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
25
#include "config-host.h"
26
#include "qemu-common.h"
27
#include "qemu-char.h"
28
#include "qemu-queue.h"
34
typedef struct IOHandlerRecord {
36
IOCanReadHandler *fd_read_poll;
41
QLIST_ENTRY(IOHandlerRecord) next;
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,
58
if (!fd_read && !fd_write) {
59
QLIST_FOREACH(ioh, &io_handlers, next) {
66
QLIST_FOREACH(ioh, &io_handlers, next) {
70
ioh = qemu_mallocz(sizeof(IOHandlerRecord));
71
QLIST_INSERT_HEAD(&io_handlers, ioh, next);
74
ioh->fd_read_poll = fd_read_poll;
75
ioh->fd_read = fd_read;
76
ioh->fd_write = fd_write;
83
int qemu_set_fd_handler(int fd,
88
return qemu_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque);
91
void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds)
95
QLIST_FOREACH(ioh, &io_handlers, next) {
99
(!ioh->fd_read_poll ||
100
ioh->fd_read_poll(ioh->opaque) != 0)) {
101
FD_SET(ioh->fd, readfds);
102
if (ioh->fd > *pnfds)
106
FD_SET(ioh->fd, writefds);
107
if (ioh->fd > *pnfds)
113
void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int ret)
116
IOHandlerRecord *pioh, *ioh;
118
QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) {
119
if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, readfds)) {
120
ioh->fd_read(ioh->opaque);
122
if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, writefds)) {
123
ioh->fd_write(ioh->opaque);
126
/* Do this last in case read/write handlers marked it for deletion */
128
QLIST_REMOVE(ioh, next);
135
/* reaping of zombies. right now we're not passing the status to
136
anyone, but it would be possible to add a callback. */
138
typedef struct ChildProcessRecord {
140
QLIST_ENTRY(ChildProcessRecord) next;
141
} ChildProcessRecord;
143
static QLIST_HEAD(, ChildProcessRecord) child_watches =
144
QLIST_HEAD_INITIALIZER(child_watches);
146
static QEMUBH *sigchld_bh;
148
static void sigchld_handler(int signal)
150
qemu_bh_schedule(sigchld_bh);
153
static void sigchld_bh_handler(void *opaque)
155
ChildProcessRecord *rec, *next;
157
QLIST_FOREACH_SAFE(rec, &child_watches, next, next) {
158
if (waitpid(rec->pid, NULL, WNOHANG) == rec->pid) {
159
QLIST_REMOVE(rec, next);
165
static void qemu_init_child_watch(void)
167
struct sigaction act;
168
sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);
170
act.sa_handler = sigchld_handler;
171
act.sa_flags = SA_NOCLDSTOP;
172
sigaction(SIGCHLD, &act, NULL);
175
int qemu_add_child_watch(pid_t pid)
177
ChildProcessRecord *rec;
180
qemu_init_child_watch();
183
QLIST_FOREACH(rec, &child_watches, next) {
184
if (rec->pid == pid) {
188
rec = qemu_mallocz(sizeof(ChildProcessRecord));
190
QLIST_INSERT_HEAD(&child_watches, rec, next);