release/src/router/xl2tpd/scheduler.h

   1 /*
   2  * Layer Two Tunnelling Protocol Daemon
   3  * Copyright (C) 1998 Adtran, Inc.
   4  * Copyright (C) 2002 Jeff McAdams
   5  *
   6  * Mark Spencer
   7  *
   8  * This software is distributed under the terms
   9  * of the GPL, which you should have received
  10  * along with this source.
  11  *
  12  * Scheduler structures and functions
  13  *
  14  */
  15
  16 #ifndef _SCHEDULER_H
  17 #define _SCHEDULER_H
  18 #include <sys/time.h>
  19
  20 /*
  21  * The idea is to provide a general scheduler which can schedule
  22  * events to be run periodically
  23  */
  24
  25 struct schedule_entry
  26 {
  27     struct timeval tv;          /* Scheduled time to execute */
  28     void (*func) (void *);      /* Function to execute */
  29     void *data;                 /* Data to be passed to func */
  30     struct schedule_entry *next;        /* Next entry in queue */
  31 };
  32
  33 extern struct schedule_entry *events;
  34
  35 /* Schedule func to be executed with argument data sometime
  36    tv in the future. */
  37
  38 struct schedule_entry *schedule (struct timeval tv, void (*func) (void *),
  39                                  void *data);
  40
  41 /* Like schedule() but tv represents an absolute time in the future */
  42
  43 struct schedule_entry *aschedule (struct timeval tv, void (*func) (void *),
  44                                   void *data);
  45
  46 /* Remove a scheduled event from the queue */
  47
  48 void deschedule (struct schedule_entry *);
  49
  50 /* Initialization function */
  51 void init_scheduler (void);
  52
  53 /* Scheduled event processor */
  54 struct timeval *process_schedule(struct timeval *);
  55
  56 /* Compare two timeval functions and see if a <= b */
  57
  58 #define TVLESS(a,b) ((a).tv_sec == (b).tv_sec ? \
  59                                 ((a).tv_usec < (b).tv_usec) : \
  60                                 ((a).tv_sec < (b).tv_sec))
  61 #define TVLESSEQ(a,b) ((a).tv_sec == (b).tv_sec ? \
  62                                 ((a).tv_usec <= (b).tv_usec) : \
  63                                 ((a).tv_sec <= (b).tv_sec))
  64 #define TVGT(a,b) ((a).tv_sec == (b).tv_sec ? \
  65                                 ((a).tv_usec > (b).tv_usec) : \
  66                                 ((a).tv_sec > (b).tv_sec))
  67 #endif