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/* ==========================================================================
* timeout.h - Tickless hierarchical timing wheel.
* --------------------------------------------------------------------------
* Copyright (c) 2013, 2014 William Ahern
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do so, subject to the
* following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
* NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
* ==========================================================================
*/
#ifndef TIMEOUT_H
#define TIMEOUT_H
#include <stdbool.h> /* bool */
#include <stdio.h> /* FILE */
#include <inttypes.h> /* PRIu64 PRIx64 PRIX64 uint64_t */
#include "tor_queue.h" /* TAILQ(3) */
/*
* V E R S I O N I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#if !defined TIMEOUT_PUBLIC
#define TIMEOUT_PUBLIC
#endif
#define TIMEOUT_VERSION TIMEOUT_V_REL
#define TIMEOUT_VENDOR "william@25thandClement.com"
#define TIMEOUT_V_REL 0x20160226
#define TIMEOUT_V_ABI 0x20160224
#define TIMEOUT_V_API 0x20160226
TIMEOUT_PUBLIC int timeout_version(void);
TIMEOUT_PUBLIC const char *timeout_vendor(void);
TIMEOUT_PUBLIC int timeout_v_rel(void);
TIMEOUT_PUBLIC int timeout_v_abi(void);
TIMEOUT_PUBLIC int timeout_v_api(void);
/*
* I N T E G E R T Y P E I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define TIMEOUT_C(n) UINT64_C(n)
#define TIMEOUT_PRIu PRIu64
#define TIMEOUT_PRIx PRIx64
#define TIMEOUT_PRIX PRIX64
#define TIMEOUT_mHZ TIMEOUT_C(1000)
#define TIMEOUT_uHZ TIMEOUT_C(1000000)
#define TIMEOUT_nHZ TIMEOUT_C(1000000000)
typedef uint64_t timeout_t;
#define timeout_error_t int /* for documentation purposes */
/*
* C A L L B A C K I N T E R F A C E
*
* Callback function parameters unspecified to make embedding into existing
* applications easier.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#ifndef TIMEOUT_CB_OVERRIDE
struct timeout_cb {
void (*fn)(void);
void *arg;
}; /* struct timeout_cb */
#endif
/*
* T I M E O U T I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#ifndef TIMEOUT_DISABLE_INTERVALS
#define TIMEOUT_INT 0x01 /* interval (repeating) timeout */
#endif
#define TIMEOUT_ABS 0x02 /* treat timeout values as absolute */
#define TIMEOUT_INITIALIZER(flags) { (flags) }
#define timeout_setcb(to, fn, arg) do { \
(to)->callback.fn = (fn); \
(to)->callback.arg = (arg); \
} while (0)
struct timeout {
int flags;
timeout_t expires;
/* absolute expiration time */
struct timeout_list *pending;
/* timeout list if pending on wheel or expiry queue */
TOR_TAILQ_ENTRY(timeout) tqe;
/* entry member for struct timeout_list lists */
#ifndef TIMEOUT_DISABLE_CALLBACKS
struct timeout_cb callback;
/* optional callback information */
#endif
#ifndef TIMEOUT_DISABLE_INTERVALS
timeout_t interval;
/* timeout interval if periodic */
#endif
#ifndef TIMEOUT_DISABLE_RELATIVE_ACCESS
struct timeouts *timeouts;
/* timeouts collection if member of */
#endif
}; /* struct timeout */
TIMEOUT_PUBLIC struct timeout *timeout_init(struct timeout *, int);
/* initialize timeout structure (same as TIMEOUT_INITIALIZER) */
#ifndef TIMEOUT_DISABLE_RELATIVE_ACCESS
TIMEOUT_PUBLIC bool timeout_pending(struct timeout *);
/* true if on timing wheel, false otherwise */
TIMEOUT_PUBLIC bool timeout_expired(struct timeout *);
/* true if on expired queue, false otherwise */
TIMEOUT_PUBLIC void timeout_del(struct timeout *);
/* remove timeout from any timing wheel (okay if not member of any) */
#endif
/*
* T I M I N G W H E E L I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct timeouts;
TIMEOUT_PUBLIC struct timeouts *timeouts_open(timeout_t, timeout_error_t *);
/* open a new timing wheel, setting optional HZ (for float conversions) */
TIMEOUT_PUBLIC void timeouts_close(struct timeouts *);
/* destroy timing wheel */
TIMEOUT_PUBLIC timeout_t timeouts_hz(struct timeouts *);
/* return HZ setting (for float conversions) */
TIMEOUT_PUBLIC void timeouts_update(struct timeouts *, timeout_t);
/* update timing wheel with current absolute time */
TIMEOUT_PUBLIC void timeouts_step(struct timeouts *, timeout_t);
/* step timing wheel by relative time */
TIMEOUT_PUBLIC timeout_t timeouts_get_curtime(struct timeouts *);
/* Return the current tick. */
TIMEOUT_PUBLIC timeout_t timeouts_timeout(struct timeouts *);
/* return interval to next required update */
TIMEOUT_PUBLIC void timeouts_add(struct timeouts *, struct timeout *, timeout_t);
/* add timeout to timing wheel */
TIMEOUT_PUBLIC void timeouts_del(struct timeouts *, struct timeout *);
/* remove timeout from any timing wheel or expired queue (okay if on neither) */
TIMEOUT_PUBLIC struct timeout *timeouts_get(struct timeouts *);
/* return any expired timeout (caller should loop until NULL-return) */
TIMEOUT_PUBLIC bool timeouts_pending(struct timeouts *);
/* return true if any timeouts pending on timing wheel */
TIMEOUT_PUBLIC bool timeouts_expired(struct timeouts *);
/* return true if any timeouts on expired queue */
TIMEOUT_PUBLIC bool timeouts_check(struct timeouts *, FILE *);
/* return true if invariants hold. describes failures to optional file handle. */
#define TIMEOUTS_PENDING 0x10
#define TIMEOUTS_EXPIRED 0x20
#define TIMEOUTS_ALL (TIMEOUTS_PENDING|TIMEOUTS_EXPIRED)
#define TIMEOUTS_CLEAR 0x40
#define TIMEOUTS_IT_INITIALIZER(flags) { (flags), 0, 0, 0, 0 }
#define TIMEOUTS_IT_INIT(cur, _flags) do { \
(cur)->flags = (_flags); \
(cur)->pc = 0; \
} while (0)
struct timeouts_it {
int flags;
unsigned pc, i, j;
struct timeout *to;
}; /* struct timeouts_it */
TIMEOUT_PUBLIC struct timeout *timeouts_next(struct timeouts *, struct timeouts_it *);
/* return next timeout in pending wheel or expired queue. caller can delete
* the returned timeout, but should not otherwise manipulate the timing
* wheel. in particular, caller SHOULD NOT delete any other timeout as that
* could invalidate cursor state and trigger a use-after-free.
*/
#define TIMEOUTS_FOREACH(var, T, flags) \
struct timeouts_it _it = TIMEOUTS_IT_INITIALIZER((flags)); \
while (((var) = timeouts_next((T), &_it)))
/*
* B O N U S W H E E L I N T E R F A C E S
*
* I usually use floating point timeouts in all my code, but it's cleaner to
* separate it to keep the core algorithmic code simple.
*
* Using macros instead of static inline routines where <math.h> routines
* might be used to keep -lm linking optional.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#include <math.h> /* ceil(3) */
#define timeouts_f2i(T, f) \
((timeout_t)ceil((f) * timeouts_hz((T)))) /* prefer late expiration over early */
#define timeouts_i2f(T, i) \
((double)(i) / timeouts_hz((T)))
#define timeouts_addf(T, to, timeout) \
timeouts_add((T), (to), timeouts_f2i((T), (timeout)))
#endif /* TIMEOUT_H */
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