YurCO - Yurial's coroutines.

Little epoll-reactor based on libc coroutines.

class Stack // single stack for coroutine
{
        Stack(size_t size, bool protect=true);  // size - size of stack without size of stack protect-pages,
                                                // protect - create two protect-pages (at begin and at end of stack area).

char*   data() const noexcept;                  // address of begin stack area
size_t  size() const noexcept;                  // size of stack area
};


class StackPool // pool of stacks
{
        StackPool(const size_t stack_size, bool protect=true);  // arguments passed to Stack() contructor
Stack   pop();                                                  // pop one Stack from pool or create new
void    push(Stack&& stack);                                    // push Stack to pool;
};


class Coroutine // single coroutine
{
template <class Func, class... Args, typename = typename std::enable_if<std::is_invocable_r_v<void, Func, Coroutine&, Args&...>>::type>
        Coroutine(Stack&& stack, Func&& func, Args&&... args) noexcept; // create a new Coroutine
bool    is_completed() const noexcept;                                  // true when the coroutine is completely completed
bool    is_running() const noexcept;                                    // coroutine now in progress
void    yield();                                                        // switch to called thread
void    operator() ();                                                  // switch to coroutine
void    operator() (const std::nothrow_t&) noexcept;                    // --//--
void    set_exception(const std::exception_ptr& e) noexcept;            // set exception to send to or from coroutine
                                                                        // exception raised at end of operator() or yield() call
const std::exception_ptr& get_exception() const noexcept;               // inspect current exception
void    rethrow();                                                      // throw exception, if possible
Stack&& take_away_stack() noexcept;                                     // take stack from coroutine. 
                                                                        // used to store stack in pool, before coroutine deleted.
};


class Reactor // epoll reactor
{
        Reactor(const size_t stack_size, bool protect_stack=true) noexcept;             // arguments passed to StackPool
void    coroutine(Func&& func, Args&&... args) noexcept;                                // create new coroutine, arguments passed to Coroutine()
void    run(const size_t batch_size=16, const size_t events_at_once=32*1024) noexcept;  // run reactor, execute coroutines
void    terminate() noexcept;                                                           // terminate coroutines and exit from run()
void    suspend(Coroutine& coro, yurco::fd& fd, int events);                            // suspend coroutine while events on fd not occour
                                                                                        // this method useful for epoll-handled filr descriptors
void    close(unistd::fd::native_type fd);                                              // remove file descriptor from epoll and close
int     close(unistd::fd::native_type fd, const std::nothrow_t&) noexcept;              // --//--
};