32#ifndef _GLIBCXX_MEMORY_RESOURCE
33#define _GLIBCXX_MEMORY_RESOURCE 1
35#pragma GCC system_header
39#if __cplusplus >= 201703L
62#include <shared_mutex>
66namespace std _GLIBCXX_VISIBILITY(default)
68_GLIBCXX_BEGIN_NAMESPACE_VERSION
71#ifdef _GLIBCXX_HAS_GTHREADS
73# define __cpp_lib_memory_resource 201603L
76# define __cpp_lib_memory_resource 1
79#if __cplusplus >= 202002L
80# define __cpp_lib_polymorphic_allocator 201902L
81 template<
typename _Tp = std::
byte>
82 class polymorphic_allocator;
93 [[nodiscard, __gnu__::__returns_nonnull__, __gnu__::__const__]]
98 [[nodiscard, __gnu__::__returns_nonnull__, __gnu__::__const__]]
100 null_memory_resource() noexcept;
103 [[__gnu__::__returns_nonnull__]]
108 [[__gnu__::__returns_nonnull__]]
110 get_default_resource() noexcept;
114#ifdef _GLIBCXX_HAS_GTHREADS
140 size_t largest_required_pool_block = 0;
144 class __pool_resource
153 __pool_resource(
const __pool_resource&) =
delete;
154 __pool_resource& operator=(
const __pool_resource&) =
delete;
158 allocate(
size_t __bytes,
size_t __alignment);
162 deallocate(
void* __p,
size_t __bytes,
size_t __alignment);
166 void release()
noexcept;
169 {
return _M_unpooled.get_allocator().resource(); }
173 _Pool* _M_alloc_pools();
175 const pool_options _M_opts;
180 _GLIBCXX_STD_C::pmr::vector<_BigBlock> _M_unpooled;
185#ifdef _GLIBCXX_HAS_GTHREADS
197 __attribute__((__nonnull__));
205 __attribute__((__nonnull__))
223 upstream_resource()
const noexcept
224 __attribute__((__returns_nonnull__))
225 {
return _M_impl.resource(); }
227 pool_options options()
const noexcept {
return _M_impl._M_opts; }
231 do_allocate(
size_t __bytes,
size_t __alignment)
override;
234 do_deallocate(
void* __p,
size_t __bytes,
size_t __alignment)
override;
238 {
return this == &__other; }
247 auto _M_thread_specific_pools()
noexcept;
249 __pool_resource _M_impl;
250 __gthread_key_t _M_key;
252 _TPools* _M_tpools =
nullptr;
266 [[__gnu__::__nonnull__]]
274 [[__gnu__::__nonnull__]]
293 [[__gnu__::__returns_nonnull__]]
295 upstream_resource()
const noexcept
296 {
return _M_impl.resource(); }
298 pool_options options()
const noexcept {
return _M_impl._M_opts; }
302 do_allocate(
size_t __bytes,
size_t __alignment)
override;
305 do_deallocate(
void* __p,
size_t __bytes,
size_t __alignment)
override;
309 {
return this == &__other; }
312 using _Pool = __pool_resource::_Pool;
314 auto _M_find_pool(
size_t)
noexcept;
316 __pool_resource _M_impl;
317 _Pool* _M_pools =
nullptr;
346 __attribute__((__nonnull__))
347 : _M_upstream(__upstream)
348 { _GLIBCXX_DEBUG_ASSERT(__upstream !=
nullptr); }
352 __attribute__((__nonnull__))
353 : _M_next_bufsiz(__initial_size),
354 _M_upstream(__upstream)
356 _GLIBCXX_DEBUG_ASSERT(__upstream !=
nullptr);
357 _GLIBCXX_DEBUG_ASSERT(__initial_size > 0);
362 __attribute__((__nonnull__(4)))
363 : _M_current_buf(__buffer), _M_avail(__buffer_size),
364 _M_next_bufsiz(_S_next_bufsize(__buffer_size)),
365 _M_upstream(__upstream),
366 _M_orig_buf(__buffer), _M_orig_size(__buffer_size)
368 _GLIBCXX_DEBUG_ASSERT(__upstream !=
nullptr);
369 _GLIBCXX_DEBUG_ASSERT(__buffer !=
nullptr || __buffer_size == 0);
396 _M_release_buffers();
399 if ((_M_current_buf = _M_orig_buf))
401 _M_avail = _M_orig_size;
402 _M_next_bufsiz = _S_next_bufsize(_M_orig_size);
407 _M_next_bufsiz = _M_orig_size;
412 upstream_resource()
const noexcept
413 __attribute__((__returns_nonnull__))
414 {
return _M_upstream; }
418 do_allocate(
size_t __bytes,
size_t __alignment)
override
420 if (__builtin_expect(__bytes == 0,
false))
423 void* __p =
std::align(__alignment, __bytes, _M_current_buf, _M_avail);
424 if (__builtin_expect(__p ==
nullptr,
false))
426 _M_new_buffer(__bytes, __alignment);
427 __p = _M_current_buf;
429 _M_current_buf = (
char*)_M_current_buf + __bytes;
435 do_deallocate(
void*,
size_t,
size_t)
override
440 {
return this == &__other; }
446 _M_new_buffer(
size_t __bytes,
size_t __alignment);
450 _M_release_buffers()
noexcept;
453 _S_next_bufsize(
size_t __buffer_size)
noexcept
455 if (__builtin_expect(__buffer_size == 0,
false))
457 return __buffer_size * _S_growth_factor;
460 static constexpr size_t _S_init_bufsize = 128 *
sizeof(
void*);
461 static constexpr float _S_growth_factor = 1.5;
463 void* _M_current_buf =
nullptr;
465 size_t _M_next_bufsiz = _S_init_bufsize;
469 void*
const _M_orig_buf =
nullptr;
470 size_t const _M_orig_size = _M_next_bufsiz;
473 _Chunk* _M_head =
nullptr;
477_GLIBCXX_END_NAMESPACE_VERSION
void * align(size_t __align, size_t __size, void *&__ptr, size_t &__space) noexcept
Fit aligned storage in buffer.
memory_resource * new_delete_resource() noexcept
A pmr::memory_resource that uses new to allocate memory.
ISO C++ entities toplevel namespace is std.
Parameters for tuning a pool resource's behaviour.
size_t max_blocks_per_chunk
Upper limit on number of blocks in a chunk.
A thread-safe memory resource that manages pools of fixed-size blocks.
A non-thread-safe memory resource that manages pools of fixed-size blocks.
A memory resource that allocates from a fixed-size buffer.
The standard shared mutex type.
A simple scoped lock type.