git.m6w6.name Git - awesomized/libmemcached/blob - poll/poll.c

   1 /* LibMemcached
   2  * Copyright (C) 2010 Brian Aker, Trond Norbye
   3  * All rights reserved.
   4  *
   5  * Use and distribution licensed under the BSD license.  See
   6  * the COPYING file in the parent directory for full text.
   7  *
   8  * Summary: Implementation of poll by using select
   9  *
  10  */
  11 #include "config.h"
  12 #include <sys/time.h>
  13 #include <strings.h>
  14
  15 int poll(struct pollfd fds[], nfds_t nfds, int tmo)
  16 {
  17   fd_set readfds, writefds, errorfds;
  18   FD_ZERO(&readfds);
  19   FD_ZERO(&writefds);
  20   FD_ZERO(&errorfds);
  21
  22   int maxfd= 0;
  23
  24   for (nfds_t x= 0; x < nfds; ++x)
  25   {
  26     if (fds[x].events & (POLLIN | POLLOUT))
  27     {
  28 #ifndef WIN32
  29       if (fds[x].fd > maxfd)
  30       {
  31         maxfd= fds[x].fd;
  32       }
  33 #endif
  34       if (fds[x].events & POLLIN)
  35       {
  36         FD_SET(fds[x].fd, &readfds);
  37       }
  38       if (fds[x].events & POLLOUT)
  39       {
  40         FD_SET(fds[x].fd, &writefds);
  41       }
  42     }
  43   }
  44
  45   struct timeval timeout= { .tv_sec = tmo / 1000,
  46                             .tv_usec= (tmo % 1000) * 1000 };
  47   struct timeval *tp= &timeout;
  48   if (tmo == -1)
  49   {
  50     tp= NULL;
  51   }
  52   int ret= select(maxfd + 1, &readfds, &writefds, &errorfds, tp);
  53   if (ret <= 0)
  54   {
  55     return ret;
  56   }
  57
  58   /* Iterate through all of them because I need to clear the revent map */
  59   for (nfds_t x= 0; x < nfds; ++x)
  60   {
  61     fds[x].revents= 0;
  62     if (FD_ISSET(fds[x].fd, &readfds))
  63     {
  64       fds[x].revents |= POLLIN;
  65     }
  66     if (FD_ISSET(fds[x].fd, &writefds))
  67     {
  68       fds[x].revents |= POLLOUT;
  69     }
  70     if (FD_ISSET(fds[x].fd, &errorfds))
  71     {
  72       fds[x].revents |= POLLERR;
  73     }
  74   }
  75
  76    return ret;
  77 }