From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55725) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dvJlA-000454-L9 for qemu-devel@nongnu.org; Fri, 22 Sep 2017 04:56:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dvJl9-0004zw-Lb for qemu-devel@nongnu.org; Fri, 22 Sep 2017 04:56:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55168) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dvJl9-0004ys-D1 for qemu-devel@nongnu.org; Fri, 22 Sep 2017 04:56:31 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5A6844E4D1 for ; Fri, 22 Sep 2017 08:56:30 +0000 (UTC) From: Peter Xu Date: Fri, 22 Sep 2017 16:56:11 +0800 Message-Id: <1506070572-7549-3-git-send-email-peterx@redhat.com> In-Reply-To: <1506070572-7549-1-git-send-email-peterx@redhat.com> References: <1506070572-7549-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH 2/3] iothread: export iothread_stop() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , "Daniel P . Berrange" , Stefan Hajnoczi , Fam Zheng , "Dr . David Alan Gilbert" , peterx@redhat.com So that internal iothread users can explicitly stop one iothread without destroying it. Since at it, fix iothread_stop() to allow re-entrance. Before this patch we may call iothread_stop() twice on single iothread, while that may not be correct since qemu_thread_join() is not allowed to run twice. >>From manual of pthread_join(): Joining with a thread that has previously been joined results in undefined behavior. Signed-off-by: Peter Xu --- include/sysemu/iothread.h | 1 + iothread.c | 24 ++++++++++++++++-------- 2 files changed, 17 insertions(+), 8 deletions(-) diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h index b07663f..110329b 100644 --- a/include/sysemu/iothread.h +++ b/include/sysemu/iothread.h @@ -52,6 +52,7 @@ GMainContext *iothread_get_g_main_context(IOThread *iothread); * "query-iothreads". */ IOThread *iothread_create(const char *id, Error **errp); +void iothread_stop(IOThread *iothread); void iothread_destroy(IOThread *iothread); #endif /* IOTHREAD_H */ diff --git a/iothread.c b/iothread.c index 74e400c..894756b 100644 --- a/iothread.c +++ b/iothread.c @@ -80,13 +80,10 @@ static void *iothread_run(void *opaque) return NULL; } -static int iothread_stop(Object *object, void *opaque) +void iothread_stop(IOThread *iothread) { - IOThread *iothread; - - iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); - if (!iothread || !iothread->ctx) { - return 0; + if (iothread->stopping) { + return; } iothread->stopping = true; aio_notify(iothread->ctx); @@ -94,6 +91,17 @@ static int iothread_stop(Object *object, void *opaque) g_main_loop_quit(iothread->main_loop); } qemu_thread_join(&iothread->thread); +} + +static int iothread_stop_iter(Object *object, void *opaque) +{ + IOThread *iothread; + + iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); + if (!iothread || !iothread->ctx) { + return 0; + } + iothread_stop(iothread); return 0; } @@ -108,7 +116,7 @@ static void iothread_instance_finalize(Object *obj) { IOThread *iothread = IOTHREAD(obj); - iothread_stop(obj, NULL); + iothread_stop(iothread); qemu_cond_destroy(&iothread->init_done_cond); qemu_mutex_destroy(&iothread->init_done_lock); if (!iothread->ctx) { @@ -328,7 +336,7 @@ void iothread_stop_all(void) aio_context_release(ctx); } - object_child_foreach(container, iothread_stop, NULL); + object_child_foreach(container, iothread_stop_iter, NULL); } static gpointer iothread_g_main_context_init(gpointer opaque) -- 2.7.4