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/*
* Event loop thread implementation for unit tests
*
* Copyright Red Hat Inc., 2013, 2016
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
* Paolo Bonzini <pbonzini@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 "qemu/osdep.h"
#include "qapi/error.h"
#include "block/aio.h"
#include "qemu/main-loop.h"
#include "qemu/rcu.h"
#include "iothread.h"
struct IOThread {
AioContext *ctx;
GMainContext *worker_context;
GMainLoop *main_loop;
QemuThread thread;
QemuMutex init_done_lock;
QemuCond init_done_cond; /* is thread initialization done? */
bool stopping;
};
static __thread IOThread *my_iothread;
AioContext *qemu_get_current_aio_context(void)
{
return my_iothread ? my_iothread->ctx : qemu_get_aio_context();
}
static void iothread_init_gcontext(IOThread *iothread)
{
GSource *source;
iothread->worker_context = g_main_context_new();
source = aio_get_g_source(iothread_get_aio_context(iothread));
g_source_attach(source, iothread->worker_context);
g_source_unref(source);
iothread->main_loop = g_main_loop_new(iothread->worker_context, TRUE);
}
static void *iothread_run(void *opaque)
{
IOThread *iothread = opaque;
rcu_register_thread();
my_iothread = iothread;
qemu_mutex_lock(&iothread->init_done_lock);
iothread->ctx = aio_context_new(&error_abort);
/*
* We must connect the ctx to a GMainContext, because in older versions
* of glib the g_source_ref()/unref() functions are not threadsafe
* on sources without a context.
*/
iothread_init_gcontext(iothread);
/*
* g_main_context_push_thread_default() must be called before anything
* in this new thread uses glib.
*/
g_main_context_push_thread_default(iothread->worker_context);
qemu_cond_signal(&iothread->init_done_cond);
qemu_mutex_unlock(&iothread->init_done_lock);
while (!qatomic_read(&iothread->stopping)) {
aio_poll(iothread->ctx, true);
}
g_main_context_pop_thread_default(iothread->worker_context);
rcu_unregister_thread();
return NULL;
}
static void iothread_stop_bh(void *opaque)
{
IOThread *iothread = opaque;
iothread->stopping = true;
}
void iothread_join(IOThread *iothread)
{
aio_bh_schedule_oneshot(iothread->ctx, iothread_stop_bh, iothread);
qemu_thread_join(&iothread->thread);
g_main_context_unref(iothread->worker_context);
g_main_loop_unref(iothread->main_loop);
qemu_cond_destroy(&iothread->init_done_cond);
qemu_mutex_destroy(&iothread->init_done_lock);
aio_context_unref(iothread->ctx);
g_free(iothread);
}
IOThread *iothread_new(void)
{
IOThread *iothread = g_new0(IOThread, 1);
qemu_mutex_init(&iothread->init_done_lock);
qemu_cond_init(&iothread->init_done_cond);
qemu_thread_create(&iothread->thread, NULL, iothread_run,
iothread, QEMU_THREAD_JOINABLE);
/* Wait for initialization to complete */
qemu_mutex_lock(&iothread->init_done_lock);
while (iothread->ctx == NULL) {
qemu_cond_wait(&iothread->init_done_cond,
&iothread->init_done_lock);
}
qemu_mutex_unlock(&iothread->init_done_lock);
return iothread;
}
AioContext *iothread_get_aio_context(IOThread *iothread)
{
return iothread->ctx;
}
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