Files
scylla/reactor.hh
2014-08-10 08:56:33 +03:00

169 lines
3.7 KiB
C++

/*
* reactor.hh
*
* Created on: Aug 1, 2014
* Author: avi
*/
#ifndef REACTOR_HH_
#define REACTOR_HH_
#include <memory>
#include <libaio.h>
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unordered_map>
#include <netinet/ip.h>
#include <cstring>
#include <cassert>
class socket_address;
class reactor;
class pollable_fd;
struct ipv4_addr {
uint8_t host[4];
uint16_t port;
};
socket_address make_ipv4_address(ipv4_addr addr);
class socket_address {
private:
union {
::sockaddr_storage sas;
::sockaddr sa;
::sockaddr_in in;
} u;
friend socket_address make_ipv4_address(ipv4_addr addr);
friend class reactor;
};
template <typename T>
class promise;
template <typename T>
struct future_state {
virtual ~future_state();
promise<T>* promise;
bool value_valid = false;
bool ex_valid = false;
union {
T value;
std::exception_ptr ex;
} u;
void set(const T& value);
void set(T&& value);
void set_exception(std::exception_ptr ex);
T get() {
while (promise) {
promise->wait();
}
if (ex) {
std::rethrow_exception(ex);
}
return std::move(u.value);
}
};
template <typename T>
class future {
std::unique_ptr<future_state<T>> _state;
public:
T get() {
return _state.get();
}
template <typename Func>
void then(Func func) {
}
};
class reactor {
class task;
public:
int _epollfd;
io_context_t _io_context;
private:
class task {
public:
virtual ~task() {}
virtual void run() = 0;
};
template <typename Func>
class lambda_task : public task {
Func _func;
public:
lambda_task(Func func) : _func(func) {}
virtual void run() { _func(); }
};
template <typename Func>
std::unique_ptr<task>
make_task(Func func) {
return std::make_unique<lambda_task<Func>>(func);
}
void epoll_add_in(pollable_fd& fd, std::unique_ptr<task> t);
void epoll_add_out(pollable_fd& fd, std::unique_ptr<task> t);
void abort_on_error(int ret);
public:
reactor();
~reactor();
std::unique_ptr<pollable_fd> listen(socket_address sa);
template <typename Func>
void accept(pollable_fd& listenfd, Func with_pfd_sockaddr);
future<std::unique_ptr<pollable_fd>> accept(pollable_fd& listen_fd)
future<size_t> read_some(pollable_fd& fd, void* buffer, size_t size);
template <typename Func>
void read_some(pollable_fd& fd, void* buffer, size_t len, Func with_len);
void run();
friend class pollable_fd;
};
class pollable_fd {
protected:
explicit pollable_fd(int fd) : fd(fd) {}
pollable_fd(const pollable_fd&) = delete;
void operator=(const pollable_fd&) = delete;
int fd;
int events = 0;
std::unique_ptr<reactor::task> pollin;
std::unique_ptr<reactor::task> pollout;
friend class reactor;
};
template <typename Func>
inline
void reactor::accept(pollable_fd& listenfd, Func with_pfd_sockaddr) {
auto lfd = listenfd.fd;
epoll_add_in(listenfd, make_task([=] {
socket_address sa;
socklen_t sl = sizeof(&sa.u.sas);
int fd = ::accept4(lfd, &sa.u.sa, &sl, SOCK_NONBLOCK | SOCK_CLOEXEC);
assert(fd != -1);
auto pfd = std::unique_ptr<pollable_fd>(new pollable_fd(fd));
with_pfd_sockaddr(std::move(pfd), sa);
}));
}
template <typename Func>
void reactor::read_some(pollable_fd& fd, void* buffer, size_t len, Func with_len) {
auto rfd = fd.fd;
epoll_add_in(fd, make_task([=] {
ssize_t r = ::recv(rfd, buffer, len, 0);
assert(r != -1);
with_len(len);
}));
}
#endif /* REACTOR_HH_ */