You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
534 lines
13 KiB
534 lines
13 KiB
#pragma once
|
|
#include <mutex>
|
|
#include <algorithm>
|
|
#include <functional>
|
|
#include <memory>
|
|
#include <thread>
|
|
#include <optional>
|
|
|
|
namespace _details {
|
|
template<typename T>
|
|
using optional = std::optional<T>; //< Configuration constant on which optional to use to implement the rest of this file
|
|
auto nullopt = std::nullopt; //< Configuration constant on which optional to use to implement the rest of this file
|
|
|
|
struct awaiter {
|
|
void operator()(int duration) {
|
|
std::this_thread::sleep_for(std::chrono::milliseconds(duration));
|
|
}
|
|
};
|
|
|
|
struct defer_impl {
|
|
std::function<void(void)> fn;
|
|
|
|
~defer_impl() {
|
|
fn();
|
|
}
|
|
};
|
|
|
|
#ifdef defer
|
|
#warning "A defer macro is already defined and will be undefined after this file"
|
|
#undef defer
|
|
#endif
|
|
#define defer(name, h) _details::defer_impl _defer_slice ## name {[&](){(h);}};
|
|
|
|
struct _do_not_use_t {
|
|
};
|
|
constexpr _do_not_use_t do_not_use{};
|
|
}
|
|
|
|
namespace container {
|
|
|
|
template<typename T>
|
|
class circular_buffer_iterator {
|
|
struct M {
|
|
T *buffer;
|
|
size_t capacity;
|
|
size_t index;
|
|
};
|
|
|
|
M m;
|
|
|
|
explicit circular_buffer_iterator(M members)
|
|
: m{members} {}
|
|
|
|
public:
|
|
using difference_type = size_t;
|
|
using value_type = T;
|
|
using pointer = T *;
|
|
using reference = T &;
|
|
using iterator_category = std::bidirectional_iterator_tag;
|
|
|
|
|
|
circular_buffer_iterator(T *buffer, size_t capacity, size_t index)
|
|
: m{M{
|
|
.buffer = buffer,
|
|
.capacity = capacity,
|
|
.index = index
|
|
}} {}
|
|
|
|
circular_buffer_iterator &operator++() {
|
|
m.index = (m.index + 1) bitand (m.capacity - 1);
|
|
return *this;
|
|
}
|
|
|
|
circular_buffer_iterator operator++(int) {
|
|
M oth = m;
|
|
m.index = (m.index + 1) bitand (m.capacity - 1);
|
|
return circular_buffer_iterator{oth};
|
|
}
|
|
|
|
circular_buffer_iterator &operator--() {
|
|
m.index = (m.index - 1) bitand (m.capacity - 1);
|
|
return *this;
|
|
}
|
|
|
|
circular_buffer_iterator operator--(int) {
|
|
M oth = m;
|
|
m.index = (m.index - 1) bitand (m.capacity - 1);
|
|
return circular_buffer_iterator{oth};
|
|
}
|
|
|
|
T &operator*() {
|
|
return m.buffer[m.index];
|
|
}
|
|
|
|
bool operator==(const circular_buffer_iterator &oth) {
|
|
return m == oth.m;
|
|
}
|
|
|
|
bool operator!=(const circular_buffer_iterator &oth) {
|
|
return m.buffer != oth.m.buffer or m.index != oth.m.index or m.capacity != oth.m.capacity;
|
|
}
|
|
};
|
|
|
|
template<typename T>
|
|
class circular_buffer {
|
|
struct M {
|
|
std::unique_ptr<char[]> buffer;
|
|
size_t capacity;
|
|
size_t start;
|
|
size_t end;
|
|
};
|
|
|
|
M m;
|
|
|
|
M null_members() {
|
|
return M{
|
|
.buffer = nullptr,
|
|
.capacity = 0,
|
|
.start = 0,
|
|
.end = 0
|
|
};
|
|
}
|
|
|
|
static size_t validate_capacity(size_t new_capacity) {
|
|
if (new_capacity < 2) return 2;
|
|
if ((new_capacity bitand (new_capacity - 1))) {
|
|
new_capacity = new_capacity & (new_capacity >> 1);
|
|
new_capacity = new_capacity & (new_capacity >> 2);
|
|
new_capacity = new_capacity & (new_capacity >> 4);
|
|
new_capacity = new_capacity & (new_capacity >> 8);
|
|
new_capacity = new_capacity & (new_capacity >> 16);
|
|
new_capacity = new_capacity & (new_capacity >> 31);
|
|
return new_capacity + 1;
|
|
}
|
|
return new_capacity;
|
|
}
|
|
|
|
explicit circular_buffer(M s) : m(std::move(s)) {}
|
|
|
|
public:
|
|
circular_buffer()
|
|
: m{null_members()} {}
|
|
|
|
circular_buffer(const circular_buffer &oth)
|
|
: m(null_members()) {
|
|
if (oth.m.capacity == 0) return;
|
|
reserve(oth.m.capacity);
|
|
for (const auto &elem: oth) {
|
|
push_back(elem);
|
|
}
|
|
}
|
|
|
|
circular_buffer(circular_buffer &&oth) noexcept
|
|
: m{std::exchange(oth.m, null_members())} {}
|
|
|
|
circular_buffer &operator=(const circular_buffer &oth) {
|
|
if (this == &oth) return *this;
|
|
while (pop_front());
|
|
reserve(oth.m.capacity);
|
|
for (const auto &elem: oth) {
|
|
push_back(elem);
|
|
}
|
|
};
|
|
|
|
circular_buffer &operator=(circular_buffer &&oth) noexcept {
|
|
std::swap(m, oth.m);
|
|
}
|
|
|
|
circular_buffer_iterator<T> begin() {
|
|
return circular_buffer_iterator<T>(reinterpret_cast<T *>(m.buffer.get()), m.capacity, m.start);
|
|
}
|
|
|
|
circular_buffer_iterator<T> end() {
|
|
return circular_buffer_iterator<T>(reinterpret_cast<T *>(m.buffer.get()), m.capacity, m.end);
|
|
}
|
|
|
|
circular_buffer_iterator<const T> begin() const {
|
|
return circular_buffer_iterator<const T>{
|
|
m.buffer.get(), m.capacity, m.start
|
|
};
|
|
}
|
|
|
|
circular_buffer_iterator<const T> end() const {
|
|
return circular_buffer_iterator<const T>{
|
|
m.buffer.get(), m.capacity, m.end
|
|
};
|
|
}
|
|
|
|
void reserve(size_t new_capacity) {
|
|
new_capacity = validate_capacity(new_capacity);
|
|
if (new_capacity <= m.capacity) return;
|
|
|
|
circular_buffer temp{M{
|
|
.buffer = std::make_unique<char[]>(new_capacity * sizeof(T)),
|
|
.capacity = new_capacity,
|
|
.start = 0,
|
|
.end = 0
|
|
}};
|
|
|
|
_details::optional <T> value = pop_front();
|
|
while (value) {
|
|
temp.push_back(std::move(value.value()));
|
|
value = pop_front();
|
|
}
|
|
std::swap(m, temp.m);
|
|
}
|
|
|
|
void push_front(T value) {
|
|
if (m.capacity == 0) reserve(2);
|
|
size_t new_start = (m.start - 1) bitand (m.capacity - 1);
|
|
if (new_start == m.end) {
|
|
reserve(m.capacity << 1);
|
|
}
|
|
new_start = (m.start - 1) bitand (m.capacity - 1);
|
|
::new(reinterpret_cast<T *>(m.buffer.get()) + new_start) T(value);
|
|
m.start = new_start;
|
|
}
|
|
|
|
_details::optional <T> pop_front() noexcept {
|
|
if (m.start == m.end) return _details::nullopt;
|
|
_details::optional <T> ret = std::move(*begin());
|
|
(*begin()).~T();
|
|
m.start = (m.start + 1) bitand (m.capacity - 1);
|
|
return ret;
|
|
}
|
|
|
|
void push_back(T value) {
|
|
if (m.capacity == 0) reserve(2);
|
|
size_t new_end = (m.end + 1) bitand (m.capacity - 1);
|
|
if (new_end == m.start) {
|
|
reserve(m.capacity << 1);
|
|
}
|
|
new_end = (m.end + 1) bitand (m.capacity - 1);
|
|
::new(reinterpret_cast<T *>(m.buffer.get()) + m.end) T(value);
|
|
m.end = new_end;
|
|
}
|
|
|
|
_details::optional <T> pop_back() noexcept {
|
|
if (m.start == m.end) return _details::nullopt;
|
|
auto last = --end();
|
|
_details::optional <T> ret = std::move(*last);
|
|
(*last).~T();
|
|
m.end = (m.end - 1) bitand (m.capacity - 1);
|
|
return ret;
|
|
}
|
|
|
|
bool empty() const {
|
|
return m.start == m.end;
|
|
}
|
|
|
|
~circular_buffer() {
|
|
while (not empty()) {
|
|
pop_front();
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
namespace _details {
|
|
template<typename T>
|
|
class channel_impl {
|
|
mutable std::mutex lock;
|
|
container::circular_buffer<T> data;
|
|
int active_writer = 0;
|
|
int active_reader = 0;
|
|
public:
|
|
struct reader_t{};
|
|
struct writer_t{};
|
|
static constexpr reader_t reader{};
|
|
static constexpr writer_t writer{};
|
|
void close(reader_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
active_reader -= 1;
|
|
}
|
|
void close(writer_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
active_writer -=1;
|
|
}
|
|
void register_one(reader_t, _details::_do_not_use_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
active_reader += 1;
|
|
}
|
|
void register_one(writer_t, _details::_do_not_use_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
active_writer += 1;
|
|
}
|
|
bool closed(reader_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
return active_reader == 0;
|
|
}
|
|
bool closed(writer_t) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
return active_writer == 0;
|
|
}
|
|
bool push(const T& elem) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
if(active_reader == 0) return true;
|
|
if(active_writer == 0) return false;
|
|
data.push_front(elem);
|
|
return true;
|
|
}
|
|
bool push(T&& elem) {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
if(active_reader == 0) return true;
|
|
if(active_writer == 0) return false;
|
|
data.push_front(elem);
|
|
return true;
|
|
}
|
|
_details::optional<T> pop() {
|
|
std::lock_guard<std::mutex> d{lock};
|
|
if(active_reader == 0) return _details::nullopt;
|
|
return data.pop_back();
|
|
}
|
|
bool empty() const {
|
|
return active_writer == 0 && data.empty();
|
|
}
|
|
};
|
|
}
|
|
|
|
/**
|
|
* This is a read only channel of its specified template parameter type
|
|
* @tparam T The type of element that is transmitted through the channel
|
|
*/
|
|
template<typename T>
|
|
class channel_r {
|
|
std::shared_ptr<_details::channel_impl<T>> impl;
|
|
public:
|
|
/**
|
|
* This constructor should **NOT** be used
|
|
*/
|
|
channel_r(_details::_do_not_use_t, std::shared_ptr<_details::channel_impl<T>> _impl)
|
|
: impl(_impl) {
|
|
impl->register_one(_details::channel_impl<T>::reader, _details::do_not_use);
|
|
}
|
|
|
|
/**
|
|
* Copy constructor for channel receiver
|
|
*/
|
|
channel_r(const channel_r& oth) {
|
|
if(oth.impl.get() == impl.get()) return;
|
|
impl = oth.impl;
|
|
if(impl) impl->register_one(_details::channel_impl<T>::reader, _details::do_not_use);
|
|
}
|
|
|
|
/**
|
|
* Obtains a value from the queue
|
|
* @return either a value if one is available in the queue, or no value
|
|
*/
|
|
_details::optional<T> pop() {
|
|
return impl->pop();
|
|
}
|
|
|
|
/**
|
|
* Verifies if the queue is empty and has no sender available
|
|
* @return true if the queue will never contain new elements
|
|
* @return false if the queue may at some point in the future contain new elements
|
|
*/
|
|
bool empty() const {
|
|
return impl->empty();
|
|
}
|
|
|
|
~channel_r() {
|
|
impl->close(_details::channel_impl<T>::reader);
|
|
}
|
|
|
|
/**
|
|
* Verifies if the writer side is still open
|
|
* @return true if the writer side is closed
|
|
* @return false if the writer side is still open
|
|
*/
|
|
bool closed() {
|
|
return impl->closed(_details::channel_impl<T>::writer);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* This is a write only channel of its specified template parameter type
|
|
* @tparam T The type of element that is transmitted through the channel
|
|
*/
|
|
template<typename T>
|
|
class channel_w {
|
|
std::shared_ptr<_details::channel_impl<T>> impl;
|
|
public:
|
|
/**
|
|
* This constructor should **NOT** be used
|
|
*/
|
|
channel_w(_details::_do_not_use_t, std::shared_ptr<_details::channel_impl<T>> _impl)
|
|
: impl(_impl) {
|
|
impl->register_one(_details::channel_impl<T>::writer, _details::do_not_use);
|
|
}
|
|
|
|
/**
|
|
* Copy constructor for channel sender
|
|
*/
|
|
channel_w(const channel_w& oth) {
|
|
if(oth.impl.get() == impl.get()) return;
|
|
impl = oth.impl;
|
|
if(impl) impl->register_one(_details::channel_impl<T>::writer, _details::do_not_use);
|
|
}
|
|
|
|
/**
|
|
* Sends an element through the channel
|
|
* @param elem the element to send
|
|
* @return true is the element was successfully pushed
|
|
*/
|
|
bool push(const T& elem) {
|
|
return impl->push(elem);
|
|
}
|
|
/**
|
|
* Sends an element through the channel
|
|
* @param elem the element to send
|
|
* @return true is the element was successfully pushed
|
|
*/
|
|
bool push(T&& elem) {
|
|
return impl->push(std::forward<T>(elem));
|
|
}
|
|
~channel_w() {
|
|
impl->close(_details::channel_impl<T>::writer);
|
|
}
|
|
|
|
/**
|
|
* Verifies if the reader side is still open
|
|
* @return true if the reader side is closed
|
|
* @return false if the reader side is still open
|
|
*/
|
|
bool closed() {
|
|
return impl->closed(_details::channel_impl<T>::reader);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Creates a pipe made of a reader channel and a writer channel allowing to transmit objects of the specified type between units of concurrency
|
|
* @tparam T The type to allow transfers of
|
|
* @return a pair `[writer, reader]` that are connected
|
|
*/
|
|
template<typename T>
|
|
std::pair<channel_w<T>, channel_r<T>> make_pipe() {
|
|
auto shared_ch = std::make_shared<_details::channel_impl<T>>();
|
|
return {{_details::do_not_use, shared_ch}, {_details::do_not_use, shared_ch}};
|
|
}
|
|
|
|
template<typename T, typename awaiter = _details::awaiter>
|
|
class promise;
|
|
|
|
/**
|
|
* This class allows instantiation and manipulation of the receiving side of a promise
|
|
* @tparam T The type that will be received
|
|
* @tparam awaiter A type that has an `operator()(int)` that represent how this object must wait
|
|
*/
|
|
template<typename T, typename awaiter = _details::awaiter>
|
|
class future {
|
|
channel_r<T> conduit;
|
|
friend class promise<T, awaiter>;
|
|
|
|
future(channel_r<T>&& c) : conduit(c) {};
|
|
|
|
public:
|
|
/**
|
|
* Waits for the future to be set
|
|
*/
|
|
void wait() {
|
|
for(;;) {
|
|
if (conduit.closed()) return;
|
|
awaiter{}(30);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Obtains the received value.
|
|
*
|
|
* @note This method should never be called before wait, and should not be called more than once
|
|
* @return
|
|
*/
|
|
_details::optional<T> get() {
|
|
return conduit.pop();
|
|
}
|
|
};
|
|
|
|
/**
|
|
* This class allows to represent waiting for a value from one unit of concurrency into another one.
|
|
* @tparam T The type of the value that will be transmitted
|
|
* @tparam awaiter A type that has an `operator()(int)` that represent how `future`s created by this object must wait
|
|
*/
|
|
template<typename T, typename awaiter>
|
|
class promise {
|
|
_details::optional<channel_w<T>> conduit;
|
|
_details::optional<channel_r<T>> future_conduit;
|
|
public:
|
|
/**
|
|
* Initializes a valid promise
|
|
*/
|
|
promise() {
|
|
auto pipe = make_pipe<T>();
|
|
conduit = std::move(pipe.first);
|
|
future_conduit = std::move(pipe.second);
|
|
}
|
|
|
|
/**
|
|
* Obtains the receiving end of this promise
|
|
*
|
|
* @note This method should never be called more than once
|
|
* @return A future that can be awaited from
|
|
*/
|
|
future<T, awaiter> get_future() {
|
|
defer(cleanup, future_conduit = _details::nullopt);
|
|
return future<T, awaiter> {
|
|
std::move(future_conduit.value())
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Sets the value of the future to the provided value
|
|
*
|
|
* @note This method and methods sharing the same name should never be called more than once
|
|
* @param value The value to transmit
|
|
*/
|
|
void set_value(T&& value) {
|
|
conduit.value().push(std::forward<T>(value));
|
|
conduit = _details::nullopt;
|
|
}
|
|
|
|
/**
|
|
* Sets the value of the future to the provided value
|
|
*
|
|
* @note This method and methods sharing the same name should never be called more than once
|
|
* @param value The value to transmit
|
|
*/
|
|
void set_value(const T& value) {
|
|
conduit.value().push(value);
|
|
conduit = _details::nullopt;
|
|
}
|
|
};
|
|
|
|
#undef defer
|