From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47280) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fR8Uy-00045W-4v for qemu-devel@nongnu.org; Thu, 07 Jun 2018 23:55:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fR8Uw-00070F-Qg for qemu-devel@nongnu.org; Thu, 07 Jun 2018 23:55:35 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53988 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 1fR8Uw-000707-LD for qemu-devel@nongnu.org; Thu, 07 Jun 2018 23:55:34 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2EB5C4023156 for ; Fri, 8 Jun 2018 03:55:34 +0000 (UTC) From: Peter Xu Date: Fri, 8 Jun 2018 11:55:07 +0800 Message-Id: <20180608035511.7439-4-peterx@redhat.com> In-Reply-To: <20180608035511.7439-1-peterx@redhat.com> References: <20180608035511.7439-1-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v10 3/7] monitor: more comments on lock-free elements 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 comments for both Readline and cpu_set/cpu_get helpers that they do not need the mon_lock protection. Reviewed-by: Stefan Hajnoczi Reviewed-by: Markus Armbruster Signed-off-by: Peter Xu --- monitor.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/monitor.c b/monitor.c index 0fba3ccc20..5c60bf08cc 100644 --- a/monitor.c +++ b/monitor.c @@ -206,7 +206,15 @@ struct Monitor { int suspend_cnt; /* Needs to be accessed atomically */ bool skip_flush; bool use_io_thr; + + /* + * State used only in the thread "owning" the monitor. + * If @use_io_thr, this is mon_global.mon_iothread. + * Else, it's the main thread. + * These members can be safely accessed without locks. + */ ReadLineState *rs; + MonitorQMP qmp; gchar *mon_cpu_path; BlockCompletionFunc *password_completion_cb; @@ -1311,7 +1319,7 @@ 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; @@ -1325,6 +1333,7 @@ int monitor_set_cpu(int cpu_index) return 0; } +/* Callers must hold BQL. */ static CPUState *mon_get_cpu_sync(bool synchronize) { CPUState *cpu; -- 2.17.1