src/ae_epoll.c

   1 /* Linux epoll(2) based ae.c module
   2  * Copyright (C) 2009-2010 Salvatore Sanfilippo - antirez@gmail.com
   3  * Released under the BSD license. See the COPYING file for more info. */
   4
   5 #include <sys/epoll.h>
   6
   7 typedef struct aeApiState {
   8     int epfd;
   9     struct epoll_event events[AE_SETSIZE];
  10 } aeApiState;
  11
  12 static int aeApiCreate(aeEventLoop *eventLoop) {
  13     aeApiState *state = zmalloc(sizeof(aeApiState));
  14
  15     if (!state) return -1;
  16     state->epfd = epoll_create(1024); /* 1024 is just an hint for the kernel */
  17     if (state->epfd == -1) {
  18         zfree(state);
  19         return -1;
  20     }
  21     eventLoop->apidata = state;
  22     return 0;
  23 }
  24
  25 static void aeApiFree(aeEventLoop *eventLoop) {
  26     aeApiState *state = eventLoop->apidata;
  27
  28     close(state->epfd);
  29     zfree(state);
  30 }
  31
  32 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
  33     aeApiState *state = eventLoop->apidata;
  34     struct epoll_event ee;
  35     /* If the fd was already monitored for some event, we need a MOD
  36      * operation. Otherwise we need an ADD operation. */
  37     int op = eventLoop->events[fd].mask == AE_NONE ?
  38             EPOLL_CTL_ADD : EPOLL_CTL_MOD;
  39
  40     ee.events = 0;
  41     mask |= eventLoop->events[fd].mask; /* Merge old events */
  42     if (mask & AE_READABLE) ee.events |= EPOLLIN;
  43     if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
  44     ee.data.u64 = 0; /* avoid valgrind warning */
  45     ee.data.fd = fd;
  46     if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1;
  47     return 0;
  48 }
  49
  50 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) {
  51     aeApiState *state = eventLoop->apidata;
  52     struct epoll_event ee;
  53     int mask = eventLoop->events[fd].mask & (~delmask);
  54
  55     ee.events = 0;
  56     if (mask & AE_READABLE) ee.events |= EPOLLIN;
  57     if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
  58     ee.data.u64 = 0; /* avoid valgrind warning */
  59     ee.data.fd = fd;
  60     if (mask != AE_NONE) {
  61         epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee);
  62     } else {
  63         /* Note, Kernel < 2.6.9 requires a non null event pointer even for
  64          * EPOLL_CTL_DEL. */
  65         epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee);
  66     }
  67 }
  68
  69 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
  70     aeApiState *state = eventLoop->apidata;
  71     int retval, numevents = 0;
  72
  73     retval = epoll_wait(state->epfd,state->events,AE_SETSIZE,
  74             tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1);
  75     if (retval > 0) {
  76         int j;
  77
  78         numevents = retval;
  79         for (j = 0; j < numevents; j++) {
  80             int mask = 0;
  81             struct epoll_event *e = state->events+j;
  82
  83             if (e->events & EPOLLIN) mask |= AE_READABLE;
  84             if (e->events & EPOLLOUT) mask |= AE_WRITABLE;
  85             eventLoop->fired[j].fd = e->data.fd;
  86             eventLoop->fired[j].mask = mask;
  87         }
  88     }
  89     return numevents;
  90 }
  91
  92 static char *aeApiName(void) {
  93     return "epoll";
  94 }