From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJdEI-0006Tt-PD for qemu-devel@nongnu.org; Fri, 18 May 2018 07:07:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJdEF-0005eV-Ix for qemu-devel@nongnu.org; Fri, 18 May 2018 07:07:22 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42948 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fJdEF-0005eM-FK for qemu-devel@nongnu.org; Fri, 18 May 2018 07:07:19 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 264DC81FE159 for ; Fri, 18 May 2018 11:07:19 +0000 (UTC) From: Peter Xu Date: Fri, 18 May 2018 19:07:03 +0800 Message-Id: <20180518110704.10849-4-peterx@redhat.com> In-Reply-To: <20180518110704.10849-1-peterx@redhat.com> References: <20180518110704.10849-1-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v6 3/4] monitor: more comments on lock-free fleids/funcs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Eric Blake , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Markus Armbruster , Stefan Hajnoczi , "Dr . David Alan Gilbert" , peterx@redhat.com Add some explicit comment for both Readline and cpu_set/cpu_get helpers that they do not need the mon_lock protection. Signed-off-by: Peter Xu --- monitor.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/monitor.c b/monitor.c index d6c3c08932..696109acb4 100644 --- a/monitor.c +++ b/monitor.c @@ -207,7 +207,14 @@ struct Monitor { int suspend_cnt; /* Needs to be accessed atomically */ bool skip_flush; bool use_io_thr; + + /* + * ReadLineState is only used in parser, and the parser of a + * monitor will only be run either in main thread or monitor + * IOThread but never both, so no lock is needed when accessing. + */ ReadLineState *rs; + MonitorQMP qmp; gchar *mon_cpu_path; BlockCompletionFunc *password_completion_cb; @@ -1313,7 +1320,7 @@ void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable, cur_mon->qmp.commands = &qmp_commands; } -/* set the current CPU defined by the user */ +/* Set the current CPU defined by the user. Callers must hold BQL. */ int monitor_set_cpu(int cpu_index) { CPUState *cpu; @@ -1327,6 +1334,7 @@ int monitor_set_cpu(int cpu_index) return 0; } +/* Callers must hold BQL. */ static CPUState *mon_get_cpu_sync(bool synchronize) { CPUState *cpu; -- 2.17.0