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/* Copyright (C) 2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*!
* \brief I/O multiplexing with context and timeouts for each fd.
*/
#pragma once
#include <stddef.h>
#include <poll.h>
#include <sys/time.h>
#include <signal.h>
#define FDSET_INIT_SIZE 256 /* Resize step. */
/*! \brief Set of filedescriptors with associated context and timeouts. */
typedef struct fdset {
unsigned n; /*!< Active fds. */
unsigned size; /*!< Array size (allocated). */
void* *ctx; /*!< Context for each fd. */
struct pollfd *pfd; /*!< poll state for each fd */
time_t *timeout; /*!< Timeout for each fd (seconds precision). */
} fdset_t;
/*! \brief Mark-and-sweep state. */
enum fdset_sweep_state {
FDSET_KEEP,
FDSET_SWEEP
};
/*! \brief Sweep callback (set, index, data) */
typedef enum fdset_sweep_state (*fdset_sweep_cb_t)(fdset_t*, int, void*);
/*!
* \brief Initialize fdset to given size.
*/
int fdset_init(fdset_t *set, unsigned size);
/*!
* \brief Destroy FDSET.
*
* \retval 0 if successful.
* \retval -1 on error.
*/
int fdset_clear(fdset_t* set);
/*!
* \brief Add file descriptor to watched set.
*
* \param set Target set.
* \param fd Added file descriptor.
* \param events Mask of watched events.
* \param ctx Context (optional).
*
* \retval index of the added fd if successful.
* \retval -1 on errors.
*/
int fdset_add(fdset_t *set, int fd, unsigned events, void *ctx);
/*!
* \brief Remove file descriptor from watched set.
*
* \param set Target set.
* \param i Index of the removed fd.
*
* \retval 0 if successful.
* \retval -1 on errors.
*/
int fdset_remove(fdset_t *set, unsigned i);
/*!
* \brief Set file descriptor watchdog interval.
*
* Set time (interval from now) after which the associated file descriptor
* should be sweeped (see fdset_sweep). Good example is setting a grace period
* of N seconds between socket activity. If socket is not active within
* <now, now + interval>, it is sweeped and potentially closed.
*
* \param set Target set.
* \param i Index for the file descriptor.
* \param interval Allowed interval without activity (seconds).
* -1 disables watchdog timer
*
* \retval 0 if successful.
* \retval -1 on errors.
*/
int fdset_set_watchdog(fdset_t* set, int i, int interval);
/*!
* \brief Sweep file descriptors with exceeding inactivity period.
*
* \param set Target set.
* \param cb Callback for sweeped descriptors.
* \param data Pointer to extra data.
*
* \retval number of sweeped descriptors.
* \retval -1 on errors.
*/
int fdset_sweep(fdset_t* set, fdset_sweep_cb_t cb, void *data);
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