libjava/boehm.cc

   1 // boehm.cc - interface between libjava and Boehm GC.
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4    Free Software Foundation
   5
   6    This file is part of libgcj.
   7
   8 This software is copyrighted work licensed under the terms of the
   9 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
  10 details.  */
  11
  12 #include <config.h>
  13
  14 #include <stdio.h>
  15 #include <limits.h>
  16
  17 #include <jvm.h>
  18 #include <gcj/cni.h>
  19
  20 #include <java/lang/Class.h>
  21 #include <java/lang/reflect/Modifier.h>
  22 #include <java-interp.h>
  23
  24 // More nastiness: the GC wants to define TRUE and FALSE.  We don't
  25 // need the Java definitions (themselves a hack), so we undefine them.
  26 #undef TRUE
  27 #undef FALSE
  28
  29 // We include two autoconf headers. Avoid multiple definition warnings.
  30 #undef PACKAGE_NAME
  31 #undef PACKAGE_STRING
  32 #undef PACKAGE_TARNAME
  33 #undef PACKAGE_VERSION
  34
  35 #ifdef HAVE_DLFCN_H
  36 #undef _GNU_SOURCE
  37 #define _GNU_SOURCE
  38 #include <dlfcn.h>
  39 #endif
  40
  41 extern "C"
  42 {
  43 #include <gc_config.h>
  44
  45 // Set GC_DEBUG before including gc.h!
  46 #ifdef LIBGCJ_GC_DEBUG
  47 # define GC_DEBUG
  48 #endif
  49
  50 #include <gc_mark.h>
  51 #include <gc_gcj.h>
  52 #include <javaxfc.h>  // GC_finalize_all declaration.
  53
  54 #ifdef THREAD_LOCAL_ALLOC
  55 # define GC_REDIRECT_TO_LOCAL
  56 # include <gc_local_alloc.h>
  57 #endif
  58
  59   // From boehm's misc.c
  60   void GC_enable();
  61   void GC_disable();
  62 };
  63
  64 #define MAYBE_MARK(Obj, Top, Limit, Source)  \
  65         Top=GC_MARK_AND_PUSH((GC_PTR) Obj, Top, Limit, (GC_PTR *) Source)
  66
  67 // `kind' index used when allocating Java arrays.
  68 static int array_kind_x;
  69
  70 // Freelist used for Java arrays.
  71 static void **array_free_list;
  72
  73 static int _Jv_GC_has_static_roots (const char *filename, void *, size_t);
  74
  75 \f
  76
  77 // This is called by the GC during the mark phase.  It marks a Java
  78 // object.  We use `void *' arguments and return, and not what the
  79 // Boehm GC wants, to avoid pollution in our headers.
  80 void *
  81 _Jv_MarkObj (void *addr, void *msp, void *msl, void *env)
  82 {
  83   struct GC_ms_entry *mark_stack_ptr = (struct GC_ms_entry *)msp;
  84   struct GC_ms_entry *mark_stack_limit = (struct GC_ms_entry *)msl;
  85
  86   if (env == (void *)1) /* Object allocated with debug allocator.       */
  87     addr = (GC_PTR)GC_USR_PTR_FROM_BASE(addr);
  88   jobject obj = (jobject) addr;
  89
  90   _Jv_VTable *dt = *(_Jv_VTable **) addr;
  91   // The object might not yet have its vtable set, or it might
  92   // really be an object on the freelist.  In either case, the vtable slot
  93   // will either be 0, or it will point to a cleared object.
  94   // This assumes Java objects have size at least 3 words,
  95   // including the header.   But this should remain true, since this
  96   // should only be used with debugging allocation or with large objects.
  97   if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
  98     return mark_stack_ptr;
  99   jclass klass = dt->clas;
 100   GC_PTR p;
 101
 102   p = (GC_PTR) dt;
 103   MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
 104
 105 # ifndef JV_HASH_SYNCHRONIZATION
 106     // Every object has a sync_info pointer.
 107     p = (GC_PTR) obj->sync_info;
 108     MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
 109 # endif
 110
 111   if (__builtin_expect (klass == &java::lang::Class::class$, false))
 112     {
 113       // Currently we allocate some of the memory referenced from class objects
 114       // as pointerfree memory, and then mark it more intelligently here.
 115       // We ensure that the ClassClass mark descriptor forces invocation of
 116       // this procedure.
 117       // Correctness of this is subtle, but it looks OK to me for now.  For the incremental
 118       // collector, we need to make sure that the class object is written whenever
 119       // any of the subobjects are altered and may need rescanning.  This may be tricky
 120       // during construction, and this may not be the right way to do this with
 121       // incremental collection.
 122       // If we overflow the mark stack, we will rescan the class object, so we should
 123       // be OK.  The same applies if we redo the mark phase because win32 unmapped part
 124       // of our root set.               - HB
 125       jclass c = (jclass) addr;
 126
 127       p = (GC_PTR) c->name;
 128       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 129       p = (GC_PTR) c->superclass;
 130       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 131
 132       p = (GC_PTR) c->constants.tags;
 133       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 134       p = (GC_PTR) c->constants.data;
 135       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 136
 137       // If the class is an array, then the methods field holds a
 138       // pointer to the element class.  If the class is primitive,
 139       // then the methods field holds a pointer to the array class.
 140       p = (GC_PTR) c->methods;
 141       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 142
 143       p = (GC_PTR) c->fields;
 144       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 145
 146       // The vtable might be allocated even for compiled code.
 147       p = (GC_PTR) c->vtable;
 148       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 149
 150       p = (GC_PTR) c->interfaces;
 151       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 152       p = (GC_PTR) c->loader;
 153       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 154
 155       // The dispatch tables can be allocated at runtime.
 156       p = (GC_PTR) c->ancestors;
 157       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 158
 159       p = (GC_PTR) c->idt;
 160       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 161
 162       p = (GC_PTR) c->arrayclass;
 163       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 164       p = (GC_PTR) c->protectionDomain;
 165       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 166       p = (GC_PTR) c->hack_signers;
 167       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 168       p = (GC_PTR) c->aux_info;
 169       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 170
 171       p = (GC_PTR) c->reflection_data;
 172       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 173
 174       // The class chain must be marked for runtime-allocated Classes
 175       // loaded by the bootstrap ClassLoader.
 176       p = (GC_PTR) c->next_or_version;
 177       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
 178     }
 179   else
 180     {
 181       // NOTE: each class only holds information about the class
 182       // itself.  So we must do the marking for the entire inheritance
 183       // tree in order to mark all fields.  FIXME: what about
 184       // interfaces?  We skip Object here, because Object only has a
 185       // sync_info, and we handled that earlier.
 186       // Note: occasionally `klass' can be null.  For instance, this
 187       // can happen if a GC occurs between the point where an object
 188       // is allocated and where the vtbl slot is set.
 189       while (klass && klass != &java::lang::Object::class$)
 190         {
 191           jfieldID field = JvGetFirstInstanceField (klass);
 192           jint max = JvNumInstanceFields (klass);
 193
 194           for (int i = 0; i < max; ++i)
 195             {
 196               if (JvFieldIsRef (field))
 197                 {
 198                   jobject val = JvGetObjectField (obj, field);
 199                   p = (GC_PTR) val;
 200                   MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
 201                 }
 202               field = field->getNextField ();
 203             }
 204           klass = klass->getSuperclass();
 205         }
 206     }
 207
 208   return mark_stack_ptr;
 209 }
 210
 211 // This is called by the GC during the mark phase.  It marks a Java
 212 // array (of objects).  We use `void *' arguments and return, and not
 213 // what the Boehm GC wants, to avoid pollution in our headers.
 214 void *
 215 _Jv_MarkArray (void *addr, void *msp, void *msl, void *env)
 216 {
 217   struct GC_ms_entry *mark_stack_ptr = (struct GC_ms_entry *)msp;
 218   struct GC_ms_entry *mark_stack_limit = (struct GC_ms_entry *)msl;
 219
 220   if (env == (void *)1) /* Object allocated with debug allocator.       */
 221     addr = (void *)GC_USR_PTR_FROM_BASE(addr);
 222   jobjectArray array = (jobjectArray) addr;
 223
 224   _Jv_VTable *dt = *(_Jv_VTable **) addr;
 225   // Assumes size >= 3 words.  That's currently true since arrays have
 226   // a vtable, sync pointer, and size.  If the sync pointer goes away,
 227   // we may need to round up the size.
 228   if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
 229     return mark_stack_ptr;
 230   GC_PTR p;
 231
 232   p = (GC_PTR) dt;
 233   MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array);
 234
 235 # ifndef JV_HASH_SYNCHRONIZATION
 236     // Every object has a sync_info pointer.
 237     p = (GC_PTR) array->sync_info;
 238     MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array);
 239 # endif
 240
 241   for (int i = 0; i < JvGetArrayLength (array); ++i)
 242     {
 243       jobject obj = elements (array)[i];
 244       p = (GC_PTR) obj;
 245       MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array);
 246     }
 247
 248   return mark_stack_ptr;
 249 }
 250
 251 // Generate a GC marking descriptor for a class.
 252 //
 253 // We assume that the gcj mark proc has index 0.  This is a dubious assumption,
 254 // since another one could be registered first.  But the compiler also
 255 // knows this, so in that case everything else will break, too.
 256 #define GCJ_DEFAULT_DESCR GC_MAKE_PROC(GC_GCJ_RESERVED_MARK_PROC_INDEX,0)
 257
 258 void *
 259 _Jv_BuildGCDescr(jclass self)
 260 {
 261   jlong desc = 0;
 262   jint bits_per_word = CHAR_BIT * sizeof (void *);
 263
 264   // Note: for now we only consider a bitmap mark descriptor.  We
 265   // could also handle the case where the first N fields of a type are
 266   // references.  However, this is not very likely to be used by many
 267   // classes, and it is easier to compute things this way.
 268
 269   // The vtable pointer.
 270   desc |= 1ULL << (bits_per_word - 1);
 271 #ifndef JV_HASH_SYNCHRONIZATION
 272   // The sync_info field.
 273   desc |= 1ULL << (bits_per_word - 2);
 274 #endif
 275
 276   for (jclass klass = self; klass != NULL; klass = klass->getSuperclass())
 277     {
 278       jfieldID field = JvGetFirstInstanceField(klass);
 279       int count = JvNumInstanceFields(klass);
 280
 281       for (int i = 0; i < count; ++i)
 282         {
 283           if (field->isRef())
 284             {
 285               unsigned int off = field->getOffset();
 286               // If we run into a weird situation, we bail.
 287               if (off % sizeof (void *) != 0)
 288                 return (void *) (GCJ_DEFAULT_DESCR);
 289               off /= sizeof (void *);
 290               // If we find a field outside the range of our bitmap,
 291               // fall back to procedure marker. The bottom 2 bits are
 292               // reserved.
 293               if (off >= (unsigned) bits_per_word - 2)
 294                 return (void *) (GCJ_DEFAULT_DESCR);
 295               desc |= 1ULL << (bits_per_word - off - 1);
 296             }
 297
 298           field = field->getNextField();
 299         }
 300     }
 301
 302   // For bitmap mark type, bottom bits are 01.
 303   desc |= 1;
 304   // Bogus warning avoidance (on many platforms).
 305   return (void *) (unsigned long) desc;
 306 }
 307
 308 // Allocate some space that is known to be pointer-free.
 309 void *
 310 _Jv_AllocBytes (jsize size)
 311 {
 312   void *r = GC_MALLOC_ATOMIC (size);
 313   // We have to explicitly zero memory here, as the GC doesn't
 314   // guarantee that PTRFREE allocations are zeroed.  Note that we
 315   // don't have to do this for other allocation types because we set
 316   // the `ok_init' flag in the type descriptor.
 317   memset (r, 0, size);
 318   return r;
 319 }
 320
 321 #ifdef LIBGCJ_GC_DEBUG
 322
 323 void *
 324 _Jv_AllocObj (jsize size, jclass klass)
 325 {
 326   return GC_GCJ_MALLOC (size, klass->vtable);
 327 }
 328
 329 void *
 330 _Jv_AllocPtrFreeObj (jsize size, jclass klass)
 331 {
 332 #ifdef JV_HASH_SYNCHRONIZATION
 333   void * obj = GC_MALLOC_ATOMIC(size);
 334   *((_Jv_VTable **) obj) = klass->vtable;
 335 #else
 336   void * obj = GC_GCJ_MALLOC(size, klass->vtable);
 337 #endif
 338   return obj;
 339 }
 340
 341 #endif /* LIBGCJ_GC_DEBUG */
 342 // In the non-debug case, the above two functions are defined
 343 // as inline functions in boehm-gc.h.  In the debug case we
 344 // really want to take advantage of the definitions in gc_gcj.h.
 345
 346 // Allocate space for a new Java array.
 347 // Used only for arrays of objects.
 348 void *
 349 _Jv_AllocArray (jsize size, jclass klass)
 350 {
 351   void *obj;
 352
 353 #ifdef LIBGCJ_GC_DEBUG
 354   // There isn't much to lose by scanning this conservatively.
 355   // If we didn't, the mark proc would have to understand that
 356   // it needed to skip the header.
 357   obj = GC_MALLOC(size);
 358 #else
 359   const jsize min_heap_addr = 16*1024;
 360   // A heuristic.  If size is less than this value, the size
 361   // stored in the array can't possibly be misinterpreted as
 362   // a pointer.   Thus we lose nothing by scanning the object
 363   // completely conservatively, since no misidentification can
 364   // take place.
 365
 366   if (size < min_heap_addr)
 367     obj = GC_MALLOC(size);
 368   else
 369     obj = GC_generic_malloc (size, array_kind_x);
 370 #endif
 371   *((_Jv_VTable **) obj) = klass->vtable;
 372   return obj;
 373 }
 374
 375 /* Allocate space for a new non-Java object, which does not have the usual
 376    Java object header but may contain pointers to other GC'ed objects. */
 377 void *
 378 _Jv_AllocRawObj (jsize size)
 379 {
 380   return (void *) GC_MALLOC (size ? size : 1);
 381 }
 382
 383 #ifdef INTERPRETER
 384 typedef _Jv_ClosureList *closure_list_pointer;
 385
 386 /* Release closures in a _Jv_ClosureList.  */
 387 static void
 388 finalize_closure_list (GC_PTR obj, GC_PTR)
 389 {
 390   _Jv_ClosureList **clpp = (_Jv_ClosureList **)obj;
 391   _Jv_ClosureList::releaseClosures (clpp);
 392 }
 393
 394 /* Allocate a double-indirect pointer to a _Jv_ClosureList that will
 395    get garbage-collected after this double-indirect pointer becomes
 396    unreachable by any other objects, including finalizable ones.  */
 397 _Jv_ClosureList **
 398 _Jv_ClosureListFinalizer ()
 399 {
 400   _Jv_ClosureList **clpp;
 401   clpp = (_Jv_ClosureList **)_Jv_AllocBytes (sizeof (*clpp));
 402   GC_REGISTER_FINALIZER_UNREACHABLE (clpp, finalize_closure_list,
 403                                      NULL, NULL, NULL);
 404   return clpp;
 405 }
 406 #endif // INTERPRETER
 407
 408 static void
 409 call_finalizer (GC_PTR obj, GC_PTR client_data)
 410 {
 411   _Jv_FinalizerFunc *fn = (_Jv_FinalizerFunc *) client_data;
 412   jobject jobj = (jobject) obj;
 413
 414   (*fn) (jobj);
 415 }
 416
 417 void
 418 _Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *meth)
 419 {
 420   GC_REGISTER_FINALIZER_NO_ORDER (object, call_finalizer, (GC_PTR) meth,
 421                                   NULL, NULL);
 422 }
 423
 424 void
 425 _Jv_RunFinalizers (void)
 426 {
 427   GC_invoke_finalizers ();
 428 }
 429
 430 void
 431 _Jv_RunAllFinalizers (void)
 432 {
 433   GC_finalize_all ();
 434 }
 435
 436 void
 437 _Jv_RunGC (void)
 438 {
 439   GC_gcollect ();
 440 }
 441
 442 long
 443 _Jv_GCTotalMemory (void)
 444 {
 445   return GC_get_heap_size ();
 446 }
 447
 448 long
 449 _Jv_GCFreeMemory (void)
 450 {
 451   return GC_get_free_bytes ();
 452 }
 453
 454 void
 455 _Jv_GCSetInitialHeapSize (size_t size)
 456 {
 457   size_t current = GC_get_heap_size ();
 458   if (size > current)
 459     GC_expand_hp (size - current);
 460 }
 461
 462 void
 463 _Jv_GCSetMaximumHeapSize (size_t size)
 464 {
 465   GC_set_max_heap_size ((GC_word) size);
 466 }
 467
 468 void
 469 _Jv_DisableGC (void)
 470 {
 471   GC_disable();
 472 }
 473
 474 void
 475 _Jv_EnableGC (void)
 476 {
 477   GC_enable();
 478 }
 479
 480 static void * handle_out_of_memory(size_t)
 481 {
 482   _Jv_ThrowNoMemory();
 483 }
 484
 485 static void
 486 gcj_describe_type_fn(void *obj, char *out_buf)
 487 {
 488   _Jv_VTable *dt = *(_Jv_VTable **) obj;
 489
 490   if (! dt /* Shouldn't happen */)
 491     {
 492       strcpy(out_buf, "GCJ (bad)");
 493       return;
 494     }
 495   jclass klass = dt->clas;
 496   if (!klass /* shouldn't happen */)
 497     {
 498       strcpy(out_buf, "GCJ (bad)");
 499       return;
 500     }
 501   jstring name = klass -> getName();
 502   size_t len = name -> length();
 503   if (len >= GC_TYPE_DESCR_LEN) len = GC_TYPE_DESCR_LEN - 1;
 504   JvGetStringUTFRegion (name, 0, len, out_buf);
 505   out_buf[len] = '\0';
 506 }
 507
 508 void
 509 _Jv_InitGC (void)
 510 {
 511   int proc;
 512   static bool gc_initialized;
 513
 514   if (gc_initialized)
 515     return;
 516
 517   gc_initialized = 1;
 518
 519   // Ignore pointers that do not point to the start of an object.
 520   GC_all_interior_pointers = 0;
 521
 522 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 523   // Tell the collector to ask us before scanning DSOs.
 524   GC_register_has_static_roots_callback (_Jv_GC_has_static_roots);
 525 #endif
 526
 527   // Configure the collector to use the bitmap marking descriptors that we
 528   // stash in the class vtable.
 529   // We always use mark proc descriptor 0, since the compiler knows
 530   // about it.
 531   GC_init_gcj_malloc (0, (void *) _Jv_MarkObj);
 532
 533   // Cause an out of memory error to be thrown from the allocators,
 534   // instead of returning 0.  This is cheaper than checking on allocation.
 535   GC_oom_fn = handle_out_of_memory;
 536
 537   GC_java_finalization = 1;
 538
 539   // We use a different mark procedure for object arrays. This code
 540   // configures a different object `kind' for object array allocation and
 541   // marking.
 542   array_free_list = GC_new_free_list();
 543   proc = GC_new_proc((GC_mark_proc)_Jv_MarkArray);
 544   array_kind_x = GC_new_kind(array_free_list, GC_MAKE_PROC (proc, 0), 0, 1);
 545
 546   // Arrange to have the GC print Java class names in backtraces, etc.
 547   GC_register_describe_type_fn(GC_gcj_kind, gcj_describe_type_fn);
 548   GC_register_describe_type_fn(GC_gcj_debug_kind, gcj_describe_type_fn);
 549 }
 550
 551 #ifdef JV_HASH_SYNCHRONIZATION
 552 // Allocate an object with a fake vtable pointer, which causes only
 553 // the first field (beyond the fake vtable pointer) to be traced.
 554 // Eventually this should probably be generalized.
 555
 556 static _Jv_VTable trace_one_vtable = {
 557     0,                  // class pointer
 558     (void *)(2 * sizeof(void *)),
 559                         // descriptor; scan 2 words incl. vtable ptr.
 560                         // Least significant bits must be zero to
 561                         // identify this as a length descriptor
 562     {0}                 // First method
 563 };
 564
 565 void *
 566 _Jv_AllocTraceOne (jsize size /* includes vtable slot */)
 567 {
 568   return GC_GCJ_MALLOC (size, &trace_one_vtable);
 569 }
 570
 571 // Ditto for two words.
 572 // the first field (beyond the fake vtable pointer) to be traced.
 573 // Eventually this should probably be generalized.
 574
 575 static _Jv_VTable trace_two_vtable =
 576 {
 577   0,                    // class pointer
 578   (void *)(3 * sizeof(void *)),
 579                         // descriptor; scan 3 words incl. vtable ptr.
 580   {0}                   // First method
 581 };
 582
 583 void *
 584 _Jv_AllocTraceTwo (jsize size /* includes vtable slot */)
 585 {
 586   return GC_GCJ_MALLOC (size, &trace_two_vtable);
 587 }
 588
 589 #endif /* JV_HASH_SYNCHRONIZATION */
 590
 591 void
 592 _Jv_GCInitializeFinalizers (void (*notifier) (void))
 593 {
 594   GC_finalize_on_demand = 1;
 595   GC_finalizer_notifier = notifier;
 596 }
 597
 598 void
 599 _Jv_GCRegisterDisappearingLink (jobject *objp)
 600 {
 601   // This test helps to ensure that we meet a precondition of
 602   // GC_general_register_disappearing_link, viz. "Obj must be a
 603   // pointer to the first word of an object we allocated."
 604   if (GC_base(*objp))
 605     GC_general_register_disappearing_link ((GC_PTR *) objp, (GC_PTR) *objp);
 606 }
 607
 608 jboolean
 609 _Jv_GCCanReclaimSoftReference (jobject)
 610 {
 611   // For now, always reclaim soft references.  FIXME.
 612   return true;
 613 }
 614
 615 \f
 616
 617 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 618
 619 // We keep a store of the filenames of DSOs that need to be
 620 // conservatively scanned by the garbage collector.  During collection
 621 // the gc calls _Jv_GC_has_static_roots() to see if the data segment
 622 // of a DSO should be scanned.
 623 typedef struct filename_node
 624 {
 625   char *name;
 626   struct filename_node *link;
 627 } filename_node;
 628
 629 #define FILENAME_STORE_SIZE 17
 630 static filename_node *filename_store[FILENAME_STORE_SIZE];
 631
 632 // Find a filename in filename_store.
 633 static filename_node **
 634 find_file (const char *filename)
 635 {
 636   int index = strlen (filename) % FILENAME_STORE_SIZE;
 637   filename_node **node = &filename_store[index];
 638
 639   while (*node)
 640     {
 641       if (strcmp ((*node)->name, filename) == 0)
 642         return node;
 643       node = &(*node)->link;
 644     }
 645
 646   return node;
 647 }
 648
 649 // Print the store of filenames of DSOs that need collection.
 650 void
 651 _Jv_print_gc_store (void)
 652 {
 653   for (int i = 0; i < FILENAME_STORE_SIZE; i++)
 654     {
 655       filename_node *node = filename_store[i];
 656       while (node)
 657         {
 658           fprintf (stderr, "%s\n", node->name);
 659           node = node->link;
 660         }
 661     }
 662 }
 663
 664 // Create a new node in the store of libraries to collect.
 665 static filename_node *
 666 new_node (const char *filename)
 667 {
 668   filename_node *node = (filename_node*)_Jv_Malloc (sizeof (filename_node));
 669   node->name = (char *)_Jv_Malloc (strlen (filename) + 1);
 670   node->link = NULL;
 671   strcpy (node->name, filename);
 672
 673   return node;
 674 }
 675
 676 // Nonzero if the gc should scan this lib.
 677 static int
 678 _Jv_GC_has_static_roots (const char *filename, void *, size_t)
 679 {
 680   if (filename == NULL || strlen (filename) == 0)
 681     // No filename; better safe than sorry.
 682     return 1;
 683
 684   filename_node **node = find_file (filename);
 685   if (*node)
 686     return 1;
 687
 688   return 0;
 689 }
 690
 691 #endif
 692
 693 // Register the DSO that contains p for collection.
 694 void
 695 _Jv_RegisterLibForGc (const void *p __attribute__ ((__unused__)))
 696 {
 697 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 698   Dl_info info;
 699
 700   if (dladdr (const_cast<void *>(p), &info) != 0)
 701     {
 702       filename_node **node = find_file (info.dli_fname);
 703       if (! *node)
 704         *node = new_node (info.dli_fname);
 705     }
 706 #endif
 707 }
 708
 709 void
 710 _Jv_SuspendThread (_Jv_Thread_t *thread)
 711 {
 712 #if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \
 713      && !defined(GC_WIN32_THREADS) && !defined(GC_DARWIN_THREADS)
 714   GC_suspend_thread (_Jv_GetPlatformThreadID (thread));
 715 #endif
 716 }
 717
 718 void
 719 _Jv_ResumeThread (_Jv_Thread_t *thread)
 720 {
 721 #if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \
 722      && !defined(GC_WIN32_THREADS) && !defined(GC_DARWIN_THREADS)
 723   GC_resume_thread (_Jv_GetPlatformThreadID (thread));
 724 #endif
 725 }
 726
 727 int
 728 _Jv_IsThreadSuspended (_Jv_Thread_t *thread)
 729 {
 730 #if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \
 731      && !defined(GC_WIN32_THREADS) && !defined(GC_DARWIN_THREADS)
 732   return GC_is_thread_suspended (_Jv_GetPlatformThreadID (thread));
 733 #else
 734   return 0;
 735 #endif
 736 }
 737
 738 void
 739 _Jv_GCAttachThread ()
 740 {
 741   // The registration interface is only defined on posixy systems and
 742   // only actually works if pthread_getattr_np is defined.
 743   // FIXME: until gc7 it is simpler to disable this on solaris.
 744 #if defined(HAVE_PTHREAD_GETATTR_NP) && !defined(GC_SOLARIS_THREADS)
 745   GC_register_my_thread ();
 746 #endif
 747 }
 748
 749 void
 750 _Jv_GCDetachThread ()
 751 {
 752 #if defined(HAVE_PTHREAD_GETATTR_NP) && !defined(GC_SOLARIS_THREADS)
 753   GC_unregister_my_thread ();
 754 #endif
 755 }