1 files changed, 159 insertions, 0 deletions
diff --git a/io/task.c b/io/task.c
new file mode 100644
index 0000000000..3127fca771
--- /dev/null
+++ b/io/task.c
@@ -0,0 +1,159 @@
+/*
+ * 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 "io/task.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;
+}