On Wed, Mar 06, 2019 at 07:55:28PM +0800, Peter Xu wrote: > Only sending an init-done message using lock+cond seems an overkill to > me. Replacing it with a simpler semaphore. > > Meanwhile, init the semaphore unconditionally, then we can destroy it > unconditionally too in finalize which seems cleaner. > > Signed-off-by: Peter Xu <pet...@redhat.com>
Sorry I've definitely lost Stefan's r-b for this patch. It's the same patch as the one I posted in v1. > --- > include/sysemu/iothread.h | 3 +-- > iothread.c | 17 ++++------------- > 2 files changed, 5 insertions(+), 15 deletions(-) > > diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h > index 8a7ac2c528..50411ba54a 100644 > --- a/include/sysemu/iothread.h > +++ b/include/sysemu/iothread.h > @@ -27,8 +27,7 @@ typedef struct { > GMainContext *worker_context; > GMainLoop *main_loop; > GOnce once; > - QemuMutex init_done_lock; > - QemuCond init_done_cond; /* is thread initialization done? */ > + QemuSemaphore init_done_sem; /* is thread init done? */ > bool stopping; /* has iothread_stop() been called? */ > bool running; /* should iothread_run() continue? */ > int thread_id; > diff --git a/iothread.c b/iothread.c > index e615b7ae52..6e297e9ef1 100644 > --- a/iothread.c > +++ b/iothread.c > @@ -55,10 +55,8 @@ static void *iothread_run(void *opaque) > rcu_register_thread(); > > my_iothread = iothread; > - qemu_mutex_lock(&iothread->init_done_lock); > iothread->thread_id = qemu_get_thread_id(); > - qemu_cond_signal(&iothread->init_done_cond); > - qemu_mutex_unlock(&iothread->init_done_lock); > + qemu_sem_post(&iothread->init_done_sem); > > while (iothread->running) { > aio_poll(iothread->ctx, true); > @@ -115,6 +113,7 @@ static void iothread_instance_init(Object *obj) > > iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT; > iothread->thread_id = -1; > + qemu_sem_init(&iothread->init_done_sem, 0); > } > > static void iothread_instance_finalize(Object *obj) > @@ -123,10 +122,6 @@ static void iothread_instance_finalize(Object *obj) > > iothread_stop(iothread); > > - if (iothread->thread_id != -1) { > - qemu_cond_destroy(&iothread->init_done_cond); > - qemu_mutex_destroy(&iothread->init_done_lock); > - } > /* > * Before glib2 2.33.10, there is a glib2 bug that GSource context > * pointer may not be cleared even if the context has already been > @@ -145,6 +140,7 @@ static void iothread_instance_finalize(Object *obj) > g_main_context_unref(iothread->worker_context); > iothread->worker_context = NULL; > } > + qemu_sem_destroy(&iothread->init_done_sem); > } > > static void iothread_complete(UserCreatable *obj, Error **errp) > @@ -173,8 +169,6 @@ static void iothread_complete(UserCreatable *obj, Error > **errp) > return; > } > > - qemu_mutex_init(&iothread->init_done_lock); > - qemu_cond_init(&iothread->init_done_cond); > iothread->once = (GOnce) G_ONCE_INIT; > > /* This assumes we are called from a thread with useful CPU affinity for > us > @@ -188,12 +182,9 @@ static void iothread_complete(UserCreatable *obj, Error > **errp) > g_free(name); > > /* Wait for initialization to complete */ > - qemu_mutex_lock(&iothread->init_done_lock); > while (iothread->thread_id == -1) { > - qemu_cond_wait(&iothread->init_done_cond, > - &iothread->init_done_lock); > + qemu_sem_wait(&iothread->init_done_sem); > } > - qemu_mutex_unlock(&iothread->init_done_lock); > } > > typedef struct { > -- > 2.17.1 > Regards, -- Peter Xu