summaryrefslogtreecommitdiff
path: root/io/task.c
blob: c7f97a9b16e926c293a2390da75f59577e9cec3a (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
/*
 * QEMU I/O task
 *
 * Copyright (c) 2015 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "qemu/osdep.h"
#include "io/task.h"
#include "qapi/error.h"
#include "qemu/thread.h"
#include "trace.h"

struct QIOTask {
    Object *source;
    QIOTaskFunc func;
    gpointer opaque;
    GDestroyNotify destroy;
};


QIOTask *qio_task_new(Object *source,
                      QIOTaskFunc func,
                      gpointer opaque,
                      GDestroyNotify destroy)
{
    QIOTask *task;

    task = g_new0(QIOTask, 1);

    task->source = source;
    object_ref(source);
    task->func = func;
    task->opaque = opaque;
    task->destroy = destroy;

    trace_qio_task_new(task, source, func, opaque);

    return task;
}

static void qio_task_free(QIOTask *task)
{
    if (task->destroy) {
        task->destroy(task->opaque);
    }
    object_unref(task->source);

    g_free(task);
}


struct QIOTaskThreadData {
    QIOTask *task;
    QIOTaskWorker worker;
    gpointer opaque;
    GDestroyNotify destroy;
    Error *err;
    int ret;
};


static gboolean gio_task_thread_result(gpointer opaque)
{
    struct QIOTaskThreadData *data = opaque;

    trace_qio_task_thread_result(data->task);
    if (data->ret == 0) {
        qio_task_complete(data->task);
    } else {
        qio_task_abort(data->task, data->err);
    }

    error_free(data->err);
    if (data->destroy) {
        data->destroy(data->opaque);
    }

    g_free(data);

    return FALSE;
}


static gpointer qio_task_thread_worker(gpointer opaque)
{
    struct QIOTaskThreadData *data = opaque;

    trace_qio_task_thread_run(data->task);
    data->ret = data->worker(data->task, &data->err, data->opaque);
    if (data->ret < 0 && data->err == NULL) {
        error_setg(&data->err, "Task worker failed but did not set an error");
    }

    /* We're running in the background thread, and must only
     * ever report the task results in the main event loop
     * thread. So we schedule an idle callback to report
     * the worker results
     */
    trace_qio_task_thread_exit(data->task);
    g_idle_add(gio_task_thread_result, data);
    return NULL;
}


void qio_task_run_in_thread(QIOTask *task,
                            QIOTaskWorker worker,
                            gpointer opaque,
                            GDestroyNotify destroy)
{
    struct QIOTaskThreadData *data = g_new0(struct QIOTaskThreadData, 1);
    QemuThread thread;

    data->task = task;
    data->worker = worker;
    data->opaque = opaque;
    data->destroy = destroy;

    trace_qio_task_thread_start(task, worker, opaque);
    qemu_thread_create(&thread,
                       "io-task-worker",
                       qio_task_thread_worker,
                       data,
                       QEMU_THREAD_DETACHED);
}


void qio_task_complete(QIOTask *task)
{
    task->func(task->source, NULL, task->opaque);
    trace_qio_task_complete(task);
    qio_task_free(task);
}

void qio_task_abort(QIOTask *task,
                    Error *err)
{
    task->func(task->source, err, task->opaque);
    trace_qio_task_abort(task);
    qio_task_free(task);
}


Object *qio_task_get_source(QIOTask *task)
{
    object_ref(task->source);
    return task->source;
}