__cxx03/__memory_resource/unsynchronized_pool_resource.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CXX03___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H
0010 #define _LIBCPP___CXX03___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H
0011
0012 #include <__cxx03/__config>
0013 #include <__cxx03/__memory_resource/memory_resource.h>
0014 #include <__cxx03/__memory_resource/pool_options.h>
0015 #include <__cxx03/cstddef>
0016 #include <__cxx03/cstdint>
0017
0018 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0019 #  pragma GCC system_header
0020 #endif
0021
0022 #if _LIBCPP_STD_VER >= 17
0023
0024 _LIBCPP_BEGIN_NAMESPACE_STD
0025
0026 namespace pmr {
0027
0028 // [mem.res.pool.overview]
0029
0030 class _LIBCPP_AVAILABILITY_PMR _LIBCPP_EXPORTED_FROM_ABI unsynchronized_pool_resource : public memory_resource {
0031   class __fixed_pool;
0032
0033   class __adhoc_pool {
0034     struct __chunk_footer;
0035     __chunk_footer* __first_;
0036
0037   public:
0038     _LIBCPP_HIDE_FROM_ABI explicit __adhoc_pool() : __first_(nullptr) {}
0039
0040     void __release_ptr(memory_resource* __upstream);
0041     void* __do_allocate(memory_resource* __upstream, size_t __bytes, size_t __align);
0042     void __do_deallocate(memory_resource* __upstream, void* __p, size_t __bytes, size_t __align);
0043   };
0044
0045   static const size_t __min_blocks_per_chunk = 16;
0046   static const size_t __min_bytes_per_chunk  = 1024;
0047   static const size_t __max_blocks_per_chunk = (size_t(1) << 20);
0048   static const size_t __max_bytes_per_chunk  = (size_t(1) << 30);
0049
0050   static const int __log2_smallest_block_size      = 3;
0051   static const size_t __smallest_block_size        = 8;
0052   static const size_t __default_largest_block_size = (size_t(1) << 20);
0053   static const size_t __max_largest_block_size     = (size_t(1) << 30);
0054
0055   size_t __pool_block_size(int __i) const;
0056   int __log2_pool_block_size(int __i) const;
0057   int __pool_index(size_t __bytes, size_t __align) const;
0058
0059 public:
0060   unsynchronized_pool_resource(const pool_options& __opts, memory_resource* __upstream);
0061
0062   _LIBCPP_HIDE_FROM_ABI unsynchronized_pool_resource()
0063       : unsynchronized_pool_resource(pool_options(), get_default_resource()) {}
0064
0065   _LIBCPP_HIDE_FROM_ABI explicit unsynchronized_pool_resource(memory_resource* __upstream)
0066       : unsynchronized_pool_resource(pool_options(), __upstream) {}
0067
0068   _LIBCPP_HIDE_FROM_ABI explicit unsynchronized_pool_resource(const pool_options& __opts)
0069       : unsynchronized_pool_resource(__opts, get_default_resource()) {}
0070
0071   unsynchronized_pool_resource(const unsynchronized_pool_resource&) = delete;
0072
0073   _LIBCPP_HIDE_FROM_ABI_VIRTUAL ~unsynchronized_pool_resource() override { release(); }
0074
0075   unsynchronized_pool_resource& operator=(const unsynchronized_pool_resource&) = delete;
0076
0077   void release();
0078
0079   _LIBCPP_HIDE_FROM_ABI memory_resource* upstream_resource() const { return __res_; }
0080
0081   [[__gnu__::__pure__]] pool_options options() const;
0082
0083 protected:
0084   void* do_allocate(size_t __bytes, size_t __align) override; // key function
0085
0086   void do_deallocate(void* __p, size_t __bytes, size_t __align) override;
0087
0088   _LIBCPP_HIDE_FROM_ABI_VIRTUAL bool do_is_equal(const memory_resource& __other) const _NOEXCEPT override {
0089     return &__other == this;
0090   }
0091
0092 private:
0093   memory_resource* __res_;
0094   __adhoc_pool __adhoc_pool_;
0095   __fixed_pool* __fixed_pools_;
0096   int __num_fixed_pools_;
0097   uint32_t __options_max_blocks_per_chunk_;
0098 };
0099
0100 } // namespace pmr
0101
0102 _LIBCPP_END_NAMESPACE_STD
0103
0104 #endif // _LIBCPP_STD_VER >= 17
0105
0106 #endif // _LIBCPP___CXX03___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H