// Zak's kqueue implementation
#ifndef SYS_EVENT_H
#define SYS_EVENT_H

#include <stdint.h>

// The kevent structure is used for waiting/receiving notifications.
struct kevent {
  uintptr_t ident;
  int16_t filter;
  uint16_t flags;
  uint32_t fflags;
  int64_t data;
  void* udata;
  uint64_t ext[4];
};

// kqueue1 is the kqueue system call with a flags argument,
// as defined on NetBSD & OpenBSD.
int kqueue1(int flags);

// kqueue() without flags is equivalent to kqueue1(0)
#define kqueue() kqueue1(0)

// On FreeBSD, kqueue1 is also known as kqueuex
#define kqueuex(flags) kqueue1(flags)

// After creating a kqueue, kevent is the main syscall used.
// This accepts a list of changes and can receive multiple events.
int kevent(int queue, const struct kevent* changes, int nch, struct kevent* events, int nev, void* todo_timeout);

// The EV_SET() macro is for initialising a struct kevent*
#define EV_SET(ev,idn,flt,flg,ffl,dat,udt) \
  do { \
    (ev)->ident = idn; \
    (ev)->filter = flt; \
    (ev)->flags = flg; \
    (ev)->fflags = ffl; \
    (ev)->data = dat; \
    (ev)->udata = udt; \
    (ev)->ext[0] = 0; \
    (ev)->ext[1] = 0; \
    (ev)->ext[2] = 0; \
    (ev)->ext[3] = 0; \
  } while(0)

// From ifndef at top of file:
#endif