| 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 | /* Multipoll is a framework to poll on several file descriptors and to call |
| 22 | * a specific callback depending on the fd that had activity. |
| 23 | */ |
| 24 | |
| 25 | #include <poll.h> |
| 26 | #include <stdlib.h> |
| 27 | #include "multipoll.h" |
| 28 | #include "usterr.h" |
| 29 | |
| 30 | #define INITIAL_N_AVAIL 16 |
| 31 | |
| 32 | /* multipoll_init |
| 33 | * |
| 34 | * Initialize an mpentries struct, which is initially empty of any fd. |
| 35 | */ |
| 36 | |
| 37 | int multipoll_init(struct mpentries *ent) |
| 38 | { |
| 39 | ent->n_used = 0; |
| 40 | ent->n_avail = INITIAL_N_AVAIL; |
| 41 | |
| 42 | ent->pollfds = (struct pollfd *) malloc(sizeof(struct pollfd) * INITIAL_N_AVAIL); |
| 43 | ent->extras = (struct pollfd_extra *) malloc(sizeof(struct pollfd_extra) * INITIAL_N_AVAIL); |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | /* multipoll_destroy: free a struct mpentries |
| 49 | */ |
| 50 | |
| 51 | int multipoll_destroy(struct mpentries *ent) |
| 52 | { |
| 53 | int i; |
| 54 | |
| 55 | for(i=0; i<ent->n_used; i++) { |
| 56 | if(ent->extras[i].destroy_priv) { |
| 57 | ent->extras[i].destroy_priv(ent->extras[i].priv); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | free(ent->pollfds); |
| 62 | free(ent->extras); |
| 63 | |
| 64 | return 0; |
| 65 | } |
| 66 | |
| 67 | /* multipoll_add |
| 68 | * |
| 69 | * Add a file descriptor to be waited on in a struct mpentries. |
| 70 | * |
| 71 | * @ent: the struct mpentries to add an fd to |
| 72 | * @fd: the fd to wait on |
| 73 | * @events: a mask of the types of events to wait on, see the poll(2) man page |
| 74 | * @func: the callback function to be called if there is activity on the fd |
| 75 | * @priv: the private pointer to pass to func |
| 76 | * @destroy_priv: a callback to destroy the priv pointer when the mpentries |
| 77 | is destroyed; may be NULL |
| 78 | */ |
| 79 | |
| 80 | int multipoll_add(struct mpentries *ent, int fd, short events, int (*func)(void *priv, int fd, short events), void *priv, int (*destroy_priv)(void *)) |
| 81 | { |
| 82 | int cur; |
| 83 | |
| 84 | if(ent->n_used == ent->n_avail) { |
| 85 | ent->n_avail *= 2; |
| 86 | ent->pollfds = (struct pollfd *) realloc(ent->pollfds, sizeof(struct pollfd) * ent->n_avail); |
| 87 | ent->extras = (struct pollfd_extra *) realloc(ent->extras, sizeof(struct pollfd_extra) * ent->n_avail); |
| 88 | } |
| 89 | |
| 90 | cur = ent->n_used; |
| 91 | ent->n_used++; |
| 92 | |
| 93 | ent->pollfds[cur].fd = fd; |
| 94 | ent->pollfds[cur].events = events; |
| 95 | ent->extras[cur].func = func; |
| 96 | ent->extras[cur].priv = priv; |
| 97 | ent->extras[cur].destroy_priv = destroy_priv; |
| 98 | |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | /* multipoll_poll: do the actual poll on a struct mpentries |
| 103 | * |
| 104 | * File descriptors should have been already added with multipoll_add(). |
| 105 | * |
| 106 | * A struct mpentries may be reused for multiple multipoll_poll calls. |
| 107 | * |
| 108 | * @ent: the struct mpentries to poll on. |
| 109 | * @timeout: the timeout after which to return if there was no activity. |
| 110 | */ |
| 111 | |
| 112 | int multipoll_poll(struct mpentries *ent, int timeout) |
| 113 | { |
| 114 | int result; |
| 115 | int i; |
| 116 | |
| 117 | result = poll(ent->pollfds, ent->n_used, timeout); |
| 118 | if(result == -1) { |
| 119 | PERROR("poll"); |
| 120 | return -1; |
| 121 | } |
| 122 | |
| 123 | for(i=0; i<ent->n_used; i++) { |
| 124 | if(ent->pollfds[i].revents) { |
| 125 | ent->extras[i].func(ent->extras[i].priv, ent->pollfds[i].fd, ent->pollfds[i].revents); |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | return 0; |
| 130 | } |