Merge remote-tracking branch 'stefanha/trivial-patches' into staging
[qemu.git] / iohandler.c
blob4cc1c5ade616eedb5c5687e9b62a7c7b4d187e31
1 /*
2 * QEMU System Emulator - managing I/O handler
4 * Copyright (c) 2003-2008 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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.
25 #include "config-host.h"
26 #include "qemu-common.h"
27 #include "qemu-char.h"
28 #include "qemu-queue.h"
30 #ifndef _WIN32
31 #include <sys/wait.h>
32 #endif
34 typedef struct IOHandlerRecord {
35 int fd;
36 IOCanReadHandler *fd_read_poll;
37 IOHandler *fd_read;
38 IOHandler *fd_write;
39 int deleted;
40 void *opaque;
41 QLIST_ENTRY(IOHandlerRecord) next;
42 } IOHandlerRecord;
44 static QLIST_HEAD(, IOHandlerRecord) io_handlers =
45 QLIST_HEAD_INITIALIZER(io_handlers);
48 /* XXX: fd_read_poll should be suppressed, but an API change is
49 necessary in the character devices to suppress fd_can_read(). */
50 int qemu_set_fd_handler2(int fd,
51 IOCanReadHandler *fd_read_poll,
52 IOHandler *fd_read,
53 IOHandler *fd_write,
54 void *opaque)
56 IOHandlerRecord *ioh;
58 if (!fd_read && !fd_write) {
59 QLIST_FOREACH(ioh, &io_handlers, next) {
60 if (ioh->fd == fd) {
61 ioh->deleted = 1;
62 break;
65 } else {
66 QLIST_FOREACH(ioh, &io_handlers, next) {
67 if (ioh->fd == fd)
68 goto found;
70 ioh = g_malloc0(sizeof(IOHandlerRecord));
71 QLIST_INSERT_HEAD(&io_handlers, ioh, next);
72 found:
73 ioh->fd = fd;
74 ioh->fd_read_poll = fd_read_poll;
75 ioh->fd_read = fd_read;
76 ioh->fd_write = fd_write;
77 ioh->opaque = opaque;
78 ioh->deleted = 0;
80 return 0;
83 typedef struct IOTrampoline
85 GIOChannel *chan;
86 IOHandler *fd_read;
87 IOHandler *fd_write;
88 void *opaque;
89 guint tag;
90 } IOTrampoline;
92 static gboolean fd_trampoline(GIOChannel *chan, GIOCondition cond, gpointer opaque)
94 IOTrampoline *tramp = opaque;
96 if ((cond & G_IO_IN) && tramp->fd_read) {
97 tramp->fd_read(tramp->opaque);
100 if ((cond & G_IO_OUT) && tramp->fd_write) {
101 tramp->fd_write(tramp->opaque);
104 return TRUE;
107 int qemu_set_fd_handler(int fd,
108 IOHandler *fd_read,
109 IOHandler *fd_write,
110 void *opaque)
112 static IOTrampoline fd_trampolines[FD_SETSIZE];
113 IOTrampoline *tramp = &fd_trampolines[fd];
115 if (tramp->tag != 0) {
116 g_io_channel_unref(tramp->chan);
117 g_source_remove(tramp->tag);
118 tramp->tag = 0;
121 if (fd_read || fd_write || opaque) {
122 GIOCondition cond = 0;
124 tramp->fd_read = fd_read;
125 tramp->fd_write = fd_write;
126 tramp->opaque = opaque;
128 if (fd_read) {
129 cond |= G_IO_IN | G_IO_ERR;
132 if (fd_write) {
133 cond |= G_IO_OUT | G_IO_ERR;
136 tramp->chan = g_io_channel_unix_new(fd);
137 tramp->tag = g_io_add_watch(tramp->chan, cond, fd_trampoline, tramp);
140 return 0;
143 void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds)
145 IOHandlerRecord *ioh;
147 QLIST_FOREACH(ioh, &io_handlers, next) {
148 if (ioh->deleted)
149 continue;
150 if (ioh->fd_read &&
151 (!ioh->fd_read_poll ||
152 ioh->fd_read_poll(ioh->opaque) != 0)) {
153 FD_SET(ioh->fd, readfds);
154 if (ioh->fd > *pnfds)
155 *pnfds = ioh->fd;
157 if (ioh->fd_write) {
158 FD_SET(ioh->fd, writefds);
159 if (ioh->fd > *pnfds)
160 *pnfds = ioh->fd;
165 void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int ret)
167 if (ret > 0) {
168 IOHandlerRecord *pioh, *ioh;
170 QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) {
171 if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, readfds)) {
172 ioh->fd_read(ioh->opaque);
174 if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, writefds)) {
175 ioh->fd_write(ioh->opaque);
178 /* Do this last in case read/write handlers marked it for deletion */
179 if (ioh->deleted) {
180 QLIST_REMOVE(ioh, next);
181 g_free(ioh);
187 /* reaping of zombies. right now we're not passing the status to
188 anyone, but it would be possible to add a callback. */
189 #ifndef _WIN32
190 typedef struct ChildProcessRecord {
191 int pid;
192 QLIST_ENTRY(ChildProcessRecord) next;
193 } ChildProcessRecord;
195 static QLIST_HEAD(, ChildProcessRecord) child_watches =
196 QLIST_HEAD_INITIALIZER(child_watches);
198 static QEMUBH *sigchld_bh;
200 static void sigchld_handler(int signal)
202 qemu_bh_schedule(sigchld_bh);
205 static void sigchld_bh_handler(void *opaque)
207 ChildProcessRecord *rec, *next;
209 QLIST_FOREACH_SAFE(rec, &child_watches, next, next) {
210 if (waitpid(rec->pid, NULL, WNOHANG) == rec->pid) {
211 QLIST_REMOVE(rec, next);
212 g_free(rec);
217 static void qemu_init_child_watch(void)
219 struct sigaction act;
220 sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);
222 act.sa_handler = sigchld_handler;
223 act.sa_flags = SA_NOCLDSTOP;
224 sigaction(SIGCHLD, &act, NULL);
227 int qemu_add_child_watch(pid_t pid)
229 ChildProcessRecord *rec;
231 if (!sigchld_bh) {
232 qemu_init_child_watch();
235 QLIST_FOREACH(rec, &child_watches, next) {
236 if (rec->pid == pid) {
237 return 1;
240 rec = g_malloc0(sizeof(ChildProcessRecord));
241 rec->pid = pid;
242 QLIST_INSERT_HEAD(&child_watches, rec, next);
243 return 0;
245 #endif