poll.hpp

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/* SPDX-License-Identifier: MPL-2.0 */
 
#ifndef __ZMQ_POLL_HPP_INCLUDED__
#define __ZMQ_POLL_HPP_INCLUDED__
 
//  poller.hpp decides which polling mechanism to use.
#include "poller.hpp"
#if defined ZMQ_IOTHREAD_POLLER_USE_POLL
 
#if defined ZMQ_HAVE_WINDOWS
#error                                                                         \
  "poll is broken on Windows for the purpose of the I/O thread poller, use select instead; "\
  "see https://github.com/zeromq/libzmq/issues/3107"
#endif
 
#include <poll.h>
#include <stddef.h>
#include <vector>
 
#include "ctx.hpp"
#include "fd.hpp"
#include "thread.hpp"
#include "poller_base.hpp"
 
namespace zmq
{
struct i_poll_events;
 
//  Implements socket polling mechanism using the POSIX.1-2001
//  poll() system call.
 
class poll_t ZMQ_FINAL : public worker_poller_base_t
{
  public:
    typedef fd_t handle_t;
 
    poll_t (const thread_ctx_t &ctx_);
    ~poll_t ();
 
    //  "poller" concept.
    //  These methods may only be called from an event callback; add_fd may also be called before start.
    handle_t add_fd (fd_t fd_, zmq::i_poll_events *events_);
    void rm_fd (handle_t handle_);
    void set_pollin (handle_t handle_);
    void reset_pollin (handle_t handle_);
    void set_pollout (handle_t handle_);
    void reset_pollout (handle_t handle_);
    void stop ();
 
    static int max_fds ();
 
  private:
    //  Main event loop.
    void loop () ZMQ_FINAL;
 
    void cleanup_retired ();
 
    struct fd_entry_t
    {
        fd_t index;
        zmq::i_poll_events *events;
    };
 
    //  This table stores data for registered descriptors.
    typedef std::vector<fd_entry_t> fd_table_t;
    fd_table_t fd_table;
 
    //  Pollset to pass to the poll function.
    typedef std::vector<pollfd> pollset_t;
    pollset_t pollset;
 
    //  If true, there's at least one retired event source.
    bool retired;
 
    ZMQ_NON_COPYABLE_NOR_MOVABLE (poll_t)
};
 
typedef poll_t poller_t;
}
 
#endif
 
#endif