src/threads/threads-common.c

   1 /* src/threads/threads-common.c - machine independent thread functions
   2
   3    Copyright (C) 2007 R. Grafl, A. Krall, C. Kruegel,
   4    C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
   5    E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
   6    J. Wenninger, Institut f. Computersprachen - TU Wien
   7
   8    This file is part of CACAO.
   9
  10    This program is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU General Public License as
  12    published by the Free Software Foundation; either version 2, or (at
  13    your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful, but
  16    WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  23    02110-1301, USA.
  24
  25 */
  26
  27
  28 #include "config.h"
  29
  30 #include <assert.h>
  31 #include <stdint.h>
  32 #include <unistd.h>
  33
  34 #include "vm/types.h"
  35
  36 #include "mm/memory.h"
  37
  38 #include "native/jni.h"
  39 #include "native/llni.h"
  40
  41 #include "native/include/java_lang_Object.h"
  42 #include "native/include/java_lang_String.h"
  43 #include "native/include/java_lang_Thread.h"
  44
  45 #if defined(WITH_CLASSPATH_GNU)
  46 # include "native/include/java_lang_VMThread.h"
  47 #endif
  48
  49 #include "threads/critical.h"
  50 #include "threads/lock-common.h"
  51 #include "threads/threads-common.h"
  52
  53 #include "toolbox/list.h"
  54
  55 #include "vm/builtin.h"
  56 #include "vm/stringlocal.h"
  57 #include "vm/vm.h"
  58
  59 #include "vm/jit/stacktrace.h"
  60
  61 #include "vmcore/class.h"
  62
  63 #if defined(ENABLE_STATISTICS)
  64 # include "vmcore/options.h"
  65 # include "vmcore/statistics.h"
  66 #endif
  67
  68 #include "vmcore/utf8.h"
  69
  70
  71 /* global variables ***********************************************************/
  72
  73 /* global threads list */
  74 static list_t *list_threads;
  75
  76 /* global threads free-list */
  77 static list_t *list_threads_free;
  78
  79 #if defined(__LINUX__)
  80 /* XXX Remove for exact-GC. */
  81 bool threads_pthreads_implementation_nptl;
  82 #endif
  83
  84
  85 /* threads_preinit *************************************************************
  86
  87    Do some early initialization of stuff required.
  88
  89    ATTENTION: Do NOT use any Java heap allocation here, as gc_init()
  90    is called AFTER this function!
  91
  92 *******************************************************************************/
  93
  94 void threads_preinit(void)
  95 {
  96         threadobject *mainthread;
  97 #if defined(__LINUX__) && defined(_CS_GNU_LIBPTHREAD_VERSION)
  98         char         *pathbuf;
  99         size_t        len;
 100 #endif
 101
 102 #if defined(__LINUX__)
 103         /* XXX Remove for exact-GC. */
 104
 105         /* On Linux we need to check the pthread implementation. */
 106
 107         /* _CS_GNU_LIBPTHREAD_VERSION (GNU C library only; since glibc 2.3.2) */
 108         /* If the glibc is a pre-2.3.2 version, we fall back to
 109            linuxthreads. */
 110
 111 # if defined(_CS_GNU_LIBPTHREAD_VERSION)
 112         len = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, (size_t) 0);
 113
 114         /* Some systems return as length 0 (maybe cross-compilation
 115            related).  In this case we also fall back to linuxthreads. */
 116
 117         if (len > 0) {
 118                 pathbuf = MNEW(char, len);
 119
 120                 (void) confstr(_CS_GNU_LIBPTHREAD_VERSION, pathbuf, len);
 121
 122                 if (strstr(pathbuf, "NPTL") != NULL)
 123                         threads_pthreads_implementation_nptl = true;
 124                 else
 125                         threads_pthreads_implementation_nptl = false;
 126         }
 127         else
 128                 threads_pthreads_implementation_nptl = false;
 129 # else
 130         threads_pthreads_implementation_nptl = false;
 131 # endif
 132 #endif
 133
 134         /* initialize the threads lists */
 135
 136         list_threads      = list_create(OFFSET(threadobject, linkage));
 137         list_threads_free = list_create(OFFSET(threadobject, linkage));
 138
 139         /* Initialize the threads implementation (sets the thinlock on the
 140            main thread). */
 141
 142         threads_impl_preinit();
 143
 144         /* create internal thread data-structure for the main thread */
 145
 146         mainthread = threads_thread_new();
 147
 148         /* thread is a Java thread and running */
 149
 150         mainthread->flags = THREAD_FLAG_JAVA;
 151         mainthread->state = THREAD_STATE_RUNNABLE;
 152
 153         /* store the internal thread data-structure in the TSD */
 154
 155         threads_set_current_threadobject(mainthread);
 156
 157         /* initialize locking subsystems */
 158
 159         lock_init();
 160
 161         /* initialize the critical section */
 162
 163         critical_init();
 164 }
 165
 166
 167 /* threads_list_first **********************************************************
 168
 169    Return the first entry in the threads list.
 170
 171    NOTE: This function does not lock the lists.
 172
 173 *******************************************************************************/
 174
 175 threadobject *threads_list_first(void)
 176 {
 177         threadobject *t;
 178
 179         t = list_first_unsynced(list_threads);
 180
 181         return t;
 182 }
 183
 184
 185 /* threads_list_next ***********************************************************
 186
 187    Return the next entry in the threads list.
 188
 189    NOTE: This function does not lock the lists.
 190
 191 *******************************************************************************/
 192
 193 threadobject *threads_list_next(threadobject *t)
 194 {
 195         threadobject *next;
 196
 197         next = list_next_unsynced(list_threads, t);
 198
 199         return next;
 200 }
 201
 202
 203 /* threads_list_get_non_daemons ************************************************
 204
 205    Return the number of non-daemon threads.
 206
 207    NOTE: This function does a linear-search over the threads list,
 208          because it's only used for joining the threads.
 209
 210 *******************************************************************************/
 211
 212 s4 threads_list_get_non_daemons(void)
 213 {
 214         threadobject *t;
 215         s4            nondaemons;
 216
 217         /* lock the threads lists */
 218
 219         threads_list_lock();
 220
 221         nondaemons = 0;
 222
 223         for (t = threads_list_first(); t != NULL; t = threads_list_next(t)) {
 224                 if (!(t->flags & THREAD_FLAG_DAEMON))
 225                         nondaemons++;
 226         }
 227
 228         /* unlock the threads lists */
 229
 230         threads_list_unlock();
 231
 232         return nondaemons;
 233 }
 234
 235
 236 /* threads_thread_new **********************************************************
 237
 238    Allocates and initializes an internal thread data-structure and
 239    adds it to the threads list.
 240
 241 *******************************************************************************/
 242
 243 threadobject *threads_thread_new(void)
 244 {
 245         threadobject *t;
 246
 247         /* lock the threads-lists */
 248
 249         threads_list_lock();
 250
 251         /* try to get a thread from the free-list */
 252
 253         t = list_first_unsynced(list_threads_free);
 254
 255         /* is a free thread available? */
 256
 257         if (t != NULL) {
 258                 /* yes, remove it from the free list */
 259
 260                 list_remove_unsynced(list_threads_free, t);
 261         }
 262         else {
 263                 /* no, allocate a new one */
 264
 265 #if defined(ENABLE_GC_BOEHM)
 266                 t = GCNEW_UNCOLLECTABLE(threadobject, 1);
 267 #else
 268                 t = NEW(threadobject);
 269 #endif
 270
 271 #if defined(ENABLE_STATISTICS)
 272                 if (opt_stat)
 273                         size_threadobject += sizeof(threadobject);
 274 #endif
 275
 276                 /* clear memory */
 277
 278                 MZERO(t, threadobject, 1);
 279
 280                 /* set the threads-index */
 281
 282                 t->index = list_threads->size + 1;
 283         }
 284
 285         /* pre-compute the thinlock-word */
 286
 287         assert(t->index != 0);
 288
 289         t->thinlock = lock_pre_compute_thinlock(t->index);
 290         t->state    = THREAD_STATE_NEW;
 291
 292         /* initialize the implementation-specific bits */
 293
 294         threads_impl_thread_new(t);
 295
 296         /* add the thread to the threads-list */
 297
 298         list_add_last_unsynced(list_threads, t);
 299
 300         /* unlock the threads-lists */
 301
 302         threads_list_unlock();
 303
 304         return t;
 305 }
 306
 307
 308 /* threads_thread_free *********************************************************
 309
 310    Frees an internal thread data-structure by removing it from the
 311    threads-list and adding it to the free-list.
 312
 313    NOTE: The data-structure is NOT freed, the pointer keeps valid!
 314
 315 *******************************************************************************/
 316
 317 void threads_thread_free(threadobject *t)
 318 {
 319         int32_t  index;
 320         uint32_t state;
 321
 322         /* lock the threads-lists */
 323
 324         threads_list_lock();
 325
 326         /* cleanup the implementation-specific bits */
 327
 328         threads_impl_thread_free(t);
 329
 330         /* remove the thread from the threads-list */
 331
 332         list_remove_unsynced(list_threads, t);
 333
 334         /* Clear memory, but keep the thread-index and the
 335            thread-state. */
 336
 337         /* ATTENTION: Do this after list_remove, otherwise the linkage
 338            pointers are invalid. */
 339
 340         index = t->index;
 341         state = t->state;
 342
 343         MZERO(t, threadobject, 1);
 344
 345         t->index = index;
 346         t->state = state;
 347
 348         /* add the thread to the free list */
 349
 350         list_add_first_unsynced(list_threads_free, t);
 351
 352         /* unlock the threads-lists */
 353
 354         threads_list_unlock();
 355 }
 356
 357
 358 /* threads_thread_start_internal ***********************************************
 359
 360    Start an internal thread in the JVM.  No Java thread objects exists
 361    so far.
 362
 363    IN:
 364       name.......UTF-8 name of the thread
 365       f..........function pointer to C function to start
 366
 367 *******************************************************************************/
 368
 369 bool threads_thread_start_internal(utf *name, functionptr f)
 370 {
 371         threadobject       *t;
 372         java_lang_Thread   *object;
 373 #if defined(WITH_CLASSPATH_GNU)
 374         java_lang_VMThread *vmt;
 375 #endif
 376
 377         /* Enter the join-mutex, so if the main-thread is currently
 378            waiting to join all threads, the number of non-daemon threads
 379            is correct. */
 380
 381         threads_mutex_join_lock();
 382
 383         /* create internal thread data-structure */
 384
 385         t = threads_thread_new();
 386
 387         t->flags = THREAD_FLAG_INTERNAL | THREAD_FLAG_DAEMON;
 388
 389         /* The thread is flagged as (non-)daemon thread, we can leave the
 390            mutex. */
 391
 392         threads_mutex_join_unlock();
 393
 394         /* create the java thread object */
 395
 396         object = (java_lang_Thread *) builtin_new(class_java_lang_Thread);
 397
 398         /* XXX memory leak!!! */
 399         if (object == NULL)
 400                 return false;
 401
 402 #if defined(WITH_CLASSPATH_GNU)
 403         vmt = (java_lang_VMThread *) builtin_new(class_java_lang_VMThread);
 404
 405         /* XXX memory leak!!! */
 406         if (vmt == NULL)
 407                 return false;
 408
 409         LLNI_field_set_ref(vmt, thread, object);
 410         LLNI_field_set_val(vmt, vmdata, (java_lang_Object *) t);
 411
 412         LLNI_field_set_ref(object, vmThread, vmt);
 413 #elif defined(WITH_CLASSPATH_CLDC1_1)
 414         LLNI_field_set_val(object, vm_thread, (java_lang_Object *) t);
 415 #endif
 416
 417         t->object = object;
 418
 419         /* set java.lang.Thread fields */
 420
 421 #if defined(WITH_CLASSPATH_GNU)
 422         LLNI_field_set_ref(object, name    , (java_lang_String *) javastring_new(name));
 423 #elif defined(WITH_CLASSPATH_CLDC1_1)
 424         /* FIXME: In cldc the name is a char[] */
 425 /*      LLNI_field_set_ref(object, name    , (java_chararray *) javastring_new(name)); */
 426         LLNI_field_set_ref(object, name    , NULL);
 427 #endif
 428
 429 #if defined(ENABLE_JAVASE)
 430         LLNI_field_set_val(object, daemon  , true);
 431 #endif
 432
 433         LLNI_field_set_val(object, priority, NORM_PRIORITY);
 434
 435         /* start the thread */
 436
 437         threads_impl_thread_start(t, f);
 438
 439         /* everything's ok */
 440
 441         return true;
 442 }
 443
 444
 445 /* threads_thread_start ********************************************************
 446
 447    Start a Java thread in the JVM.  Only the java thread object exists
 448    so far.
 449
 450    IN:
 451       object.....the java thread object java.lang.Thread
 452
 453 *******************************************************************************/
 454
 455 void threads_thread_start(java_lang_Thread *object)
 456 {
 457         threadobject *thread;
 458 #if defined(WITH_CLASSPATH_GNU)
 459         java_lang_VMThread *vmt;
 460 #endif
 461
 462         /* Enter the join-mutex, so if the main-thread is currently
 463            waiting to join all threads, the number of non-daemon threads
 464            is correct. */
 465
 466         threads_mutex_join_lock();
 467
 468         /* create internal thread data-structure */
 469
 470         thread = threads_thread_new();
 471
 472         /* this is a normal Java thread */
 473
 474         thread->flags = THREAD_FLAG_JAVA;
 475
 476 #if defined(ENABLE_JAVASE)
 477         /* is this a daemon thread? */
 478
 479         if (LLNI_field_direct(object, daemon) == true)
 480                 thread->flags |= THREAD_FLAG_DAEMON;
 481 #endif
 482
 483         /* The thread is flagged and (non-)daemon thread, we can leave the
 484            mutex. */
 485
 486         threads_mutex_join_unlock();
 487
 488         /* link the two objects together */
 489
 490         thread->object = object;
 491
 492 #if defined(WITH_CLASSPATH_GNU)
 493         LLNI_field_get_ref(object, vmThread, vmt);
 494
 495         assert(vmt);
 496         assert(LLNI_field_direct(vmt, vmdata) == NULL);
 497
 498         LLNI_field_set_val(vmt, vmdata, (java_lang_Object *) thread);
 499 #elif defined(WITH_CLASSPATH_CLDC1_1)
 500         LLNI_field_set_val(object, vm_thread, (java_lang_Object *) thread);
 501 #endif
 502
 503         /* Start the thread.  Don't pass a function pointer (NULL) since
 504            we want Thread.run()V here. */
 505
 506         threads_impl_thread_start(thread, NULL);
 507 }
 508
 509
 510 /* threads_thread_print_info ***************************************************
 511
 512    Print information of the passed thread.
 513
 514 *******************************************************************************/
 515
 516 void threads_thread_print_info(threadobject *t)
 517 {
 518         java_lang_Thread *object;
 519         utf              *name;
 520
 521         assert(t->state != THREAD_STATE_NEW);
 522
 523         /* the thread may be currently in initalization, don't print it */
 524
 525         object = t->object;
 526
 527         if (object != NULL) {
 528                 /* get thread name */
 529
 530 #if defined(WITH_CLASSPATH_GNU)
 531                 name = javastring_toutf((java_handle_t *) LLNI_field_direct(object, name), false);
 532 #elif defined(WITH_CLASSPATH_SUN) || defined(WITH_CLASSPATH_CLDC1_1)
 533                 /* FIXME: In cldc the name is a char[] */
 534 /*              name = object->name; */
 535                 name = utf_null;
 536 #else
 537 # error unknown classpath configuration
 538 #endif
 539
 540                 printf("\"");
 541                 utf_display_printable_ascii(name);
 542                 printf("\"");
 543
 544                 if (t->flags & THREAD_FLAG_DAEMON)
 545                         printf(" daemon");
 546
 547                 printf(" prio=%d", LLNI_field_direct(object, priority));
 548
 549 #if SIZEOF_VOID_P == 8
 550                 printf(" t=0x%016lx tid=0x%016lx (%ld)",
 551                            (ptrint) t, (ptrint) t->tid, (ptrint) t->tid);
 552 #else
 553                 printf(" t=0x%08x tid=0x%08x (%d)",
 554                            (ptrint) t, (ptrint) t->tid, (ptrint) t->tid);
 555 #endif
 556
 557                 printf(" index=%d", t->index);
 558
 559                 /* print thread state */
 560
 561                 switch (t->state) {
 562                 case THREAD_STATE_NEW:
 563                         printf(" new");
 564                         break;
 565                 case THREAD_STATE_RUNNABLE:
 566                         printf(" runnable");
 567                         break;
 568                 case THREAD_STATE_BLOCKED:
 569                         printf(" blocked");
 570                         break;
 571                 case THREAD_STATE_WAITING:
 572                         printf(" waiting");
 573                         break;
 574                 case THREAD_STATE_TIMED_WAITING:
 575                         printf(" waiting on condition");
 576                         break;
 577                 case THREAD_STATE_TERMINATED:
 578                         printf(" terminated");
 579                         break;
 580                 default:
 581                         vm_abort("threads_thread_print_info: unknown thread state %d",
 582                                          t->state);
 583                 }
 584         }
 585 }
 586
 587
 588 /* threads_get_current_tid *****************************************************
 589
 590    Return the tid of the current thread.
 591
 592    RETURN VALUE:
 593        the current tid
 594
 595 *******************************************************************************/
 596
 597 ptrint threads_get_current_tid(void)
 598 {
 599         threadobject *thread;
 600
 601         thread = THREADOBJECT;
 602
 603         /* this may happen during bootstrap */
 604
 605         if (thread == NULL)
 606                 return 0;
 607
 608         return (ptrint) thread->tid;
 609 }
 610
 611
 612 /* threads_thread_state_runnable ***********************************************
 613
 614    Set the current state of the given thread to THREAD_STATE_RUNNABLE.
 615
 616 *******************************************************************************/
 617
 618 void threads_thread_state_runnable(threadobject *t)
 619 {
 620         /* set the state inside the lock */
 621
 622         threads_list_lock();
 623
 624         t->state = THREAD_STATE_RUNNABLE;
 625
 626         threads_list_unlock();
 627 }
 628
 629
 630 /* threads_thread_state_waiting ************************************************
 631
 632    Set the current state of the given thread to THREAD_STATE_WAITING.
 633
 634 *******************************************************************************/
 635
 636 void threads_thread_state_waiting(threadobject *t)
 637 {
 638         /* set the state in the lock */
 639
 640         threads_list_lock();
 641
 642         t->state = THREAD_STATE_WAITING;
 643
 644         threads_list_unlock();
 645 }
 646
 647
 648 /* threads_thread_state_timed_waiting ******************************************
 649
 650    Set the current state of the given thread to
 651    THREAD_STATE_TIMED_WAITING.
 652
 653 *******************************************************************************/
 654
 655 void threads_thread_state_timed_waiting(threadobject *t)
 656 {
 657         /* set the state in the lock */
 658
 659         threads_list_lock();
 660
 661         t->state = THREAD_STATE_TIMED_WAITING;
 662
 663         threads_list_unlock();
 664 }
 665
 666
 667 /* threads_thread_state_terminated *********************************************
 668
 669    Set the current state of the given thread to
 670    THREAD_STATE_TERMINATED.
 671
 672 *******************************************************************************/
 673
 674 void threads_thread_state_terminated(threadobject *t)
 675 {
 676         /* set the state in the lock */
 677
 678         threads_list_lock();
 679
 680         t->state = THREAD_STATE_TERMINATED;
 681
 682         threads_list_unlock();
 683 }
 684
 685
 686 /* threads_thread_get_state ****************************************************
 687
 688    Returns the current state of the given thread.
 689
 690 *******************************************************************************/
 691
 692 utf *threads_thread_get_state(threadobject *t)
 693 {
 694         utf *u;
 695
 696         switch (t->state) {
 697         case THREAD_STATE_NEW:
 698                 u = utf_new_char("NEW");
 699                 break;
 700         case THREAD_STATE_RUNNABLE:
 701                 u = utf_new_char("RUNNABLE");
 702                 break;
 703         case THREAD_STATE_BLOCKED:
 704                 u = utf_new_char("BLOCKED");
 705                 break;
 706         case THREAD_STATE_WAITING:
 707                 u = utf_new_char("WAITING");
 708                 break;
 709         case THREAD_STATE_TIMED_WAITING:
 710                 u = utf_new_char("TIMED_WAITING");
 711                 break;
 712         case THREAD_STATE_TERMINATED:
 713                 u = utf_new_char("TERMINATED");
 714                 break;
 715         default:
 716                 vm_abort("threads_get_state: unknown thread state %d", t->state);
 717
 718                 /* keep compiler happy */
 719
 720                 u = NULL;
 721         }
 722
 723         return u;
 724 }
 725
 726
 727 /* threads_thread_is_alive *****************************************************
 728
 729    Returns if the give thread is alive.
 730
 731 *******************************************************************************/
 732
 733 bool threads_thread_is_alive(threadobject *thread)
 734 {
 735         bool result;
 736
 737         switch (thread->state) {
 738         case THREAD_STATE_NEW:
 739         case THREAD_STATE_TERMINATED:
 740                 result = false;
 741                 break;
 742
 743         case THREAD_STATE_RUNNABLE:
 744         case THREAD_STATE_BLOCKED:
 745         case THREAD_STATE_WAITING:
 746         case THREAD_STATE_TIMED_WAITING:
 747                 result = true;
 748                 break;
 749
 750         default:
 751                 vm_abort("threads_is_alive: unknown thread state %d", thread->state);
 752
 753                 /* keep compiler happy */
 754
 755                 result = false;
 756         }
 757
 758         return result;
 759 }
 760
 761
 762 /* threads_dump ****************************************************************
 763
 764    Dumps info for all threads running in the JVM.  This function is
 765    called when SIGQUIT (<ctrl>-\) is sent to CACAO.
 766
 767 *******************************************************************************/
 768
 769 void threads_dump(void)
 770 {
 771         threadobject *t;
 772
 773         /* XXX we should stop the world here */
 774
 775         /* lock the threads lists */
 776
 777         threads_list_lock();
 778
 779         printf("Full thread dump CACAO "VERSION":\n");
 780
 781         /* iterate over all started threads */
 782
 783         for (t = threads_list_first(); t != NULL; t = threads_list_next(t)) {
 784                 /* print thread info */
 785
 786                 printf("\n");
 787                 threads_thread_print_info(t);
 788                 printf("\n");
 789
 790                 /* print trace of thread */
 791
 792                 threads_thread_print_stacktrace(t);
 793         }
 794
 795         /* unlock the threads lists */
 796
 797         threads_list_unlock();
 798 }
 799
 800
 801 /* threads_thread_print_stacktrace *********************************************
 802
 803    Print the current stacktrace of the current thread.
 804
 805 *******************************************************************************/
 806
 807 void threads_thread_print_stacktrace(threadobject *thread)
 808 {
 809         stackframeinfo   *sfi;
 810         stacktracebuffer *stb;
 811         s4                dumpsize;
 812
 813         /* mark start of dump memory area */
 814
 815         dumpsize = dump_size();
 816
 817         /* create a stacktrace for the passed thread */
 818
 819         sfi = thread->_stackframeinfo;
 820
 821         stb = stacktrace_create(sfi);
 822
 823         /* print stacktrace */
 824
 825         if (stb != NULL)
 826                 stacktrace_print_trace_from_buffer(stb);
 827         else {
 828                 puts("\t<<No stacktrace available>>");
 829                 fflush(stdout);
 830         }
 831
 832         dump_release(dumpsize);
 833 }
 834
 835
 836 /* threads_print_stacktrace ****************************************************
 837
 838    Print the current stacktrace of the current thread.
 839
 840 *******************************************************************************/
 841
 842 void threads_print_stacktrace(void)
 843 {
 844         threadobject *thread;
 845
 846         thread = THREADOBJECT;
 847
 848         threads_thread_print_stacktrace(thread);
 849 }
 850
 851
 852 /*
 853  * These are local overrides for various environment variables in Emacs.
 854  * Please do not remove this and leave it at the end of the file, where
 855  * Emacs will automagically detect them.
 856  * ---------------------------------------------------------------------
 857  * Local variables:
 858  * mode: c
 859  * indent-tabs-mode: t
 860  * c-basic-offset: 4
 861  * tab-width: 4
 862  * End:
 863  * vim:noexpandtab:sw=4:ts=4:
 864  */