ceph/src/seastar/include/seastar/core/aligned_buffer.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright (C) 2016 ScyllaDB.
  20  */
  21 #pragma once
  22 #include <stdlib.h>
  23 #include <memory>
  24 #include <stdexcept>
  25 #include <seastar/core/print.hh>
  26
  27 namespace seastar {
  28
  29
  30 struct free_deleter {
  31     void operator()(void* p) { ::free(p); }
  32 };
  33
  34 template <typename CharType>
  35 inline
  36 std::unique_ptr<CharType[], free_deleter> allocate_aligned_buffer(size_t size, size_t align) {
  37     static_assert(sizeof(CharType) == 1, "must allocate byte type");
  38     void* ret;
  39     auto r = posix_memalign(&ret, align, size);
  40     if (r == ENOMEM) {
  41         throw std::bad_alloc();
  42     } else if (r == EINVAL) {
  43         throw std::runtime_error(format("Invalid alignment of {:d}; allocating {:d} bytes", align, size));
  44     } else {
  45         assert(r == 0);
  46         return std::unique_ptr<CharType[], free_deleter>(reinterpret_cast<CharType *>(ret));
  47     }
  48 }
  49
  50
  51 }