368 lines
10 KiB
C++
368 lines
10 KiB
C++
// boehm.cc - interface between libjava and Boehm GC.
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/* Copyright (C) 1998, 1999 Cygnus Solutions
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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#include <config.h>
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#include <stdio.h>
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#include <cni.h>
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#include <java/lang/Class.h>
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#include <jvm.h>
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#include <java-field.h>
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// We need to include gc_priv.h. However, it tries to include
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// config.h if it hasn't already been included. So we force the
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// inclusion of the Boehm config.h.
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extern "C"
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{
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#include <boehm-config.h>
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#include <gc_priv.h>
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#include <gc_mark.h>
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// These aren't declared in any Boehm GC header.
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void GC_finalize_all (void);
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ptr_t GC_debug_generic_malloc (size_t size, int k, GC_EXTRA_PARAMS);
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};
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// FIXME: this should probably be defined in some GC header.
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#ifdef GC_DEBUG
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# define GC_GENERIC_MALLOC(Size, Type) \
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GC_debug_generic_malloc (Size, Type, GC_EXTRAS)
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#else
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# define GC_GENERIC_MALLOC(Size, Type) GC_generic_malloc (Size, Type)
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#endif
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// We must check for plausibility ourselves.
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#define MAYBE_MARK(Obj, Top, Limit, Source, Exit) \
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if ((ptr_t) (Obj) >= GC_least_plausible_heap_addr \
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&& (ptr_t) (Obj) <= GC_greatest_plausible_heap_addr) \
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PUSH_CONTENTS (Obj, Top, Limit, Source, Exit)
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#define ObjectClass _CL_Q34java4lang6Object
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extern java::lang::Class ObjectClass;
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#define ClassClass _CL_Q34java4lang5Class
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extern java::lang::Class ClassClass;
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// Nonzero if this module has been initialized.
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static int initialized = 0;
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// `kind' index used when allocating Java objects.
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static int obj_kind_x;
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// `kind' index used when allocating Java arrays.
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static int array_kind_x;
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// Freelist used for Java objects.
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static ptr_t *obj_free_list;
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// Freelist used for Java arrays.
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static ptr_t *array_free_list;
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// This is called by the GC during the mark phase. It marks a Java
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// object. We use `void *' arguments and return, and not what the
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// Boehm GC wants, to avoid pollution in our headers.
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void *
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_Jv_MarkObj (void *addr, void *msp, void *msl, void * /*env*/)
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{
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mse *mark_stack_ptr = (mse *) msp;
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mse *mark_stack_limit = (mse *) msl;
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jobject obj = (jobject) addr;
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_Jv_VTable *dt = *(_Jv_VTable **) addr;
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// We check this in case a GC occurs before the vtbl is set. FIXME:
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// should use allocation lock while initializing object.
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if (! dt)
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return mark_stack_ptr;
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jclass klass = dt->clas;
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// Every object has a sync_info pointer.
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word w = (word) obj->sync_info;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o1label);
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// Mark the object's class.
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w = (word) klass;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o2label);
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if (klass == &ClassClass)
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{
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jclass c = (jclass) addr;
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w = (word) c->next;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c2label);
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w = (word) c->name;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c3label);
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w = (word) c->superclass;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c4label);
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for (int i = 0; i < c->constants.size; ++i)
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{
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w = (word) c->constants.data[i];
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c5label);
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}
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// If the class is an array, then the methods field holds a
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// pointer to the element class. If the class is primitive,
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// then the methods field holds a pointer to the array class.
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w = (word) c->methods;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c6label);
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if (! c->isArray() && ! c->isPrimitive())
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{
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// Scan each method in the cases where `methods' really
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// points to a methods structure.
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for (int i = 0; i < c->method_count; ++i)
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{
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w = (word) c->methods[i].name;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c,
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cm1label);
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w = (word) c->methods[i].signature;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c,
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cm2label);
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// FIXME: `ncode' entry?
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}
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}
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// Mark all the fields.
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w = (word) c->fields;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8label);
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for (int i = 0; i < c->field_count; ++i)
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{
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#ifndef COMPACT_FIELDS
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w = (word) c->fields[i].name;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8alabel);
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#endif
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w = (word) c->fields[i].type;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c8blabel);
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}
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w = (word) c->vtable;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, c9label);
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w = (word) c->interfaces;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cAlabel);
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for (int i = 0; i < c->interface_count; ++i)
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{
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w = (word) c->interfaces[i];
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cClabel);
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}
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w = (word) c->loader;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, c, cBlabel);
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}
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else
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{
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// NOTE: each class only holds information about the class
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// itself. So we must do the marking for the entire inheritance
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// tree in order to mark all fields. FIXME: what about
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// interfaces? We skip Object here, because Object only has a
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// sync_info, and we handled that earlier.
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// Note: occasionally `klass' can be null. For instance, this
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// can happen if a GC occurs between the point where an object
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// is allocated and where the vtbl slot is set.
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while (klass && klass != &ObjectClass)
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{
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jfieldID field = JvGetFirstInstanceField (klass);
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jint max = JvNumInstanceFields (klass);
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for (int i = 0; i < max; ++i)
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{
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if (JvFieldIsRef (field))
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{
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jobject val = JvGetObjectField (obj, field);
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w = (word) val;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit,
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obj, elabel);
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}
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field = field->getNextInstanceField ();
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}
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klass = klass->getSuperclass();
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}
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}
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return mark_stack_ptr;
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}
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// This is called by the GC during the mark phase. It marks a Java
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// array (of objects). We use `void *' arguments and return, and not
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// what the Boehm GC wants, to avoid pollution in our headers.
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void *
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_Jv_MarkArray (void *addr, void *msp, void *msl, void * /*env*/)
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{
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mse *mark_stack_ptr = (mse *) msp;
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mse *mark_stack_limit = (mse *) msl;
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jobjectArray array = (jobjectArray) addr;
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_Jv_VTable *dt = *(_Jv_VTable **) addr;
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// We check this in case a GC occurs before the vtbl is set. FIXME:
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// should use allocation lock while initializing object.
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if (! dt)
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return mark_stack_ptr;
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jclass klass = dt->clas;
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// Every object has a sync_info pointer.
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word w = (word) array->sync_info;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, array, e1label);
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// Mark the object's class.
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w = (word) klass;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, obj, o2label);
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for (int i = 0; i < JvGetArrayLength (array); ++i)
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{
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jobject obj = elements (array)[i];
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w = (word) obj;
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MAYBE_MARK (w, mark_stack_ptr, mark_stack_limit, array, e2label);
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}
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return mark_stack_ptr;
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}
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// Allocate space for a new Java object. FIXME: this might be the
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// wrong interface; we might prefer to pass in the object type as
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// well. It isn't important for this collector, but it might be for
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// other collectors.
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void *
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_Jv_AllocObj (jsize size)
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{
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return GC_GENERIC_MALLOC (size, obj_kind_x);
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}
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// Allocate space for a new Java array. FIXME: again, this might be
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// the wrong interface.
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void *
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_Jv_AllocArray (jsize size)
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{
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return GC_GENERIC_MALLOC (size, array_kind_x);
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}
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// Allocate some space that is known to be pointer-free.
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void *
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_Jv_AllocBytes (jsize size)
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{
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return GC_GENERIC_MALLOC (size, PTRFREE);
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}
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static void
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call_finalizer (GC_PTR obj, GC_PTR client_data)
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{
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_Jv_FinalizerFunc *fn = (_Jv_FinalizerFunc *) client_data;
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jobject jobj = (jobject) obj;
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(*fn) (jobj);
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}
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void
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_Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *meth)
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{
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GC_REGISTER_FINALIZER_NO_ORDER (object, call_finalizer, meth,
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NULL, NULL);
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}
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void
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_Jv_RunFinalizers (void)
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{
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GC_invoke_finalizers ();
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}
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void
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_Jv_RunAllFinalizers (void)
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{
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GC_finalize_all ();
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}
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void
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_Jv_RunGC (void)
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{
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GC_gcollect ();
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}
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long
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_Jv_GCTotalMemory (void)
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{
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return GC_get_heap_size ();
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}
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/* Sum size of each hblk. */
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static void
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sum_blocks (struct hblk *h, word arg)
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{
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long *sump = (long *) arg;
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/* This evil computation is from boehm-gc/checksums.c. */
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hdr *hhdr = HDR (h);
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int bytes = WORDS_TO_BYTES (hhdr->hb_sz);
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bytes += HDR_BYTES + HBLKSIZE - 1;
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bytes &= ~ (HBLKSIZE - 1);
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*sump += bytes;
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}
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/* This turns out to be expensive to implement. For now, we don't
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care. We could make it less expensive, perhaps, but that would
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require some changes to the collector. */
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long
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_Jv_GCFreeMemory (void)
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{
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long sum = 0;
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GC_apply_to_all_blocks (sum_blocks, &sum);
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return sum;
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}
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void
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_Jv_InitGC (void)
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{
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int proc;
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DCL_LOCK_STATE;
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DISABLE_SIGNALS ();
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LOCK ();
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if (initialized)
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{
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UNLOCK ();
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ENABLE_SIGNALS ();
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return;
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}
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initialized = 1;
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// Set up state for marking and allocation of Java objects.
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obj_free_list = (ptr_t *) GC_generic_malloc_inner ((MAXOBJSZ + 1)
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* sizeof (ptr_t),
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PTRFREE);
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memset (obj_free_list, 0, (MAXOBJSZ + 1) * sizeof (ptr_t));
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proc = GC_n_mark_procs++;
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GC_mark_procs[proc] = (mark_proc) _Jv_MarkObj;
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obj_kind_x = GC_n_kinds++;
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GC_obj_kinds[obj_kind_x].ok_freelist = obj_free_list;
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GC_obj_kinds[obj_kind_x].ok_reclaim_list = 0;
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GC_obj_kinds[obj_kind_x].ok_descriptor = MAKE_PROC (proc, 0);
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GC_obj_kinds[obj_kind_x].ok_relocate_descr = FALSE;
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GC_obj_kinds[obj_kind_x].ok_init = TRUE;
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// Set up state for marking and allocation of arrays of Java
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// objects.
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array_free_list = (ptr_t *) GC_generic_malloc_inner ((MAXOBJSZ + 1)
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* sizeof (ptr_t),
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PTRFREE);
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memset (array_free_list, 0, (MAXOBJSZ + 1) * sizeof (ptr_t));
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proc = GC_n_mark_procs++;
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GC_mark_procs[proc] = (mark_proc) _Jv_MarkArray;
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array_kind_x = GC_n_kinds++;
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GC_obj_kinds[array_kind_x].ok_freelist = array_free_list;
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GC_obj_kinds[array_kind_x].ok_reclaim_list = 0;
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GC_obj_kinds[array_kind_x].ok_descriptor = MAKE_PROC (proc, 0);
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GC_obj_kinds[array_kind_x].ok_relocate_descr = FALSE;
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GC_obj_kinds[array_kind_x].ok_init = TRUE;
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UNLOCK ();
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ENABLE_SIGNALS ();
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}
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