qemu/io/task.c
Peter Xu a17536c594 qio: non-default context for threaded qtask
qio_task_run_in_thread() allows main thread to run blocking operations
in the background. However it has an assumption on that it's always
working with the default context. This patch tries to allow the threaded
QIO task framework to run with non-default gcontext.

Currently no functional change so far, so the QIOTasks are still always
running on main context.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-03-06 10:19:05 +00:00

203 lines
4.5 KiB
C

/*
* 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;
Error *err;
gpointer result;
GDestroyNotify destroyResult;
};
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);
}
if (task->destroyResult) {
task->destroyResult(task->result);
}
if (task->err) {
error_free(task->err);
}
object_unref(task->source);
g_free(task);
}
struct QIOTaskThreadData {
QIOTask *task;
QIOTaskWorker worker;
gpointer opaque;
GDestroyNotify destroy;
GMainContext *context;
};
static gboolean qio_task_thread_result(gpointer opaque)
{
struct QIOTaskThreadData *data = opaque;
trace_qio_task_thread_result(data->task);
qio_task_complete(data->task);
if (data->destroy) {
data->destroy(data->opaque);
}
if (data->context) {
g_main_context_unref(data->context);
}
g_free(data);
return FALSE;
}
static gpointer qio_task_thread_worker(gpointer opaque)
{
struct QIOTaskThreadData *data = opaque;
GSource *idle;
trace_qio_task_thread_run(data->task);
data->worker(data->task, data->opaque);
/* 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);
idle = g_idle_source_new();
g_source_set_callback(idle, qio_task_thread_result, data, NULL);
g_source_attach(idle, data->context);
return NULL;
}
void qio_task_run_in_thread(QIOTask *task,
QIOTaskWorker worker,
gpointer opaque,
GDestroyNotify destroy,
GMainContext *context)
{
struct QIOTaskThreadData *data = g_new0(struct QIOTaskThreadData, 1);
QemuThread thread;
if (context) {
g_main_context_ref(context);
}
data->task = task;
data->worker = worker;
data->opaque = opaque;
data->destroy = destroy;
data->context = context;
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, task->opaque);
trace_qio_task_complete(task);
qio_task_free(task);
}
void qio_task_set_error(QIOTask *task,
Error *err)
{
error_propagate(&task->err, err);
}
bool qio_task_propagate_error(QIOTask *task,
Error **errp)
{
if (task->err) {
error_propagate(errp, task->err);
task->err = NULL;
return true;
}
return false;
}
void qio_task_set_result_pointer(QIOTask *task,
gpointer result,
GDestroyNotify destroy)
{
task->result = result;
task->destroyResult = destroy;
}
gpointer qio_task_get_result_pointer(QIOTask *task)
{
return task->result;
}
Object *qio_task_get_source(QIOTask *task)
{
return task->source;
}