From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54757) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gTiav-00024Z-AT for qemu-devel@nongnu.org; Mon, 03 Dec 2018 02:24:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gTiX5-0008Dm-Bu for qemu-devel@nongnu.org; Mon, 03 Dec 2018 02:20:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48752) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gTiX5-0008DO-4j for qemu-devel@nongnu.org; Mon, 03 Dec 2018 02:20:43 -0500 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 1600885A07 for ; Mon, 3 Dec 2018 07:20:42 +0000 (UTC) From: Markus Armbruster References: <20181029125733.14597-1-marcandre.lureau@redhat.com> <20181029125733.14597-4-marcandre.lureau@redhat.com> Date: Mon, 03 Dec 2018 08:20:34 +0100 In-Reply-To: <20181029125733.14597-4-marcandre.lureau@redhat.com> (=?utf-8?Q?=22Marc-Andr=C3=A9?= Lureau"'s message of "Mon, 29 Oct 2018 16:57:30 +0400") Message-ID: <87d0qj84al.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 3/6] char: add a QEMU_CHAR_FEATURE_GCONTEXT flag List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Dr. David Alan Gilbert" , peterx@redhat.com This one needs review by a chardev guy, with an eye on its use in the next patch. Paolo? Marc-Andr=C3=A9 Lureau writes: > The feature should be set if the chardev is able to switch > GMainContext. Callers that want to put a chardev in a different thread > context can/should check this capabilities. > > Signed-off-by: Marc-Andr=C3=A9 Lureau > --- > include/chardev/char.h | 3 +++ > chardev/char.c | 11 +++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/include/chardev/char.h b/include/chardev/char.h > index 7becd8c80c..014566c3de 100644 > --- a/include/chardev/char.h > +++ b/include/chardev/char.h > @@ -47,6 +47,9 @@ typedef enum { > QEMU_CHAR_FEATURE_FD_PASS, > /* Whether replay or record mode is enabled */ > QEMU_CHAR_FEATURE_REPLAY, > + /* Whether the gcontext can be changed after calling > + * qemu_chr_be_update_read_handlers() */ > + QEMU_CHAR_FEATURE_GCONTEXT, >=20=20 > QEMU_CHAR_FEATURE_LAST, > } ChardevFeature; > diff --git a/chardev/char.c b/chardev/char.c > index 7f07a1bfbd..b5ee58b7d2 100644 > --- a/chardev/char.c > +++ b/chardev/char.c > @@ -196,6 +196,8 @@ void qemu_chr_be_update_read_handlers(Chardev *s, > s->gcontext =3D context; > if (cc->chr_update_read_handler) { > cc->chr_update_read_handler(s); > + } else if (s->gcontext) { > + error_report("switching context isn't supported by this chardev"= ); Code smell: error_report() without returning failure. If it's truly an error, then the function should fail. We'd still need to decide how: error_report() and return -1, or error_setg(). Except if it's a programming error; then we should assert(). If it's not an error, it's probably a warning, and we should use warn_report(). > } > } >=20=20 > @@ -240,6 +242,15 @@ static void char_init(Object *obj) >=20=20 > chr->logfd =3D -1; > qemu_mutex_init(&chr->chr_write_lock); > + > + /* > + * Assume if chr_update_read_handler is implemented it will > + * take the updated gcontext into account. > + */ > + if (CHARDEV_GET_CLASS(chr)->chr_update_read_handler) { > + qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT); > + } > + > } >=20=20 > static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)