1 /* 2 * Event loop thread 3 * 4 * Copyright Red Hat Inc., 2013 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qom/object.h" 15 #include "qom/object_interfaces.h" 16 #include "qemu/module.h" 17 #include "block/aio.h" 18 #include "sysemu/iothread.h" 19 #include "qmp-commands.h" 20 21 #define IOTHREADS_PATH "/objects" 22 23 typedef ObjectClass IOThreadClass; 24 25 #define IOTHREAD_GET_CLASS(obj) \ 26 OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD) 27 #define IOTHREAD_CLASS(klass) \ 28 OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD) 29 30 static void *iothread_run(void *opaque) 31 { 32 IOThread *iothread = opaque; 33 34 qemu_mutex_lock(&iothread->init_done_lock); 35 iothread->thread_id = qemu_get_thread_id(); 36 qemu_cond_signal(&iothread->init_done_cond); 37 qemu_mutex_unlock(&iothread->init_done_lock); 38 39 while (!iothread->stopping) { 40 aio_context_acquire(iothread->ctx); 41 while (!iothread->stopping && aio_poll(iothread->ctx, true)) { 42 /* Progress was made, keep going */ 43 } 44 aio_context_release(iothread->ctx); 45 } 46 return NULL; 47 } 48 49 static void iothread_instance_finalize(Object *obj) 50 { 51 IOThread *iothread = IOTHREAD(obj); 52 53 iothread->stopping = true; 54 aio_notify(iothread->ctx); 55 qemu_thread_join(&iothread->thread); 56 qemu_cond_destroy(&iothread->init_done_cond); 57 qemu_mutex_destroy(&iothread->init_done_lock); 58 aio_context_unref(iothread->ctx); 59 } 60 61 static void iothread_complete(UserCreatable *obj, Error **errp) 62 { 63 IOThread *iothread = IOTHREAD(obj); 64 65 iothread->stopping = false; 66 iothread->ctx = aio_context_new(); 67 iothread->thread_id = -1; 68 69 qemu_mutex_init(&iothread->init_done_lock); 70 qemu_cond_init(&iothread->init_done_cond); 71 72 /* This assumes we are called from a thread with useful CPU affinity for us 73 * to inherit. 74 */ 75 qemu_thread_create(&iothread->thread, "iothread", iothread_run, 76 iothread, QEMU_THREAD_JOINABLE); 77 78 /* Wait for initialization to complete */ 79 qemu_mutex_lock(&iothread->init_done_lock); 80 while (iothread->thread_id == -1) { 81 qemu_cond_wait(&iothread->init_done_cond, 82 &iothread->init_done_lock); 83 } 84 qemu_mutex_unlock(&iothread->init_done_lock); 85 } 86 87 static void iothread_class_init(ObjectClass *klass, void *class_data) 88 { 89 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); 90 ucc->complete = iothread_complete; 91 } 92 93 static const TypeInfo iothread_info = { 94 .name = TYPE_IOTHREAD, 95 .parent = TYPE_OBJECT, 96 .class_init = iothread_class_init, 97 .instance_size = sizeof(IOThread), 98 .instance_finalize = iothread_instance_finalize, 99 .interfaces = (InterfaceInfo[]) { 100 {TYPE_USER_CREATABLE}, 101 {} 102 }, 103 }; 104 105 static void iothread_register_types(void) 106 { 107 type_register_static(&iothread_info); 108 } 109 110 type_init(iothread_register_types) 111 112 IOThread *iothread_find(const char *id) 113 { 114 Object *container = container_get(object_get_root(), IOTHREADS_PATH); 115 Object *child; 116 117 child = object_property_get_link(container, id, NULL); 118 if (!child) { 119 return NULL; 120 } 121 return (IOThread *)object_dynamic_cast(child, TYPE_IOTHREAD); 122 } 123 124 char *iothread_get_id(IOThread *iothread) 125 { 126 return object_get_canonical_path_component(OBJECT(iothread)); 127 } 128 129 AioContext *iothread_get_aio_context(IOThread *iothread) 130 { 131 return iothread->ctx; 132 } 133 134 static int query_one_iothread(Object *object, void *opaque) 135 { 136 IOThreadInfoList ***prev = opaque; 137 IOThreadInfoList *elem; 138 IOThreadInfo *info; 139 IOThread *iothread; 140 141 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 142 if (!iothread) { 143 return 0; 144 } 145 146 info = g_new0(IOThreadInfo, 1); 147 info->id = iothread_get_id(iothread); 148 info->thread_id = iothread->thread_id; 149 150 elem = g_new0(IOThreadInfoList, 1); 151 elem->value = info; 152 elem->next = NULL; 153 154 **prev = elem; 155 *prev = &elem->next; 156 return 0; 157 } 158 159 IOThreadInfoList *qmp_query_iothreads(Error **errp) 160 { 161 IOThreadInfoList *head = NULL; 162 IOThreadInfoList **prev = &head; 163 Object *container = container_get(object_get_root(), IOTHREADS_PATH); 164 165 object_child_foreach(container, query_one_iothread, &prev); 166 return head; 167 } 168