xref: /openbmc/qemu/io/channel-watch.c (revision c964b660)
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 }
200