libubox/uloop.h
Jo-Philipp Wich 82fa6480de uloop: add support for interval timers
So far, the only way to implement periodic interval timers was to use
one-shot uloop_timeout timers which are rearmed within their completion
callback immediately on expiration.

While simple, this approach is not very precise and interval lengths will
slowly drift over time, due to callback execution overhead, scheduling
granularity etc.

In order to make uloop provide stable and precise interval timer
capabilities, this commit introduces a new `uloop_interval` structure
along with the new related `uloop_interval_set()`, `uloop_interval_cancel()`
and `uloop_interval_remaining()` api functions.

Periodic timers are implemented using the timerfd facility an Linux and
kqueue EVFILT_TIMER events on macOS/BSD.

The Lua binding has been updated to include support for the new timer type
as well.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2023-11-02 17:49:55 +01:00

138 lines
3.4 KiB
C

/*
* uloop - event loop implementation
*
* Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _ULOOP_H__
#define _ULOOP_H__
#include <sys/time.h>
#include <sys/types.h>
#include <stdbool.h>
#include <stdint.h>
#include <signal.h>
#if defined(__APPLE__) || defined(__FreeBSD__)
#define USE_KQUEUE
#else
#define USE_EPOLL
#endif
#include "list.h"
struct uloop_fd;
struct uloop_timeout;
struct uloop_process;
struct uloop_interval;
typedef void (*uloop_fd_handler)(struct uloop_fd *u, unsigned int events);
typedef void (*uloop_timeout_handler)(struct uloop_timeout *t);
typedef void (*uloop_process_handler)(struct uloop_process *c, int ret);
typedef void (*uloop_interval_handler)(struct uloop_interval *t);
#define ULOOP_READ (1 << 0)
#define ULOOP_WRITE (1 << 1)
#define ULOOP_EDGE_TRIGGER (1 << 2)
#define ULOOP_BLOCKING (1 << 3)
#define ULOOP_EVENT_MASK (ULOOP_READ | ULOOP_WRITE)
/* internal flags */
#define ULOOP_EVENT_BUFFERED (1 << 4)
#ifdef USE_KQUEUE
#define ULOOP_EDGE_DEFER (1 << 5)
#endif
#define ULOOP_ERROR_CB (1 << 6)
struct uloop_fd
{
uloop_fd_handler cb;
int fd;
bool eof;
bool error;
bool registered;
uint8_t flags;
};
struct uloop_timeout
{
struct list_head list;
bool pending;
uloop_timeout_handler cb;
struct timeval time;
};
struct uloop_process
{
struct list_head list;
bool pending;
uloop_process_handler cb;
pid_t pid;
};
struct uloop_interval
{
uloop_interval_handler cb;
uint64_t expirations;
union {
struct uloop_fd ufd;
struct {
int64_t fired;
unsigned int msecs;
} time;
} private;
};
extern bool uloop_cancelled;
extern bool uloop_handle_sigchld;
extern uloop_fd_handler uloop_fd_set_cb;
int uloop_fd_add(struct uloop_fd *sock, unsigned int flags);
int uloop_fd_delete(struct uloop_fd *sock);
int uloop_get_next_timeout(void);
int uloop_timeout_add(struct uloop_timeout *timeout);
int uloop_timeout_set(struct uloop_timeout *timeout, int msecs);
int uloop_timeout_cancel(struct uloop_timeout *timeout);
int uloop_timeout_remaining(struct uloop_timeout *timeout) __attribute__((deprecated("use uloop_timeout_remaining64")));
int64_t uloop_timeout_remaining64(struct uloop_timeout *timeout);
int uloop_process_add(struct uloop_process *p);
int uloop_process_delete(struct uloop_process *p);
int uloop_interval_set(struct uloop_interval *timer, unsigned int msecs);
int uloop_interval_cancel(struct uloop_interval *timer);
int64_t uloop_interval_remaining(struct uloop_interval *timer);
bool uloop_cancelling(void);
static inline void uloop_end(void)
{
uloop_cancelled = true;
}
int uloop_init(void);
int uloop_run_timeout(int timeout);
static inline int uloop_run(void)
{
return uloop_run_timeout(-1);
}
void uloop_done(void);
#endif