From patchwork Tue Apr 9 16:45:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony PERARD X-Patchwork-Id: 10891727 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9C7281669 for ; Tue, 9 Apr 2019 16:47:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B30B285A5 for ; Tue, 9 Apr 2019 16:47:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7F7DB2888E; Tue, 9 Apr 2019 16:47:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 382A3285A5 for ; Tue, 9 Apr 2019 16:47:38 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hDtsb-00088O-Qh; Tue, 09 Apr 2019 16:45:49 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hDtsb-00088D-1I for xen-devel@lists.xenproject.org; Tue, 09 Apr 2019 16:45:49 +0000 X-Inumbo-ID: ec6ee936-5ae6-11e9-92d7-bc764e045a96 Received: from SMTP03.CITRIX.COM (unknown [162.221.156.55]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTPS id ec6ee936-5ae6-11e9-92d7-bc764e045a96; Tue, 09 Apr 2019 16:45:47 +0000 (UTC) X-IronPort-AV: E=Sophos;i="5.60,330,1549929600"; d="scan'208";a="83137609" From: Anthony PERARD To: Date: Tue, 9 Apr 2019 17:45:35 +0100 Message-ID: <20190409164542.30274-3-anthony.perard@citrix.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190409164542.30274-1-anthony.perard@citrix.com> References: <20190409164542.30274-1-anthony.perard@citrix.com> MIME-Version: 1.0 Subject: [Xen-devel] [PATCH 2/9] libxl: Pointer on usage of libxl__domain_userdata_lock X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Anthony PERARD , Wei Liu , Ian Jackson Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP It is currently difficult to know how/when/why the userdata lock is supposed to be used. Add some pointers to the hotplug comments. Signed-off-by: Anthony PERARD Acked-by: Ian Jackson --- tools/libxl/libxl_internal.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index 98a1ee6159..702acc6d5d 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -4500,6 +4500,12 @@ void libxl__unlock_domain_userdata(libxl__domain_userdata_lock *lock); * data store. The registry entry in libxl private data store * is "libxl-json". * Caller must hold user data lock. + * + * Other names used for this lock throughout the libxl code are json_lock, + * libxl__domain_userdata_lock, "libxl-json", data store lock. + * + * See comments about libxl__ao_device and "Algorithm for handling device + * removal" on how the libxl-json lock / json_lock can be used. */ int libxl__get_domain_configuration(libxl__gc *gc, uint32_t domid, libxl_domain_config *d_config);