1 files changed, 178 insertions, 0 deletions
diff --git a/iothread.c b/iothread.c
new file mode 100644
index 0000000000..cb5986b6c9
--- /dev/null
+++ b/iothread.c
@@ -0,0 +1,178 @@
+/*
+ * 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 "qemu/thread.h"
+#include "block/aio.h"
+#include "sysemu/iothread.h"
+#include "qmp-commands.h"
+
+#define IOTHREADS_PATH "/objects"
+
+typedef ObjectClass IOThreadClass;
+struct IOThread {
+    Object parent_obj;
+
+    QemuThread thread;
+    AioContext *ctx;
+    QemuMutex init_done_lock;
+    QemuCond init_done_cond;    /* is thread initialization done? */
+    bool stopping;
+    int thread_id;
+};
+
+#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 (!iothread->stopping) {
+        aio_context_acquire(iothread->ctx);
+        while (!iothread->stopping && aio_poll(iothread->ctx, true)) {
+            /* Progress was made, keep going */
+        }
+        aio_context_release(iothread->ctx);
+    }
+    return NULL;
+}
+
+static void iothread_instance_finalize(Object *obj)
+{
+    IOThread *iothread = IOTHREAD(obj);
+
+    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)
+{
+    IOThread *iothread = IOTHREAD(obj);
+
+    iothread->stopping = false;
+    iothread->ctx = aio_context_new();
+    iothread->thread_id = -1;
+
+    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;
+}