2 * Event loop thread implementation for unit tests
4 * Copyright Red Hat Inc., 2013, 2016
7 * Stefan Hajnoczi <stefanha@redhat.com>
8 * Paolo Bonzini <pbonzini@redhat.com>
10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
11 * See the COPYING file in the top-level directory.
15 #include "qemu/osdep.h"
16 #include "qapi/error.h"
17 #include "block/aio.h"
18 #include "qemu/main-loop.h"
24 GMainContext *worker_context;
28 QemuMutex init_done_lock;
29 QemuCond init_done_cond; /* is thread initialization done? */
33 static void iothread_init_gcontext(IOThread *iothread)
37 iothread->worker_context = g_main_context_new();
38 source = aio_get_g_source(iothread_get_aio_context(iothread));
39 g_source_attach(source, iothread->worker_context);
40 g_source_unref(source);
41 iothread->main_loop = g_main_loop_new(iothread->worker_context, TRUE);
44 static void *iothread_run(void *opaque)
46 IOThread *iothread = opaque;
48 rcu_register_thread();
50 qemu_mutex_lock(&iothread->init_done_lock);
51 iothread->ctx = aio_context_new(&error_abort);
52 qemu_set_current_aio_context(iothread->ctx);
55 * We must connect the ctx to a GMainContext, because in older versions
56 * of glib the g_source_ref()/unref() functions are not threadsafe
57 * on sources without a context.
59 iothread_init_gcontext(iothread);
62 * g_main_context_push_thread_default() must be called before anything
63 * in this new thread uses glib.
65 g_main_context_push_thread_default(iothread->worker_context);
67 qemu_cond_signal(&iothread->init_done_cond);
68 qemu_mutex_unlock(&iothread->init_done_lock);
70 while (!qatomic_read(&iothread->stopping)) {
71 aio_poll(iothread->ctx, true);
74 g_main_context_pop_thread_default(iothread->worker_context);
75 rcu_unregister_thread();
79 static void iothread_stop_bh(void *opaque)
81 IOThread *iothread = opaque;
83 iothread->stopping = true;
86 void iothread_join(IOThread *iothread)
88 aio_bh_schedule_oneshot(iothread->ctx, iothread_stop_bh, iothread);
89 qemu_thread_join(&iothread->thread);
90 g_main_context_unref(iothread->worker_context);
91 g_main_loop_unref(iothread->main_loop);
92 qemu_cond_destroy(&iothread->init_done_cond);
93 qemu_mutex_destroy(&iothread->init_done_lock);
94 aio_context_unref(iothread->ctx);
98 IOThread *iothread_new(void)
100 IOThread *iothread = g_new0(IOThread, 1);
102 qemu_mutex_init(&iothread->init_done_lock);
103 qemu_cond_init(&iothread->init_done_cond);
104 qemu_thread_create(&iothread->thread, NULL, iothread_run,
105 iothread, QEMU_THREAD_JOINABLE);
107 /* Wait for initialization to complete */
108 qemu_mutex_lock(&iothread->init_done_lock);
109 while (iothread->ctx == NULL) {
110 qemu_cond_wait(&iothread->init_done_cond,
111 &iothread->init_done_lock);
113 qemu_mutex_unlock(&iothread->init_done_lock);
117 AioContext *iothread_get_aio_context(IOThread *iothread)
119 return iothread->ctx;