// boehm.cc - interface between libjava and Boehm GC.
-/* Copyright (C) 1998, 1999, 2000 Free Software Foundation
+/* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation
This file is part of libgcj.
#include <config.h>
#include <stdio.h>
+#include <limits.h>
#include <jvm.h>
#include <gcj/cni.h>
extern "C"
{
-#include <gc_priv.h>
-#include <gc_mark.h>
-#include <include/gc_gcj.h>
+#include <private/gc_pmark.h>
+#include <gc_gcj.h>
+
+#ifdef THREAD_LOCAL_ALLOC
+# define GC_REDIRECT_TO_LOCAL
+# include <gc_local_alloc.h>
+#endif
// These aren't declared in any Boehm GC header.
void GC_finalize_all (void);
ptr_t GC_debug_generic_malloc (size_t size, int k, GC_EXTRA_PARAMS);
};
-// FIXME: this should probably be defined in some GC header.
-#ifdef GC_DEBUG
-# define GC_GENERIC_MALLOC(Size, Type) \
- GC_debug_generic_malloc (Size, Type, GC_EXTRAS)
-#else
-# define GC_GENERIC_MALLOC(Size, Type) GC_generic_malloc (Size, Type)
-#endif
-
-// We must check for plausibility ourselves.
#define MAYBE_MARK(Obj, Top, Limit, Source, Exit) \
- if ((ptr_t) (Obj) >= GC_least_plausible_heap_addr \
- && (ptr_t) (Obj) <= GC_greatest_plausible_heap_addr) \
- PUSH_CONTENTS (Obj, Top, Limit, Source, Exit)
-
-#define ObjectClass _CL_Q34java4lang6Object
-extern java::lang::Class ObjectClass;
-#define ClassClass _CL_Q34java4lang5Class
-extern java::lang::Class ClassClass;
-
-\f
-
-// Nonzero if this module has been initialized.
-static int initialized = 0;
-
-#if 0
-// `kind' index used when allocating Java objects.
-static int obj_kind_x;
-
-// Freelist used for Java objects.
-static ptr_t *obj_free_list;
-#endif /* 0 */
+ Top=GC_MARK_AND_PUSH((GC_PTR)Obj, Top, Limit, (GC_PTR *)Source)
// `kind' index used when allocating Java arrays.
static int array_kind_x;
if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
return mark_stack_ptr;
jclass klass = dt->clas;
+ ptr_t p;
- // Every object has a sync_info pointer.
- ptr_t p = (ptr_t) obj->sync_info;
- MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj, o1label);
+# ifndef JV_HASH_SYNCHRONIZATION
+ // Every object has a sync_info pointer.
+ p = (ptr_t) obj->sync_info;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj, o1label);
+# endif
// Mark the object's class.
p = (ptr_t) klass;
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj, o2label);
- if (__builtin_expect (klass == &ClassClass, false))
+ if (__builtin_expect (klass == &java::lang::Class::class$, false))
{
// Currently we allocate some of the memory referenced from class objects
// as pointerfree memory, and then mark it more intelligently here.
p = (ptr_t) c->methods;
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c, c6label);
+ // The vtable might have been set, but the rest of the class
+ // could still be uninitialized. If this is the case, then
+ // c.isArray will SEGV. We check for this, and if it is the
+ // case we just return.
+ if (__builtin_expect (c->name == NULL, false))
+ return mark_stack_ptr;
if (! c->isArray() && ! c->isPrimitive())
{
p = (ptr_t) c->methods[i].signature;
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c,
cm2label);
-
- // FIXME: `ncode' entry?
-
-#ifdef INTERPRETER
- // The interpreter installs a heap-allocated
- // trampoline here, so we'll mark it.
- if (_Jv_IsInterpretedClass (c))
- {
- p = (ptr_t) c->methods[i].ncode;
- MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c,
- cm3label);
- }
-#endif
}
}
}
p = (ptr_t) c->loader;
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c, cBlabel);
+ p = (ptr_t) c->arrayclass;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c, cDlabel);
+ p = (ptr_t) c->protectionDomain;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c, cPlabel);
+ p = (ptr_t) c->hack_signers;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c, cSlabel);
#ifdef INTERPRETER
if (_Jv_IsInterpretedClass (c))
{
- _Jv_InterpClass* ic = (_Jv_InterpClass*)c;
+ _Jv_InterpClass* ic = (_Jv_InterpClass*) c;
p = (ptr_t) ic->interpreted_methods;
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic, cElabel);
p = (ptr_t) ic->interpreted_methods[i];
MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic, \
cFlabel);
+
+ // Mark the direct-threaded code.
+ if ((c->methods[i].accflags
+ & java::lang::reflect::Modifier::NATIVE) == 0)
+ {
+ _Jv_InterpMethod *im
+ = (_Jv_InterpMethod *) ic->interpreted_methods[i];
+ if (im)
+ {
+ p = (ptr_t) im->prepared;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, ic, \
+ cFlabel);
+ }
+ }
+
+ // The interpreter installs a heap-allocated trampoline
+ // here, so we'll mark it.
+ p = (ptr_t) c->methods[i].ncode;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, c,
+ cm3label);
}
p = (ptr_t) ic->field_initializers;
// Note: occasionally `klass' can be null. For instance, this
// can happen if a GC occurs between the point where an object
// is allocated and where the vtbl slot is set.
- while (klass && klass != &ObjectClass)
+ while (klass && klass != &java::lang::Object::class$)
{
jfieldID field = JvGetFirstInstanceField (klass);
jint max = JvNumInstanceFields (klass);
if (__builtin_expect (! dt || !(dt -> get_finalizer()), false))
return mark_stack_ptr;
jclass klass = dt->clas;
+ ptr_t p;
- // Every object has a sync_info pointer.
- ptr_t p = (ptr_t) array->sync_info;
- MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array, e1label);
+# ifndef JV_HASH_SYNCHRONIZATION
+ // Every object has a sync_info pointer.
+ p = (ptr_t) array->sync_info;
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, array, e1label);
+# endif
// Mark the object's class.
p = (ptr_t) klass;
- MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, obj, o2label);
+ MAYBE_MARK (p, mark_stack_ptr, mark_stack_limit, &(dt -> clas), o2label);
for (int i = 0; i < JvGetArrayLength (array); ++i)
{
return mark_stack_ptr;
}
-// Return GC descriptor for interpreted class
-#ifdef INTERPRETER
-
+// Generate a GC marking descriptor for a class.
+//
// We assume that the gcj mark proc has index 0. This is a dubious assumption,
// since another one could be registered first. But the compiler also
// knows this, so in that case everything else will break, too.
-#define GCJ_DEFAULT_DESCR MAKE_PROC(GCJ_RESERVED_MARK_PROC_INDEX,0)
+#define GCJ_DEFAULT_DESCR GC_MAKE_PROC(GC_GCJ_RESERVED_MARK_PROC_INDEX,0)
+
void *
-_Jv_BuildGCDescr(jclass klass)
+_Jv_BuildGCDescr(jclass self)
{
- /* FIXME: We should really look at the class and build the descriptor. */
- return (void *)(GCJ_DEFAULT_DESCR);
-}
+ jlong desc = 0;
+ jint bits_per_word = CHAR_BIT * sizeof (void *);
+
+ // Note: for now we only consider a bitmap mark descriptor. We
+ // could also handle the case where the first N fields of a type are
+ // references. However, this is not very likely to be used by many
+ // classes, and it is easier to compute things this way.
+
+ // The vtable pointer.
+ desc |= 1ULL << (bits_per_word - 1);
+#ifndef JV_HASH_SYNCHRONIZATION
+ // The sync_info field.
+ desc |= 1ULL << (bits_per_word - 2);
#endif
-// Allocate space for a new Java object.
+ for (jclass klass = self; klass != NULL; klass = klass->getSuperclass())
+ {
+ jfieldID field = JvGetFirstInstanceField(klass);
+ int count = JvNumInstanceFields(klass);
+
+ for (int i = 0; i < count; ++i)
+ {
+ if (field->isRef())
+ {
+ unsigned int off = field->getOffset();
+ // If we run into a weird situation, we bail.
+ if (off % sizeof (void *) != 0)
+ return (void *) (GCJ_DEFAULT_DESCR);
+ off /= sizeof (void *);
+ // If we find a field outside the range of our bitmap,
+ // fall back to procedure marker. The bottom 2 bits are
+ // reserved.
+ if (off >= bits_per_word - 2)
+ return (void *) (GCJ_DEFAULT_DESCR);
+ desc |= 1ULL << (bits_per_word - off - 1);
+ }
+
+ field = field->getNextField();
+ }
+ }
+
+ // For bitmap mark type, bottom bits are 01.
+ desc |= 1;
+ // Bogus warning avoidance (on many platforms).
+ return (void *) (unsigned long) desc;
+}
+
+// Allocate some space that is known to be pointer-free.
void *
-_Jv_AllocObj (jsize size, jclass klass)
+_Jv_AllocBytes (jsize size)
{
- return GC_GCJ_MALLOC (size, klass->vtable);
+ void *r = GC_MALLOC_ATOMIC (size);
+ // We have to explicitly zero memory here, as the GC doesn't
+ // guarantee that PTRFREE allocations are zeroed. Note that we
+ // don't have to do this for other allocation types because we set
+ // the `ok_init' flag in the type descriptor.
+ memset (r, 0, size);
+ return r;
}
// Allocate space for a new Java array.
if (size < min_heap_addr)
obj = GC_MALLOC(size);
else
- obj = GC_GENERIC_MALLOC (size, array_kind_x);
+ obj = GC_generic_malloc (size, array_kind_x);
#endif
*((_Jv_VTable **) obj) = klass->vtable;
return obj;
}
-// Allocate some space that is known to be pointer-free.
+/* Allocate space for a new non-Java object, which does not have the usual
+ Java object header but may contain pointers to other GC'ed objects. */
void *
-_Jv_AllocBytes (jsize size)
+_Jv_AllocRawObj (jsize size)
{
- void *r = GC_MALLOC_ATOMIC (size);
- // We have to explicitly zero memory here, as the GC doesn't
- // guarantee that PTRFREE allocations are zeroed. Note that we
- // don't have to do this for other allocation types because we set
- // the `ok_init' flag in the type descriptor.
- if (__builtin_expect (r != NULL, !NULL))
- memset (r, 0, size);
- return r;
+ return (void *) GC_MALLOC (size);
}
static void
_Jv_MutexUnlock (&disable_gc_mutex);
}
+static void * handle_out_of_memory(size_t)
+{
+ _Jv_ThrowNoMemory();
+}
+
void
_Jv_InitGC (void)
{
int proc;
- DCL_LOCK_STATE;
-
- DISABLE_SIGNALS ();
- LOCK ();
- if (initialized)
- {
- UNLOCK ();
- ENABLE_SIGNALS ();
- return;
- }
- initialized = 1;
- UNLOCK ();
+ // Ignore pointers that do not point to the start of an object.
+ GC_all_interior_pointers = 0;
// Configure the collector to use the bitmap marking descriptors that we
// stash in the class vtable.
GC_init_gcj_malloc (0, (void *) _Jv_MarkObj);
- LOCK ();
+ // Cause an out of memory error to be thrown from the allocators,
+ // instead of returning 0. This is cheaper than checking on allocation.
+ GC_oom_fn = handle_out_of_memory;
+
GC_java_finalization = 1;
// We use a different mark procedure for object arrays. This code
memset (array_free_list, 0, (MAXOBJSZ + 1) * sizeof (ptr_t));
proc = GC_n_mark_procs++;
- GC_mark_procs[proc] = (mark_proc) _Jv_MarkArray;
+ GC_mark_procs[proc] = (GC_mark_proc) _Jv_MarkArray;
array_kind_x = GC_n_kinds++;
GC_obj_kinds[array_kind_x].ok_freelist = array_free_list;
GC_obj_kinds[array_kind_x].ok_reclaim_list = 0;
- GC_obj_kinds[array_kind_x].ok_descriptor = MAKE_PROC (proc, 0);
+ GC_obj_kinds[array_kind_x].ok_descriptor = GC_MAKE_PROC (proc, 0);
GC_obj_kinds[array_kind_x].ok_relocate_descr = FALSE;
GC_obj_kinds[array_kind_x].ok_init = TRUE;
_Jv_MutexInit (&disable_gc_mutex);
-
- UNLOCK ();
- ENABLE_SIGNALS ();
}
-#if 0
-void
-_Jv_InitGC (void)
-{
- int proc;
- DCL_LOCK_STATE;
-
- DISABLE_SIGNALS ();
- LOCK ();
-
- if (initialized)
- {
- UNLOCK ();
- ENABLE_SIGNALS ();
- return;
- }
- initialized = 1;
-
- GC_java_finalization = 1;
+#ifdef JV_HASH_SYNCHRONIZATION
+// Allocate an object with a fake vtable pointer, which causes only
+// the first field (beyond the fake vtable pointer) to be traced.
+// Eventually this should probably be generalized.
+
+static _Jv_VTable trace_one_vtable = {
+ 0, // class pointer
+ (void *)(2 * sizeof(void *)),
+ // descriptor; scan 2 words incl. vtable ptr.
+ // Least significant bits must be zero to
+ // identify this as a length descriptor
+ {0} // First method
+};
- // Set up state for marking and allocation of Java objects.
- obj_free_list = (ptr_t *) GC_generic_malloc_inner ((MAXOBJSZ + 1)
- * sizeof (ptr_t),
- PTRFREE);
- memset (obj_free_list, 0, (MAXOBJSZ + 1) * sizeof (ptr_t));
+void *
+_Jv_AllocTraceOne (jsize size /* includes vtable slot */)
+{
+ return GC_GCJ_MALLOC (size, &trace_one_vtable);
+}
- proc = GC_n_mark_procs++;
- GC_mark_procs[proc] = (mark_proc) _Jv_MarkObj;
+// Ditto for two words.
+// the first field (beyond the fake vtable pointer) to be traced.
+// Eventually this should probably be generalized.
- obj_kind_x = GC_n_kinds++;
- GC_obj_kinds[obj_kind_x].ok_freelist = obj_free_list;
- GC_obj_kinds[obj_kind_x].ok_reclaim_list = 0;
- GC_obj_kinds[obj_kind_x].ok_descriptor = MAKE_PROC (proc, 0);
- GC_obj_kinds[obj_kind_x].ok_relocate_descr = FALSE;
- GC_obj_kinds[obj_kind_x].ok_init = TRUE;
+static _Jv_VTable trace_two_vtable =
+{
+ 0, // class pointer
+ (void *)(3 * sizeof(void *)),
+ // descriptor; scan 3 words incl. vtable ptr.
+ {0} // First method
+};
- // Set up state for marking and allocation of arrays of Java
- // objects.
- array_free_list = (ptr_t *) GC_generic_malloc_inner ((MAXOBJSZ + 1)
- * sizeof (ptr_t),
- PTRFREE);
- memset (array_free_list, 0, (MAXOBJSZ + 1) * sizeof (ptr_t));
+void *
+_Jv_AllocTraceTwo (jsize size /* includes vtable slot */)
+{
+ return GC_GCJ_MALLOC (size, &trace_two_vtable);
+}
- proc = GC_n_mark_procs++;
- GC_mark_procs[proc] = (mark_proc) _Jv_MarkArray;
+#endif /* JV_HASH_SYNCHRONIZATION */
- array_kind_x = GC_n_kinds++;
- GC_obj_kinds[array_kind_x].ok_freelist = array_free_list;
- GC_obj_kinds[array_kind_x].ok_reclaim_list = 0;
- GC_obj_kinds[array_kind_x].ok_descriptor = MAKE_PROC (proc, 0);
- GC_obj_kinds[array_kind_x].ok_relocate_descr = FALSE;
- GC_obj_kinds[array_kind_x].ok_init = TRUE;
+void
+_Jv_GCInitializeFinalizers (void (*notifier) (void))
+{
+ GC_finalize_on_demand = 1;
+ GC_finalizer_notifier = notifier;
+}
- _Jv_MutexInit (&disable_gc_mutex);
+void
+_Jv_GCRegisterDisappearingLink (jobject *objp)
+{
+ GC_general_register_disappearing_link ((GC_PTR *) objp, (GC_PTR) *objp);
+}
- UNLOCK ();
- ENABLE_SIGNALS ();
+jboolean
+_Jv_GCCanReclaimSoftReference (jobject)
+{
+ // For now, always reclaim soft references. FIXME.
+ return true;
}
-#endif /* 0 */
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