2005-08-16 Thomas Koenig <Thomas.Koenig@online.de>
[official-gcc.git] / libjava / boehm.cc
blob06b8f9889e86ed5c6690c39a96d1509db0fc9724
1 // boehm.cc - interface between libjava and Boehm GC.
3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
4 Free Software Foundation
6 This file is part of libgcj.
8 This software is copyrighted work licensed under the terms of the
9 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
10 details. */
12 #include <config.h>
14 #include <stdio.h>
15 #include <limits.h>
17 #include <jvm.h>
18 #include <gcj/cni.h>
20 #include <java/lang/Class.h>
21 #include <java/lang/reflect/Modifier.h>
22 #include <java-interp.h>
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
29 extern "C"
31 #include <gc_config.h>
33 // Set GC_DEBUG before including gc.h!
34 #ifdef LIBGCJ_GC_DEBUG
35 # define GC_DEBUG
36 #endif
38 #include <gc_mark.h>
39 #include <gc_gcj.h>
40 #include <javaxfc.h> // GC_finalize_all declaration.
42 #ifdef THREAD_LOCAL_ALLOC
43 # define GC_REDIRECT_TO_LOCAL
44 # include <gc_local_alloc.h>
45 #endif
47 // From boehm's misc.c
48 void GC_enable();
49 void GC_disable();
52 #define MAYBE_MARK(Obj, Top, Limit, Source) \
53 Top=GC_MARK_AND_PUSH((GC_PTR) Obj, Top, Limit, (GC_PTR *) Source)
55 // `kind' index used when allocating Java arrays.
56 static int array_kind_x;
58 // Freelist used for Java arrays.
59 static void **array_free_list;
63 // This is called by the GC during the mark phase. It marks a Java
64 // object. We use `void *' arguments and return, and not what the
65 // Boehm GC wants, to avoid pollution in our headers.
66 void *
67 _Jv_MarkObj (void *addr, void *msp, void *msl, void *env)
69 struct GC_ms_entry *mark_stack_ptr = (struct GC_ms_entry *)msp;
70 struct GC_ms_entry *mark_stack_limit = (struct GC_ms_entry *)msl;
72 if (env == (void *)1) /* Object allocated with debug allocator. */
73 addr = (GC_PTR)GC_USR_PTR_FROM_BASE(addr);
74 jobject obj = (jobject) addr;
76 _Jv_VTable *dt = *(_Jv_VTable **) addr;
77 // The object might not yet have its vtable set, or it might
78 // really be an object on the freelist. In either case, the vtable slot
79 // will either be 0, or it will point to a cleared object.
80 // This assumes Java objects have size at least 3 words,
81 // including the header. But this should remain true, since this
82 // should only be used with debugging allocation or with large objects.
83 if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
84 return mark_stack_ptr;
85 jclass klass = dt->clas;
86 GC_PTR p;
88 # ifndef JV_HASH_SYNCHRONIZATION
89 // Every object has a sync_info pointer.
90 p = (GC_PTR) obj->sync_info;
91 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
92 # endif
93 // Mark the object's class.
94 p = (GC_PTR) klass;
95 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
97 if (__builtin_expect (klass == &java::lang::Class::class$, false))
99 // Currently we allocate some of the memory referenced from class objects
100 // as pointerfree memory, and then mark it more intelligently here.
101 // We ensure that the ClassClass mark descriptor forces invocation of
102 // this procedure.
103 // Correctness of this is subtle, but it looks OK to me for now. For the incremental
104 // collector, we need to make sure that the class object is written whenever
105 // any of the subobjects are altered and may need rescanning. This may be tricky
106 // during construction, and this may not be the right way to do this with
107 // incremental collection.
108 // If we overflow the mark stack, we will rescan the class object, so we should
109 // be OK. The same applies if we redo the mark phase because win32 unmapped part
110 // of our root set. - HB
111 jclass c = (jclass) addr;
113 p = (GC_PTR) c->name;
114 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
115 p = (GC_PTR) c->superclass;
116 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
117 for (int i = 0; i < c->constants.size; ++i)
119 /* FIXME: We could make this more precise by using the tags -KKT */
120 p = (GC_PTR) c->constants.data[i].p;
121 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
124 #ifdef INTERPRETER
125 if (_Jv_IsInterpretedClass (c))
127 p = (GC_PTR) c->constants.tags;
128 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
129 p = (GC_PTR) c->constants.data;
130 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
132 #endif
134 // The vtable might be allocated even for compiled code.
135 p = (GC_PTR) c->vtable;
136 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
138 // If the class is an array, then the methods field holds a
139 // pointer to the element class. If the class is primitive,
140 // then the methods field holds a pointer to the array class.
141 p = (GC_PTR) c->methods;
142 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
144 // The vtable might have been set, but the rest of the class
145 // could still be uninitialized. If this is the case, then
146 // c.isArray will SEGV. We check for this, and if it is the
147 // case we just return.
148 if (__builtin_expect (c->name == NULL, false))
149 return mark_stack_ptr;
151 if (! c->isArray() && ! c->isPrimitive())
153 // Scan each method in the cases where `methods' really
154 // points to a methods structure.
155 for (int i = 0; i < c->method_count; ++i)
157 p = (GC_PTR) c->methods[i].name;
158 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
159 p = (GC_PTR) c->methods[i].signature;
160 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
162 // Note that we don't have to mark each individual throw
163 // separately, as these are stored in the constant pool.
164 p = (GC_PTR) c->methods[i].throws;
165 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
169 // Mark all the fields.
170 p = (GC_PTR) c->fields;
171 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
172 for (int i = 0; i < c->field_count; ++i)
174 _Jv_Field* field = &c->fields[i];
176 p = (GC_PTR) field->name;
177 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
178 p = (GC_PTR) field->type;
179 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
181 // For the interpreter, we also need to mark the memory
182 // containing static members
183 if ((field->flags & java::lang::reflect::Modifier::STATIC))
185 p = (GC_PTR) field->u.addr;
186 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
188 // also, if the static member is a reference,
189 // mark also the value pointed to. We check for isResolved
190 // since marking can happen before memory is allocated for
191 // static members.
192 // Note that field->u.addr may be null if the class c is
193 // JV_STATE_LOADED but not JV_STATE_PREPARED (initialized).
194 // Note also that field->type could be NULL in some
195 // situations, for instance if the class has state
196 // JV_STATE_ERROR.
197 if (field->type && JvFieldIsRef (field)
198 && p && field->isResolved())
200 jobject val = *(jobject*) p;
201 p = (GC_PTR) val;
202 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
207 p = (GC_PTR) c->vtable;
208 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
209 p = (GC_PTR) c->interfaces;
210 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
211 for (int i = 0; i < c->interface_count; ++i)
213 p = (GC_PTR) c->interfaces[i];
214 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
216 p = (GC_PTR) c->loader;
217 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
219 // The dispatch tables can be allocated at runtime.
220 p = (GC_PTR) c->ancestors;
221 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
222 if (c->idt)
224 p = (GC_PTR) c->idt;
225 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
227 if (c->isInterface())
229 p = (GC_PTR) c->idt->iface.ioffsets;
230 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c->idt);
232 else if (! c->isPrimitive())
234 // This field is only valid for ordinary classes.
235 p = (GC_PTR) c->idt->cls.itable;
236 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c->idt);
240 p = (GC_PTR) c->arrayclass;
241 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
242 p = (GC_PTR) c->protectionDomain;
243 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
244 p = (GC_PTR) c->hack_signers;
245 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
246 p = (GC_PTR) c->aux_info;
247 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
249 #ifdef INTERPRETER
250 if (_Jv_IsInterpretedClass (c) && c->aux_info)
252 _Jv_InterpClass* ic = (_Jv_InterpClass*) c->aux_info;
254 p = (GC_PTR) ic->interpreted_methods;
255 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
257 p = (GC_PTR) ic->source_file_name;
258 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
260 for (int i = 0; i < c->method_count; i++)
262 // The interpreter installs a heap-allocated trampoline
263 // here, so we'll mark it.
264 p = (GC_PTR) c->methods[i].ncode;
265 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c);
267 using namespace java::lang::reflect;
269 // Mark the direct-threaded code. Note a subtlety here:
270 // when we add Miranda methods to a class, we don't
271 // resize its interpreted_methods array. If we try to
272 // reference one of these methods, we may crash.
273 // However, we know these are all abstract, and we know
274 // that abstract methods have nothing useful in this
275 // array. So, we skip all abstract methods to avoid the
276 // problem. FIXME: this is pretty obscure, it may be
277 // better to add a methods to the execution engine and
278 // resize the array.
279 if ((c->methods[i].accflags & Modifier::ABSTRACT) != 0)
280 continue;
282 p = (GC_PTR) ic->interpreted_methods[i];
283 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
285 if ((c->methods[i].accflags & Modifier::NATIVE) != 0)
287 _Jv_JNIMethod *jm
288 = (_Jv_JNIMethod *) ic->interpreted_methods[i];
289 if (jm)
291 p = (GC_PTR) jm->jni_arg_types;
292 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, p);
295 else
297 _Jv_InterpMethod *im
298 = (_Jv_InterpMethod *) ic->interpreted_methods[i];
299 if (im)
301 p = (GC_PTR) im->line_table;
302 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
303 p = (GC_PTR) im->prepared;
304 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
309 p = (GC_PTR) ic->field_initializers;
310 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic);
313 #endif
316 else
318 // NOTE: each class only holds information about the class
319 // itself. So we must do the marking for the entire inheritance
320 // tree in order to mark all fields. FIXME: what about
321 // interfaces? We skip Object here, because Object only has a
322 // sync_info, and we handled that earlier.
323 // Note: occasionally `klass' can be null. For instance, this
324 // can happen if a GC occurs between the point where an object
325 // is allocated and where the vtbl slot is set.
326 while (klass && klass != &java::lang::Object::class$)
328 jfieldID field = JvGetFirstInstanceField (klass);
329 jint max = JvNumInstanceFields (klass);
331 for (int i = 0; i < max; ++i)
333 if (JvFieldIsRef (field))
335 jobject val = JvGetObjectField (obj, field);
336 p = (GC_PTR) val;
337 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj);
339 field = field->getNextField ();
341 klass = klass->getSuperclass();
345 return mark_stack_ptr;
348 // This is called by the GC during the mark phase. It marks a Java
349 // array (of objects). We use `void *' arguments and return, and not
350 // what the Boehm GC wants, to avoid pollution in our headers.
351 void *
352 _Jv_MarkArray (void *addr, void *msp, void *msl, void *env)
354 struct GC_ms_entry *mark_stack_ptr = (struct GC_ms_entry *)msp;
355 struct GC_ms_entry *mark_stack_limit = (struct GC_ms_entry *)msl;
357 if (env == (void *)1) /* Object allocated with debug allocator. */
358 addr = (void *)GC_USR_PTR_FROM_BASE(addr);
359 jobjectArray array = (jobjectArray) addr;
361 _Jv_VTable *dt = *(_Jv_VTable **) addr;
362 // Assumes size >= 3 words. That's currently true since arrays have
363 // a vtable, sync pointer, and size. If the sync pointer goes away,
364 // we may need to round up the size.
365 if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
366 return mark_stack_ptr;
367 jclass klass = dt->clas;
368 GC_PTR p;
370 # ifndef JV_HASH_SYNCHRONIZATION
371 // Every object has a sync_info pointer.
372 p = (GC_PTR) array->sync_info;
373 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array);
374 # endif
375 // Mark the object's class.
376 p = (GC_PTR) klass;
377 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, &(dt -> clas));
379 for (int i = 0; i < JvGetArrayLength (array); ++i)
381 jobject obj = elements (array)[i];
382 p = (GC_PTR) obj;
383 MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array);
386 return mark_stack_ptr;
389 // Generate a GC marking descriptor for a class.
391 // We assume that the gcj mark proc has index 0. This is a dubious assumption,
392 // since another one could be registered first. But the compiler also
393 // knows this, so in that case everything else will break, too.
394 #define GCJ_DEFAULT_DESCR GC_MAKE_PROC(GC_GCJ_RESERVED_MARK_PROC_INDEX,0)
396 void *
397 _Jv_BuildGCDescr(jclass self)
399 jlong desc = 0;
400 jint bits_per_word = CHAR_BIT * sizeof (void *);
402 // Note: for now we only consider a bitmap mark descriptor. We
403 // could also handle the case where the first N fields of a type are
404 // references. However, this is not very likely to be used by many
405 // classes, and it is easier to compute things this way.
407 // The vtable pointer.
408 desc |= 1ULL << (bits_per_word - 1);
409 #ifndef JV_HASH_SYNCHRONIZATION
410 // The sync_info field.
411 desc |= 1ULL << (bits_per_word - 2);
412 #endif
414 for (jclass klass = self; klass != NULL; klass = klass->getSuperclass())
416 jfieldID field = JvGetFirstInstanceField(klass);
417 int count = JvNumInstanceFields(klass);
419 for (int i = 0; i < count; ++i)
421 if (field->isRef())
423 unsigned int off = field->getOffset();
424 // If we run into a weird situation, we bail.
425 if (off % sizeof (void *) != 0)
426 return (void *) (GCJ_DEFAULT_DESCR);
427 off /= sizeof (void *);
428 // If we find a field outside the range of our bitmap,
429 // fall back to procedure marker. The bottom 2 bits are
430 // reserved.
431 if (off >= (unsigned) bits_per_word - 2)
432 return (void *) (GCJ_DEFAULT_DESCR);
433 desc |= 1ULL << (bits_per_word - off - 1);
436 field = field->getNextField();
440 // For bitmap mark type, bottom bits are 01.
441 desc |= 1;
442 // Bogus warning avoidance (on many platforms).
443 return (void *) (unsigned long) desc;
446 // Allocate some space that is known to be pointer-free.
447 void *
448 _Jv_AllocBytes (jsize size)
450 void *r = GC_MALLOC_ATOMIC (size);
451 // We have to explicitly zero memory here, as the GC doesn't
452 // guarantee that PTRFREE allocations are zeroed. Note that we
453 // don't have to do this for other allocation types because we set
454 // the `ok_init' flag in the type descriptor.
455 memset (r, 0, size);
456 return r;
459 #ifdef LIBGCJ_GC_DEBUG
461 void *
462 _Jv_AllocObj (jsize size, jclass klass)
464 return GC_GCJ_MALLOC (size, klass->vtable);
467 void *
468 _Jv_AllocPtrFreeObj (jsize size, jclass klass)
470 #ifdef JV_HASH_SYNCHRONIZATION
471 void * obj = GC_MALLOC_ATOMIC(size);
472 *((_Jv_VTable **) obj) = klass->vtable;
473 #else
474 void * obj = GC_GCJ_MALLOC(size, klass->vtable);
475 #endif
476 return obj;
479 #endif /* LIBGCJ_GC_DEBUG */
480 // In the non-debug case, the above two functions are defined
481 // as inline functions in boehm-gc.h. In the debug case we
482 // really want to take advantage of the definitions in gc_gcj.h.
484 // Allocate space for a new Java array.
485 // Used only for arrays of objects.
486 void *
487 _Jv_AllocArray (jsize size, jclass klass)
489 void *obj;
491 #ifdef LIBGCJ_GC_DEBUG
492 // There isn't much to lose by scanning this conservatively.
493 // If we didn't, the mark proc would have to understand that
494 // it needed to skip the header.
495 obj = GC_MALLOC(size);
496 #else
497 const jsize min_heap_addr = 16*1024;
498 // A heuristic. If size is less than this value, the size
499 // stored in the array can't possibly be misinterpreted as
500 // a pointer. Thus we lose nothing by scanning the object
501 // completely conservatively, since no misidentification can
502 // take place.
504 if (size < min_heap_addr)
505 obj = GC_MALLOC(size);
506 else
507 obj = GC_generic_malloc (size, array_kind_x);
508 #endif
509 *((_Jv_VTable **) obj) = klass->vtable;
510 return obj;
513 /* Allocate space for a new non-Java object, which does not have the usual
514 Java object header but may contain pointers to other GC'ed objects. */
515 void *
516 _Jv_AllocRawObj (jsize size)
518 return (void *) GC_MALLOC (size);
521 static void
522 call_finalizer (GC_PTR obj, GC_PTR client_data)
524 _Jv_FinalizerFunc *fn = (_Jv_FinalizerFunc *) client_data;
525 jobject jobj = (jobject) obj;
527 (*fn) (jobj);
530 void
531 _Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *meth)
533 GC_REGISTER_FINALIZER_NO_ORDER (object, call_finalizer, (GC_PTR) meth,
534 NULL, NULL);
537 void
538 _Jv_RunFinalizers (void)
540 GC_invoke_finalizers ();
543 void
544 _Jv_RunAllFinalizers (void)
546 GC_finalize_all ();
549 void
550 _Jv_RunGC (void)
552 GC_gcollect ();
555 long
556 _Jv_GCTotalMemory (void)
558 return GC_get_heap_size ();
561 long
562 _Jv_GCFreeMemory (void)
564 return GC_get_free_bytes ();
567 void
568 _Jv_GCSetInitialHeapSize (size_t size)
570 size_t current = GC_get_heap_size ();
571 if (size > current)
572 GC_expand_hp (size - current);
575 void
576 _Jv_GCSetMaximumHeapSize (size_t size)
578 GC_set_max_heap_size ((GC_word) size);
581 void
582 _Jv_DisableGC (void)
584 GC_disable();
587 void
588 _Jv_EnableGC (void)
590 GC_enable();
593 static void * handle_out_of_memory(size_t)
595 _Jv_ThrowNoMemory();
598 static void
599 gcj_describe_type_fn(void *obj, char *out_buf)
601 _Jv_VTable *dt = *(_Jv_VTable **) obj;
603 if (! dt /* Shouldn't happen */)
605 strcpy(out_buf, "GCJ (bad)");
606 return;
608 jclass klass = dt->clas;
609 if (!klass /* shouldn't happen */)
611 strcpy(out_buf, "GCJ (bad)");
612 return;
614 jstring name = klass -> getName();
615 size_t len = name -> length();
616 if (len >= GC_TYPE_DESCR_LEN) len = GC_TYPE_DESCR_LEN - 1;
617 JvGetStringUTFRegion (name, 0, len, out_buf);
618 out_buf[len] = '\0';
621 void
622 _Jv_InitGC (void)
624 int proc;
626 // Ignore pointers that do not point to the start of an object.
627 GC_all_interior_pointers = 0;
629 // Configure the collector to use the bitmap marking descriptors that we
630 // stash in the class vtable.
631 // We always use mark proc descriptor 0, since the compiler knows
632 // about it.
633 GC_init_gcj_malloc (0, (void *) _Jv_MarkObj);
635 // Cause an out of memory error to be thrown from the allocators,
636 // instead of returning 0. This is cheaper than checking on allocation.
637 GC_oom_fn = handle_out_of_memory;
639 GC_java_finalization = 1;
641 // We use a different mark procedure for object arrays. This code
642 // configures a different object `kind' for object array allocation and
643 // marking.
644 array_free_list = GC_new_free_list();
645 proc = GC_new_proc((GC_mark_proc)_Jv_MarkArray);
646 array_kind_x = GC_new_kind(array_free_list, GC_MAKE_PROC (proc, 0), 0, 1);
648 // Arrange to have the GC print Java class names in backtraces, etc.
649 GC_register_describe_type_fn(GC_gcj_kind, gcj_describe_type_fn);
650 GC_register_describe_type_fn(GC_gcj_debug_kind, gcj_describe_type_fn);
653 #ifdef JV_HASH_SYNCHRONIZATION
654 // Allocate an object with a fake vtable pointer, which causes only
655 // the first field (beyond the fake vtable pointer) to be traced.
656 // Eventually this should probably be generalized.
658 static _Jv_VTable trace_one_vtable = {
659 0, // class pointer
660 (void *)(2 * sizeof(void *)),
661 // descriptor; scan 2 words incl. vtable ptr.
662 // Least significant bits must be zero to
663 // identify this as a length descriptor
664 {0} // First method
667 void *
668 _Jv_AllocTraceOne (jsize size /* includes vtable slot */)
670 return GC_GCJ_MALLOC (size, &trace_one_vtable);
673 // Ditto for two words.
674 // the first field (beyond the fake vtable pointer) to be traced.
675 // Eventually this should probably be generalized.
677 static _Jv_VTable trace_two_vtable =
679 0, // class pointer
680 (void *)(3 * sizeof(void *)),
681 // descriptor; scan 3 words incl. vtable ptr.
682 {0} // First method
685 void *
686 _Jv_AllocTraceTwo (jsize size /* includes vtable slot */)
688 return GC_GCJ_MALLOC (size, &trace_two_vtable);
691 #endif /* JV_HASH_SYNCHRONIZATION */
693 void
694 _Jv_GCInitializeFinalizers (void (*notifier) (void))
696 GC_finalize_on_demand = 1;
697 GC_finalizer_notifier = notifier;
700 void
701 _Jv_GCRegisterDisappearingLink (jobject *objp)
703 // This test helps to ensure that we meet a precondition of
704 // GC_general_register_disappearing_link, viz. "Obj must be a
705 // pointer to the first word of an object we allocated."
706 if (GC_base(*objp))
707 GC_general_register_disappearing_link ((GC_PTR *) objp, (GC_PTR) *objp);
710 jboolean
711 _Jv_GCCanReclaimSoftReference (jobject)
713 // For now, always reclaim soft references. FIXME.
714 return true;