diff options
Diffstat (limited to 'src/msg/async/dpdk/transfer.h')
-rw-r--r-- | src/msg/async/dpdk/transfer.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/msg/async/dpdk/transfer.h b/src/msg/async/dpdk/transfer.h new file mode 100644 index 00000000..599db5bd --- /dev/null +++ b/src/msg/async/dpdk/transfer.h @@ -0,0 +1,64 @@ +/* + * This file is open source software, licensed to you under the terms + * of the Apache License, Version 2.0 (the "License"). See the NOTICE file + * distributed with this work for additional information regarding copyright + * ownership. You may not use this file except in compliance with the License. + * + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +/* + * Copyright (C) 2014 Cloudius Systems, Ltd. + */ + +#ifndef CEPH_TRANSFER_H_ +#define CEPH_TRANSFER_H_ + +// Helper functions for copying or moving multiple objects in an exception +// safe manner, then destroying the sources. +// +// To transfer, call transfer_pass1(allocator, &from, &to) on all object pairs, +// (this copies the object from @from to @to). If no exceptions are encountered, +// call transfer_pass2(allocator, &from, &to). This destroys the object at the +// origin. If exceptions were encountered, simply destroy all copied objects. +// +// As an optimization, if the objects are moveable without throwing (noexcept) +// transfer_pass1() simply moves the objects and destroys the source, and +// transfer_pass2() does nothing. + +#include <type_traits> +#include <utility> + +template <typename T, typename Alloc> +inline void transfer_pass1(Alloc& a, T* from, T* to, + typename std::enable_if<std::is_nothrow_move_constructible<T>::value>::type* = nullptr) { + a.construct(to, std::move(*from)); + a.destroy(from); +} + +template <typename T, typename Alloc> +inline void transfer_pass2(Alloc& a, T* from, T* to, + typename std::enable_if<std::is_nothrow_move_constructible<T>::value>::type* = nullptr) { +} + +template <typename T, typename Alloc> +inline void transfer_pass1(Alloc& a, T* from, T* to, + typename std::enable_if<!std::is_nothrow_move_constructible<T>::value>::type* = nullptr) { + a.construct(to, *from); +} + +template <typename T, typename Alloc> +inline void transfer_pass2(Alloc& a, T* from, T* to, + typename std::enable_if<!std::is_nothrow_move_constructible<T>::value>::type* = nullptr) { + a.destroy(from); +} + +#endif /* CEPH_TRANSFER_H_ */ |