text: /* Kqueue(2)-based ae.c module
   * Copyright (C) 2009 Harish Mallipeddi - harish.mallipeddi@gmail.com
   * Released under the BSD license. See the COPYING file for more info. */
  
  #include <sys/types.h>
  #include <sys/event.h>
  #include <sys/time.h>
  
  typedef struct aeApiState {
      int kqfd;
      struct kevent events[AE_SETSIZE];
  } aeApiState;
  
  static int aeApiCreate(EventLoop *eventLoop) {
      aeApiState *state = malloc(sizeof(aeApiState));
  
      if (!state) return -1;
      state->kqfd = kqueue();
      if (state->kqfd == -1) return -1;
      eventLoop->apidata = state;
      
      return 0;    
  }
  
  static void aeApiFree(EventLoop *eventLoop) {
      aeApiState *state = eventLoop->apidata;
  
      close(state->kqfd);
      free(state);
  }
  
  static int aeApiAddEvent(EventLoop *eventLoop, int fd, int mask) {
      aeApiState *state = eventLoop->apidata;
      struct kevent ke;
      
      if (mask & AE_READABLE) {
          EV_SET(&ke, fd, EVFILT_READ, EV_ADD, 0, 0, NULL);
          if (kevent(state->kqfd, &ke, 1, NULL, 0, NULL) == -1) return -1;
      }
      if (mask & AE_WRITABLE) {
          EV_SET(&ke, fd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
          if (kevent(state->kqfd, &ke, 1, NULL, 0, NULL) == -1) return -1;
      }
      return 0;
  }
  
  static int aeApiUpdateEvent(EventLoop *eventLoop, int fd, int mask) {
      return aeApiAddEvent(eventLoop, fd, mask);
  }
  
  static int aeApiDelEvent(EventLoop *eventLoop, int fd) {
      aeApiState *state = eventLoop->apidata;
      struct kevent ke;
  
      EV_SET(&ke, fd, EVFILT_READ | EVFILT_WRITE, EV_DELETE, 0, 0, NULL);
      kevent(state->kqfd, &ke, 1, NULL, 0, NULL);
      return 0;
  }
  
  static int aeApiPoll(EventLoop *eventLoop, struct timeval *tvp) {
      aeApiState *state = eventLoop->apidata;
      int retval, numevents = 0;
  
      if (tvp != NULL) {
          struct timespec timeout;
          timeout.tv_sec = tvp->tv_sec;
          timeout.tv_nsec = tvp->tv_usec * 1000;
          retval = kevent(state->kqfd, NULL, 0, state->events, AE_SETSIZE, &timeout);
      } else {
          retval = kevent(state->kqfd, NULL, 0, state->events, AE_SETSIZE, NULL);
      }    
  
      if (retval > 0) {
          int j;
          
          numevents = retval;
          for(j = 0; j < numevents; j++) {
              int mask = 0;
              struct kevent *e = state->events+j;
              
              if (e->filter == EVFILT_READ) mask |= AE_READABLE;
              if (e->filter == EVFILT_WRITE) mask |= AE_WRITABLE;
              eventLoop->fired[j] = e->ident; 
          }
      }
      return numevents;
  }
  
  static char *aeApiName(void) {
      return "kqueue";
  }
  