Merge "libbinder_ndk: fix race related to bpbinder" am: af45ec09

void ABpBinder::onLastStrongRef(const void* id) {

    // Since ABpBinder is OBJECT_LIFETIME_WEAK, we must remove this weak reference in order for

    // the ABpBinder to be deleted. Since a strong reference to this ABpBinder object should no

    // longer be able to exist at the time of this method call, there is no longer a need to

    // recover it.

    // the ABpBinder to be deleted. Even though we have no more references on the ABpBinder

    // (BpRefBase), the remote object may still exist (for instance, if we

    // receive it from another process, before the ABpBinder is attached).

    ABpBinderTag::Value* value =

            static_cast<ABpBinderTag::Value*>(remote()->detachObject(ABpBinderTag::kId));

    if (value) ABpBinderTag::clean(ABpBinderTag::kId, value, nullptr /*cookie*/);

            static_cast<ABpBinderTag::Value*>(remote()->findObject(ABpBinderTag::kId));

    CHECK_NE(nullptr, value) << "ABpBinder must always be attached";

    remote()->withLock([&]() { value->binder = nullptr; });

    BpRefBase::onLastStrongRef(id);

}

        return static_cast<ABBinder*>(binder.get());

    }

    // The following code ensures that for a given binder object (remote or local), if it is not an

    // ABBinder then at most one ABpBinder object exists in a given process representing it.

    auto* value = static_cast<ABpBinderTag::Value*>(binder->findObject(ABpBinderTag::kId));

    if (value == nullptr) {

        value = new ABpBinderTag::Value;