1be8d8537SStefan Hajnoczi /* 2be8d8537SStefan Hajnoczi * Event loop thread 3be8d8537SStefan Hajnoczi * 4be8d8537SStefan Hajnoczi * Copyright Red Hat Inc., 2013 5be8d8537SStefan Hajnoczi * 6be8d8537SStefan Hajnoczi * Authors: 7be8d8537SStefan Hajnoczi * Stefan Hajnoczi <stefanha@redhat.com> 8be8d8537SStefan Hajnoczi * 9be8d8537SStefan Hajnoczi * This work is licensed under the terms of the GNU GPL, version 2 or later. 10be8d8537SStefan Hajnoczi * See the COPYING file in the top-level directory. 11be8d8537SStefan Hajnoczi * 12be8d8537SStefan Hajnoczi */ 13be8d8537SStefan Hajnoczi 14d38ea87aSPeter Maydell #include "qemu/osdep.h" 15be8d8537SStefan Hajnoczi #include "qom/object.h" 16be8d8537SStefan Hajnoczi #include "qom/object_interfaces.h" 17be8d8537SStefan Hajnoczi #include "qemu/module.h" 18be8d8537SStefan Hajnoczi #include "block/aio.h" 19d16341faSPaolo Bonzini #include "block/block.h" 20be8d8537SStefan Hajnoczi #include "sysemu/iothread.h" 21e688df6bSMarkus Armbruster #include "qapi/error.h" 22112ed241SMarkus Armbruster #include "qapi/qapi-commands-misc.h" 232f78e491SChrysostomos Nanakos #include "qemu/error-report.h" 24ab28bd23SPaolo Bonzini #include "qemu/rcu.h" 25e4370165SPaolo Bonzini #include "qemu/main-loop.h" 26be8d8537SStefan Hajnoczi 27be8d8537SStefan Hajnoczi typedef ObjectClass IOThreadClass; 28be8d8537SStefan Hajnoczi 29be8d8537SStefan Hajnoczi #define IOTHREAD_GET_CLASS(obj) \ 30be8d8537SStefan Hajnoczi OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD) 31be8d8537SStefan Hajnoczi #define IOTHREAD_CLASS(klass) \ 32be8d8537SStefan Hajnoczi OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD) 33be8d8537SStefan Hajnoczi 3490c558beSPeter Xu #ifdef CONFIG_POSIX 35cdd7abfdSStefan Hajnoczi /* Benchmark results from 2016 on NVMe SSD drives show max polling times around 36cdd7abfdSStefan Hajnoczi * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32 37cdd7abfdSStefan Hajnoczi * workloads. 38cdd7abfdSStefan Hajnoczi */ 39cdd7abfdSStefan Hajnoczi #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL 4090c558beSPeter Xu #else 4190c558beSPeter Xu #define IOTHREAD_POLL_MAX_NS_DEFAULT 0ULL 4290c558beSPeter Xu #endif 43cdd7abfdSStefan Hajnoczi 44e4370165SPaolo Bonzini static __thread IOThread *my_iothread; 45e4370165SPaolo Bonzini 46e4370165SPaolo Bonzini AioContext *qemu_get_current_aio_context(void) 47e4370165SPaolo Bonzini { 48e4370165SPaolo Bonzini return my_iothread ? my_iothread->ctx : qemu_get_aio_context(); 49e4370165SPaolo Bonzini } 50e4370165SPaolo Bonzini 51be8d8537SStefan Hajnoczi static void *iothread_run(void *opaque) 52be8d8537SStefan Hajnoczi { 53be8d8537SStefan Hajnoczi IOThread *iothread = opaque; 54be8d8537SStefan Hajnoczi 55ab28bd23SPaolo Bonzini rcu_register_thread(); 56ab28bd23SPaolo Bonzini 57e4370165SPaolo Bonzini my_iothread = iothread; 5888eb7c29SStefan Hajnoczi qemu_mutex_lock(&iothread->init_done_lock); 5988eb7c29SStefan Hajnoczi iothread->thread_id = qemu_get_thread_id(); 6088eb7c29SStefan Hajnoczi qemu_cond_signal(&iothread->init_done_cond); 6188eb7c29SStefan Hajnoczi qemu_mutex_unlock(&iothread->init_done_lock); 6288eb7c29SStefan Hajnoczi 632362a28eSStefan Hajnoczi while (iothread->running) { 6465c1b5b6SPaolo Bonzini aio_poll(iothread->ctx, true); 65329163cbSWang Yong 66*6c95363dSPeter Xu /* 67*6c95363dSPeter Xu * We must check the running state again in case it was 68*6c95363dSPeter Xu * changed in previous aio_poll() 69*6c95363dSPeter Xu */ 70*6c95363dSPeter Xu if (iothread->running && atomic_read(&iothread->worker_context)) { 71329163cbSWang Yong GMainLoop *loop; 72329163cbSWang Yong 73329163cbSWang Yong g_main_context_push_thread_default(iothread->worker_context); 74329163cbSWang Yong iothread->main_loop = 75329163cbSWang Yong g_main_loop_new(iothread->worker_context, TRUE); 76329163cbSWang Yong loop = iothread->main_loop; 77329163cbSWang Yong 78329163cbSWang Yong g_main_loop_run(iothread->main_loop); 79329163cbSWang Yong iothread->main_loop = NULL; 80329163cbSWang Yong g_main_loop_unref(loop); 81329163cbSWang Yong 82329163cbSWang Yong g_main_context_pop_thread_default(iothread->worker_context); 83329163cbSWang Yong } 84be8d8537SStefan Hajnoczi } 85ab28bd23SPaolo Bonzini 86ab28bd23SPaolo Bonzini rcu_unregister_thread(); 87be8d8537SStefan Hajnoczi return NULL; 88be8d8537SStefan Hajnoczi } 89be8d8537SStefan Hajnoczi 902362a28eSStefan Hajnoczi /* Runs in iothread_run() thread */ 912362a28eSStefan Hajnoczi static void iothread_stop_bh(void *opaque) 922362a28eSStefan Hajnoczi { 932362a28eSStefan Hajnoczi IOThread *iothread = opaque; 942362a28eSStefan Hajnoczi 952362a28eSStefan Hajnoczi iothread->running = false; /* stop iothread_run() */ 962362a28eSStefan Hajnoczi 972362a28eSStefan Hajnoczi if (iothread->main_loop) { 982362a28eSStefan Hajnoczi g_main_loop_quit(iothread->main_loop); 992362a28eSStefan Hajnoczi } 1002362a28eSStefan Hajnoczi } 1012362a28eSStefan Hajnoczi 10282d90705SPeter Xu void iothread_stop(IOThread *iothread) 103be8d8537SStefan Hajnoczi { 10482d90705SPeter Xu if (!iothread->ctx || iothread->stopping) { 10582d90705SPeter Xu return; 1062f78e491SChrysostomos Nanakos } 107be8d8537SStefan Hajnoczi iothread->stopping = true; 1082362a28eSStefan Hajnoczi aio_bh_schedule_oneshot(iothread->ctx, iothread_stop_bh, iothread); 109be8d8537SStefan Hajnoczi qemu_thread_join(&iothread->thread); 11082d90705SPeter Xu } 11182d90705SPeter Xu 112cdd7abfdSStefan Hajnoczi static void iothread_instance_init(Object *obj) 113cdd7abfdSStefan Hajnoczi { 114cdd7abfdSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 115cdd7abfdSStefan Hajnoczi 116cdd7abfdSStefan Hajnoczi iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT; 11714a2d118SMarc-André Lureau iothread->thread_id = -1; 118cdd7abfdSStefan Hajnoczi } 119cdd7abfdSStefan Hajnoczi 120dce8921bSFam Zheng static void iothread_instance_finalize(Object *obj) 121dce8921bSFam Zheng { 122dce8921bSFam Zheng IOThread *iothread = IOTHREAD(obj); 123dce8921bSFam Zheng 12482d90705SPeter Xu iothread_stop(iothread); 12514a2d118SMarc-André Lureau 12614a2d118SMarc-André Lureau if (iothread->thread_id != -1) { 12714a2d118SMarc-André Lureau qemu_cond_destroy(&iothread->init_done_cond); 12814a2d118SMarc-André Lureau qemu_mutex_destroy(&iothread->init_done_lock); 12914a2d118SMarc-André Lureau } 13015544349SPeter Xu /* 13115544349SPeter Xu * Before glib2 2.33.10, there is a glib2 bug that GSource context 13215544349SPeter Xu * pointer may not be cleared even if the context has already been 13315544349SPeter Xu * destroyed (while it should). Here let's free the AIO context 13415544349SPeter Xu * earlier to bypass that glib bug. 13515544349SPeter Xu * 13615544349SPeter Xu * We can remove this comment after the minimum supported glib2 13715544349SPeter Xu * version boosts to 2.33.10. Before that, let's free the 13815544349SPeter Xu * GSources first before destroying any GMainContext. 13915544349SPeter Xu */ 14015544349SPeter Xu if (iothread->ctx) { 14115544349SPeter Xu aio_context_unref(iothread->ctx); 14215544349SPeter Xu iothread->ctx = NULL; 14315544349SPeter Xu } 1445b3ac23fSPeter Xu if (iothread->worker_context) { 1455b3ac23fSPeter Xu g_main_context_unref(iothread->worker_context); 1465b3ac23fSPeter Xu iothread->worker_context = NULL; 1475b3ac23fSPeter Xu } 148be8d8537SStefan Hajnoczi } 149be8d8537SStefan Hajnoczi 150be8d8537SStefan Hajnoczi static void iothread_complete(UserCreatable *obj, Error **errp) 151be8d8537SStefan Hajnoczi { 1522f78e491SChrysostomos Nanakos Error *local_error = NULL; 153be8d8537SStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 154d21e8776SPaolo Bonzini char *name, *thread_name; 155be8d8537SStefan Hajnoczi 156be8d8537SStefan Hajnoczi iothread->stopping = false; 1572362a28eSStefan Hajnoczi iothread->running = true; 1582f78e491SChrysostomos Nanakos iothread->ctx = aio_context_new(&local_error); 1592f78e491SChrysostomos Nanakos if (!iothread->ctx) { 1602f78e491SChrysostomos Nanakos error_propagate(errp, local_error); 1612f78e491SChrysostomos Nanakos return; 1622f78e491SChrysostomos Nanakos } 16388eb7c29SStefan Hajnoczi 1645e5db499SStefan Hajnoczi aio_context_set_poll_params(iothread->ctx, 1655e5db499SStefan Hajnoczi iothread->poll_max_ns, 1665e5db499SStefan Hajnoczi iothread->poll_grow, 1675e5db499SStefan Hajnoczi iothread->poll_shrink, 1680d9d86fbSStefan Hajnoczi &local_error); 1690d9d86fbSStefan Hajnoczi if (local_error) { 1700d9d86fbSStefan Hajnoczi error_propagate(errp, local_error); 1710d9d86fbSStefan Hajnoczi aio_context_unref(iothread->ctx); 1720d9d86fbSStefan Hajnoczi iothread->ctx = NULL; 1730d9d86fbSStefan Hajnoczi return; 1740d9d86fbSStefan Hajnoczi } 1750d9d86fbSStefan Hajnoczi 17688eb7c29SStefan Hajnoczi qemu_mutex_init(&iothread->init_done_lock); 17788eb7c29SStefan Hajnoczi qemu_cond_init(&iothread->init_done_cond); 178329163cbSWang Yong iothread->once = (GOnce) G_ONCE_INIT; 179be8d8537SStefan Hajnoczi 180be8d8537SStefan Hajnoczi /* This assumes we are called from a thread with useful CPU affinity for us 181be8d8537SStefan Hajnoczi * to inherit. 182be8d8537SStefan Hajnoczi */ 183d21e8776SPaolo Bonzini name = object_get_canonical_path_component(OBJECT(obj)); 184d21e8776SPaolo Bonzini thread_name = g_strdup_printf("IO %s", name); 185d21e8776SPaolo Bonzini qemu_thread_create(&iothread->thread, thread_name, iothread_run, 186be8d8537SStefan Hajnoczi iothread, QEMU_THREAD_JOINABLE); 187d21e8776SPaolo Bonzini g_free(thread_name); 188d21e8776SPaolo Bonzini g_free(name); 18988eb7c29SStefan Hajnoczi 19088eb7c29SStefan Hajnoczi /* Wait for initialization to complete */ 19188eb7c29SStefan Hajnoczi qemu_mutex_lock(&iothread->init_done_lock); 19288eb7c29SStefan Hajnoczi while (iothread->thread_id == -1) { 19388eb7c29SStefan Hajnoczi qemu_cond_wait(&iothread->init_done_cond, 19488eb7c29SStefan Hajnoczi &iothread->init_done_lock); 19588eb7c29SStefan Hajnoczi } 19688eb7c29SStefan Hajnoczi qemu_mutex_unlock(&iothread->init_done_lock); 197be8d8537SStefan Hajnoczi } 198be8d8537SStefan Hajnoczi 1995e5db499SStefan Hajnoczi typedef struct { 2005e5db499SStefan Hajnoczi const char *name; 2015e5db499SStefan Hajnoczi ptrdiff_t offset; /* field's byte offset in IOThread struct */ 2025e5db499SStefan Hajnoczi } PollParamInfo; 2035e5db499SStefan Hajnoczi 2045e5db499SStefan Hajnoczi static PollParamInfo poll_max_ns_info = { 2055e5db499SStefan Hajnoczi "poll-max-ns", offsetof(IOThread, poll_max_ns), 2065e5db499SStefan Hajnoczi }; 2075e5db499SStefan Hajnoczi static PollParamInfo poll_grow_info = { 2085e5db499SStefan Hajnoczi "poll-grow", offsetof(IOThread, poll_grow), 2095e5db499SStefan Hajnoczi }; 2105e5db499SStefan Hajnoczi static PollParamInfo poll_shrink_info = { 2115e5db499SStefan Hajnoczi "poll-shrink", offsetof(IOThread, poll_shrink), 2125e5db499SStefan Hajnoczi }; 2135e5db499SStefan Hajnoczi 2145e5db499SStefan Hajnoczi static void iothread_get_poll_param(Object *obj, Visitor *v, 2150d9d86fbSStefan Hajnoczi const char *name, void *opaque, Error **errp) 2160d9d86fbSStefan Hajnoczi { 2170d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 2185e5db499SStefan Hajnoczi PollParamInfo *info = opaque; 2195e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 2200d9d86fbSStefan Hajnoczi 2215e5db499SStefan Hajnoczi visit_type_int64(v, name, field, errp); 2220d9d86fbSStefan Hajnoczi } 2230d9d86fbSStefan Hajnoczi 2245e5db499SStefan Hajnoczi static void iothread_set_poll_param(Object *obj, Visitor *v, 2250d9d86fbSStefan Hajnoczi const char *name, void *opaque, Error **errp) 2260d9d86fbSStefan Hajnoczi { 2270d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 2285e5db499SStefan Hajnoczi PollParamInfo *info = opaque; 2295e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 2300d9d86fbSStefan Hajnoczi Error *local_err = NULL; 2310d9d86fbSStefan Hajnoczi int64_t value; 2320d9d86fbSStefan Hajnoczi 2330d9d86fbSStefan Hajnoczi visit_type_int64(v, name, &value, &local_err); 2340d9d86fbSStefan Hajnoczi if (local_err) { 2350d9d86fbSStefan Hajnoczi goto out; 2360d9d86fbSStefan Hajnoczi } 2370d9d86fbSStefan Hajnoczi 2380d9d86fbSStefan Hajnoczi if (value < 0) { 2395e5db499SStefan Hajnoczi error_setg(&local_err, "%s value must be in range [0, %"PRId64"]", 2405e5db499SStefan Hajnoczi info->name, INT64_MAX); 2410d9d86fbSStefan Hajnoczi goto out; 2420d9d86fbSStefan Hajnoczi } 2430d9d86fbSStefan Hajnoczi 2445e5db499SStefan Hajnoczi *field = value; 2450d9d86fbSStefan Hajnoczi 2460d9d86fbSStefan Hajnoczi if (iothread->ctx) { 2475e5db499SStefan Hajnoczi aio_context_set_poll_params(iothread->ctx, 2485e5db499SStefan Hajnoczi iothread->poll_max_ns, 2495e5db499SStefan Hajnoczi iothread->poll_grow, 2505e5db499SStefan Hajnoczi iothread->poll_shrink, 2515e5db499SStefan Hajnoczi &local_err); 2520d9d86fbSStefan Hajnoczi } 2530d9d86fbSStefan Hajnoczi 2540d9d86fbSStefan Hajnoczi out: 2550d9d86fbSStefan Hajnoczi error_propagate(errp, local_err); 2560d9d86fbSStefan Hajnoczi } 2570d9d86fbSStefan Hajnoczi 258be8d8537SStefan Hajnoczi static void iothread_class_init(ObjectClass *klass, void *class_data) 259be8d8537SStefan Hajnoczi { 260be8d8537SStefan Hajnoczi UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); 261be8d8537SStefan Hajnoczi ucc->complete = iothread_complete; 2620d9d86fbSStefan Hajnoczi 2630d9d86fbSStefan Hajnoczi object_class_property_add(klass, "poll-max-ns", "int", 2645e5db499SStefan Hajnoczi iothread_get_poll_param, 2655e5db499SStefan Hajnoczi iothread_set_poll_param, 2665e5db499SStefan Hajnoczi NULL, &poll_max_ns_info, &error_abort); 2675e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-grow", "int", 2685e5db499SStefan Hajnoczi iothread_get_poll_param, 2695e5db499SStefan Hajnoczi iothread_set_poll_param, 2705e5db499SStefan Hajnoczi NULL, &poll_grow_info, &error_abort); 2715e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-shrink", "int", 2725e5db499SStefan Hajnoczi iothread_get_poll_param, 2735e5db499SStefan Hajnoczi iothread_set_poll_param, 2745e5db499SStefan Hajnoczi NULL, &poll_shrink_info, &error_abort); 275be8d8537SStefan Hajnoczi } 276be8d8537SStefan Hajnoczi 277be8d8537SStefan Hajnoczi static const TypeInfo iothread_info = { 278be8d8537SStefan Hajnoczi .name = TYPE_IOTHREAD, 279be8d8537SStefan Hajnoczi .parent = TYPE_OBJECT, 280be8d8537SStefan Hajnoczi .class_init = iothread_class_init, 281be8d8537SStefan Hajnoczi .instance_size = sizeof(IOThread), 282cdd7abfdSStefan Hajnoczi .instance_init = iothread_instance_init, 283be8d8537SStefan Hajnoczi .instance_finalize = iothread_instance_finalize, 284be8d8537SStefan Hajnoczi .interfaces = (InterfaceInfo[]) { 285be8d8537SStefan Hajnoczi {TYPE_USER_CREATABLE}, 286be8d8537SStefan Hajnoczi {} 287be8d8537SStefan Hajnoczi }, 288be8d8537SStefan Hajnoczi }; 289be8d8537SStefan Hajnoczi 290be8d8537SStefan Hajnoczi static void iothread_register_types(void) 291be8d8537SStefan Hajnoczi { 292be8d8537SStefan Hajnoczi type_register_static(&iothread_info); 293be8d8537SStefan Hajnoczi } 294be8d8537SStefan Hajnoczi 295be8d8537SStefan Hajnoczi type_init(iothread_register_types) 296be8d8537SStefan Hajnoczi 297be8d8537SStefan Hajnoczi char *iothread_get_id(IOThread *iothread) 298be8d8537SStefan Hajnoczi { 299be8d8537SStefan Hajnoczi return object_get_canonical_path_component(OBJECT(iothread)); 300be8d8537SStefan Hajnoczi } 301be8d8537SStefan Hajnoczi 302be8d8537SStefan Hajnoczi AioContext *iothread_get_aio_context(IOThread *iothread) 303be8d8537SStefan Hajnoczi { 304be8d8537SStefan Hajnoczi return iothread->ctx; 305be8d8537SStefan Hajnoczi } 306dc3dd0d2SStefan Hajnoczi 307dc3dd0d2SStefan Hajnoczi static int query_one_iothread(Object *object, void *opaque) 308dc3dd0d2SStefan Hajnoczi { 309dc3dd0d2SStefan Hajnoczi IOThreadInfoList ***prev = opaque; 310dc3dd0d2SStefan Hajnoczi IOThreadInfoList *elem; 311dc3dd0d2SStefan Hajnoczi IOThreadInfo *info; 312dc3dd0d2SStefan Hajnoczi IOThread *iothread; 313dc3dd0d2SStefan Hajnoczi 314dc3dd0d2SStefan Hajnoczi iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 315dc3dd0d2SStefan Hajnoczi if (!iothread) { 316dc3dd0d2SStefan Hajnoczi return 0; 317dc3dd0d2SStefan Hajnoczi } 318dc3dd0d2SStefan Hajnoczi 319dc3dd0d2SStefan Hajnoczi info = g_new0(IOThreadInfo, 1); 320dc3dd0d2SStefan Hajnoczi info->id = iothread_get_id(iothread); 321dc3dd0d2SStefan Hajnoczi info->thread_id = iothread->thread_id; 3225fc00480SPavel Hrdina info->poll_max_ns = iothread->poll_max_ns; 3235fc00480SPavel Hrdina info->poll_grow = iothread->poll_grow; 3245fc00480SPavel Hrdina info->poll_shrink = iothread->poll_shrink; 325dc3dd0d2SStefan Hajnoczi 326dc3dd0d2SStefan Hajnoczi elem = g_new0(IOThreadInfoList, 1); 327dc3dd0d2SStefan Hajnoczi elem->value = info; 328dc3dd0d2SStefan Hajnoczi elem->next = NULL; 329dc3dd0d2SStefan Hajnoczi 330dc3dd0d2SStefan Hajnoczi **prev = elem; 331dc3dd0d2SStefan Hajnoczi *prev = &elem->next; 332dc3dd0d2SStefan Hajnoczi return 0; 333dc3dd0d2SStefan Hajnoczi } 334dc3dd0d2SStefan Hajnoczi 335dc3dd0d2SStefan Hajnoczi IOThreadInfoList *qmp_query_iothreads(Error **errp) 336dc3dd0d2SStefan Hajnoczi { 337dc3dd0d2SStefan Hajnoczi IOThreadInfoList *head = NULL; 338dc3dd0d2SStefan Hajnoczi IOThreadInfoList **prev = &head; 339bc2256c4SDaniel P. Berrange Object *container = object_get_objects_root(); 340dc3dd0d2SStefan Hajnoczi 341dc3dd0d2SStefan Hajnoczi object_child_foreach(container, query_one_iothread, &prev); 342dc3dd0d2SStefan Hajnoczi return head; 343dc3dd0d2SStefan Hajnoczi } 344dce8921bSFam Zheng 345329163cbSWang Yong static gpointer iothread_g_main_context_init(gpointer opaque) 346329163cbSWang Yong { 347329163cbSWang Yong AioContext *ctx; 348329163cbSWang Yong IOThread *iothread = opaque; 349329163cbSWang Yong GSource *source; 350329163cbSWang Yong 351329163cbSWang Yong iothread->worker_context = g_main_context_new(); 352329163cbSWang Yong 353329163cbSWang Yong ctx = iothread_get_aio_context(iothread); 354329163cbSWang Yong source = aio_get_g_source(ctx); 355329163cbSWang Yong g_source_attach(source, iothread->worker_context); 356329163cbSWang Yong g_source_unref(source); 357329163cbSWang Yong 358329163cbSWang Yong aio_notify(iothread->ctx); 359329163cbSWang Yong return NULL; 360329163cbSWang Yong } 361329163cbSWang Yong 362329163cbSWang Yong GMainContext *iothread_get_g_main_context(IOThread *iothread) 363329163cbSWang Yong { 364329163cbSWang Yong g_once(&iothread->once, iothread_g_main_context_init, iothread); 365329163cbSWang Yong 366329163cbSWang Yong return iothread->worker_context; 367329163cbSWang Yong } 3680173e21bSPeter Xu 3690173e21bSPeter Xu IOThread *iothread_create(const char *id, Error **errp) 3700173e21bSPeter Xu { 3710173e21bSPeter Xu Object *obj; 3720173e21bSPeter Xu 3730173e21bSPeter Xu obj = object_new_with_props(TYPE_IOTHREAD, 3740173e21bSPeter Xu object_get_internal_root(), 3750173e21bSPeter Xu id, errp, NULL); 3760173e21bSPeter Xu 3770173e21bSPeter Xu return IOTHREAD(obj); 3780173e21bSPeter Xu } 3790173e21bSPeter Xu 3800173e21bSPeter Xu void iothread_destroy(IOThread *iothread) 3810173e21bSPeter Xu { 3820173e21bSPeter Xu object_unparent(OBJECT(iothread)); 3830173e21bSPeter Xu } 384fbcc6923SStefan Hajnoczi 385fbcc6923SStefan Hajnoczi /* Lookup IOThread by its id. Only finds user-created objects, not internal 386fbcc6923SStefan Hajnoczi * iothread_create() objects. */ 387fbcc6923SStefan Hajnoczi IOThread *iothread_by_id(const char *id) 388fbcc6923SStefan Hajnoczi { 389fbcc6923SStefan Hajnoczi return IOTHREAD(object_resolve_path_type(id, TYPE_IOTHREAD, NULL)); 390fbcc6923SStefan Hajnoczi } 391