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#include "stdafx.h"
#include "VTableCpp.h"
#include "Utils/Platform.h"
#include "Utils/Memory.h"
#include "Core/GcType.h"
#include "Exception.h"
#include "Function.h"
#include "Engine.h"
namespace storm {
VTableCpp *VTableCpp::wrap(Engine &e, const void *vtable) {
return new (e) VTableCpp(vtable, vtable::count(vtable), false);
}
VTableCpp *VTableCpp::wrap(Engine &e, const void *vtable, nat count) {
return new (e) VTableCpp(vtable, count, false);
}
VTableCpp *VTableCpp::copy(Engine &e, const void *vtable) {
return new (e) VTableCpp(vtable, vtable::count(vtable), true);
}
VTableCpp *VTableCpp::copy(Engine &e, const void *vtable, nat count) {
return new (e) VTableCpp(vtable, count, true);
}
VTableCpp *VTableCpp::copy(Engine &e, const VTableCpp *src) {
return new (e) VTableCpp(src->table(), src->count(), true);
}
VTableCpp::VTableCpp(const void *vtable, nat count, bool copy) {
init(vtable, count, copy);
}
void VTableCpp::init(const void *vtable, nat count, bool copy) {
refs = null;
data = null;
tabSize = count;
raw = null;
if (copy) {
data = runtime::allocArray<const void *>(engine(), &pointerArrayType, count + vtable::extraOffset);
data->filled = 0;
const void ** src = (const void **)vtable - vtable::extraOffset;
for (nat i = 1; i < count + vtable::extraOffset; i++) {
data->v[i] = src[i];
}
} else {
raw = (const void **)vtable;
}
}
const void **VTableCpp::table() const {
if (data)
return &data->v[vtable::extraOffset];
else
return raw;
}
void VTableCpp::replace(const void *vtable) {
replace(vtable, vtable::count(vtable));
}
void VTableCpp::replace(const VTableCpp *src) {
replace(src->table(), src->count());
}
class VTableSwitch : public Walker {
public:
VTableSwitch(const void **from, const void **to) : from(from), to(to) {
flags = fObjects;
}
const void **from;
const void **to;
virtual void object(RootObject *inspect) {
if (vtable::from(inspect) == from)
vtable::set(to, inspect);
}
};
void VTableCpp::replace(const void *vtable, nat count) {
if (!data || count > this->count()) {
// We need to replace the vtables on all live objects using the vtable.
bool needWalk = used();
const void **from = table();
// Create the new vtable.
init(vtable, count, true);
VTableSwitch data(from, table());
// Don't walk the heap if we don't need to. That can be *very* expensive. In most cases
// this happens right after we've created an object but before we have set the vtable to
// an object, which means it is safe not to do the expensive heap walk.
if (needWalk)
engine().gc.walk(data);
} else {
// We can copy, we know we can modify 'data'.
const void *const* src = (const void *const*)vtable - vtable::extraOffset;
for (nat i = 1; i < count + vtable::extraOffset; i++) {
data->v[i] = src[i];
}
}
}
nat VTableCpp::count() const {
return tabSize;
}
nat VTableCpp::findSlot(const void *fn) const {
return vtable::find(table(), fn, count());
}
const void *VTableCpp::extra() const {
if (data)
return data->v[0];
else
return null;
}
void VTableCpp::extra(const void *to) {
if (data)
data->v[0] = to;
}
void VTableCpp::set(nat id, const void *to) {
if (data)
data->v[id + vtable::extraOffset] = to;
}
void VTableCpp::set(nat id, Function *fn) {
assert(id < count());
if (!refs)
refs = runtime::allocArray<Function *>(engine(), &pointerArrayType, count());
refs->v[id] = fn;
set(id, fn->directRef().address());
}
Function *VTableCpp::get(nat id) const {
if (refs)
if (id < count())
return refs->v[id];
return null;
}
void VTableCpp::clear(nat id) {
assert(id < count());
if (refs) {
refs->v[id] = null;
}
if (data)
data->v[id + vtable::extraOffset] = null;
}
const void *VTableCpp::address() const {
if (data)
return data;
else
// Tag the pointer.
return (const byte *)raw + 1;
}
nat VTableCpp::size() const {
return Nat(count() * sizeof(const void *) + vtableAllocOffset());
}
bool VTableCpp::used() const {
if (data)
return data->filled != 0;
else
return true;
}
const void **VTableCpp::pointer() {
if (data)
data->filled = 1;
return table();
}
void VTableCpp::insert(RootObject *obj) {
if (data)
data->filled = 1;
vtable::set(table(), obj);
}
void VTableCpp::insert(code::Listing *to, code::Var obj, code::Ref table) {
using namespace code;
Label lbl = to->label();
// See if the pointer in 'table' is tagged with a 1 in the lower bit. If so, remove it and
// skip the mark-phase since we're dealing with a raw vtable.
*to << mov(ptrA, table);
*to << mov(ptrC, ptrConst(1));
*to << bnot(ptrC);
*to << band(ptrC, ptrA);
*to << cmp(ptrC, ptrA);
*to << jmp(lbl, ifNotEqual);
// Mark as used by setting 'filled' to 1.
*to << mov(ptrRel(ptrA, Offset::sPtr), ptrConst(1));
// The pointer is offset a bit.
*to << add(ptrA, to->engine().ref(builtin::VTableAllocOffset));
*to << lbl;
*to << mov(ptrC, obj);
*to << mov(ptrRel(ptrC, Offset()), ptrA);
}
}
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