summaryrefslogtreecommitdiffstats
path: root/iohandler.c
blob: f2fc8a9bd6c02645cf3276bf23e0fbc0516a2f7e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
/*
 * QEMU System Emulator - managing I/O handler
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/queue.h"
#include "block/aio.h"
#include "qemu/main-loop.h"

#ifndef _WIN32
#include <sys/wait.h>
#endif

/* This context runs on top of main loop. We can't reuse qemu_aio_context
 * because iohandlers mustn't be polled by aio_poll(qemu_aio_context). */
static AioContext *iohandler_ctx;

static void iohandler_init(void)
{
    if (!iohandler_ctx) {
        iohandler_ctx = aio_context_new(&error_abort);
    }
}

AioContext *iohandler_get_aio_context(void)
{
    iohandler_init();
    return iohandler_ctx;
}

GSource *iohandler_get_g_source(void)
{
    iohandler_init();
    return aio_get_g_source(iohandler_ctx);
}

void qemu_set_fd_handler(int fd,
                         IOHandler *fd_read,
                         IOHandler *fd_write,
                         void *opaque)
{
    iohandler_init();
    aio_set_fd_handler(iohandler_ctx, fd, false,
                       fd_read, fd_write, opaque);
}

/* reaping of zombies.  right now we're not passing the status to
   anyone, but it would be possible to add a callback.  */
#ifndef _WIN32
typedef struct ChildProcessRecord {
    int pid;
    QLIST_ENTRY(ChildProcessRecord) next;
} ChildProcessRecord;

static QLIST_HEAD(, ChildProcessRecord) child_watches =
    QLIST_HEAD_INITIALIZER(child_watches);

static QEMUBH *sigchld_bh;

static void sigchld_handler(int signal)
{
    qemu_bh_schedule(sigchld_bh);
}

static void sigchld_bh_handler(void *opaque)
{
    ChildProcessRecord *rec, *next;

    QLIST_FOREACH_SAFE(rec, &child_watches, next, next) {
        if (waitpid(rec->pid, NULL, WNOHANG) == rec->pid) {
            QLIST_REMOVE(rec, next);
            g_free(rec);
        }
    }
}

static void qemu_init_child_watch(void)
{
    struct sigaction act;
    sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);

    memset(&act, 0, sizeof(act));
    act.sa_handler = sigchld_handler;
    act.sa_flags = SA_NOCLDSTOP;
    sigaction(SIGCHLD, &act, NULL);
}

int qemu_add_child_watch(pid_t pid)
{
    ChildProcessRecord *rec;

    if (!sigchld_bh) {
        qemu_init_child_watch();
    }

    QLIST_FOREACH(rec, &child_watches, next) {
        if (rec->pid == pid) {
            return 1;
        }
    }
    rec = g_malloc0(sizeof(ChildProcessRecord));
    rec->pid = pid;
    QLIST_INSERT_HEAD(&child_watches, rec, next);
    return 0;
}
#endif