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