aboutsummaryrefslogtreecommitdiff
path: root/iothread.c
blob: a1f91099bc69900627b99d89caebcee013d9df8f (plain)
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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/*
 * Event loop thread
 *
 * Copyright Red Hat Inc., 2013
 *
 * Authors:
 *  Stefan Hajnoczi   <stefanha@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#include "qom/object.h"
#include "qom/object_interfaces.h"
#include "qemu/module.h"
#include "block/aio.h"
#include "sysemu/iothread.h"
#include "qmp-commands.h"
#include "qemu/error-report.h"

#define IOTHREADS_PATH "/objects"

typedef ObjectClass IOThreadClass;

#define IOTHREAD_GET_CLASS(obj) \
   OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD)
#define IOTHREAD_CLASS(klass) \
   OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)

static void *iothread_run(void *opaque)
{
    IOThread *iothread = opaque;

    qemu_mutex_lock(&iothread->init_done_lock);
    iothread->thread_id = qemu_get_thread_id();
    qemu_cond_signal(&iothread->init_done_cond);
    qemu_mutex_unlock(&iothread->init_done_lock);

    while (!atomic_read(&iothread->stopping)) {
        aio_poll(iothread->ctx, true);
    }
    return NULL;
}

static void iothread_instance_finalize(Object *obj)
{
    IOThread *iothread = IOTHREAD(obj);

    if (!iothread->ctx) {
        return;
    }
    iothread->stopping = true;
    aio_notify(iothread->ctx);
    qemu_thread_join(&iothread->thread);
    qemu_cond_destroy(&iothread->init_done_cond);
    qemu_mutex_destroy(&iothread->init_done_lock);
    aio_context_unref(iothread->ctx);
}

static void iothread_complete(UserCreatable *obj, Error **errp)
{
    Error *local_error = NULL;
    IOThread *iothread = IOTHREAD(obj);

    iothread->stopping = false;
    iothread->thread_id = -1;
    iothread->ctx = aio_context_new(&local_error);
    if (!iothread->ctx) {
        error_propagate(errp, local_error);
        return;
    }

    qemu_mutex_init(&iothread->init_done_lock);
    qemu_cond_init(&iothread->init_done_cond);

    /* This assumes we are called from a thread with useful CPU affinity for us
     * to inherit.
     */
    qemu_thread_create(&iothread->thread, "iothread", iothread_run,
                       iothread, QEMU_THREAD_JOINABLE);

    /* Wait for initialization to complete */
    qemu_mutex_lock(&iothread->init_done_lock);
    while (iothread->thread_id == -1) {
        qemu_cond_wait(&iothread->init_done_cond,
                       &iothread->init_done_lock);
    }
    qemu_mutex_unlock(&iothread->init_done_lock);
}

static void iothread_class_init(ObjectClass *klass, void *class_data)
{
    UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
    ucc->complete = iothread_complete;
}

static const TypeInfo iothread_info = {
    .name = TYPE_IOTHREAD,
    .parent = TYPE_OBJECT,
    .class_init = iothread_class_init,
    .instance_size = sizeof(IOThread),
    .instance_finalize = iothread_instance_finalize,
    .interfaces = (InterfaceInfo[]) {
        {TYPE_USER_CREATABLE},
        {}
    },
};

static void iothread_register_types(void)
{
    type_register_static(&iothread_info);
}

type_init(iothread_register_types)

IOThread *iothread_find(const char *id)
{
    Object *container = container_get(object_get_root(), IOTHREADS_PATH);
    Object *child;

    child = object_property_get_link(container, id, NULL);
    if (!child) {
        return NULL;
    }
    return (IOThread *)object_dynamic_cast(child, TYPE_IOTHREAD);
}

char *iothread_get_id(IOThread *iothread)
{
    return object_get_canonical_path_component(OBJECT(iothread));
}

AioContext *iothread_get_aio_context(IOThread *iothread)
{
    return iothread->ctx;
}

static int query_one_iothread(Object *object, void *opaque)
{
    IOThreadInfoList ***prev = opaque;
    IOThreadInfoList *elem;
    IOThreadInfo *info;
    IOThread *iothread;

    iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
    if (!iothread) {
        return 0;
    }

    info = g_new0(IOThreadInfo, 1);
    info->id = iothread_get_id(iothread);
    info->thread_id = iothread->thread_id;

    elem = g_new0(IOThreadInfoList, 1);
    elem->value = info;
    elem->next = NULL;

    **prev = elem;
    *prev = &elem->next;
    return 0;
}

IOThreadInfoList *qmp_query_iothreads(Error **errp)
{
    IOThreadInfoList *head = NULL;
    IOThreadInfoList **prev = &head;
    Object *container = container_get(object_get_root(), IOTHREADS_PATH);

    object_child_foreach(container, query_one_iothread, &prev);
    return head;
}