From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5341C433F5 for ; Tue, 5 Oct 2021 14:59:10 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9453361373 for ; Tue, 5 Oct 2021 14:59:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9453361373 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:43858 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mXluP-0004FF-Je for qemu-devel@archiver.kernel.org; Tue, 05 Oct 2021 10:59:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53808) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXlXy-0004Yz-HF for qemu-devel@nongnu.org; Tue, 05 Oct 2021 10:35:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21695) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXlXw-0005Wm-Cp for qemu-devel@nongnu.org; Tue, 05 Oct 2021 10:35:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633444555; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bZaaG8O81IlKfFB8i5VaL1pQdWPfyEk6LSOepzHE6uc=; b=H8jlRrMhnlSxsdqo5ZC1TCGrv16momuwX/2dfldgwJTFNgNi6M6c0vnysmYB4hGCzz+iQL hv+rZA28z8UkGUp/ZmT+u/rhwg+TwgUbW2WSCFw/yHzdAa9ECDIBWNQyJ8Nk9rNYGmiSMH 5fr1K78STW+ncDyWJgUlggwZQaVu/J0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-133-nJXsG3rDM-CF0bUO5yyZSA-1; Tue, 05 Oct 2021 10:35:54 -0400 X-MC-Unique: nJXsG3rDM-CF0bUO5yyZSA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 610F11084684; Tue, 5 Oct 2021 14:35:53 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 33D151045D05; Tue, 5 Oct 2021 14:35:52 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [RFC PATCH v2 24/25] job.h: split function pointers in JobDriver Date: Tue, 5 Oct 2021 10:32:14 -0400 Message-Id: <20211005143215.29500-25-eesposit@redhat.com> In-Reply-To: <20211005143215.29500-1-eesposit@redhat.com> References: <20211005143215.29500-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -9 X-Spam_score: -1.0 X-Spam_bar: - X-Spam_report: (-1.0 / 5.0 requ) DKIMWL_WL_HIGH=-0.066, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , Vladimir Sementsov-Ogievskiy , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , Juan Quintela , qemu-devel@nongnu.org, John Snow , Emanuele Giuseppe Esposito , Richard Henderson , Markus Armbruster , "Dr. David Alan Gilbert" , Hanna Reitz , Stefan Hajnoczi , Paolo Bonzini , Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The job API will be handled separately in another serie. Signed-off-by: Emanuele Giuseppe Esposito --- include/qemu/job.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/include/qemu/job.h b/include/qemu/job.h index 41162ed494..c236c43026 100644 --- a/include/qemu/job.h +++ b/include/qemu/job.h @@ -169,12 +169,21 @@ typedef struct Job { * Callbacks and other information about a Job driver. */ struct JobDriver { + + /* Fields initialized in struct definition and never changed. */ + /** Derived Job struct size */ size_t instance_size; /** Enum describing the operation */ JobType job_type; + /* + * I/O API functions. These functions are thread-safe, and therefore + * can run in any thread as long as they have called + * aio_context_acquire/release(). + */ + /** * Mandatory: Entrypoint for the Coroutine. * @@ -201,6 +210,28 @@ struct JobDriver { */ void coroutine_fn (*resume)(Job *job); + /* + * Global state (GS) API. These functions run under the BQL lock. + * + * If a function modifies the graph, it also uses drain and/or + * aio_context_acquire/release to be sure it has unique access. + * aio_context locking is needed together with BQL because of + * the thread-safe I/O API that concurrently runs and accesses + * the graph without the BQL. + * + * It is important to note that not all of these functions are + * necessarily limited to running under the BQL, but they would + * require additional auditing and may small thread-safety changes + * to move them into the I/O API. Often it's not worth doing that + * work since the APIs are only used with the BQL held at the + * moment, so they have been placed in the GS API (for now). + * + * All callers that use these function pointers must + * use this assertion: + * g_assert(qemu_in_main_thread()); + * to catch when they are accidentally called without the BQL. + */ + /** * Called when the job is resumed by the user (i.e. user_paused becomes * false). .user_resume is called before .resume. -- 2.27.0