qga: update schema for guest-get-disks 'dependents' field
[qemu.git] / chardev / char-io.c
1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "qemu/osdep.h"
25 #include "chardev/char-io.h"
26
27 typedef struct IOWatchPoll {
28 GSource parent;
29
30 QIOChannel *ioc;
31 GSource *src;
32
33 IOCanReadHandler *fd_can_read;
34 GSourceFunc fd_read;
35 void *opaque;
36 } IOWatchPoll;
37
38 static IOWatchPoll *io_watch_poll_from_source(GSource *source)
39 {
40 return container_of(source, IOWatchPoll, parent);
41 }
42
43 static gboolean io_watch_poll_prepare(GSource *source,
44 gint *timeout)
45 {
46 IOWatchPoll *iwp = io_watch_poll_from_source(source);
47 bool now_active = iwp->fd_can_read(iwp->opaque) > 0;
48 bool was_active = iwp->src != NULL;
49 if (was_active == now_active) {
50 return FALSE;
51 }
52
53 if (now_active) {
54 iwp->src = qio_channel_create_watch(
55 iwp->ioc, G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
56 g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);
57 g_source_add_child_source(source, iwp->src);
58 g_source_unref(iwp->src);
59 } else {
60 g_source_remove_child_source(source, iwp->src);
61 iwp->src = NULL;
62 }
63 return FALSE;
64 }
65
66 static gboolean io_watch_poll_dispatch(GSource *source, GSourceFunc callback,
67 gpointer user_data)
68 {
69 return G_SOURCE_CONTINUE;
70 }
71
72 static GSourceFuncs io_watch_poll_funcs = {
73 .prepare = io_watch_poll_prepare,
74 .dispatch = io_watch_poll_dispatch,
75 };
76
77 GSource *io_add_watch_poll(Chardev *chr,
78 QIOChannel *ioc,
79 IOCanReadHandler *fd_can_read,
80 QIOChannelFunc fd_read,
81 gpointer user_data,
82 GMainContext *context)
83 {
84 IOWatchPoll *iwp;
85 char *name;
86
87 iwp = (IOWatchPoll *) g_source_new(&io_watch_poll_funcs,
88 sizeof(IOWatchPoll));
89 iwp->fd_can_read = fd_can_read;
90 iwp->opaque = user_data;
91 iwp->ioc = ioc;
92 iwp->fd_read = (GSourceFunc) fd_read;
93 iwp->src = NULL;
94
95 name = g_strdup_printf("chardev-iowatch-%s", chr->label);
96 g_source_set_name((GSource *)iwp, name);
97 g_free(name);
98
99 g_source_attach(&iwp->parent, context);
100 g_source_unref(&iwp->parent);
101 return (GSource *)iwp;
102 }
103
104 void remove_fd_in_watch(Chardev *chr)
105 {
106 if (chr->gsource) {
107 g_source_destroy(chr->gsource);
108 chr->gsource = NULL;
109 }
110 }
111
112 int io_channel_send_full(QIOChannel *ioc,
113 const void *buf, size_t len,
114 int *fds, size_t nfds)
115 {
116 size_t offset = 0;
117
118 while (offset < len) {
119 ssize_t ret = 0;
120 struct iovec iov = { .iov_base = (char *)buf + offset,
121 .iov_len = len - offset };
122
123 ret = qio_channel_writev_full(
124 ioc, &iov, 1,
125 fds, nfds, NULL);
126 if (ret == QIO_CHANNEL_ERR_BLOCK) {
127 if (offset) {
128 return offset;
129 }
130
131 errno = EAGAIN;
132 return -1;
133 } else if (ret < 0) {
134 errno = EINVAL;
135 return -1;
136 }
137
138 offset += ret;
139 }
140
141 return offset;
142 }
143
144 int io_channel_send(QIOChannel *ioc, const void *buf, size_t len)
145 {
146 return io_channel_send_full(ioc, buf, len, NULL, 0);
147 }