ae_select.c

   1 /* Select()-based ae.c module
   2  * Copyright (C) 2009 Salvatore Sanfilippo - antirez@gmail.com
   3  * Released under the BSD license. See the COPYING file for more info. */
   4
   5 #include <string.h>
   6
   7 typedef struct aeApiState {
   8     fd_set rfds, wfds;
   9     /* We need to have a copy of the fd sets as it's not safe to reuse
  10      * FD sets after select(). */
  11     fd_set _rfds, _wfds;
  12 } aeApiState;
  13
  14 static int aeApiCreate(aeEventLoop *eventLoop) {
  15     aeApiState *state = zmalloc(sizeof(aeApiState));
  16
  17     if (!state) return -1;
  18     FD_ZERO(&state->rfds);
  19     FD_ZERO(&state->wfds);
  20     eventLoop->apidata = state;
  21     return 0;
  22 }
  23
  24 static void aeApiFree(aeEventLoop *eventLoop) {
  25     zfree(eventLoop->apidata);
  26 }
  27
  28 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
  29     aeApiState *state = eventLoop->apidata;
  30
  31     if (mask & AE_READABLE) FD_SET(fd,&state->rfds);
  32     if (mask & AE_WRITABLE) FD_SET(fd,&state->wfds);
  33     return 0;
  34 }
  35
  36 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int mask) {
  37     aeApiState *state = eventLoop->apidata;
  38
  39     if (mask & AE_READABLE) FD_CLR(fd,&state->rfds);
  40     if (mask & AE_WRITABLE) FD_CLR(fd,&state->wfds);
  41 }
  42
  43 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
  44     aeApiState *state = eventLoop->apidata;
  45     int retval, j, numevents = 0;
  46
  47     memcpy(&state->_rfds,&state->rfds,sizeof(fd_set));
  48     memcpy(&state->_wfds,&state->wfds,sizeof(fd_set));
  49
  50     retval = select(eventLoop->maxfd+1,
  51                 &state->_rfds,&state->_wfds,NULL,tvp);
  52     if (retval > 0) {
  53         for (j = 0; j <= eventLoop->maxfd; j++) {
  54             int mask = 0;
  55             aeFileEvent *fe = &eventLoop->events[j];
  56
  57             if (fe->mask == AE_NONE) continue;
  58             if (fe->mask & AE_READABLE && FD_ISSET(j,&state->_rfds))
  59                 mask |= AE_READABLE;
  60             if (fe->mask & AE_WRITABLE && FD_ISSET(j,&state->_wfds))
  61                 mask |= AE_WRITABLE;
  62             eventLoop->fired[numevents].fd = j;
  63             eventLoop->fired[numevents].mask = mask;
  64             numevents++;
  65         }
  66     }
  67     return numevents;
  68 }
  69
  70 static char *aeApiName(void) {
  71     return "select";
  72 }