src/event.h

   1 /*
   2  * Copyright (C) 1996-2025 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_SRC_EVENT_H
  10 #define SQUID_SRC_EVENT_H
  11
  12 #include "AsyncEngine.h"
  13 #include "base/Packable.h"
  14 #include "mem/forward.h"
  15
  16 /* event scheduling facilities - run a callback after a given time period. */
  17
  18 typedef void EVH(void *);
  19
  20 void eventAdd(const char *name, EVH * func, void *arg, double when, int, bool cbdata=true);
  21 void eventAddIsh(const char *name, EVH * func, void *arg, double delta_ish, int);
  22 void eventDelete(EVH * func, void *arg);
  23 void eventInit(void);
  24 int eventFind(EVH *, void *);
  25
  26 class ev_entry
  27 {
  28     MEMPROXY_CLASS(ev_entry);
  29
  30 public:
  31     ev_entry(char const * name, EVH * func, void *arg, double when, int weight, bool cbdata=true);
  32     ~ev_entry();
  33     const char *name;
  34     EVH *func;
  35     void *arg;
  36     double when;
  37
  38     int weight;
  39     bool cbdata;
  40
  41     ev_entry *next;
  42 };
  43
  44 // manages time-based events
  45 class EventScheduler : public AsyncEngine
  46 {
  47
  48 public:
  49     EventScheduler();
  50     ~EventScheduler() override;
  51     /* cancel a scheduled but not dispatched event */
  52     void cancel(EVH * func, void * arg);
  53     /* clean up the used memory in the scheduler */
  54     void clean();
  55     /* either EVENT_IDLE or milliseconds remaining until the next event */
  56     int timeRemaining() const;
  57     /* cache manager output for the event queue */
  58     void dump(Packable *);
  59     /* find a scheduled event */
  60     bool find(EVH * func, void * arg);
  61     /* schedule a callback function to run in when seconds */
  62     void schedule(const char *name, EVH * func, void *arg, double when, int weight, bool cbdata=true);
  63     int checkEvents(int timeout) override;
  64     static EventScheduler *GetInstance();
  65
  66 private:
  67     static EventScheduler _instance;
  68     ev_entry * tasks;
  69 };
  70
  71 #endif /* SQUID_SRC_EVENT_H */
  72