[Qemu-devel] [PATCH v7 3/4] monitor: more comments on lock-free fleids/funcs

[Peter Xu <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 <peterx@redhat.com>
---
 monitor.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/monitor.c b/monitor.c
index d6c3c08932..f01589f945 100644
--- a/monitor.c
+++ b/monitor.c
@@ -207,7 +207,16 @@ 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;
+    // other members that aren't shared
+
     MonitorQMP qmp;
     gchar *mon_cpu_path;
     BlockCompletionFunc *password_completion_cb;
@@ -1313,7 +1322,7 @@ 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 +1336,7 @@ 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