libcxx/include/__memory_resource/unsynchronized_pool_resource.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H
  10 #define _LIBCPP___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H
  11
  12 #include <__availability>
  13 #include <__config>
  14 #include <__memory_resource/memory_resource.h>
  15 #include <__memory_resource/pool_options.h>
  16 #include <cstddef>
  17 #include <cstdint>
  18
  19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  20 #  pragma GCC system_header
  21 #endif
  22
  23 #if _LIBCPP_STD_VER >= 17
  24
  25 _LIBCPP_BEGIN_NAMESPACE_STD
  26
  27 namespace pmr {
  28
  29 // [mem.res.pool.overview]
  30
  31 class _LIBCPP_AVAILABILITY_PMR _LIBCPP_EXPORTED_FROM_ABI unsynchronized_pool_resource : public memory_resource {
  32   class __fixed_pool;
  33
  34   class __adhoc_pool {
  35     struct __chunk_footer;
  36     __chunk_footer* __first_;
  37
  38   public:
  39     _LIBCPP_HIDE_FROM_ABI explicit __adhoc_pool() : __first_(nullptr) {}
  40
  41     void __release_ptr(memory_resource* __upstream);
  42     void* __do_allocate(memory_resource* __upstream, size_t __bytes, size_t __align);
  43     void __do_deallocate(memory_resource* __upstream, void* __p, size_t __bytes, size_t __align);
  44   };
  45
  46   static const size_t __min_blocks_per_chunk = 16;
  47   static const size_t __min_bytes_per_chunk  = 1024;
  48   static const size_t __max_blocks_per_chunk = (size_t(1) << 20);
  49   static const size_t __max_bytes_per_chunk  = (size_t(1) << 30);
  50
  51   static const int __log2_smallest_block_size      = 3;
  52   static const size_t __smallest_block_size        = 8;
  53   static const size_t __default_largest_block_size = (size_t(1) << 20);
  54   static const size_t __max_largest_block_size     = (size_t(1) << 30);
  55
  56   size_t __pool_block_size(int __i) const;
  57   int __log2_pool_block_size(int __i) const;
  58   int __pool_index(size_t __bytes, size_t __align) const;
  59
  60 public:
  61   unsynchronized_pool_resource(const pool_options& __opts, memory_resource* __upstream);
  62
  63   _LIBCPP_HIDE_FROM_ABI unsynchronized_pool_resource()
  64       : unsynchronized_pool_resource(pool_options(), get_default_resource()) {}
  65
  66   _LIBCPP_HIDE_FROM_ABI explicit unsynchronized_pool_resource(memory_resource* __upstream)
  67       : unsynchronized_pool_resource(pool_options(), __upstream) {}
  68
  69   _LIBCPP_HIDE_FROM_ABI explicit unsynchronized_pool_resource(const pool_options& __opts)
  70       : unsynchronized_pool_resource(__opts, get_default_resource()) {}
  71
  72   unsynchronized_pool_resource(const unsynchronized_pool_resource&) = delete;
  73
  74   _LIBCPP_HIDE_FROM_ABI_VIRTUAL ~unsynchronized_pool_resource() override { release(); }
  75
  76   unsynchronized_pool_resource& operator=(const unsynchronized_pool_resource&) = delete;
  77
  78   void release();
  79
  80   _LIBCPP_HIDE_FROM_ABI memory_resource* upstream_resource() const { return __res_; }
  81
  82   [[__gnu__::__pure__]] pool_options options() const;
  83
  84 protected:
  85   void* do_allocate(size_t __bytes, size_t __align) override; // key function
  86
  87   void do_deallocate(void* __p, size_t __bytes, size_t __align) override;
  88
  89   _LIBCPP_HIDE_FROM_ABI_VIRTUAL bool do_is_equal(const memory_resource& __other) const _NOEXCEPT override {
  90     return &__other == this;
  91   }
  92
  93 private:
  94   memory_resource* __res_;
  95   __adhoc_pool __adhoc_pool_;
  96   __fixed_pool* __fixed_pools_;
  97   int __num_fixed_pools_;
  98   uint32_t __options_max_blocks_per_chunk_;
  99 };
 100
 101 } // namespace pmr
 102
 103 _LIBCPP_END_NAMESPACE_STD
 104
 105 #endif // _LIBCPP_STD_VER >= 17
 106
 107 #endif // _LIBCPP___MEMORY_RESOURCE_UNSYNCHRONIZED_POOL_RESOURCE_H