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mirror of https://github.com/matrix-construct/construct synced 2024-09-27 11:18:51 +02:00

ircd: Add another allocator.

This commit is contained in:
Jason Volk 2017-04-02 20:50:59 -07:00
parent 5f70ce28d0
commit 35587a5c9c

View file

@ -30,24 +30,22 @@ namespace ircd {
struct allocator
{
struct state;
template<class T = char> struct dynamic;
template<class T = char, size_t = 512> struct fixed;
};
template<class T,
size_t size>
struct allocator::fixed
struct allocator::state
{
struct allocator;
using word_t = unsigned long long;
using word_t = unsigned long long;
using size_type = std::size_t;
size_t size { 0 };
word_t *avail { nullptr };
size_t last { 0 };
std::array<word_t, size / 8> avail {{ 0 }};
std::array<T, size> buf alignas(16);
static constexpr uint word_bytes { sizeof(word_t) };
static constexpr uint word_bits { word_bytes * 8 };
static uint byte(const uint &i) { return i / word_bits; }
static uint bit(const uint &i) { return i % word_bits; }
static uint byte(const uint &i) { return i / (sizeof(word_t) * 8); }
static uint bit(const uint &i) { return i % (sizeof(word_t) * 8); }
static word_t mask(const uint &pos) { return word_t(1) << bit(pos); }
bool test(const uint &pos) const { return avail[byte(pos)] & mask(pos); }
@ -55,9 +53,65 @@ struct allocator::fixed
void btc(const uint &pos) { avail[byte(pos)] &= ~mask(pos); }
uint next(const size_t &n) const;
void deallocate(const uint &p, const size_t &n);
uint allocate(const size_t &n, const uint &hint = -1);
state(const size_t &size = 0,
word_t *const &avail = nullptr)
:size{size}
,avail{avail}
,last{0}
{}
};
template<class T,
size_t max>
struct allocator::fixed
:state
{
struct allocator;
std::array<word_t, max / 8> avail {{ 0 }};
std::array<T, max> buf alignas(16);
public:
allocator operator()();
operator allocator();
fixed()
:state{max, avail.data()}
{}
};
template<class T>
struct allocator::dynamic
:state
{
struct allocator;
size_t head_size, data_size;
std::unique_ptr<uint8_t[]> arena;
T *buf;
public:
allocator operator()();
operator allocator();
dynamic(const size_t &size)
:state{size}
,head_size{size / 8}
,data_size{sizeof(T) * size + 16}
,arena
{
new uint8_t[head_size + data_size]
}
,buf
{
reinterpret_cast<T *>(arena.get() + head_size + (head_size % 16))
}
{
state::avail = reinterpret_cast<word_t *>(arena.get());
}
};
template<class T,
@ -72,84 +126,125 @@ struct allocator::fixed<T, size>::allocator
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
template<class U> struct rebind
fixed *s;
public:
template<class U, size_t S> struct rebind
{
using other = typename fixed<U, size>::allocator;
using other = typename fixed<U, S>::allocator;
};
size_type max_size() const { return size; }
auto address(reference x) const { return &x; }
auto address(const_reference x) const { return &x; }
fixed *s;
pointer allocate(const size_type &n, const const_pointer &hint = nullptr)
{
const uint hintpos(hint? hint - s->buf.data() : -1);
return s->buf.data() + s->state::allocate(n, hint);
}
pointer allocate(const size_type &n, const const_pointer &hint = nullptr);
void deallocate(const pointer &p, const size_type &n);
void deallocate(const pointer &p, const size_type &n)
{
const uint pos(p - s->buf.data());
s->state::deallocate(pos, n);
}
template<class U, size_t S>
allocator(const typename fixed<U, S>::allocator &) noexcept
:s{reinterpret_cast<fixed *>(s.s)}
{}
allocator(fixed &s) noexcept
:s{&s}
{}
allocator(fixed &) noexcept;
allocator(allocator &&) = default;
allocator(const allocator &) = default;
template<class U, size_t S> allocator(const typename fixed<U, S>::allocator &) noexcept;
friend bool operator==(const allocator &a, const allocator &b)
{
return &a == &b;
}
friend bool operator!=(const allocator &a, const allocator &b)
{
return &a == &b;
}
};
template<class... T1,
class... T2>
bool operator==(const typename allocator::fixed<T1...>::allocator &,
const typename allocator::fixed<T2...>::allocator &);
template<class T>
struct allocator::dynamic<T>::allocator
{
using value_type = T;
using pointer = T *;
using const_pointer = const T *;
using reference = T &;
using const_reference = const T &;
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
template<class... T1,
class... T2>
bool operator!=(const typename allocator::fixed<T1...>::allocator &,
const typename allocator::fixed<T2...>::allocator &);
dynamic *s;
public:
template<class U> struct rebind
{
using other = typename dynamic<U>::allocator;
};
size_type max_size() const { return s->size; }
auto address(reference x) const { return &x; }
auto address(const_reference x) const { return &x; }
pointer allocate(const size_type &n, const const_pointer &hint = nullptr)
{
const uint hintpos(hint? hint - s->buf : -1);
return s->buf + s->state::allocate(n, hintpos);
}
void deallocate(const pointer &p, const size_type &n)
{
const uint pos(p - s->buf);
s->state::deallocate(pos, n);
}
template<class U>
allocator(const typename dynamic<U>::allocator &) noexcept
:s{reinterpret_cast<dynamic *>(s.s)}
{}
allocator(dynamic &s) noexcept
:s{&s}
{}
allocator(allocator &&) = default;
allocator(const allocator &) = default;
friend bool operator==(const allocator &a, const allocator &b)
{
return &a == &b;
}
friend bool operator!=(const allocator &a, const allocator &b)
{
return &a == &b;
}
};
} // namespace ircd
template<class T,
size_t size>
ircd::allocator::fixed<T, size>::allocator::allocator(fixed &s)
noexcept
:s{&s}
{}
template<class T,
size_t size>
template<class U,
size_t S>
ircd::allocator::fixed<T, size>::allocator::allocator(const typename fixed<U, S>::allocator &s)
noexcept
:s
template<class T>
typename ircd::allocator::dynamic<T>::allocator
ircd::allocator::dynamic<T>::operator()()
{
reinterpret_cast<typename fixed<T, size>::state *>(s.s)
}
{}
template<class T,
size_t size>
void
ircd::allocator::fixed<T, size>::allocator::deallocate(const pointer &p,
const size_type &n)
{
const uint pos(p - s->buf.data());
for(size_t i(0); i < n; ++i)
s->btc(pos + i);
return { *this };
}
template<class T,
size_t size>
typename ircd::allocator::fixed<T, size>::allocator::pointer
ircd::allocator::fixed<T, size>::allocator::allocate(const size_type &n,
const const_pointer &hint)
template<class T>
ircd::allocator::dynamic<T>::operator
allocator()
{
const auto next(s->next(n));
if(unlikely(next >= size)) // No block of n was found anywhere (next is past-the-end)
throw std::bad_alloc();
for(size_t i(0); i < n; ++i)
s->bts(next + i);
s->last = next + n;
return s->buf.data() + next;
return { *this };
}
template<class T,
@ -168,10 +263,31 @@ allocator()
return { *this };
}
template<class T,
size_t size>
uint
ircd::allocator::fixed<T, size>::next(const size_t &n)
inline void
ircd::allocator::state::deallocate(const uint &pos,
const size_type &n)
{
for(size_t i(0); i < n; ++i)
btc(pos + i);
}
inline uint
ircd::allocator::state::allocate(const size_type &n,
const uint &hint)
{
const auto next(this->next(n));
if(unlikely(next >= size)) // No block of n was found anywhere (next is past-the-end)
throw std::bad_alloc();
for(size_t i(0); i < n; ++i)
bts(next + i);
last = next + n;
return next;
}
inline uint
ircd::allocator::state::next(const size_t &n)
const
{
uint ret(last), rem(n);
@ -195,21 +311,3 @@ const
return ret - n;
}
template<class... T1,
class... T2>
bool
ircd::operator==(const typename allocator::fixed<T1...>::allocator &a,
const typename allocator::fixed<T2...>::allocator &b)
{
return &a == &b;
}
template<class... T1,
class... T2>
bool
ircd::operator!=(const typename allocator::fixed<T1...>::allocator &a,
const typename allocator::fixed<T2...>::allocator &b)
{
return &a != &b;
}