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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "js/ObjectWithStashedPointer.h"
#include "jsapi.h" // JS_NewObject
#include "vm/JSContext.h" // CHECK_THREAD
namespace JS::detail {
static const size_t DATA_SLOT = 0;
static const size_t FREE_FUNC_SLOT = 1;
static void ObjectWithUntypedStashedPointerFinalize(JS::GCContext*,
JSObject* obj) {
AutoAssertNoGC nogc;
void* freeFunc = GetMaybePtrFromReservedSlot<void>(obj, FREE_FUNC_SLOT);
void* data = GetMaybePtrFromReservedSlot<void>(obj, DATA_SLOT);
reinterpret_cast<UntypedFreeFunction>(freeFunc)(data);
}
static const JSClassOps classOps = {
nullptr, // addProperty
nullptr, // delProperty
nullptr, // enumerate
nullptr, // newEnumerate
nullptr, // resolve
nullptr, // mayResolve
ObjectWithUntypedStashedPointerFinalize,
nullptr, // call
nullptr, // construct
nullptr, // trace
};
static const JSClass DataOnlyClass = {
"Object",
JSCLASS_HAS_RESERVED_SLOTS(1),
};
static const JSClass FreeFuncClass = {
"Object",
JSCLASS_HAS_RESERVED_SLOTS(2) | JSCLASS_FOREGROUND_FINALIZE,
&classOps,
};
JSObject* NewObjectWithUntypedStashedPointer(JSContext* cx, void* ptr,
UntypedFreeFunction freeFunc) {
if (!freeFunc) {
JSObject* retval = JS_NewObject(cx, &DataOnlyClass);
if (!retval) {
return nullptr;
}
JS::SetReservedSlot(retval, DATA_SLOT, JS::PrivateValue(ptr));
return retval;
}
JSObject* retval = JS_NewObject(cx, &FreeFuncClass);
if (!retval) {
return nullptr;
}
JS::SetReservedSlot(retval, DATA_SLOT, JS::PrivateValue(ptr));
JS::SetReservedSlot(retval, FREE_FUNC_SLOT,
JS::PrivateValue(reinterpret_cast<void*>(freeFunc)));
return retval;
}
void* ObjectGetUntypedStashedPointer(JSContext* cx, JSObject* obj) {
MOZ_ASSERT(
obj->getClass() == &FreeFuncClass || obj->getClass() == &DataOnlyClass,
"wrong type of object");
return JS::GetMaybePtrFromReservedSlot<void>(obj, DATA_SLOT);
}
} // namespace JS::detail