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 bool blocking; 34 35 qemu_mutex_lock(&iothread->init_done_lock); 36 iothread->thread_id = qemu_get_thread_id(); 37 qemu_cond_signal(&iothread->init_done_cond); 38 qemu_mutex_unlock(&iothread->init_done_lock); 39 40 while (!iothread->stopping) { 41 aio_context_acquire(iothread->ctx); 42 blocking = true; 43 while (!iothread->stopping && aio_poll(iothread->ctx, blocking)) { 44 /* Progress was made, keep going */ 45 blocking = false; 46 } 47 aio_context_release(iothread->ctx); 48 } 49 return NULL; 50 } 51 52 static void iothread_instance_finalize(Object *obj) 53 { 54 IOThread *iothread = IOTHREAD(obj); 55 56 iothread->stopping = true; 57 aio_notify(iothread->ctx); 58 qemu_thread_join(&iothread->thread); 59 qemu_cond_destroy(&iothread->init_done_cond); 60 qemu_mutex_destroy(&iothread->init_done_lock); 61 aio_context_unref(iothread->ctx); 62 } 63 64 static void iothread_complete(UserCreatable *obj, Error **errp) 65 { 66 IOThread *iothread = IOTHREAD(obj); 67 68 iothread->stopping = false; 69 iothread->ctx = aio_context_new(); 70 iothread->thread_id = -1; 71 72 qemu_mutex_init(&iothread->init_done_lock); 73 qemu_cond_init(&iothread->init_done_cond); 74 75 /* This assumes we are called from a thread with useful CPU affinity for us 76 * to inherit. 77 */ 78 qemu_thread_create(&iothread->thread, "iothread", iothread_run, 79 iothread, QEMU_THREAD_JOINABLE); 80 81 /* Wait for initialization to complete */ 82 qemu_mutex_lock(&iothread->init_done_lock); 83 while (iothread->thread_id == -1) { 84 qemu_cond_wait(&iothread->init_done_cond, 85 &iothread->init_done_lock); 86 } 87 qemu_mutex_unlock(&iothread->init_done_lock); 88 } 89 90 static void iothread_class_init(ObjectClass *klass, void *class_data) 91 { 92 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); 93 ucc->complete = iothread_complete; 94 } 95 96 static const TypeInfo iothread_info = { 97 .name = TYPE_IOTHREAD, 98 .parent = TYPE_OBJECT, 99 .class_init = iothread_class_init, 100 .instance_size = sizeof(IOThread), 101 .instance_finalize = iothread_instance_finalize, 102 .interfaces = (InterfaceInfo[]) { 103 {TYPE_USER_CREATABLE}, 104 {} 105 }, 106 }; 107 108 static void iothread_register_types(void) 109 { 110 type_register_static(&iothread_info); 111 } 112 113 type_init(iothread_register_types) 114 115 IOThread *iothread_find(const char *id) 116 { 117 Object *container = container_get(object_get_root(), IOTHREADS_PATH); 118 Object *child; 119 120 child = object_property_get_link(container, id, NULL); 121 if (!child) { 122 return NULL; 123 } 124 return (IOThread *)object_dynamic_cast(child, TYPE_IOTHREAD); 125 } 126 127 char *iothread_get_id(IOThread *iothread) 128 { 129 return object_get_canonical_path_component(OBJECT(iothread)); 130 } 131 132 AioContext *iothread_get_aio_context(IOThread *iothread) 133 { 134 return iothread->ctx; 135 } 136 137 static int query_one_iothread(Object *object, void *opaque) 138 { 139 IOThreadInfoList ***prev = opaque; 140 IOThreadInfoList *elem; 141 IOThreadInfo *info; 142 IOThread *iothread; 143 144 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 145 if (!iothread) { 146 return 0; 147 } 148 149 info = g_new0(IOThreadInfo, 1); 150 info->id = iothread_get_id(iothread); 151 info->thread_id = iothread->thread_id; 152 153 elem = g_new0(IOThreadInfoList, 1); 154 elem->value = info; 155 elem->next = NULL; 156 157 **prev = elem; 158 *prev = &elem->next; 159 return 0; 160 } 161 162 IOThreadInfoList *qmp_query_iothreads(Error **errp) 163 { 164 IOThreadInfoList *head = NULL; 165 IOThreadInfoList **prev = &head; 166 Object *container = container_get(object_get_root(), IOTHREADS_PATH); 167 168 object_child_foreach(container, query_one_iothread, &prev); 169 return head; 170 } 171