linux.c

   1 #define _XOPEN_SOURCE 600
   2 #include <stdint.h>
   3 #include <fcntl.h>
   4 #include <stdlib.h>
   5 #include <errno.h>
   6 #include <sys/epoll.h>
   7 #include "dat.h"
   8
   9 #ifndef EPOLLRDHUP
  10 #define EPOLLRDHUP 0x2000
  11 #endif
  12
  13 static int epfd;
  14
  15
  16 /* Allocate disk space.
  17  * Expects fd's offset to be 0; may also reset fd's offset to 0.
  18  * Returns 0 on success, and a positive errno otherwise. */
  19 int
  20 rawfalloc(int fd, int len)
  21 {
  22     return posix_fallocate(fd, 0, len);
  23 }
  24
  25
  26 int
  27 sockinit(void)
  28 {
  29     epfd = epoll_create(1);
  30     if (epfd == -1) {
  31         twarn("epoll_create");
  32         return -1;
  33     }
  34     return 0;
  35 }
  36
  37
  38 int
  39 sockwant(Socket *s, int rw)
  40 {
  41     int op;
  42     struct epoll_event ev = {};
  43
  44     if (!s->added && !rw) {
  45         return 0;
  46     } else if (!s->added && rw) {
  47         s->added = 1;
  48         op = EPOLL_CTL_ADD;
  49     } else if (!rw) {
  50         op = EPOLL_CTL_DEL;
  51     } else {
  52         op = EPOLL_CTL_MOD;
  53     }
  54
  55     switch (rw) {
  56     case 'r':
  57         ev.events = EPOLLIN;
  58         break;
  59     case 'w':
  60         ev.events = EPOLLOUT;
  61         break;
  62     }
  63     ev.events |= EPOLLRDHUP | EPOLLPRI;
  64     ev.data.ptr = s;
  65
  66     return epoll_ctl(epfd, op, s->fd, &ev);
  67 }
  68
  69
  70 int
  71 socknext(Socket **s, int64 timeout)
  72 {
  73     int r;
  74     struct epoll_event ev;
  75
  76     r = epoll_wait(epfd, &ev, 1, (int)(timeout/1000000));
  77     if (r == -1 && errno != EINTR) {
  78         twarn("epoll_wait");
  79         exit(1);
  80     }
  81
  82     if (r > 0) {
  83         *s = ev.data.ptr;
  84         if (ev.events & (EPOLLHUP|EPOLLRDHUP)) {
  85             return 'h';
  86         } else if (ev.events & EPOLLIN) {
  87             return 'r';
  88         } else if (ev.events & EPOLLOUT) {
  89             return 'w';
  90         }
  91     }
  92     return 0;
  93 }