rev 7555 : imported patch 8067469-g1-ignores-alwayspretouch
rev 7556 : [mq]: david-erik-review

   1 /*
   2  * Copyright (c) 1997, 2014, 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/codeCache.hpp"
  31 #include "code/icBuffer.hpp"
  32 #include "code/vtableStubs.hpp"
  33 #include "gc_implementation/shared/vmGCOperations.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "memory/allocation.inline.hpp"
  36 #ifdef ASSERT
  37 #include "memory/guardedMemory.hpp"
  38 #endif
  39 #include "oops/oop.inline.hpp"
  40 #include "prims/jvm.h"
  41 #include "prims/jvm_misc.hpp"
  42 #include "prims/privilegedStack.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/atomic.inline.hpp"
  45 #include "runtime/frame.inline.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/java.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/mutexLocker.hpp"
  50 #include "runtime/os.inline.hpp"
  51 #include "runtime/stubRoutines.hpp"
  52 #include "runtime/thread.inline.hpp"
  53 #include "runtime/vm_version.hpp"
  54 #include "services/attachListener.hpp"
  55 #include "services/nmtCommon.hpp"
  56 #include "services/mallocTracker.hpp"
  57 #include "services/memTracker.hpp"
  58 #include "services/threadService.hpp"
  59 #include "utilities/defaultStream.hpp"
  60 #include "utilities/events.hpp"
  61 
  62 # include <signal.h>
  63 
  64 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  65 
  66 OSThread*         os::_starting_thread    = NULL;
  67 address           os::_polling_page       = NULL;
  68 volatile int32_t* os::_mem_serialize_page = NULL;
  69 uintptr_t         os::_serialize_page_mask = 0;
  70 long              os::_rand_seed          = 1;
  71 int               os::_processor_count    = 0;
  72 size_t            os::_page_sizes[os::page_sizes_max];
  73 
  74 #ifndef PRODUCT
  75 julong os::num_mallocs = 0;         // # of calls to malloc/realloc
  76 julong os::alloc_bytes = 0;         // # of bytes allocated
  77 julong os::num_frees = 0;           // # of calls to free
  78 julong os::free_bytes = 0;          // # of bytes freed
  79 #endif
  80 
  81 static juint cur_malloc_words = 0;  // current size for MallocMaxTestWords
  82 
  83 void os_init_globals() {
  84   // Called from init_globals().
  85   // See Threads::create_vm() in thread.cpp, and init.cpp.
  86   os::init_globals();
  87 }
  88 
  89 // Fill in buffer with current local time as an ISO-8601 string.
  90 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
  91 // Returns buffer, or NULL if it failed.
  92 // This would mostly be a call to
  93 //     strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
  94 // except that on Windows the %z behaves badly, so we do it ourselves.
  95 // Also, people wanted milliseconds on there,
  96 // and strftime doesn't do milliseconds.
  97 char* os::iso8601_time(char* buffer, size_t buffer_length) {
  98   // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
  99   //                                      1         2
 100   //                             12345678901234567890123456789
 101   static const char* iso8601_format =
 102     "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
 103   static const size_t needed_buffer = 29;
 104 
 105   // Sanity check the arguments
 106   if (buffer == NULL) {
 107     assert(false, "NULL buffer");
 108     return NULL;
 109   }
 110   if (buffer_length < needed_buffer) {
 111     assert(false, "buffer_length too small");
 112     return NULL;
 113   }
 114   // Get the current time
 115   jlong milliseconds_since_19700101 = javaTimeMillis();
 116   const int milliseconds_per_microsecond = 1000;
 117   const time_t seconds_since_19700101 =
 118     milliseconds_since_19700101 / milliseconds_per_microsecond;
 119   const int milliseconds_after_second =
 120     milliseconds_since_19700101 % milliseconds_per_microsecond;
 121   // Convert the time value to a tm and timezone variable
 122   struct tm time_struct;
 123   if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
 124     assert(false, "Failed localtime_pd");
 125     return NULL;
 126   }
 127 #if defined(_ALLBSD_SOURCE)
 128   const time_t zone = (time_t) time_struct.tm_gmtoff;
 129 #else
 130   const time_t zone = timezone;
 131 #endif
 132 
 133   // If daylight savings time is in effect,
 134   // we are 1 hour East of our time zone
 135   const time_t seconds_per_minute = 60;
 136   const time_t minutes_per_hour = 60;
 137   const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
 138   time_t UTC_to_local = zone;
 139   if (time_struct.tm_isdst > 0) {
 140     UTC_to_local = UTC_to_local - seconds_per_hour;
 141   }
 142   // Compute the time zone offset.
 143   //    localtime_pd() sets timezone to the difference (in seconds)
 144   //    between UTC and and local time.
 145   //    ISO 8601 says we need the difference between local time and UTC,
 146   //    we change the sign of the localtime_pd() result.
 147   const time_t local_to_UTC = -(UTC_to_local);
 148   // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
 149   char sign_local_to_UTC = '+';
 150   time_t abs_local_to_UTC = local_to_UTC;
 151   if (local_to_UTC < 0) {
 152     sign_local_to_UTC = '-';
 153     abs_local_to_UTC = -(abs_local_to_UTC);
 154   }
 155   // Convert time zone offset seconds to hours and minutes.
 156   const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
 157   const time_t zone_min =
 158     ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
 159 
 160   // Print an ISO 8601 date and time stamp into the buffer
 161   const int year = 1900 + time_struct.tm_year;
 162   const int month = 1 + time_struct.tm_mon;
 163   const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
 164                                    year,
 165                                    month,
 166                                    time_struct.tm_mday,
 167                                    time_struct.tm_hour,
 168                                    time_struct.tm_min,
 169                                    time_struct.tm_sec,
 170                                    milliseconds_after_second,
 171                                    sign_local_to_UTC,
 172                                    zone_hours,
 173                                    zone_min);
 174   if (printed == 0) {
 175     assert(false, "Failed jio_printf");
 176     return NULL;
 177   }
 178   return buffer;
 179 }
 180 
 181 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
 182 #ifdef ASSERT
 183   if (!(!thread->is_Java_thread() ||
 184          Thread::current() == thread  ||
 185          Threads_lock->owned_by_self()
 186          || thread->is_Compiler_thread()
 187         )) {
 188     assert(false, "possibility of dangling Thread pointer");
 189   }
 190 #endif
 191 
 192   if (p >= MinPriority && p <= MaxPriority) {
 193     int priority = java_to_os_priority[p];
 194     return set_native_priority(thread, priority);
 195   } else {
 196     assert(false, "Should not happen");
 197     return OS_ERR;
 198   }
 199 }
 200 
 201 // The mapping from OS priority back to Java priority may be inexact because
 202 // Java priorities can map M:1 with native priorities. If you want the definite
 203 // Java priority then use JavaThread::java_priority()
 204 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
 205   int p;
 206   int os_prio;
 207   OSReturn ret = get_native_priority(thread, &os_prio);
 208   if (ret != OS_OK) return ret;
 209 
 210   if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
 211     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
 212   } else {
 213     // niceness values are in reverse order
 214     for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
 215   }
 216   priority = (ThreadPriority)p;
 217   return OS_OK;
 218 }
 219 
 220 
 221 // --------------------- sun.misc.Signal (optional) ---------------------
 222 
 223 
 224 // SIGBREAK is sent by the keyboard to query the VM state
 225 #ifndef SIGBREAK
 226 #define SIGBREAK SIGQUIT
 227 #endif
 228 
 229 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
 230 
 231 
 232 static void signal_thread_entry(JavaThread* thread, TRAPS) {
 233   os::set_priority(thread, NearMaxPriority);
 234   while (true) {
 235     int sig;
 236     {
 237       // FIXME : Currently we have not decided what should be the status
 238       //         for this java thread blocked here. Once we decide about
 239       //         that we should fix this.
 240       sig = os::signal_wait();
 241     }
 242     if (sig == os::sigexitnum_pd()) {
 243        // Terminate the signal thread
 244        return;
 245     }
 246 
 247     switch (sig) {
 248       case SIGBREAK: {
 249         // Check if the signal is a trigger to start the Attach Listener - in that
 250         // case don't print stack traces.
 251         if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
 252           continue;
 253         }
 254         // Print stack traces
 255         // Any SIGBREAK operations added here should make sure to flush
 256         // the output stream (e.g. tty->flush()) after output.  See 4803766.
 257         // Each module also prints an extra carriage return after its output.
 258         VM_PrintThreads op;
 259         VMThread::execute(&op);
 260         VM_PrintJNI jni_op;
 261         VMThread::execute(&jni_op);
 262         VM_FindDeadlocks op1(tty);
 263         VMThread::execute(&op1);
 264         Universe::print_heap_at_SIGBREAK();
 265         if (PrintClassHistogram) {
 266           VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
 267           VMThread::execute(&op1);
 268         }
 269         if (JvmtiExport::should_post_data_dump()) {
 270           JvmtiExport::post_data_dump();
 271         }
 272         break;
 273       }
 274       default: {
 275         // Dispatch the signal to java
 276         HandleMark hm(THREAD);
 277         Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
 278         KlassHandle klass (THREAD, k);
 279         if (klass.not_null()) {
 280           JavaValue result(T_VOID);
 281           JavaCallArguments args;
 282           args.push_int(sig);
 283           JavaCalls::call_static(
 284             &result,
 285             klass,
 286             vmSymbols::dispatch_name(),
 287             vmSymbols::int_void_signature(),
 288             &args,
 289             THREAD
 290           );
 291         }
 292         if (HAS_PENDING_EXCEPTION) {
 293           // tty is initialized early so we don't expect it to be null, but
 294           // if it is we can't risk doing an initialization that might
 295           // trigger additional out-of-memory conditions
 296           if (tty != NULL) {
 297             char klass_name[256];
 298             char tmp_sig_name[16];
 299             const char* sig_name = "UNKNOWN";
 300             InstanceKlass::cast(PENDING_EXCEPTION->klass())->
 301               name()->as_klass_external_name(klass_name, 256);
 302             if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
 303               sig_name = tmp_sig_name;
 304             warning("Exception %s occurred dispatching signal %s to handler"
 305                     "- the VM may need to be forcibly terminated",
 306                     klass_name, sig_name );
 307           }
 308           CLEAR_PENDING_EXCEPTION;
 309         }
 310       }
 311     }
 312   }
 313 }
 314 
 315 void os::init_before_ergo() {
 316   // We need to initialize large page support here because ergonomics takes some
 317   // decisions depending on large page support and the calculated large page size.
 318   large_page_init();
 319 }
 320 
 321 void os::signal_init() {
 322   if (!ReduceSignalUsage) {
 323     // Setup JavaThread for processing signals
 324     EXCEPTION_MARK;
 325     Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
 326     instanceKlassHandle klass (THREAD, k);
 327     instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
 328 
 329     const char thread_name[] = "Signal Dispatcher";
 330     Handle string = java_lang_String::create_from_str(thread_name, CHECK);
 331 
 332     // Initialize thread_oop to put it into the system threadGroup
 333     Handle thread_group (THREAD, Universe::system_thread_group());
 334     JavaValue result(T_VOID);
 335     JavaCalls::call_special(&result, thread_oop,
 336                            klass,
 337                            vmSymbols::object_initializer_name(),
 338                            vmSymbols::threadgroup_string_void_signature(),
 339                            thread_group,
 340                            string,
 341                            CHECK);
 342 
 343     KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
 344     JavaCalls::call_special(&result,
 345                             thread_group,
 346                             group,
 347                             vmSymbols::add_method_name(),
 348                             vmSymbols::thread_void_signature(),
 349                             thread_oop,         // ARG 1
 350                             CHECK);
 351 
 352     os::signal_init_pd();
 353 
 354     { MutexLocker mu(Threads_lock);
 355       JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
 356 
 357       // At this point it may be possible that no osthread was created for the
 358       // JavaThread due to lack of memory. We would have to throw an exception
 359       // in that case. However, since this must work and we do not allow
 360       // exceptions anyway, check and abort if this fails.
 361       if (signal_thread == NULL || signal_thread->osthread() == NULL) {
 362         vm_exit_during_initialization("java.lang.OutOfMemoryError",
 363                                       os::native_thread_creation_failed_msg());
 364       }
 365 
 366       java_lang_Thread::set_thread(thread_oop(), signal_thread);
 367       java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
 368       java_lang_Thread::set_daemon(thread_oop());
 369 
 370       signal_thread->set_threadObj(thread_oop());
 371       Threads::add(signal_thread);
 372       Thread::start(signal_thread);
 373     }
 374     // Handle ^BREAK
 375     os::signal(SIGBREAK, os::user_handler());
 376   }
 377 }
 378 
 379 
 380 void os::terminate_signal_thread() {
 381   if (!ReduceSignalUsage)
 382     signal_notify(sigexitnum_pd());
 383 }
 384 
 385 
 386 // --------------------- loading libraries ---------------------
 387 
 388 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
 389 extern struct JavaVM_ main_vm;
 390 
 391 static void* _native_java_library = NULL;
 392 
 393 void* os::native_java_library() {
 394   if (_native_java_library == NULL) {
 395     char buffer[JVM_MAXPATHLEN];
 396     char ebuf[1024];
 397 
 398     // Try to load verify dll first. In 1.3 java dll depends on it and is not
 399     // always able to find it when the loading executable is outside the JDK.
 400     // In order to keep working with 1.2 we ignore any loading errors.
 401     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 402                        "verify")) {
 403       dll_load(buffer, ebuf, sizeof(ebuf));
 404     }
 405 
 406     // Load java dll
 407     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 408                        "java")) {
 409       _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
 410     }
 411     if (_native_java_library == NULL) {
 412       vm_exit_during_initialization("Unable to load native library", ebuf);
 413     }
 414 
 415 #if defined(__OpenBSD__)
 416     // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
 417     // ignore errors
 418     if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
 419                        "net")) {
 420       dll_load(buffer, ebuf, sizeof(ebuf));
 421     }
 422 #endif
 423   }
 424   static jboolean onLoaded = JNI_FALSE;
 425   if (onLoaded) {
 426     // We may have to wait to fire OnLoad until TLS is initialized.
 427     if (ThreadLocalStorage::is_initialized()) {
 428       // The JNI_OnLoad handling is normally done by method load in
 429       // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
 430       // explicitly so we have to check for JNI_OnLoad as well
 431       const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
 432       JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
 433           JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
 434       if (JNI_OnLoad != NULL) {
 435         JavaThread* thread = JavaThread::current();
 436         ThreadToNativeFromVM ttn(thread);
 437         HandleMark hm(thread);
 438         jint ver = (*JNI_OnLoad)(&main_vm, NULL);
 439         onLoaded = JNI_TRUE;
 440         if (!Threads::is_supported_jni_version_including_1_1(ver)) {
 441           vm_exit_during_initialization("Unsupported JNI version");
 442         }
 443       }
 444     }
 445   }
 446   return _native_java_library;
 447 }
 448 
 449 /*
 450  * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
 451  * If check_lib == true then we are looking for an
 452  * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
 453  * this library is statically linked into the image.
 454  * If check_lib == false then we will look for the appropriate symbol in the
 455  * executable if agent_lib->is_static_lib() == true or in the shared library
 456  * referenced by 'handle'.
 457  */
 458 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
 459                               const char *syms[], size_t syms_len) {
 460   assert(agent_lib != NULL, "sanity check");
 461   const char *lib_name;
 462   void *handle = agent_lib->os_lib();
 463   void *entryName = NULL;
 464   char *agent_function_name;
 465   size_t i;
 466 
 467   // If checking then use the agent name otherwise test is_static_lib() to
 468   // see how to process this lookup
 469   lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
 470   for (i = 0; i < syms_len; i++) {
 471     agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
 472     if (agent_function_name == NULL) {
 473       break;
 474     }
 475     entryName = dll_lookup(handle, agent_function_name);
 476     FREE_C_HEAP_ARRAY(char, agent_function_name);
 477     if (entryName != NULL) {
 478       break;
 479     }
 480   }
 481   return entryName;
 482 }
 483 
 484 // See if the passed in agent is statically linked into the VM image.
 485 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
 486                             size_t syms_len) {
 487   void *ret;
 488   void *proc_handle;
 489   void *save_handle;
 490 
 491   assert(agent_lib != NULL, "sanity check");
 492   if (agent_lib->name() == NULL) {
 493     return false;
 494   }
 495   proc_handle = get_default_process_handle();
 496   // Check for Agent_OnLoad/Attach_lib_name function
 497   save_handle = agent_lib->os_lib();
 498   // We want to look in this process' symbol table.
 499   agent_lib->set_os_lib(proc_handle);
 500   ret = find_agent_function(agent_lib, true, syms, syms_len);
 501   if (ret != NULL) {
 502     // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
 503     agent_lib->set_valid();
 504     agent_lib->set_static_lib(true);
 505     return true;
 506   }
 507   agent_lib->set_os_lib(save_handle);
 508   return false;
 509 }
 510 
 511 // --------------------- heap allocation utilities ---------------------
 512 
 513 char *os::strdup(const char *str, MEMFLAGS flags) {
 514   size_t size = strlen(str);
 515   char *dup_str = (char *)malloc(size + 1, flags);
 516   if (dup_str == NULL) return NULL;
 517   strcpy(dup_str, str);
 518   return dup_str;
 519 }
 520 
 521 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
 522   char* p = os::strdup(str, flags);
 523   if (p == NULL) {
 524     vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
 525   }
 526   return p;
 527 }
 528 
 529 
 530 #define paranoid                 0  /* only set to 1 if you suspect checking code has bug */
 531 
 532 #ifdef ASSERT
 533 
 534 static void verify_memory(void* ptr) {
 535   GuardedMemory guarded(ptr);
 536   if (!guarded.verify_guards()) {
 537     tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
 538     tty->print_cr("## memory stomp:");
 539     guarded.print_on(tty);
 540     fatal("memory stomping error");
 541   }
 542 }
 543 
 544 #endif
 545 
 546 //
 547 // This function supports testing of the malloc out of memory
 548 // condition without really running the system out of memory.
 549 //
 550 static u_char* testMalloc(size_t alloc_size) {
 551   assert(MallocMaxTestWords > 0, "sanity check");
 552 
 553   if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
 554     return NULL;
 555   }
 556 
 557   u_char* ptr = (u_char*)::malloc(alloc_size);
 558 
 559   if (ptr != NULL) {
 560     Atomic::add(((jint) (alloc_size / BytesPerWord)),
 561                 (volatile jint *) &cur_malloc_words);
 562   }
 563   return ptr;
 564 }
 565 
 566 void* os::malloc(size_t size, MEMFLAGS flags) {
 567   return os::malloc(size, flags, CALLER_PC);
 568 }
 569 
 570 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
 571   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
 572   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
 573 
 574 #ifdef ASSERT
 575   // checking for the WatcherThread and crash_protection first
 576   // since os::malloc can be called when the libjvm.{dll,so} is
 577   // first loaded and we don't have a thread yet.
 578   // try to find the thread after we see that the watcher thread
 579   // exists and has crash protection.
 580   WatcherThread *wt = WatcherThread::watcher_thread();
 581   if (wt != NULL && wt->has_crash_protection()) {
 582     Thread* thread = ThreadLocalStorage::get_thread_slow();
 583     if (thread == wt) {
 584       assert(!wt->has_crash_protection(),
 585           "Can't malloc with crash protection from WatcherThread");
 586     }
 587   }
 588 #endif
 589 
 590   if (size == 0) {
 591     // return a valid pointer if size is zero
 592     // if NULL is returned the calling functions assume out of memory.
 593     size = 1;
 594   }
 595 
 596   // NMT support
 597   NMT_TrackingLevel level = MemTracker::tracking_level();
 598   size_t            nmt_header_size = MemTracker::malloc_header_size(level);
 599 
 600 #ifndef ASSERT
 601   const size_t alloc_size = size + nmt_header_size;
 602 #else
 603   const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
 604   if (size + nmt_header_size > alloc_size) { // Check for rollover.
 605     return NULL;
 606   }
 607 #endif
 608 
 609   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 610 
 611   u_char* ptr;
 612   if (MallocMaxTestWords > 0) {
 613     ptr = testMalloc(alloc_size);
 614   } else {
 615     ptr = (u_char*)::malloc(alloc_size);
 616   }
 617 
 618 #ifdef ASSERT
 619   if (ptr == NULL) {
 620     return NULL;
 621   }
 622   // Wrap memory with guard
 623   GuardedMemory guarded(ptr, size + nmt_header_size);
 624   ptr = guarded.get_user_ptr();
 625 #endif
 626   if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
 627     tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
 628     breakpoint();
 629   }
 630   debug_only(if (paranoid) verify_memory(ptr));
 631   if (PrintMalloc && tty != NULL) {
 632     tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
 633   }
 634 
 635   // we do not track guard memory
 636   return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
 637 }
 638 
 639 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
 640   return os::realloc(memblock, size, flags, CALLER_PC);
 641 }
 642 
 643 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
 644 
 645 #ifndef ASSERT
 646   NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
 647   NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
 648    // NMT support
 649   void* membase = MemTracker::record_free(memblock);
 650   NMT_TrackingLevel level = MemTracker::tracking_level();
 651   size_t  nmt_header_size = MemTracker::malloc_header_size(level);
 652   void* ptr = ::realloc(membase, size + nmt_header_size);
 653   return MemTracker::record_malloc(ptr, size, memflags, stack, level);
 654 #else
 655   if (memblock == NULL) {
 656     return os::malloc(size, memflags, stack);
 657   }
 658   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
 659     tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
 660     breakpoint();
 661   }
 662   // NMT support
 663   void* membase = MemTracker::malloc_base(memblock);
 664   verify_memory(membase);
 665   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 666   if (size == 0) {
 667     return NULL;
 668   }
 669   // always move the block
 670   void* ptr = os::malloc(size, memflags, stack);
 671   if (PrintMalloc) {
 672     tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
 673   }
 674   // Copy to new memory if malloc didn't fail
 675   if ( ptr != NULL ) {
 676     GuardedMemory guarded(MemTracker::malloc_base(memblock));
 677     // Guard's user data contains NMT header
 678     size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
 679     memcpy(ptr, memblock, MIN2(size, memblock_size));
 680     if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
 681     if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
 682       tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
 683       breakpoint();
 684     }
 685     os::free(memblock);
 686   }
 687   return ptr;
 688 #endif
 689 }
 690 
 691 
 692 void  os::free(void *memblock) {
 693   NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
 694 #ifdef ASSERT
 695   if (memblock == NULL) return;
 696   if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
 697     if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
 698     breakpoint();
 699   }
 700   void* membase = MemTracker::record_free(memblock);
 701   verify_memory(membase);
 702   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
 703 
 704   GuardedMemory guarded(membase);
 705   size_t size = guarded.get_user_size();
 706   inc_stat_counter(&free_bytes, size);
 707   membase = guarded.release_for_freeing();
 708   if (PrintMalloc && tty != NULL) {
 709       fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
 710   }
 711   ::free(membase);
 712 #else
 713   void* membase = MemTracker::record_free(memblock);
 714   ::free(membase);
 715 #endif
 716 }
 717 
 718 void os::init_random(long initval) {
 719   _rand_seed = initval;
 720 }
 721 
 722 
 723 long os::random() {
 724   /* standard, well-known linear congruential random generator with
 725    * next_rand = (16807*seed) mod (2**31-1)
 726    * see
 727    * (1) "Random Number Generators: Good Ones Are Hard to Find",
 728    *      S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
 729    * (2) "Two Fast Implementations of the 'Minimal Standard' Random
 730    *     Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
 731   */
 732   const long a = 16807;
 733   const unsigned long m = 2147483647;
 734   const long q = m / a;        assert(q == 127773, "weird math");
 735   const long r = m % a;        assert(r == 2836, "weird math");
 736 
 737   // compute az=2^31p+q
 738   unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
 739   unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
 740   lo += (hi & 0x7FFF) << 16;
 741 
 742   // if q overflowed, ignore the overflow and increment q
 743   if (lo > m) {
 744     lo &= m;
 745     ++lo;
 746   }
 747   lo += hi >> 15;
 748 
 749   // if (p+q) overflowed, ignore the overflow and increment (p+q)
 750   if (lo > m) {
 751     lo &= m;
 752     ++lo;
 753   }
 754   return (_rand_seed = lo);
 755 }
 756 
 757 // The INITIALIZED state is distinguished from the SUSPENDED state because the
 758 // conditions in which a thread is first started are different from those in which
 759 // a suspension is resumed.  These differences make it hard for us to apply the
 760 // tougher checks when starting threads that we want to do when resuming them.
 761 // However, when start_thread is called as a result of Thread.start, on a Java
 762 // thread, the operation is synchronized on the Java Thread object.  So there
 763 // cannot be a race to start the thread and hence for the thread to exit while
 764 // we are working on it.  Non-Java threads that start Java threads either have
 765 // to do so in a context in which races are impossible, or should do appropriate
 766 // locking.
 767 
 768 void os::start_thread(Thread* thread) {
 769   // guard suspend/resume
 770   MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
 771   OSThread* osthread = thread->osthread();
 772   osthread->set_state(RUNNABLE);
 773   pd_start_thread(thread);
 774 }
 775 
 776 //---------------------------------------------------------------------------
 777 // Helper functions for fatal error handler
 778 
 779 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
 780   assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
 781 
 782   int cols = 0;
 783   int cols_per_line = 0;
 784   switch (unitsize) {
 785     case 1: cols_per_line = 16; break;
 786     case 2: cols_per_line = 8;  break;
 787     case 4: cols_per_line = 4;  break;
 788     case 8: cols_per_line = 2;  break;
 789     default: return;
 790   }
 791 
 792   address p = start;
 793   st->print(PTR_FORMAT ":   ", start);
 794   while (p < end) {
 795     switch (unitsize) {
 796       case 1: st->print("%02x", *(u1*)p); break;
 797       case 2: st->print("%04x", *(u2*)p); break;
 798       case 4: st->print("%08x", *(u4*)p); break;
 799       case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
 800     }
 801     p += unitsize;
 802     cols++;
 803     if (cols >= cols_per_line && p < end) {
 804        cols = 0;
 805        st->cr();
 806        st->print(PTR_FORMAT ":   ", p);
 807     } else {
 808        st->print(" ");
 809     }
 810   }
 811   st->cr();
 812 }
 813 
 814 void os::print_environment_variables(outputStream* st, const char** env_list,
 815                                      char* buffer, int len) {
 816   if (env_list) {
 817     st->print_cr("Environment Variables:");
 818 
 819     for (int i = 0; env_list[i] != NULL; i++) {
 820       if (getenv(env_list[i], buffer, len)) {
 821         st->print("%s", env_list[i]);
 822         st->print("=");
 823         st->print_cr("%s", buffer);
 824       }
 825     }
 826   }
 827 }
 828 
 829 void os::print_cpu_info(outputStream* st) {
 830   // cpu
 831   st->print("CPU:");
 832   st->print("total %d", os::processor_count());
 833   // It's not safe to query number of active processors after crash
 834   // st->print("(active %d)", os::active_processor_count());
 835   st->print(" %s", VM_Version::cpu_features());
 836   st->cr();
 837   pd_print_cpu_info(st);
 838 }
 839 
 840 void os::print_date_and_time(outputStream *st) {
 841   const int secs_per_day  = 86400;
 842   const int secs_per_hour = 3600;
 843   const int secs_per_min  = 60;
 844 
 845   time_t tloc;
 846   (void)time(&tloc);
 847   st->print("time: %s", ctime(&tloc));  // ctime adds newline.
 848 
 849   double t = os::elapsedTime();
 850   // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
 851   //       Linux. Must be a bug in glibc ? Workaround is to round "t" to int
 852   //       before printf. We lost some precision, but who cares?
 853   int eltime = (int)t;  // elapsed time in seconds
 854 
 855   // print elapsed time in a human-readable format:
 856   int eldays = eltime / secs_per_day;
 857   int day_secs = eldays * secs_per_day;
 858   int elhours = (eltime - day_secs) / secs_per_hour;
 859   int hour_secs = elhours * secs_per_hour;
 860   int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
 861   int minute_secs = elmins * secs_per_min;
 862   int elsecs = (eltime - day_secs - hour_secs - minute_secs);
 863   st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
 864 }
 865 
 866 // moved from debug.cpp (used to be find()) but still called from there
 867 // The verbose parameter is only set by the debug code in one case
 868 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
 869   address addr = (address)x;
 870   CodeBlob* b = CodeCache::find_blob_unsafe(addr);
 871   if (b != NULL) {
 872     if (b->is_buffer_blob()) {
 873       // the interpreter is generated into a buffer blob
 874       InterpreterCodelet* i = Interpreter::codelet_containing(addr);
 875       if (i != NULL) {
 876         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
 877         i->print_on(st);
 878         return;
 879       }
 880       if (Interpreter::contains(addr)) {
 881         st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
 882                      " (not bytecode specific)", addr);
 883         return;
 884       }
 885       //
 886       if (AdapterHandlerLibrary::contains(b)) {
 887         st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
 888         AdapterHandlerLibrary::print_handler_on(st, b);
 889       }
 890       // the stubroutines are generated into a buffer blob
 891       StubCodeDesc* d = StubCodeDesc::desc_for(addr);
 892       if (d != NULL) {
 893         st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
 894         d->print_on(st);
 895         st->cr();
 896         return;
 897       }
 898       if (StubRoutines::contains(addr)) {
 899         st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
 900                      "stub routine", addr);
 901         return;
 902       }
 903       // the InlineCacheBuffer is using stubs generated into a buffer blob
 904       if (InlineCacheBuffer::contains(addr)) {
 905         st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
 906         return;
 907       }
 908       VtableStub* v = VtableStubs::stub_containing(addr);
 909       if (v != NULL) {
 910         st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
 911         v->print_on(st);
 912         st->cr();
 913         return;
 914       }
 915     }
 916     nmethod* nm = b->as_nmethod_or_null();
 917     if (nm != NULL) {
 918       ResourceMark rm;
 919       st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
 920                 addr, (int)(addr - nm->entry_point()), nm);
 921       if (verbose) {
 922         st->print(" for ");
 923         nm->method()->print_value_on(st);
 924       }
 925       st->cr();
 926       nm->print_nmethod(verbose);
 927       return;
 928     }
 929     st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
 930     b->print_on(st);
 931     return;
 932   }
 933 
 934   if (Universe::heap()->is_in(addr)) {
 935     HeapWord* p = Universe::heap()->block_start(addr);
 936     bool print = false;
 937     // If we couldn't find it it just may mean that heap wasn't parsable
 938     // See if we were just given an oop directly
 939     if (p != NULL && Universe::heap()->block_is_obj(p)) {
 940       print = true;
 941     } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
 942       p = (HeapWord*) addr;
 943       print = true;
 944     }
 945     if (print) {
 946       if (p == (HeapWord*) addr) {
 947         st->print_cr(INTPTR_FORMAT " is an oop", addr);
 948       } else {
 949         st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
 950       }
 951       oop(p)->print_on(st);
 952       return;
 953     }
 954   } else {
 955     if (Universe::heap()->is_in_reserved(addr)) {
 956       st->print_cr(INTPTR_FORMAT " is an unallocated location "
 957                    "in the heap", addr);
 958       return;
 959     }
 960   }
 961   if (JNIHandles::is_global_handle((jobject) addr)) {
 962     st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
 963     return;
 964   }
 965   if (JNIHandles::is_weak_global_handle((jobject) addr)) {
 966     st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
 967     return;
 968   }
 969 #ifndef PRODUCT
 970   // we don't keep the block list in product mode
 971   if (JNIHandleBlock::any_contains((jobject) addr)) {
 972     st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
 973     return;
 974   }
 975 #endif
 976 
 977   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
 978     // Check for privilege stack
 979     if (thread->privileged_stack_top() != NULL &&
 980         thread->privileged_stack_top()->contains(addr)) {
 981       st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
 982                    "for thread: " INTPTR_FORMAT, addr, thread);
 983       if (verbose) thread->print_on(st);
 984       return;
 985     }
 986     // If the addr is a java thread print information about that.
 987     if (addr == (address)thread) {
 988       if (verbose) {
 989         thread->print_on(st);
 990       } else {
 991         st->print_cr(INTPTR_FORMAT " is a thread", addr);
 992       }
 993       return;
 994     }
 995     // If the addr is in the stack region for this thread then report that
 996     // and print thread info
 997     if (thread->stack_base() >= addr &&
 998         addr > (thread->stack_base() - thread->stack_size())) {
 999       st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1000                    INTPTR_FORMAT, addr, thread);
1001       if (verbose) thread->print_on(st);
1002       return;
1003     }
1004 
1005   }
1006 
1007   // Check if in metaspace and print types that have vptrs (only method now)
1008   if (Metaspace::contains(addr)) {
1009     if (Method::has_method_vptr((const void*)addr)) {
1010       ((Method*)addr)->print_value_on(st);
1011       st->cr();
1012     } else {
1013       // Use addr->print() from the debugger instead (not here)
1014       st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1015     }
1016     return;
1017   }
1018 
1019   // Try an OS specific find
1020   if (os::find(addr, st)) {
1021     return;
1022   }
1023 
1024   st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1025 }
1026 
1027 // Looks like all platforms except IA64 can use the same function to check
1028 // if C stack is walkable beyond current frame. The check for fp() is not
1029 // necessary on Sparc, but it's harmless.
1030 bool os::is_first_C_frame(frame* fr) {
1031 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1032   // On IA64 we have to check if the callers bsp is still valid
1033   // (i.e. within the register stack bounds).
1034   // Notice: this only works for threads created by the VM and only if
1035   // we walk the current stack!!! If we want to be able to walk
1036   // arbitrary other threads, we'll have to somehow store the thread
1037   // object in the frame.
1038   Thread *thread = Thread::current();
1039   if ((address)fr->fp() <=
1040       thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1041     // This check is a little hacky, because on Linux the first C
1042     // frame's ('start_thread') register stack frame starts at
1043     // "register_stack_base + 0x48" while on HPUX, the first C frame's
1044     // ('__pthread_bound_body') register stack frame seems to really
1045     // start at "register_stack_base".
1046     return true;
1047   } else {
1048     return false;
1049   }
1050 #elif defined(IA64) && defined(_WIN32)
1051   return true;
1052 #else
1053   // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1054   // Check usp first, because if that's bad the other accessors may fault
1055   // on some architectures.  Ditto ufp second, etc.
1056   uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1057   // sp on amd can be 32 bit aligned.
1058   uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1059 
1060   uintptr_t usp    = (uintptr_t)fr->sp();
1061   if ((usp & sp_align_mask) != 0) return true;
1062 
1063   uintptr_t ufp    = (uintptr_t)fr->fp();
1064   if ((ufp & fp_align_mask) != 0) return true;
1065 
1066   uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1067   if ((old_sp & sp_align_mask) != 0) return true;
1068   if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1069 
1070   uintptr_t old_fp = (uintptr_t)fr->link();
1071   if ((old_fp & fp_align_mask) != 0) return true;
1072   if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1073 
1074   // stack grows downwards; if old_fp is below current fp or if the stack
1075   // frame is too large, either the stack is corrupted or fp is not saved
1076   // on stack (i.e. on x86, ebp may be used as general register). The stack
1077   // is not walkable beyond current frame.
1078   if (old_fp < ufp) return true;
1079   if (old_fp - ufp > 64 * K) return true;
1080 
1081   return false;
1082 #endif
1083 }
1084 
1085 #ifdef ASSERT
1086 extern "C" void test_random() {
1087   const double m = 2147483647;
1088   double mean = 0.0, variance = 0.0, t;
1089   long reps = 10000;
1090   unsigned long seed = 1;
1091 
1092   tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1093   os::init_random(seed);
1094   long num;
1095   for (int k = 0; k < reps; k++) {
1096     num = os::random();
1097     double u = (double)num / m;
1098     assert(u >= 0.0 && u <= 1.0, "bad random number!");
1099 
1100     // calculate mean and variance of the random sequence
1101     mean += u;
1102     variance += (u*u);
1103   }
1104   mean /= reps;
1105   variance /= (reps - 1);
1106 
1107   assert(num == 1043618065, "bad seed");
1108   tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1109   tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1110   const double eps = 0.0001;
1111   t = fabsd(mean - 0.5018);
1112   assert(t < eps, "bad mean");
1113   t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1114   assert(t < eps, "bad variance");
1115 }
1116 #endif
1117 
1118 
1119 // Set up the boot classpath.
1120 
1121 char* os::format_boot_path(const char* format_string,
1122                            const char* home,
1123                            int home_len,
1124                            char fileSep,
1125                            char pathSep) {
1126     assert((fileSep == '/' && pathSep == ':') ||
1127            (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1128 
1129     // Scan the format string to determine the length of the actual
1130     // boot classpath, and handle platform dependencies as well.
1131     int formatted_path_len = 0;
1132     const char* p;
1133     for (p = format_string; *p != 0; ++p) {
1134         if (*p == '%') formatted_path_len += home_len - 1;
1135         ++formatted_path_len;
1136     }
1137 
1138     char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1139     if (formatted_path == NULL) {
1140         return NULL;
1141     }
1142 
1143     // Create boot classpath from format, substituting separator chars and
1144     // java home directory.
1145     char* q = formatted_path;
1146     for (p = format_string; *p != 0; ++p) {
1147         switch (*p) {
1148         case '%':
1149             strcpy(q, home);
1150             q += home_len;
1151             break;
1152         case '/':
1153             *q++ = fileSep;
1154             break;
1155         case ':':
1156             *q++ = pathSep;
1157             break;
1158         default:
1159             *q++ = *p;
1160         }
1161     }
1162     *q = '\0';
1163 
1164     assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1165     return formatted_path;
1166 }
1167 
1168 // returns a PATH of all entries in the given directory that do not start with a '.'
1169 static char* expand_entries_to_path(char* directory, char fileSep, char pathSep) {
1170   DIR* dir = os::opendir(directory);
1171   if (dir == NULL) return NULL;
1172 
1173   char* path = NULL;
1174   size_t path_len = 0;  // path length including \0 terminator
1175 
1176   size_t directory_len = strlen(directory);
1177   struct dirent *entry;
1178   char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory), mtInternal);
1179   while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
1180     const char* name = entry->d_name;
1181     if (name[0] == '.') continue;
1182 
1183     size_t name_len = strlen(name);
1184     size_t needed = directory_len + name_len + 2;
1185     size_t new_len = path_len + needed;
1186     if (path == NULL) {
1187       path = NEW_C_HEAP_ARRAY(char, new_len, mtInternal);
1188     } else {
1189       path = REALLOC_C_HEAP_ARRAY(char, path, new_len, mtInternal);
1190     }
1191     if (path == NULL)
1192       break;
1193 
1194     // append <pathSep>directory<fileSep>name
1195     char* p = path;
1196     if (path_len > 0) {
1197       p += (path_len -1);
1198       *p = pathSep;
1199       p++;
1200     }
1201 
1202     strcpy(p, directory);
1203     p += directory_len;
1204 
1205     *p = fileSep;
1206     p++;
1207 
1208     strcpy(p, name);
1209     p += name_len;
1210 
1211     path_len = new_len;
1212   }
1213 
1214   FREE_C_HEAP_ARRAY(char, dbuf);
1215   os::closedir(dir);
1216 
1217   return path;
1218 }
1219 
1220 bool os::set_boot_path(char fileSep, char pathSep) {
1221   const char* home = Arguments::get_java_home();
1222   int home_len = (int)strlen(home);
1223 
1224   static const char* meta_index_dir_format = "%/lib/";
1225   static const char* meta_index_format = "%/lib/meta-index";
1226   char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1227   if (meta_index == NULL) return false;
1228   char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1229   if (meta_index_dir == NULL) return false;
1230   Arguments::set_meta_index_path(meta_index, meta_index_dir);
1231 
1232   char* sysclasspath = NULL;
1233   struct stat st;
1234 
1235   // modular image if bootmodules.jimage exists
1236   char* jimage = format_boot_path("%/lib/modules/bootmodules.jimage", home, home_len, fileSep, pathSep);
1237   if (jimage == NULL) return false;
1238   bool has_jimage = (os::stat(jimage, &st) == 0);
1239   if (has_jimage) {
1240     Arguments::set_sysclasspath(jimage);
1241     return true;
1242   }
1243   FREE_C_HEAP_ARRAY(char, jimage);
1244 
1245   // images build if rt.jar exists
1246   char* rt_jar = format_boot_path("%/lib/rt.jar", home, home_len, fileSep, pathSep);
1247   if (rt_jar == NULL) return false;
1248   bool has_rt_jar = (os::stat(rt_jar, &st) == 0);
1249   FREE_C_HEAP_ARRAY(char, rt_jar);
1250 
1251   if (has_rt_jar) {
1252     // Any modification to the JAR-file list, for the boot classpath must be
1253     // aligned with install/install/make/common/Pack.gmk. Note: boot class
1254     // path class JARs, are stripped for StackMapTable to reduce download size.
1255     static const char classpath_format[] =
1256       "%/lib/resources.jar:"
1257       "%/lib/rt.jar:"
1258       "%/lib/jsse.jar:"
1259       "%/lib/jce.jar:"
1260       "%/lib/charsets.jar:"
1261       "%/lib/jfr.jar:"
1262       "%/classes";
1263     sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1264   } else {
1265     // no rt.jar, check if developer build with exploded modules
1266     char* modules_dir = format_boot_path("%/modules", home, home_len, fileSep, pathSep);
1267     if (os::stat(modules_dir, &st) == 0) {
1268       if ((st.st_mode & S_IFDIR) == S_IFDIR) {
1269         sysclasspath = expand_entries_to_path(modules_dir, fileSep, pathSep);
1270       }
1271     }
1272 
1273     // fallback to classes
1274     if (sysclasspath == NULL)
1275       sysclasspath = format_boot_path("%/classes", home, home_len, fileSep, pathSep);
1276   }
1277 
1278   if (sysclasspath == NULL) return false;
1279   Arguments::set_sysclasspath(sysclasspath);
1280 
1281   return true;
1282 }
1283 
1284 /*
1285  * Splits a path, based on its separator, the number of
1286  * elements is returned back in n.
1287  * It is the callers responsibility to:
1288  *   a> check the value of n, and n may be 0.
1289  *   b> ignore any empty path elements
1290  *   c> free up the data.
1291  */
1292 char** os::split_path(const char* path, int* n) {
1293   *n = 0;
1294   if (path == NULL || strlen(path) == 0) {
1295     return NULL;
1296   }
1297   const char psepchar = *os::path_separator();
1298   char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1299   if (inpath == NULL) {
1300     return NULL;
1301   }
1302   strcpy(inpath, path);
1303   int count = 1;
1304   char* p = strchr(inpath, psepchar);
1305   // Get a count of elements to allocate memory
1306   while (p != NULL) {
1307     count++;
1308     p++;
1309     p = strchr(p, psepchar);
1310   }
1311   char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1312   if (opath == NULL) {
1313     return NULL;
1314   }
1315 
1316   // do the actual splitting
1317   p = inpath;
1318   for (int i = 0 ; i < count ; i++) {
1319     size_t len = strcspn(p, os::path_separator());
1320     if (len > JVM_MAXPATHLEN) {
1321       return NULL;
1322     }
1323     // allocate the string and add terminator storage
1324     char* s  = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1325     if (s == NULL) {
1326       return NULL;
1327     }
1328     strncpy(s, p, len);
1329     s[len] = '\0';
1330     opath[i] = s;
1331     p += len + 1;
1332   }
1333   FREE_C_HEAP_ARRAY(char, inpath);
1334   *n = count;
1335   return opath;
1336 }
1337 
1338 void os::set_memory_serialize_page(address page) {
1339   int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1340   _mem_serialize_page = (volatile int32_t *)page;
1341   // We initialize the serialization page shift count here
1342   // We assume a cache line size of 64 bytes
1343   assert(SerializePageShiftCount == count,
1344          "thread size changed, fix SerializePageShiftCount constant");
1345   set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1346 }
1347 
1348 static volatile intptr_t SerializePageLock = 0;
1349 
1350 // This method is called from signal handler when SIGSEGV occurs while the current
1351 // thread tries to store to the "read-only" memory serialize page during state
1352 // transition.
1353 void os::block_on_serialize_page_trap() {
1354   if (TraceSafepoint) {
1355     tty->print_cr("Block until the serialize page permission restored");
1356   }
1357   // When VMThread is holding the SerializePageLock during modifying the
1358   // access permission of the memory serialize page, the following call
1359   // will block until the permission of that page is restored to rw.
1360   // Generally, it is unsafe to manipulate locks in signal handlers, but in
1361   // this case, it's OK as the signal is synchronous and we know precisely when
1362   // it can occur.
1363   Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1364   Thread::muxRelease(&SerializePageLock);
1365 }
1366 
1367 // Serialize all thread state variables
1368 void os::serialize_thread_states() {
1369   // On some platforms such as Solaris & Linux, the time duration of the page
1370   // permission restoration is observed to be much longer than expected  due to
1371   // scheduler starvation problem etc. To avoid the long synchronization
1372   // time and expensive page trap spinning, 'SerializePageLock' is used to block
1373   // the mutator thread if such case is encountered. See bug 6546278 for details.
1374   Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1375   os::protect_memory((char *)os::get_memory_serialize_page(),
1376                      os::vm_page_size(), MEM_PROT_READ);
1377   os::protect_memory((char *)os::get_memory_serialize_page(),
1378                      os::vm_page_size(), MEM_PROT_RW);
1379   Thread::muxRelease(&SerializePageLock);
1380 }
1381 
1382 // Returns true if the current stack pointer is above the stack shadow
1383 // pages, false otherwise.
1384 
1385 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1386   assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1387   address sp = current_stack_pointer();
1388   // Check if we have StackShadowPages above the yellow zone.  This parameter
1389   // is dependent on the depth of the maximum VM call stack possible from
1390   // the handler for stack overflow.  'instanceof' in the stack overflow
1391   // handler or a println uses at least 8k stack of VM and native code
1392   // respectively.
1393   const int framesize_in_bytes =
1394     Interpreter::size_top_interpreter_activation(method()) * wordSize;
1395   int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1396                       * vm_page_size()) + framesize_in_bytes;
1397   // The very lower end of the stack
1398   address stack_limit = thread->stack_base() - thread->stack_size();
1399   return (sp > (stack_limit + reserved_area));
1400 }
1401 
1402 size_t os::page_size_for_region(size_t region_size, size_t min_pages) {
1403   assert(min_pages > 0, "sanity");
1404   if (UseLargePages) {
1405     const size_t max_page_size = region_size / min_pages;
1406 
1407     for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1408       const size_t page_size = _page_sizes[i];
1409       if (page_size <= max_page_size && is_size_aligned(region_size, page_size)) {
1410         return page_size;
1411       }
1412     }
1413   }
1414 
1415   return vm_page_size();
1416 }
1417 
1418 #ifndef PRODUCT
1419 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1420 {
1421   if (TracePageSizes) {
1422     tty->print("%s: ", str);
1423     for (int i = 0; i < count; ++i) {
1424       tty->print(" " SIZE_FORMAT, page_sizes[i]);
1425     }
1426     tty->cr();
1427   }
1428 }
1429 
1430 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1431                           const size_t region_max_size, const size_t page_size,
1432                           const char* base, const size_t size)
1433 {
1434   if (TracePageSizes) {
1435     tty->print_cr("%s:  min=" SIZE_FORMAT " max=" SIZE_FORMAT
1436                   " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1437                   " size=" SIZE_FORMAT,
1438                   str, region_min_size, region_max_size,
1439                   page_size, base, size);
1440   }
1441 }
1442 #endif  // #ifndef PRODUCT
1443 
1444 // This is the working definition of a server class machine:
1445 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1446 // because the graphics memory (?) sometimes masks physical memory.
1447 // If you want to change the definition of a server class machine
1448 // on some OS or platform, e.g., >=4GB on Windows platforms,
1449 // then you'll have to parameterize this method based on that state,
1450 // as was done for logical processors here, or replicate and
1451 // specialize this method for each platform.  (Or fix os to have
1452 // some inheritance structure and use subclassing.  Sigh.)
1453 // If you want some platform to always or never behave as a server
1454 // class machine, change the setting of AlwaysActAsServerClassMachine
1455 // and NeverActAsServerClassMachine in globals*.hpp.
1456 bool os::is_server_class_machine() {
1457   // First check for the early returns
1458   if (NeverActAsServerClassMachine) {
1459     return false;
1460   }
1461   if (AlwaysActAsServerClassMachine) {
1462     return true;
1463   }
1464   // Then actually look at the machine
1465   bool         result            = false;
1466   const unsigned int    server_processors = 2;
1467   const julong server_memory     = 2UL * G;
1468   // We seem not to get our full complement of memory.
1469   //     We allow some part (1/8?) of the memory to be "missing",
1470   //     based on the sizes of DIMMs, and maybe graphics cards.
1471   const julong missing_memory   = 256UL * M;
1472 
1473   /* Is this a server class machine? */
1474   if ((os::active_processor_count() >= (int)server_processors) &&
1475       (os::physical_memory() >= (server_memory - missing_memory))) {
1476     const unsigned int logical_processors =
1477       VM_Version::logical_processors_per_package();
1478     if (logical_processors > 1) {
1479       const unsigned int physical_packages =
1480         os::active_processor_count() / logical_processors;
1481       if (physical_packages > server_processors) {
1482         result = true;
1483       }
1484     } else {
1485       result = true;
1486     }
1487   }
1488   return result;
1489 }
1490 
1491 void os::SuspendedThreadTask::run() {
1492   assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1493   internal_do_task();
1494   _done = true;
1495 }
1496 
1497 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1498   return os::pd_create_stack_guard_pages(addr, bytes);
1499 }
1500 
1501 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1502   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1503   if (result != NULL) {
1504     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1505   }
1506 
1507   return result;
1508 }
1509 
1510 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1511    MEMFLAGS flags) {
1512   char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1513   if (result != NULL) {
1514     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1515     MemTracker::record_virtual_memory_type((address)result, flags);
1516   }
1517 
1518   return result;
1519 }
1520 
1521 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1522   char* result = pd_attempt_reserve_memory_at(bytes, addr);
1523   if (result != NULL) {
1524     MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1525   }
1526   return result;
1527 }
1528 
1529 void os::split_reserved_memory(char *base, size_t size,
1530                                  size_t split, bool realloc) {
1531   pd_split_reserved_memory(base, size, split, realloc);
1532 }
1533 
1534 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1535   bool res = pd_commit_memory(addr, bytes, executable);
1536   if (res) {
1537     MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1538   }
1539   return res;
1540 }
1541 
1542 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1543                               bool executable) {
1544   bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1545   if (res) {
1546     MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1547   }
1548   return res;
1549 }
1550 
1551 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1552                                const char* mesg) {
1553   pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1554   MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1555 }
1556 
1557 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1558                                bool executable, const char* mesg) {
1559   os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1560   MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1561 }
1562 
1563 bool os::uncommit_memory(char* addr, size_t bytes) {
1564   bool res;
1565   if (MemTracker::tracking_level() > NMT_minimal) {
1566     Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1567     res = pd_uncommit_memory(addr, bytes);
1568     if (res) {
1569       tkr.record((address)addr, bytes);
1570     }
1571   } else {
1572     res = pd_uncommit_memory(addr, bytes);
1573   }
1574   return res;
1575 }
1576 
1577 bool os::release_memory(char* addr, size_t bytes) {
1578   bool res;
1579   if (MemTracker::tracking_level() > NMT_minimal) {
1580     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1581     res = pd_release_memory(addr, bytes);
1582     if (res) {
1583       tkr.record((address)addr, bytes);
1584     }
1585   } else {
1586     res = pd_release_memory(addr, bytes);
1587   }
1588   return res;
1589 }
1590 





1591 
1592 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1593                            char *addr, size_t bytes, bool read_only,
1594                            bool allow_exec) {
1595   char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1596   if (result != NULL) {
1597     MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1598   }
1599   return result;
1600 }
1601 
1602 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1603                              char *addr, size_t bytes, bool read_only,
1604                              bool allow_exec) {
1605   return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1606                     read_only, allow_exec);
1607 }
1608 
1609 bool os::unmap_memory(char *addr, size_t bytes) {
1610   bool result;
1611   if (MemTracker::tracking_level() > NMT_minimal) {
1612     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1613     result = pd_unmap_memory(addr, bytes);
1614     if (result) {
1615       tkr.record((address)addr, bytes);
1616     }
1617   } else {
1618     result = pd_unmap_memory(addr, bytes);
1619   }
1620   return result;
1621 }
1622 
1623 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1624   pd_free_memory(addr, bytes, alignment_hint);
1625 }
1626 
1627 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1628   pd_realign_memory(addr, bytes, alignment_hint);
1629 }
1630 
1631 #ifndef TARGET_OS_FAMILY_windows
1632 /* try to switch state from state "from" to state "to"
1633  * returns the state set after the method is complete
1634  */
1635 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1636                                                          os::SuspendResume::State to)
1637 {
1638   os::SuspendResume::State result =
1639     (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1640   if (result == from) {
1641     // success
1642     return to;
1643   }
1644   return result;
1645 }
1646 #endif
1647 
1648 /////////////// Unit tests ///////////////
1649 
1650 #ifndef PRODUCT
1651 
1652 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b))
1653 
1654 class TestOS : AllStatic {
1655   static size_t small_page_size() {
1656     return os::vm_page_size();
1657   }
1658 
1659   static size_t large_page_size() {
1660     const size_t large_page_size_example = 4 * M;
1661     return os::page_size_for_region(large_page_size_example, 1);
1662   }
1663 
1664   static void test_page_size_for_region() {
1665     if (UseLargePages) {
1666       const size_t small_page = small_page_size();
1667       const size_t large_page = large_page_size();
1668 
1669       if (large_page > small_page) {
1670         size_t num_small_pages_in_large = large_page / small_page;
1671         size_t page = os::page_size_for_region(large_page, num_small_pages_in_large);
1672 
1673         assert_eq(page, small_page);
1674       }
1675     }
1676   }
1677 
1678   static void test_page_size_for_region_alignment() {
1679     if (UseLargePages) {
1680       const size_t small_page = small_page_size();
1681       const size_t large_page = large_page_size();
1682       if (large_page > small_page) {
1683         const size_t unaligned_region = large_page + 17;
1684         size_t page = os::page_size_for_region(unaligned_region, 1);
1685         assert_eq(page, small_page);
1686 
1687         const size_t num_pages = 5;
1688         const size_t aligned_region = large_page * num_pages;
1689         page = os::page_size_for_region(aligned_region, num_pages);
1690         assert_eq(page, large_page);
1691       }
1692     }
1693   }
1694 
1695  public:
1696   static void run_tests() {
1697     test_page_size_for_region();
1698     test_page_size_for_region_alignment();
1699   }
1700 };
1701 
1702 void TestOS_test() {
1703   TestOS::run_tests();
1704 }
1705 
1706 #endif // PRODUCT
--- EOF ---