io/channel-watch.c

   1 /*
   2  * QEMU I/O channels watch helper APIs
   3  *
   4  * Copyright (c) 2015 Red Hat, Inc.
   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 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, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "io/channel-watch.h"
  23
  24 typedef struct QIOChannelFDSource QIOChannelFDSource;
  25 struct QIOChannelFDSource {
  26     GSource parent;
  27     GPollFD fd;
  28     QIOChannel *ioc;
  29     GIOCondition condition;
  30 };
  31
  32
  33 typedef struct QIOChannelFDPairSource QIOChannelFDPairSource;
  34 struct QIOChannelFDPairSource {
  35     GSource parent;
  36     GPollFD fdread;
  37     GPollFD fdwrite;
  38     QIOChannel *ioc;
  39     GIOCondition condition;
  40 };
  41
  42
  43 static gboolean
  44 qio_channel_fd_source_prepare(GSource *source G_GNUC_UNUSED,
  45                               gint *timeout)
  46 {
  47     *timeout = -1;
  48
  49     return FALSE;
  50 }
  51
  52
  53 static gboolean
  54 qio_channel_fd_source_check(GSource *source)
  55 {
  56     QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
  57
  58     return ssource->fd.revents & ssource->condition;
  59 }
  60
  61
  62 static gboolean
  63 qio_channel_fd_source_dispatch(GSource *source,
  64                                GSourceFunc callback,
  65                                gpointer user_data)
  66 {
  67     QIOChannelFunc func = (QIOChannelFunc)callback;
  68     QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
  69
  70     return (*func)(ssource->ioc,
  71                    ssource->fd.revents & ssource->condition,
  72                    user_data);
  73 }
  74
  75
  76 static void
  77 qio_channel_fd_source_finalize(GSource *source)
  78 {
  79     QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
  80
  81     object_unref(OBJECT(ssource->ioc));
  82 }
  83
  84
  85 static gboolean
  86 qio_channel_fd_pair_source_prepare(GSource *source G_GNUC_UNUSED,
  87                                    gint *timeout)
  88 {
  89     *timeout = -1;
  90
  91     return FALSE;
  92 }
  93
  94
  95 static gboolean
  96 qio_channel_fd_pair_source_check(GSource *source)
  97 {
  98     QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
  99     GIOCondition poll_condition = ssource->fdread.revents |
 100         ssource->fdwrite.revents;
 101
 102     return poll_condition & ssource->condition;
 103 }
 104
 105
 106 static gboolean
 107 qio_channel_fd_pair_source_dispatch(GSource *source,
 108                                     GSourceFunc callback,
 109                                     gpointer user_data)
 110 {
 111     QIOChannelFunc func = (QIOChannelFunc)callback;
 112     QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
 113     GIOCondition poll_condition = ssource->fdread.revents |
 114         ssource->fdwrite.revents;
 115
 116     return (*func)(ssource->ioc,
 117                    poll_condition & ssource->condition,
 118                    user_data);
 119 }
 120
 121
 122 static void
 123 qio_channel_fd_pair_source_finalize(GSource *source)
 124 {
 125     QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
 126
 127     object_unref(OBJECT(ssource->ioc));
 128 }
 129
 130
 131 GSourceFuncs qio_channel_fd_source_funcs = {
 132     qio_channel_fd_source_prepare,
 133     qio_channel_fd_source_check,
 134     qio_channel_fd_source_dispatch,
 135     qio_channel_fd_source_finalize
 136 };
 137
 138
 139 GSourceFuncs qio_channel_fd_pair_source_funcs = {
 140     qio_channel_fd_pair_source_prepare,
 141     qio_channel_fd_pair_source_check,
 142     qio_channel_fd_pair_source_dispatch,
 143     qio_channel_fd_pair_source_finalize
 144 };
 145
 146
 147 GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
 148                                      int fd,
 149                                      GIOCondition condition)
 150 {
 151     GSource *source;
 152     QIOChannelFDSource *ssource;
 153
 154     source = g_source_new(&qio_channel_fd_source_funcs,
 155                           sizeof(QIOChannelFDSource));
 156     ssource = (QIOChannelFDSource *)source;
 157
 158     ssource->ioc = ioc;
 159     object_ref(OBJECT(ioc));
 160
 161     ssource->condition = condition;
 162
 163     ssource->fd.fd = fd;
 164     ssource->fd.events = condition;
 165
 166     g_source_add_poll(source, &ssource->fd);
 167
 168     return source;
 169 }
 170
 171
 172 GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
 173                                           int fdread,
 174                                           int fdwrite,
 175                                           GIOCondition condition)
 176 {
 177     GSource *source;
 178     QIOChannelFDPairSource *ssource;
 179
 180     source = g_source_new(&qio_channel_fd_pair_source_funcs,
 181                           sizeof(QIOChannelFDPairSource));
 182     ssource = (QIOChannelFDPairSource *)source;
 183
 184     ssource->ioc = ioc;
 185     object_ref(OBJECT(ioc));
 186
 187     ssource->condition = condition;
 188
 189     ssource->fdread.fd = fdread;
 190     ssource->fdread.events = condition & G_IO_IN;
 191
 192     ssource->fdwrite.fd = fdwrite;
 193     ssource->fdwrite.events = condition & G_IO_OUT;
 194
 195     g_source_add_poll(source, &ssource->fdread);
 196     g_source_add_poll(source, &ssource->fdwrite);
 197
 198     return source;
 199 }