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, efds;
   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, _efds;
  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     FD_ZERO(&state->efds);
  21     eventLoop->apidata = state;
  22     return 0;
  23 }
  24
  25 static void aeApiFree(aeEventLoop *eventLoop) {
  26     zfree(eventLoop->apidata);
  27 }
  28
  29 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
  30     aeApiState *state = eventLoop->apidata;
  31
  32     if (mask & AE_READABLE) FD_SET(fd,&state->rfds);
  33     if (mask & AE_WRITABLE) FD_SET(fd,&state->wfds);
  34     if (mask & AE_EXCEPTION) FD_SET(fd,&state->efds);
  35     return 0;
  36 }
  37
  38 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int mask) {
  39     aeApiState *state = eventLoop->apidata;
  40
  41     if (mask & AE_READABLE) FD_CLR(fd,&state->rfds);
  42     if (mask & AE_WRITABLE) FD_CLR(fd,&state->wfds);
  43     if (mask & AE_EXCEPTION) FD_CLR(fd,&state->efds);
  44 }
  45
  46 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
  47     aeApiState *state = eventLoop->apidata;
  48     int retval, j, numevents = 0;
  49
  50     memcpy(&state->_rfds,&state->rfds,sizeof(fd_set));
  51     memcpy(&state->_wfds,&state->wfds,sizeof(fd_set));
  52     memcpy(&state->_efds,&state->efds,sizeof(fd_set));
  53
  54     retval = select(eventLoop->maxfd+1,
  55                 &state->_rfds,&state->_wfds,&state->_efds,tvp);
  56     if (retval > 0) {
  57         for (j = 0; j <= eventLoop->maxfd; j++) {
  58             int mask = 0;
  59             aeFileEvent *fe = &eventLoop->events[j];
  60
  61             if (fe->mask == AE_NONE) continue;
  62             if (fe->mask & AE_READABLE && FD_ISSET(j,&state->_rfds))
  63                 mask |= AE_READABLE;
  64             if (fe->mask & AE_WRITABLE && FD_ISSET(j,&state->_wfds))
  65                 mask |= AE_WRITABLE;
  66             if (fe->mask & AE_EXCEPTION && FD_ISSET(j,&state->_efds))
  67                 mask |= AE_EXCEPTION;
  68             eventLoop->fired[numevents].fd = j;
  69             eventLoop->fired[numevents].mask = mask;
  70             numevents++;
  71         }
  72     }
  73     return numevents;
  74 }
  75
  76 static char *aeApiName(void) {
  77     return "select";
  78 }