xref: /freebsd/contrib/llvm-project/libcxx/include/__memory_resource/unsynchronized_pool_resource.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 <__memory_resource/memory_resource.h>
14 #include <__memory_resource/pool_options.h>
15 #include <cstddef>
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:
__adhoc_pool()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 
unsynchronized_pool_resource()62   _LIBCPP_HIDE_FROM_ABI unsynchronized_pool_resource()
63       : unsynchronized_pool_resource(pool_options(), get_default_resource()) {}
64 
unsynchronized_pool_resource(memory_resource * __upstream)65   _LIBCPP_HIDE_FROM_ABI explicit unsynchronized_pool_resource(memory_resource* __upstream)
66       : unsynchronized_pool_resource(pool_options(), __upstream) {}
67 
unsynchronized_pool_resource(const pool_options & __opts)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 
~unsynchronized_pool_resource()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 
upstream_resource()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 
do_is_equal(const memory_resource & __other)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
107