From d9f252809ebb8761549f2ac5e67ece1928f42bb6 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Fri, 8 Jun 2018 11:55:07 +0800 Subject: [PATCH] monitor: more comments on lock-free elements 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 Message-Id: <20180608035511.7439-4-peterx@redhat.com> Signed-off-by: Markus Armbruster --- 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;