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