gcc/libjava/boehm.cc

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// boehm.cc - interface between libjava and Boehm GC.
/* Copyright (C) 1998, 1999 Cygnus Solutions
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
#include <config.h>
#include <stdio.h>
#include <jvm.h>
#include <gcj/cni.h>
#include <java/lang/Class.h>
#include <java-interp.h>
// More nastiness: the GC wants to define TRUE and FALSE. We don't
// need the Java definitions (themselves a hack), so we undefine them.
#undef TRUE
#undef FALSE
extern "C"
{
#include <gc_priv.h>
#include <gc_mark.h>
// 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;
// Nonzero if this module has been initialized.
static int initialized = 0;
// `kind' index used when allocating Java objects.
static int obj_kind_x;
// `kind' index used when allocating Java arrays.
static int array_kind_x;
// Freelist used for Java objects.
static ptr_t *obj_free_list;
// Freelist used for Java arrays.
static ptr_t *array_free_list;
// This is called by the GC during the mark phase. It marks a Java
// object. We use `void *' arguments and return, and not what the
// Boehm GC wants, to avoid pollution in our headers.
void *
_Jv_MarkObj (void *addr, void *msp, void *msl, void * /*env*/)
{
mse *mark_stack_ptr = (mse *) msp;
mse *mark_stack_limit = (mse *) msl;
jobject obj = (jobject) addr;
_Jv_VTable *dt = *(_Jv_VTable **) addr;
// We check this in case a GC occurs before the vtbl is set. FIXME:
// should use allocation lock while initializing object.
if (! dt)
return mark_stack_ptr;
jclass klass = dt->clas;
// Every object has a sync_info pointer.
word w = (word) obj->sync_info;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o1label);
// Mark the object's class.
w = (word) klass;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o2label);
if (klass == &ClassClass)
{
jclass c = (jclass) addr;
#if 0
// The next field should probably not be marked, since this is
// only used in the class hash table. Marking this field
// basically prohibits class unloading. --Kresten
w = (word) c->next;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c2label);
#endif
w = (word) c->name;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c3label);
w = (word) c->superclass;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c4label);
for (int i = 0; i < c->constants.size; ++i)
{
/* FIXME: We could make this more precise by using the tags -KKT */
w = (word) c->constants.data[i].p;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c5label);
}
#ifdef INTERPRETER
if (_Jv_IsInterpretedClass (c))
{
w = (word) c->constants.tags;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c5alabel);
w = (word) c->constants.data;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c5blabel);
}
#endif
// If the class is an array, then the methods field holds a
// pointer to the element class. If the class is primitive,
// then the methods field holds a pointer to the array class.
w = (word) c->methods;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c6label);
if (! c->isArray() && ! c->isPrimitive())
{
// Scan each method in the cases where `methods' really
// points to a methods structure.
for (int i = 0; i < c->method_count; ++i)
{
w = (word) c->methods[i].name;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c,
cm1label);
w = (word) c->methods[i].signature;
MAYBE_MARK (w, 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))
{
w = (word) c->methods[i].ncode;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c,
cm3label);
}
#endif
}
}
// Mark all the fields.
w = (word) c->fields;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8label);
for (int i = 0; i < c->field_count; ++i)
{
_Jv_Field* field = &c->fields[i];
#ifndef COMPACT_FIELDS
w = (word) field->name;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8alabel);
#endif
w = (word) field->type;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8blabel);
// For the interpreter, we also need to mark the memory
// containing static members
if (field->flags & 0x0008)
{
w = (word) field->u.addr;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8clabel);
// also, if the static member is a reference,
// mark also the value pointed to. We check for isResolved
// since marking can happen before memory is allocated for
// static members.
if (JvFieldIsRef (field) && field->isResolved())
{
jobject val = *(jobject*) field->u.addr;
w = (word) val;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit,
c, c8elabel);
}
}
}
w = (word) c->vtable;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c9label);
w = (word) c->interfaces;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cAlabel);
for (int i = 0; i < c->interface_count; ++i)
{
w = (word) c->interfaces[i];
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cClabel);
}
w = (word) c->loader;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cBlabel);
#ifdef INTERPRETER
if (_Jv_IsInterpretedClass (c))
{
_Jv_InterpClass* ic = (_Jv_InterpClass*)c;
w = (word) ic->interpreted_methods;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, ic, cElabel);
for (int i = 0; i < c->method_count; i++)
{
w = (word) ic->interpreted_methods[i];
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, ic, \
cFlabel);
}
w = (word) ic->field_initializers;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, ic, cGlabel);
}
#endif
}
else
{
// NOTE: each class only holds information about the class
// itself. So we must do the marking for the entire inheritance
// tree in order to mark all fields. FIXME: what about
// interfaces? We skip Object here, because Object only has a
// sync_info, and we handled that earlier.
// 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)
{
jfieldID field = JvGetFirstInstanceField (klass);
jint max = JvNumInstanceFields (klass);
for (int i = 0; i < max; ++i)
{
if (JvFieldIsRef (field))
{
jobject val = JvGetObjectField (obj, field);
w = (word) val;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit,
obj, elabel);
}
field = field->getNextInstanceField ();
}
klass = klass->getSuperclass();
}
}
return mark_stack_ptr;
}
// This is called by the GC during the mark phase. It marks a Java
// array (of objects). We use `void *' arguments and return, and not
// what the Boehm GC wants, to avoid pollution in our headers.
void *
_Jv_MarkArray (void *addr, void *msp, void *msl, void * /*env*/)
{
mse *mark_stack_ptr = (mse *) msp;
mse *mark_stack_limit = (mse *) msl;
jobjectArray array = (jobjectArray) addr;
_Jv_VTable *dt = *(_Jv_VTable **) addr;
// We check this in case a GC occurs before the vtbl is set. FIXME:
// should use allocation lock while initializing object.
if (! dt)
return mark_stack_ptr;
jclass klass = dt->clas;
// Every object has a sync_info pointer.
word w = (word) array->sync_info;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, array, e1label);
// Mark the object's class.
w = (word) klass;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o2label);
for (int i = 0; i < JvGetArrayLength (array); ++i)
{
jobject obj = elements (array)[i];
w = (word) obj;
MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, array, e2label);
}
return mark_stack_ptr;
}
// Allocate space for a new Java object. FIXME: this might be the
// wrong interface; we might prefer to pass in the object type as
// well. It isn't important for this collector, but it might be for
// other collectors.
void *
_Jv_AllocObj (jsize size)
{
return GC_GENERIC_MALLOC (size, obj_kind_x);
}
// Allocate space for a new Java array. FIXME: again, this might be
// the wrong interface.
void *
_Jv_AllocArray (jsize size)
{
return GC_GENERIC_MALLOC (size, array_kind_x);
}
// Allocate some space that is known to be pointer-free.
void *
_Jv_AllocBytes (jsize size)
{
return GC_GENERIC_MALLOC (size, PTRFREE);
}
static void
call_finalizer (GC_PTR obj, GC_PTR client_data)
{
_Jv_FinalizerFunc *fn = (_Jv_FinalizerFunc *) client_data;
jobject jobj = (jobject) obj;
(*fn) (jobj);
}
void
_Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *meth)
{
GC_REGISTER_FINALIZER_NO_ORDER (object, call_finalizer, (GC_PTR) meth,
NULL, NULL);
}
void
_Jv_RunFinalizers (void)
{
GC_invoke_finalizers ();
}
void
_Jv_RunAllFinalizers (void)
{
GC_finalize_all ();
}
void
_Jv_RunGC (void)
{
GC_gcollect ();
}
long
_Jv_GCTotalMemory (void)
{
return GC_get_heap_size ();
}
long
_Jv_GCFreeMemory (void)
{
return GC_get_free_bytes ();
}
void
_Jv_GCSetInitialHeapSize (size_t size)
{
size_t current = GC_get_heap_size ();
if (size > current)
GC_expand_hp (size - current);
}
void
_Jv_GCSetMaximumHeapSize (size_t size)
{
GC_set_max_heap_size ((GC_word) size);
}
void
_Jv_InitGC (void)
{
int proc;
DCL_LOCK_STATE;
DISABLE_SIGNALS ();
LOCK ();
if (initialized)
{
UNLOCK ();
ENABLE_SIGNALS ();
return;
}
initialized = 1;
GC_java_finalization = 1;
// 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));
proc = GC_n_mark_procs++;
GC_mark_procs[proc] = (mark_proc) _Jv_MarkObj;
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;
// 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));
proc = GC_n_mark_procs++;
GC_mark_procs[proc] = (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_relocate_descr = FALSE;
GC_obj_kinds[array_kind_x].ok_init = TRUE;
UNLOCK ();
ENABLE_SIGNALS ();
}