162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
/*
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 * QEMU I/O task
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 *
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 * Copyright (c) 2015 Red Hat, Inc.
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
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 *
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 */
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#include "qemu/osdep.h"
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#include "io/task.h"
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#include "qapi/error.h"
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#include "qemu/thread.h"
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#include "trace.h"
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struct QIOTask {
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    Object *source;
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    QIOTaskFunc func;
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    gpointer opaque;
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    GDestroyNotify destroy;
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};
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QIOTask *qio_task_new(Object *source,
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                      QIOTaskFunc func,
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                      gpointer opaque,
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                      GDestroyNotify destroy)
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{
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    QIOTask *task;
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    task = g_new0(QIOTask, 1);
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    task->source = source;
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    object_ref(source);
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    task->func = func;
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    task->opaque = opaque;
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    task->destroy = destroy;
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    trace_qio_task_new(task, source, func, opaque);
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    return task;
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}
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static void qio_task_free(QIOTask *task)
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{
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    if (task->destroy) {
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        task->destroy(task->opaque);
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    }
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    object_unref(task->source);
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    g_free(task);
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}
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struct QIOTaskThreadData {
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    QIOTask *task;
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    QIOTaskWorker worker;
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    gpointer opaque;
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    GDestroyNotify destroy;
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    Error *err;
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    int ret;
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};
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static gboolean gio_task_thread_result(gpointer opaque)
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{
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    struct QIOTaskThreadData *data = opaque;
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    trace_qio_task_thread_result(data->task);
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    if (data->ret == 0) {
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        qio_task_complete(data->task);
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    } else {
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        qio_task_abort(data->task, data->err);
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    }
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    error_free(data->err);
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    if (data->destroy) {
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        data->destroy(data->opaque);
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    }
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    g_free(data);
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    return FALSE;
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}
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static gpointer qio_task_thread_worker(gpointer opaque)
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{
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    struct QIOTaskThreadData *data = opaque;
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    trace_qio_task_thread_run(data->task);
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    data->ret = data->worker(data->task, &data->err, data->opaque);
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    if (data->ret < 0 && data->err == NULL) {
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        error_setg(&data->err, "Task worker failed but did not set an error");
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    }
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    /* We're running in the background thread, and must only
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     * ever report the task results in the main event loop
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     * thread. So we schedule an idle callback to report
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     * the worker results
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     */
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    trace_qio_task_thread_exit(data->task);
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    g_idle_add(gio_task_thread_result, data);
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    return NULL;
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}
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void qio_task_run_in_thread(QIOTask *task,
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                            QIOTaskWorker worker,
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                            gpointer opaque,
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                            GDestroyNotify destroy)
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{
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    struct QIOTaskThreadData *data = g_new0(struct QIOTaskThreadData, 1);
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    QemuThread thread;
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    data->task = task;
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    data->worker = worker;
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    data->opaque = opaque;
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    data->destroy = destroy;
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    trace_qio_task_thread_start(task, worker, opaque);
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    qemu_thread_create(&thread,
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                       "io-task-worker",
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                       qio_task_thread_worker,
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                       data,
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                       QEMU_THREAD_DETACHED);
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}
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void qio_task_complete(QIOTask *task)
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{
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    task->func(task->source, NULL, task->opaque);
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    trace_qio_task_complete(task);
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    qio_task_free(task);
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}
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void qio_task_abort(QIOTask *task,
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                    Error *err)
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{
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    task->func(task->source, err, task->opaque);
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    trace_qio_task_abort(task);
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    qio_task_free(task);
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}
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Object *qio_task_get_source(QIOTask *task)
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{
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    object_ref(task->source);
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    return task->source;
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}
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