libustcomm/multipoll.c

   1 /*
   2  * multipoll.c
   3  *
   4  * Copyright (C) 2010 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca)
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <poll.h>
  22 #include <stdlib.h>
  23 #include "multipoll.h"
  24 #include "usterr.h"
  25
  26 #define INITIAL_N_AVAIL 16
  27
  28 int multipoll_init(struct mpentries *ent)
  29 {
  30         ent->n_used = 0;
  31         ent->n_avail = INITIAL_N_AVAIL;
  32
  33         ent->pollfds = (struct pollfd *) malloc(sizeof(struct pollfd) * INITIAL_N_AVAIL);
  34         ent->extras = (struct pollfd_extra *) malloc(sizeof(struct pollfd_extra) * INITIAL_N_AVAIL);
  35
  36         return 0;
  37 }
  38
  39 int multipoll_destroy(struct mpentries *ent)
  40 {
  41         int i;
  42
  43         for(i=0; i<ent->n_used; i++) {
  44                 if(ent->extras[i].destroy_priv) {
  45                         ent->extras[i].destroy_priv(ent->extras[i].priv);
  46                 }
  47         }
  48
  49         free(ent->pollfds);
  50         free(ent->extras);
  51
  52         return 0;
  53 }
  54
  55 int multipoll_add(struct mpentries *ent, int fd, short events, int (*func)(void *priv, int fd, short events), void *priv, int (*destroy_priv)(void *))
  56 {
  57         int cur;
  58
  59         if(ent->n_used == ent->n_avail) {
  60                 ent->n_avail *= 2;
  61                 ent->pollfds = (struct pollfd *) realloc(ent->pollfds, sizeof(struct pollfd) * ent->n_avail);
  62                 ent->extras = (struct pollfd_extra *) realloc(ent->extras, sizeof(struct pollfd_extra) * ent->n_avail);
  63         }
  64
  65         cur = ent->n_used;
  66         ent->n_used++;
  67
  68         ent->pollfds[cur].fd = fd;
  69         ent->pollfds[cur].events = events;
  70         ent->extras[cur].func = func;
  71         ent->extras[cur].priv = priv;
  72         ent->extras[cur].destroy_priv = destroy_priv;
  73
  74         return 0;
  75 }
  76
  77 int multipoll_poll(struct mpentries *ent, int timeout)
  78 {
  79         int result;
  80         int i;
  81
  82         result = poll(ent->pollfds, ent->n_used, timeout);
  83         if(result == -1) {
  84                 PERROR("poll");
  85                 return -1;
  86         }
  87
  88         for(i=0; i<ent->n_used; i++) {
  89                 if(ent->pollfds[i].revents) {
  90                         ent->extras[i].func(ent->extras[i].priv, ent->pollfds[i].fd, ent->pollfds[i].revents);
  91                 }
  92         }
  93
  94         return 0;
  95 }