linux.c

   1 #define _XOPEN_SOURCE 600
   2 #include <unistd.h>
   3 #include <sys/types.h>
   4 #include <stdint.h>
   5 #include <fcntl.h>
   6 #include <stdlib.h>
   7 #include <errno.h>
   8 #include <sys/epoll.h>
   9 #include "dat.h"
  10
  11 #ifndef EPOLLRDHUP
  12 #define EPOLLRDHUP 0x2000
  13 #endif
  14
  15 static int epfd;
  16
  17
  18 /* Allocate disk space.
  19  * Expects fd's offset to be 0; may also reset fd's offset to 0.
  20  * Returns 0 on success, and a positive errno otherwise. */
  21 int
  22 rawfalloc(int fd, int len)
  23 {
  24     return ftruncate(fd, len);
  25 }
  26
  27
  28 int
  29 sockinit(void)
  30 {
  31     epfd = epoll_create(1);
  32     if (epfd == -1) {
  33         twarn("epoll_create");
  34         return -1;
  35     }
  36     return 0;
  37 }
  38
  39
  40 int
  41 sockwant(Socket *s, int rw)
  42 {
  43     int op;
  44     struct epoll_event ev = {};
  45
  46     if (!s->added && !rw) {
  47         return 0;
  48     } else if (!s->added && rw) {
  49         s->added = 1;
  50         op = EPOLL_CTL_ADD;
  51     } else if (!rw) {
  52         op = EPOLL_CTL_DEL;
  53     } else {
  54         op = EPOLL_CTL_MOD;
  55     }
  56
  57     switch (rw) {
  58     case 'r':
  59         ev.events = EPOLLIN;
  60         break;
  61     case 'w':
  62         ev.events = EPOLLOUT;
  63         break;
  64     }
  65     ev.events |= EPOLLRDHUP | EPOLLPRI;
  66     ev.data.ptr = s;
  67
  68     return epoll_ctl(epfd, op, s->fd, &ev);
  69 }
  70
  71
  72 int
  73 socknext(Socket **s, int64 timeout)
  74 {
  75     int r;
  76     struct epoll_event ev;
  77
  78     r = epoll_wait(epfd, &ev, 1, (int)(timeout/1000000));
  79     if (r == -1 && errno != EINTR) {
  80         twarn("epoll_wait");
  81         exit(1);
  82     }
  83
  84     if (r > 0) {
  85         *s = ev.data.ptr;
  86         if (ev.events & (EPOLLHUP|EPOLLRDHUP)) {
  87             return 'h';
  88         } else if (ev.events & EPOLLIN) {
  89             return 'r';
  90         } else if (ev.events & EPOLLOUT) {
  91             return 'w';
  92         }
  93     }
  94     return 0;
  95 }