klass (THREAD, k);
 324     instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
 325 
 326     const char thread_name[] = "Signal Dispatcher";
 327     Handle string = java_lang_String::create_from_str(thread_name, CHECK);
 328 
 329     // Initialize thread_oop to put it into the system threadGroup
 330     Handle thread_group (THREAD, Universe::system_thread_group());
 331     JavaValue result(T_VOID);
 332     JavaCalls::call_special(&result, thread_oop,
 333                            klass,
 334                            vmSymbols::object_initializer_name(),
 335                            vmSymbols::threadgroup_string_void_signature(),
 336                            thread_group,
 337                            string,
 338                            CHECK);
 339 
 340     KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
 341     JavaCalls::call_special(&result,
 342                             thread_group,
 343                             group,
 344                             vmSymbols::add_method_name(),
 345                             vmSymbols::thread_void_signature(),
 346                             thread_oop,         // ARG 1
 347                             CHECK);
 348 
 349     os::signal_init_pd();
 350 
 351     { MutexLocker mu(Threads_lock);
 352       JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
 353 
 354       // At this point it may be possible that no osthread was created for the
 355       // JavaThread due to lack of memory. We would have to throw an exception
 356       // in that case. However, since this must work and we do not allow
 357       // exceptions anyway, check and abort if this fails.
 358       if (signal_thread == NULL || signal_thread->osthread() == NULL) {
 359         vm_exit_during_initialization("java.lang.OutOfMemoryError",
 360                                       "unable to create new native thread");
 361       }
 362 
 363       java_lang_Thread::set_thread(thread_oop(), signal_thread);
 364       java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
 365       java_lang_Thread::set_daemon(thread_oop());
 366 
 367       signal_thread->set_threadObj(thread_oop());
 368       Threads::add(signal_thread);
 369       Thread::start(signal_thread);
 370     }
 371     // Handle ^BREAK
 372     os::signal(SIGBREAK, os::user_handler());
 373   }
 374 }
 375 
 376 
 377 void os::terminate_signal_thread() {
 378   if (!ReduceSignalUsage)
 379     signal_notify(sigexitnum_pd());
 380 }
 381 
 382 
 383 // --------------------- loading libraries ---------------------
 384 
 385 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
 386 extern struct JavaVM_ main_vm;
 387 
 388 static void* _native_java_library = NULL;
 389 
 390 void* os::native_java_library() {
 391   if (_native_java_library == NULL) {
 392     char buffer[JVM_MAXPATHLEN];
 393     char ebuf[1024];
 394 
 395     // Try to load verify dll first. In 1.3 java dll depends on it and is not
 396     // always able to find it when the loading executable is outside the JDK.
 397     // In order to keep working with 1.2 we ignore any loading errors.
 398     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 399                        "verify")) {
 400       dll_load(buffer, ebuf, sizeof(ebuf));
 401     }
 402 
 403     // Load java dll
 404     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 405                        "java")) {
 406       _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
 407     }
 408     if (_native_java_library == NULL) {
 409       vm_exit_during_initialization("Unable to load native library", ebuf);
 410     }
 411 
 412 #if defined(__OpenBSD__)
 413     // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
 414     // ignore errors
 415     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 416                        "net")) {
 417       dll_load(buffer, ebuf, sizeof(ebuf));
 418     }
 419 #endif
 420   }
 421   static jboolean onLoaded = JNI_FALSE;
 422   if (onLoaded) {
 423     // We may have to wait to fire OnLoad until TLS is initialized.
 424     if (ThreadLocalStorage::is_initialized()) {
 425       // The JNI_OnLoad handling is normally done by method load in
 426       // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
 427       // explicitly so we have to check for JNI_OnLoad as well
 428       const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
 429       JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
 430           JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
 431       if (JNI_OnLoad != NULL) {
 432         JavaThread* thread = JavaThread::current();
 433         ThreadToNativeFromVM ttn(thread);
 434         HandleMark hm(thread);
 435         jint ver = (*JNI_OnLoad)(&main_vm, NULL);
 436         onLoaded = JNI_TRUE;
 437         if (!Threads::is_supported_jni_version_including_1_1(ver)) {
 438           vm_exit_during_initialization("Unsupported JNI version");
 439         }
 440       }
 441     }
 442   }
 443   return _native_java_library;
 444 }
 445 
 446 // --------------------- heap allocation utilities ---------------------
 447 
 448 char *os::strdup(const char *str, MEMFLAGS flags) {
 449   size_t size = strlen(str);
 450   char *dup_str = (char *)malloc(size + 1, flags);
 451   if (dup_str == NULL) return NULL;
 452   strcpy(dup_str, str);
 453   return dup_str;
 454 }
 455 
 456 
 457 
 458 #ifdef ASSERT
 459 #define space_before             (MallocCushion + sizeof(double))
 460 #define space_after              MallocCushion
 461 #define size_addr_from_base(p)   (size_t*)(p + space_before - sizeof(size_t))
 462 #define size_addr_from_obj(p)    ((size_t*)p - 1)
 463 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
 464 // NB: cannot be debug variable, because these aren't set from the command line until
 465 // *after* the first few allocs already happened
 466 #define MallocCushion            16
 467 #else
 468 #define space_before             0
 469 #define space_after              0
 470 #define size_addr_from_base(p)   should not use w/o ASSERT
 471 #define size_addr_from_obj(p)    should not use w/o ASSERT
 472 #define MallocCushion            0
 473 #endif
 474 #define paranoid                 0  /* only set to 1 if you suspect checking code has bug */
 475 
 476 #ifdef ASSERT
 477 inline size_t get_size(void* obj) {
 478   size_t size = *size_addr_from_obj(obj);
 479   if (size < 0) {
 480     fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
 481                   SIZE_FORMAT ")", obj, size));
 482   }
 483   return size;
 484 }
 485 
 486 u_char* find_cushion_backwards(u_char* start) {
 487   u_char* p = start;
 488   while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
 489          p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
 490   // ok, we have four consecutive marker bytes; find start
 491   u_char* q = p - 4;
 492   while (*q == badResourceValue) q--;
 493   return q + 1;
 494 }
 495 
 496 u_char* find_cushion_forwards(u_char* start) {
 497   u_char* p = start;
 498   while (p[0] != badResourceValue || p[1] != badResourceValue ||
 499          p[2] != badResourceValue || p[3] != badResourceValue) p++;
 500   // ok, we have four consecutive marker bytes; find end of cushion
 501   u_char* q = p + 4;
 502   while (*q == badResourceValue) q++;
 503   return q - MallocCushion;
 504 }
 505 
 506 void print_neighbor_blocks(void* ptr) {
 507   // find block allocated before ptr (not entirely crash-proof)
 508   if (MallocCushion < 4) {
 509     tty->print_cr("### cannot find previous block (MallocCushion < 4)");
 510     return;
 511   }
 512   u_char* start_of_this_block = (u_char*)ptr - space_before;
 513   u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
 514   // look for cushion in front of prev. block
 515   u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
 516   ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
 517   u_char* obj = start_of_prev_block + space_before;
 518   if (size <= 0 ) {
 519     // start is bad; mayhave been confused by OS data inbetween objects
 520     // search one more backwards
 521     start_of_prev_block = find_cushion_backwards(start_of_prev_block);
 522     size = *size_addr_from_base(start_of_prev_block);
 523     obj = start_of_prev_block + space_before;
 524   }
 525 
 526   if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
 527     tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
 528   } else {
 529     tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
 530   }
 531 
 532   // now find successor block
 533   u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
 534   start_of_next_block = find_cushion_forwards(start_of_next_block);
 535   u_char* next_obj = start_of_next_block + space_before;
 536   ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
 537   if (start_of_next_block[0] == badResourceValue &&
 538       start_of_next_block[1] == badResourceValue &&
 539       start_of_next_block[2] == badResourceValue &&
 540       start_of_next_block[3] == badResourceValue) {
 541     tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
 542   } else {
 543     tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
 544   }
 545 }
 546 
 547 
 548 void report_heap_error(void* memblock, void* bad, const char* where) {
 549   tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
 550   tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
 551   print_neighbor_blocks(memblock);
 552   fatal("memory stomping error");
 553 }
 554 
 555 void verify_block(void* memblock) {
 556   size_t size = get_size(memblock);
 557   if (MallocCushion) {
 558     u_char* ptr = (u_char*)memblock - space_before;
 559     for (int i = 0; i < MallocCushion; i++) {
 560       if (ptr[i] != badResourceValue) {
 561         report_heap_error(memblock, ptr+i, "in front of");
 562       }
 563     }
 564     u_char* end = (u_char*)memblock + size + space_after;
 565     for (int j = -MallocCushion; j < 0; j++) {
 566       if (end[j] != badResourceValue) {
 567         report_heap_error(memblock, end+j, "after");
 568       }
 569     }
 570   }
 571 }
 572 #endif
 573 
 574 //
 575 // This function supports testing of the malloc out of memory
 576 // condition without really running the system out of memory.
 577 //
 578 static u_char* testMalloc(size_t alloc_size) {
 579   assert(MallocMaxTestWords > 0, "sanity check");
 580 
 581   if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
 582     return NULL;
 583   }
 584 
 585   u_char* ptr = (u_char*)::malloc(alloc_size);
 586 
 587   if (ptr != NULL) {
 588     Atomic::add(((jint) (alloc_size / BytesPerWord)),
 589                 (volatile jint *) &cur_malloc_words);
 590   }
 591   return ptr;
 592 }
 593 
 594 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
 595   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
 596   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
 597 
 598   if (size == 0) {
 599     // return a valid pointer if size is zero
 600     // if NULL is returned the calling functions assume out of memory.
 601     size = 1;
 602   }
 603 
 604   const size_t alloc_size = size + space_before + space_after;
 605 
 606   if (size > alloc_size) { // Check for rollover.
 607     return NULL;
 608   }
 609 
 610   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 611 
 612   u_char* ptr;
 613 
 614   if (MallocMaxTestWords > 0) {
 615     ptr = testMalloc(alloc_size);
 616   } else {
 617     ptr = (u_char*)::malloc(alloc_size);
 618   }
 619 
 620 #ifdef ASSERT
 621   if (ptr == NULL) return NULL;
 622   if (MallocCushion) {
 623     for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
 624     u_char* end = ptr + space_before + size;
 625     for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
 626     for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
 627   }
 628   // put size just before data
 629   *size_addr_from_base(ptr) = size;
 630 #endif
 631   u_char* memblock = ptr + space_before;
 632   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
 633     tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
 634     breakpoint();
 635   }
 636   debug_only(if (paranoid) verify_block(memblock));
 637   if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
 638 
 639   // we do not track MallocCushion memory
 640     MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
 641 
 642   return memblock;
 643 }
 644 
 645 
 646 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
 647 #ifndef ASSERT
 648   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
 649   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
 650   void* ptr = ::realloc(memblock, size);
 651   if (ptr != NULL) {
 652     MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags,
 653      caller == 0 ? CALLER_PC : caller);
 654   }
 655   return ptr;
 656 #else
 657   if (memblock == NULL) {
 658     return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
 659   }
 660   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
 661     tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
 662     breakpoint();
 663   }
 664   verify_block(memblock);
 665   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 666   if (size == 0) return NULL;
 667   // always move the block
 668   void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
 669   if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
 670   // Copy to new memory if malloc didn't fail
 671   if ( ptr != NULL ) {
 672     memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
 673     if (paranoid) verify_block(ptr);
 674     if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
 675       tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
 676       breakpoint();
 677     }
 678     free(memblock);
 679   }
 680   return ptr;
 681 #endif
 682 }
 683 
 684 
 685 void  os::free(void *memblock, MEMFLAGS memflags) {
 686   NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
 687 #ifdef ASSERT
 688   if (memblock == NULL) return;
 689   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
 690     if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
 691     breakpoint();
 692   }
 693   verify_block(memblock);
 694   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 695   // Added by detlefs.
 696   if (MallocCushion) {
 697     u_char* ptr = (u_char*)memblock - space_before;
 698     for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
 699       guarantee(*p == badResourceValue,
 700                 "Thing freed should be malloc result.");
 701       *p = (u_char)freeBlockPad;
 702     }
 703     size_t size = get_size(memblock);
 704     inc_stat_counter(&free_bytes, size);
 705     u_char* end = ptr + space_before + size;
 706     for (u_char* q = end; q < end + MallocCushion; q++) {
 707       guarantee(*q == badResourceValue,
 708                 "Thing freed should be malloc result.");
 709       *q = (u_char)freeBlockPad;
 710     }
 711     if (PrintMalloc && tty != NULL)
 712       fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
 713   } else if (PrintMalloc && tty != NULL) {
 714     // tty->print_cr("os::free %p", memblock);
 715     fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
 716   }
 717 #endif
 718   MemTracker::record_free((address)memblock, memflags);
 719 
 720   ::free((char*)memblock - space_before);
 721 }
 722 
 723 void os::init_random(long initval) {
 724   _rand_seed = initval;
 725 }
 726 
 727 
 728 long os::random() {
 729   /* standard, well-known linear congruential random generator with
 730    * next_rand = (16807*seed) mod (2**31-1)
 731    * see
 732    * (1) "Random Number Generators: Good Ones Are Hard to Find",
 733    *      S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
 734    * (2) "Two Fast Implementations of the 'Minimal Standard' Random
 735    *     Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
 736   */
 737   const long a = 16807;
 738   const unsigned long m = 2147483647;
 739   const long q = m / a;        assert(q == 127773, "weird math");
 740   const long r = m % a;        assert(r == 2836, "weird math");
 741 
 742   // compute az=2^31p+q
 743   unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
 744   unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
 745   lo += (hi & 0x7FFF) << 16;
 746 
 747   // if q overflowed, ignore the overflow and increment q
 748   if (lo > m) {
 749     lo &= m;
 750     ++lo;
 751   }
 752   lo += hi >> 15;
 753 
 754   // if (p+q) overflowed, ignore the overflow and increment (p+q)
 755   if (lo > m) {
 756     lo &= m;
 757     ++lo;
 758   }
 759   return (_rand_seed = lo);
 760 }
 761 
 762 // The INITIALIZED state is distinguished from the SUSPENDED state because the
 763 // conditions in which a thread is first started are different from those in which
 764 // a suspension is resumed.  These differences make it hard for us to apply the
 765 // tougher checks when starting threads that we want to do when resuming them.
 766 // However, when start_thread is called as a result of Thread.start, on a Java
 767 // thread, the operation is synchronized on the Java Thread object.  So there
 768 // cannot be a race to start the thread and hence for the thread to exit while
 769 // we are working on it.  Non-Java threads that start Java threads either have
 770 // to do so in a context in which races are impossible, or should do appropriate
 771 // locking.
 772 
 773 void os::start_thread(Thread* thread) {
 774   // guard suspend/resume
 775   MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
 776   OSThread* osthread = thread->osthread();
 777   osthread->set_state(RUNNABLE);
 778   pd_start_thread(thread);
 779 }
 780 
 781 //---------------------------------------------------------------------------
 782 // Helper functions for fatal error handler
 783 
 784 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
 785   assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
 786 
 787   int cols = 0;
 788   int cols_per_line = 0;
 789   switch (unitsize) {
 790     case 1: cols_per_line = 16; break;
 791     case 2: cols_per_line = 8;  break;
 792     case 4: cols_per_line = 4;  break;
 793     case 8: cols_per_line = 2;  break;
 794     default: return;
 795   }
 796 
 797   address p = start;
 798   st->print(PTR_FORMAT ":   ", start);
 799   while (p < end) {
 800     switch (unitsize) {
 801       case 1: st->print("%02x", *(u1*)p); break;
 802       case 2: st->print("%04x", *(u2*)p); break;
 803       case 4: st->print("%08x", *(u4*)p); break;
 804       case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
 805     }
 806     p += unitsize;
 807     cols++;
 808     if (cols >= cols_per_line && p < end) {
 809        cols = 0;
 810        st->cr();
 811        st->print(PTR_FORMAT ":   ", p);
 812     } else {
 813        st->print(" ");
 814     }
 815   }
 816   st->cr();
 817 }
 818 
 819 void os::print_environment_variables(outputStream* st, const char** env_list,
 820                                      char* buffer, int len) {
 821   if (env_list) {
 822     st->print_cr("Environment Variables:");
 823 
 824     for (int i = 0; env_list[i] != NULL; i++) {
 825       if (getenv(env_list[i], buffer, len)) {
 826         st->print(env_list[i]);
 827         st->print("=");
 828         st->print_cr(buffer);
 829       }
 830     }
 831   }
 832 }
 833 
 834 void os::print_cpu_info(outputStream* st) {
 835   // cpu
 836   st->print("CPU:");
 837   st->print("total %d", os::processor_count());
 838   // It's not safe to query number of active processors after crash
 839   // st->print("(active %d)", os::active_processor_count());
 840   st->print(" %s", VM_Version::cpu_features());
 841   st->cr();
 842   pd_print_cpu_info(st);
 843 }
 844 
 845 void os::print_date_and_time(outputStream *st) {
 846   time_t tloc;
 847   (void)time(&tloc);
 848   st->print("time: %s", ctime(&tloc));  // ctime adds newline.
 849 
 850   double t = os::elapsedTime();
 851   // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
 852   //       Linux. Must be a bug in glibc ? Workaround is to round "t" to int
 853   //       before printf. We lost some precision, but who cares?
 854   st->print_cr("elapsed time: %d seconds", (int)t);
 855 }
 856 
 857 // moved from debug.cpp (used to be find()) but still called from there
 858 // The verbose parameter is only set by the debug code in one case
 859 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
 860   address addr = (address)x;
 861   CodeBlob* b = CodeCache::find_blob_unsafe(addr);
 862   if (b != NULL) {
 863     if (b->is_buffer_blob()) {
 864       // the interpreter is generated into a buffer blob
 865       InterpreterCodelet* i = Interpreter::codelet_containing(addr);
 866       if (i != NULL) {
 867         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
 868         i->print_on(st);
 869         return;
 870       }
 871       if (Interpreter::contains(addr)) {
 872         st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
 873                      " (not bytecode specific)", addr);
 874         return;
 875       }
 876       //
 877       if (AdapterHandlerLibrary::contains(b)) {
 878         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
 879         AdapterHandlerLibrary::print_handler_on(st, b);
 880       }
 881       // the stubroutines are generated into a buffer blob
 882       StubCodeDesc* d = StubCodeDesc::desc_for(addr);
 883       if (d != NULL) {
 884         st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
 885         d->print_on(st);
 886         st->cr();
 887         return;
 888       }
 889       if (StubRoutines::contains(addr)) {
 890         st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
 891                      "stub routine", addr);
 892         return;
 893       }
 894       // the InlineCacheBuffer is using stubs generated into a buffer blob
 895       if (InlineCacheBuffer::contains(addr)) {
 896         st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
 897         return;
 898       }
 899       VtableStub* v = VtableStubs::stub_containing(addr);
 900       if (v != NULL) {
 901         st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
 902         v->print_on(st);
 903         st->cr();
 904         return;
 905       }
 906     }
 907     nmethod* nm = b->as_nmethod_or_null();
 908     if (nm != NULL) {
 909       ResourceMark rm;
 910       st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
 911                 addr, (int)(addr - nm->entry_point()), nm);
 912       if (verbose) {
 913         st->print(" for ");
 914         nm->method()->print_value_on(st);
 915       }
 916       st->cr();
 917       nm->print_nmethod(verbose);
 918       return;
 919     }
 920     st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
 921     b->print_on(st);
 922     return;
 923   }
 924 
 925   if (Universe::heap()->is_in(addr)) {
 926     HeapWord* p = Universe::heap()->block_start(addr);
 927     bool print = false;
 928     // If we couldn't find it it just may mean that heap wasn't parseable
 929     // See if we were just given an oop directly
 930     if (p != NULL && Universe::heap()->block_is_obj(p)) {
 931       print = true;
 932     } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
 933       p = (HeapWord*) addr;
 934       print = true;
 935     }
 936     if (print) {
 937       if (p == (HeapWord*) addr) {
 938         st->print_cr(INTPTR_FORMAT " is an oop", addr);
 939       } else {
 940         st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
 941       }
 942       oop(p)->print_on(st);
 943       return;
 944     }
 945   } else {
 946     if (Universe::heap()->is_in_reserved(addr)) {
 947       st->print_cr(INTPTR_FORMAT " is an unallocated location "
 948                    "in the heap", addr);
 949       return;
 950     }
 951   }
 952   if (JNIHandles::is_global_handle((jobject) addr)) {
 953     st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
 954     return;
 955   }
 956   if (JNIHandles::is_weak_global_handle((jobject) addr)) {
 957     st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
 958     return;
 959   }
 960 #ifndef PRODUCT
 961   // we don't keep the block list in product mode
 962   if (JNIHandleBlock::any_contains((jobject) addr)) {
 963     st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
 964     return;
 965   }
 966 #endif
 967 
 968   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
 969     // Check for privilege stack
 970     if (thread->privileged_stack_top() != NULL &&
 971         thread->privileged_stack_top()->contains(addr)) {
 972       st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
 973                    "for thread: " INTPTR_FORMAT, addr, thread);
 974       if (verbose) thread->print_on(st);
 975       return;
 976     }
 977     // If the addr is a java thread print information about that.
 978     if (addr == (address)thread) {
 979       if (verbose) {
 980         thread->print_on(st);
 981       } else {
 982         st->print_cr(INTPTR_FORMAT " is a thread", addr);
 983       }
 984       return;
 985     }
 986     // If the addr is in the stack region for this thread then report that
 987     // and print thread info
 988     if (thread->stack_base() >= addr &&
 989         addr > (thread->stack_base() - thread->stack_size())) {
 990       st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
 991                    INTPTR_FORMAT, addr, thread);
 992       if (verbose) thread->print_on(st);
 993       return;
 994     }
 995 
 996   }
 997 
 998 #ifndef PRODUCT
 999   // Check if in metaspace.
1000   if (ClassLoaderDataGraph::contains((address)addr)) {
1001     // Use addr->print() from the debugger instead (not here)
1002     st->print_cr(INTPTR_FORMAT
1003                  " is pointing into metadata", addr);
1004     return;
1005   }
1006 #endif
1007 
1008   // Try an OS specific find
1009   if (os::find(addr, st)) {
1010     return;
1011   }
1012 
1013   st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1014 }
1015 
1016 // Looks like all platforms except IA64 can use the same function to check
1017 // if C stack is walkable beyond current frame. The check for fp() is not
1018 // necessary on Sparc, but it's harmless.
1019 bool os::is_first_C_frame(frame* fr) {
1020 #if defined(IA64) && !defined(_WIN32)
1021   // On IA64 we have to check if the callers bsp is still valid
1022   // (i.e. within the register stack bounds).
1023   // Notice: this only works for threads created by the VM and only if
1024   // we walk the current stack!!! If we want to be able to walk
1025   // arbitrary other threads, we'll have to somehow store the thread
1026   // object in the frame.
1027   Thread *thread = Thread::current();
1028   if ((address)fr->fp() <=
1029       thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1030     // This check is a little hacky, because on Linux the first C
1031     // frame's ('start_thread') register stack frame starts at
1032     // "register_stack_base + 0x48" while on HPUX, the first C frame's
1033     // ('__pthread_bound_body') register stack frame seems to really
1034     // start at "register_stack_base".
1035     return true;
1036   } else {
1037     return false;
1038   }
1039 #elif defined(IA64) && defined(_WIN32)
1040   return true;
1041 #else
1042   // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1043   // Check usp first, because if that's bad the other accessors may fault
1044   // on some architectures.  Ditto ufp second, etc.
1045   uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1046   // sp on amd can be 32 bit aligned.
1047   uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1048 
1049   uintptr_t usp    = (uintptr_t)fr->sp();
1050   if ((usp & sp_align_mask) != 0) return true;
1051 
1052   uintptr_t ufp    = (uintptr_t)fr->fp();
1053   if ((ufp & fp_align_mask) != 0) return true;
1054 
1055   uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1056   if ((old_sp & sp_align_mask) != 0) return true;
1057   if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1058 
1059   uintptr_t old_fp = (uintptr_t)fr->link();
1060   if ((old_fp & fp_align_mask) != 0) return true;
1061   if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1062 
1063   // stack grows downwards; if old_fp is below current fp or if the stack
1064   // frame is too large, either the stack is corrupted or fp is not saved
1065   // on stack (i.e. on x86, ebp may be used as general register). The stack
1066   // is not walkable beyond current frame.
1067   if (old_fp < ufp) return true;
1068   if (old_fp - ufp > 64 * K) return true;
1069 
1070   return false;
1071 #endif
1072 }
1073 
1074 #ifdef ASSERT
1075 extern "C" void test_random() {
1076   const double m = 2147483647;
1077   double mean = 0.0, variance = 0.0, t;
1078   long reps = 10000;
1079   unsigned long seed = 1;
1080 
1081   tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1082   os::init_random(seed);
1083   long num;
1084   for (int k = 0; k < reps; k++) {
1085     num = os::random();
1086     double u = (double)num / m;
1087     assert(u >= 0.0 && u <= 1.0, "bad random number!");
1088 
1089     // calculate mean and variance of the random sequence
1090     mean += u;
1091     variance += (u*u);
1092   }
1093   mean /= reps;
1094   variance /= (reps - 1);
1095 
1096   assert(num == 1043618065, "bad seed");
1097   tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1098   tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1099   const double eps = 0.0001;
1100   t = fabsd(mean - 0.5018);
1101   assert(t < eps, "bad mean");
1102   t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1103   assert(t < eps, "bad variance");
1104 }
1105 #endif
1106 
1107 
1108 // Set up the boot classpath.
1109 
1110 char* os::format_boot_path(const char* format_string,
1111                            const char* home,
1112                            int home_len,
1113                            char fileSep,
1114                            char pathSep) {
1115     assert((fileSep == '/' && pathSep == ':') ||
1116            (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1117 
1118     // Scan the format string to determine the length of the actual
1119     // boot classpath, and handle platform dependencies as well.
1120     int formatted_path_len = 0;
1121     const char* p;
1122     for (p = format_string; *p != 0; ++p) {
1123         if (*p == '%') formatted_path_len += home_len - 1;
1124         ++formatted_path_len;
1125     }
1126 
1127     char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1128     if (formatted_path == NULL) {
1129         return NULL;
1130     }
1131 
1132     // Create boot classpath from format, substituting separator chars and
1133     // java home directory.
1134     char* q = formatted_path;
1135     for (p = format_string; *p != 0; ++p) {
1136         switch (*p) {
1137         case '%':
1138             strcpy(q, home);
1139             q += home_len;
1140             break;
1141         case '/':
1142             *q++ = fileSep;
1143             break;
1144         case ':':
1145             *q++ = pathSep;
1146             break;
1147         default:
1148             *q++ = *p;
1149         }
1150     }
1151     *q = '\0';
1152 
1153     assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1154     return formatted_path;
1155 }
1156 
1157 
1158 bool os::set_boot_path(char fileSep, char pathSep) {
1159     const char* home = Arguments::get_java_home();
1160     int home_len = (int)strlen(home);
1161 
1162     static const char* meta_index_dir_format = "%/lib/";
1163     static const char* meta_index_format = "%/lib/meta-index";
1164     char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1165     if (meta_index == NULL) return false;
1166     char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1167     if (meta_index_dir == NULL) return false;
1168     Arguments::set_meta_index_path(meta_index, meta_index_dir);
1169 
1170     // Any modification to the JAR-file list, for the boot classpath must be
1171     // aligned with install/install/make/common/Pack.gmk. Note: boot class
1172     // path class JARs, are stripped for StackMapTable to reduce download size.
1173     static const char classpath_format[] =
1174         "%/lib/resources.jar:"
1175         "%/lib/rt.jar:"
1176         "%/lib/sunrsasign.jar:"
1177         "%/lib/jsse.jar:"
1178         "%/lib/jce.jar:"
1179         "%/lib/charsets.jar:"
1180         "%/lib/jfr.jar:"
1181 #ifdef __APPLE__
1182         "%/lib/JObjC.jar:"
1183 #endif
1184         "%/classes";
1185     char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1186     if (sysclasspath == NULL) return false;
1187     Arguments::set_sysclasspath(sysclasspath);
1188 
1189     return true;
1190 }
1191 
1192 /*
1193  * Splits a path, based on its separator, the number of
1194  * elements is returned back in n.
1195  * It is the callers responsibility to:
1196  *   a> check the value of n, and n may be 0.
1197  *   b> ignore any empty path elements
1198  *   c> free up the data.
1199  */
1200 char** os::split_path(const char* path, int* n) {
1201   *n = 0;
1202   if (path == NULL || strlen(path) == 0) {
1203     return NULL;
1204   }
1205   const char psepchar = *os::path_separator();
1206   char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1207   if (inpath == NULL) {
1208     return NULL;
1209   }
1210   strcpy(inpath, path);
1211   int count = 1;
1212   char* p = strchr(inpath, psepchar);
1213   // Get a count of elements to allocate memory
1214   while (p != NULL) {
1215     count++;
1216     p++;
1217     p = strchr(p, psepchar);
1218   }
1219   char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1220   if (opath == NULL) {
1221     return NULL;
1222   }
1223 
1224   // do the actual splitting
1225   p = inpath;
1226   for (int i = 0 ; i < count ; i++) {
1227     size_t len = strcspn(p, os::path_separator());
1228     if (len > JVM_MAXPATHLEN) {
1229       return NULL;
1230     }
1231     // allocate the string and add terminator storage
1232     char* s  = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1233     if (s == NULL) {
1234       return NULL;
1235     }
1236     strncpy(s, p, len);
1237     s[len] = '\0';
1238     opath[i] = s;
1239     p += len + 1;
1240   }
1241   FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1242   *n = count;
1243   return opath;
1244 }
1245 
1246 void os::set_memory_serialize_page(address page) {
1247   int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1248   _mem_serialize_page = (volatile int32_t *)page;
1249   // We initialize the serialization page shift count here
1250   // We assume a cache line size of 64 bytes
1251   assert(SerializePageShiftCount == count,
1252          "thread size changed, fix SerializePageShiftCount constant");
1253   set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1254 }
1255 
1256 static volatile intptr_t SerializePageLock = 0;
1257 
1258 // This method is called from signal handler when SIGSEGV occurs while the current
1259 // thread tries to store to the "read-only" memory serialize page during state
1260 // transition.
1261 void os::block_on_serialize_page_trap() {
1262   if (TraceSafepoint) {
1263     tty->print_cr("Block until the serialize page permission restored");
1264   }
1265   // When VMThread is holding the SerializePageLock during modifying the
1266   // access permission of the memory serialize page, the following call
1267   // will block until the permission of that page is restored to rw.
1268   // Generally, it is unsafe to manipulate locks in signal handlers, but in
1269   // this case, it's OK as the signal is synchronous and we know precisely when
1270   // it can occur.
1271   Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1272   Thread::muxRelease(&SerializePageLock);
1273 }
1274 
1275 // Serialize all thread state variables
1276 void os::serialize_thread_states() {
1277   // On some platforms such as Solaris & Linux, the time duration of the page
1278   // permission restoration is observed to be much longer than expected  due to
1279   // scheduler starvation problem etc. To avoid the long synchronization
1280   // time and expensive page trap spinning, 'SerializePageLock' is used to block
1281   // the mutator thread if such case is encountered. See bug 6546278 for details.
1282   Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1283   os::protect_memory((char *)os::get_memory_serialize_page(),
1284                      os::vm_page_size(), MEM_PROT_READ);
1285   os::protect_memory((char *)os::get_memory_serialize_page(),
1286                      os::vm_page_size(), MEM_PROT_RW);
1287   Thread::muxRelease(&SerializePageLock);
1288 }
1289 
1290 // Returns true if the current stack pointer is above the stack shadow
1291 // pages, false otherwise.
1292 
1293 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1294   assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1295   address sp = current_stack_pointer();
1296   // Check if we have StackShadowPages above the yellow zone.  This parameter
1297   // is dependent on the depth of the maximum VM call stack possible from
1298   // the handler for stack overflow.  'instanceof' in the stack overflow
1299   // handler or a println uses at least 8k stack of VM and native code
1300   // respectively.
1301   const int framesize_in_bytes =
1302     Interpreter::size_top_interpreter_activation(method()) * wordSize;
1303   int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1304                       * vm_page_size()) + framesize_in_bytes;
1305   // The very lower end of the stack
1306   address stack_limit = thread->stack_base() - thread->stack_size();
1307   return (sp > (stack_limit + reserved_area));
1308 }
1309 
1310 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1311                                 uint min_pages)
1312 {
1313   assert(min_pages > 0, "sanity");
1314   if (UseLargePages) {
1315     const size_t max_page_size = region_max_size / min_pages;
1316 
1317     for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1318       const size_t sz = _page_sizes[i];
1319       const size_t mask = sz - 1;
1320       if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1321         // The largest page size with no fragmentation.
1322         return sz;
1323       }
1324 
1325       if (sz <= max_page_size) {
1326         // The largest page size that satisfies the min_pages requirement.
1327         return sz;
1328       }
1329     }
1330   }
1331 
1332   return vm_page_size();
1333 }
1334 
1335 #ifndef PRODUCT
1336 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1337 {
1338   if (TracePageSizes) {
1339     tty->print("%s: ", str);
1340     for (int i = 0; i < count; ++i) {
1341       tty->print(" " SIZE_FORMAT, page_sizes[i]);
1342     }
1343     tty->cr();
1344   }
1345 }
1346 
1347 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1348                           const size_t region_max_size, const size_t page_size,
1349                           const char* base, const size_t size)
1350 {
1351   if (TracePageSizes) {
1352     tty->print_cr("%s:  min=" SIZE_FORMAT " max=" SIZE_FORMAT
1353                   " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1354                   " size=" SIZE_FORMAT,
1355                   str, region_min_size, region_max_size,
1356                   page_size, base, size);
1357   }
1358 }
1359 #endif  // #ifndef PRODUCT
1360 
1361 // This is the working definition of a server class machine:
1362 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1363 // because the graphics memory (?) sometimes masks physical memory.
1364 // If you want to change the definition of a server class machine
1365 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1366 // then you'll have to parameterize this method based on that state,
1367 // as was done for logical processors here, or replicate and
1368 // specialize this method for each platform.  (Or fix os to have
1369 // some inheritance structure and use subclassing.  Sigh.)
1370 // If you want some platform to always or never behave as a server
1371 // class machine, change the setting of AlwaysActAsServerClassMachine
1372 // and NeverActAsServerClassMachine in globals*.hpp.
1373 bool os::is_server_class_machine() {
1374   // First check for the early returns
1375   if (NeverActAsServerClassMachine) {
1376     return false;
1377   }
1378   if (AlwaysActAsServerClassMachine) {
1379     return true;
1380   }
1381   // Then actually look at the machine
1382   bool         result            = false;
1383   const unsigned int    server_processors = 2;
1384   const julong server_memory     = 2UL * G;
1385   // We seem not to get our full complement of memory.
1386   //     We allow some part (1/8?) of the memory to be "missing",
1387   //     based on the sizes of DIMMs, and maybe graphics cards.
1388   const julong missing_memory   = 256UL * M;
1389 
1390   /* Is this a server class machine? */
1391   if ((os::active_processor_count() >= (int)server_processors) &&
1392       (os::physical_memory() >= (server_memory - missing_memory))) {
1393     const unsigned int logical_processors =
1394       VM_Version::logical_processors_per_package();
1395     if (logical_processors > 1) {
1396       const unsigned int physical_packages =
1397         os::active_processor_count() / logical_processors;
1398       if (physical_packages > server_processors) {
1399         result = true;
1400       }
1401     } else {
1402       result = true;
1403     }
1404   }
1405   return result;
1406 }
1407 
1408 // Read file line by line, if line is longer than bsize,
1409 // skip rest of line.
1410 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1411   size_t sz, i = 0;
1412 
1413   // read until EOF, EOL or buf is full
1414   while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1415      ++i;
1416   }
1417 
1418   if (buf[i] == '\n') {
1419     // EOL reached so ignore EOL character and return
1420 
1421     buf[i] = 0;
1422     return (int) i;
1423   }
1424 
1425   buf[i+1] = 0;
1426 
1427   if (sz != 1) {
1428     // EOF reached. if we read chars before EOF return them and
1429     // return EOF on next call otherwise return EOF
1430 
1431     return (i == 0) ? -1 : (int) i;
1432   }
1433 
1434   // line is longer than size of buf, skip to EOL
1435   char ch;
1436   while (read(fd, &ch, 1) == 1 && ch != '\n') {
1437     // Do nothing
1438   }
1439 
1440   // return initial part of line that fits in buf.
1441   // If we reached EOF, it will be returned on next call.
1442 
1443   return (int) i;
1444 }
1445 
1446 void os::SuspendedThreadTask::run() {
1447   assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1448   internal_do_task();
1449   _done = true;
1450 }
1451 
1452 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1453   return os::pd_create_stack_guard_pages(addr, bytes);
1454 }
1455 
1456 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1457   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1458   if (result != NULL) {
1459     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1460   }
1461 
1462   return result;
1463 }
1464 
1465 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1466    MEMFLAGS flags) {
1467   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1468   if (result != NULL) {
1469     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1470     MemTracker::record_virtual_memory_type((address)result, flags);
1471   }
1472 
1473   return result;
1474 }
1475 
1476 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1477   char* result = pd_attempt_reserve_memory_at(bytes, addr);
1478   if (result != NULL) {
1479     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1480   }
1481   return result;
1482 }
1483 
1484 void os::split_reserved_memory(char *base, size_t size,
1485                                  size_t split, bool realloc) {
1486   pd_split_reserved_memory(base, size, split, realloc);
1487 }
1488 
1489 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1490   bool res = pd_commit_memory(addr, bytes, executable);
1491   if (res) {
1492     MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1493   }
1494   return res;
1495 }
1496 
1497 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1498                               bool executable) {
1499   bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1500   if (res) {
1501     MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1502   }
1503   return res;
1504 }
1505 
1506 bool os::uncommit_memory(char* addr, size_t bytes) {
1507   bool res = pd_uncommit_memory(addr, bytes);
1508   if (res) {
1509     MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1510   }
1511   return res;
1512 }
1513 
1514 bool os::release_memory(char* addr, size_t bytes) {
1515   bool res = pd_release_memory(addr, bytes);
1516   if (res) {
1517     MemTracker::record_virtual_memory_release((address)addr, bytes);
1518   }
1519   return res;
1520 }
1521 
1522 
1523 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1524                            char *addr, size_t bytes, bool read_only,
1525                            bool allow_exec) {
1526   char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1527   if (result != NULL) {
1528     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1529     MemTracker::record_virtual_memory_commit((address)result, bytes, CALLER_PC);
1530   }
1531   return result;
1532 }
1533 
1534 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1535                              char *addr, size_t bytes, bool read_only,
1536                              bool allow_exec) {
1537   return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1538                     read_only, allow_exec);
1539 }
1540 
1541 bool os::unmap_memory(char *addr, size_t bytes) {
1542   bool result = pd_unmap_memory(addr, bytes);
1543   if (result) {
1544     MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1545     MemTracker::record_virtual_memory_release((address)addr, bytes);
1546   }
1547   return result;
1548 }
1549 
1550 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1551   pd_free_memory(addr, bytes, alignment_hint);
1552 }
1553 
1554 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1555   pd_realign_memory(addr, bytes, alignment_hint);
1556 }
1557 
1558 #ifndef TARGET_OS_FAMILY_windows
1559 /* try to switch state from state "from" to state "to"
1560  * returns the state set after the method is complete
1561  */
1562 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1563                                                          os::SuspendResume::State to)
1564 {
1565   os::SuspendResume::State result =
1566     (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1567   if (result == from) {
1568     // success
1569     return to;
1570   }
1571   return result;
1572 }
1573 #endif