Re: [PATCH 3/4] qmp: Fix thread race

[Paolo Bonzini]

On 12/13/25 01:14, Marc Morcos wrote:
@@ -346,7 +347,15 @@ static void monitor_qapi_event_emit(QAPIEvent event, QDict 
*qdict)
          }
  
          qmp_mon = container_of(mon, MonitorQMP, common);
-        if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
+        do_send = false;
+
+        WITH_QEMU_LOCK_GUARD(&mon->mon_lock) {
+            if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
+                do_send = true;
+            }
+        }
+
+        if (do_send) {
              qmp_send_response(qmp_mon, qdict);
          }
      }

We cannot use WITH_QEMU_LOCK_GUARD with "continue" or "break" inside, 
but we can use QEMU_LOCK_GUARD:

@@ -347,17 +346,13 @@ static void monitor_qapi_event_emit(QAPIEvent 
event, QDict *qdict)
         }

         qmp_mon = container_of(mon, MonitorQMP, common);
-        do_send = false;
-
-        WITH_QEMU_LOCK_GUARD(&mon->mon_lock) {
-            if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
-                do_send = true;
+        {
+            QEMU_LOCK_GUARD(&mon->mon_lock);
+            if (qmp_mon->commands == &qmp_cap_negotiation_commands) {
+                continue;
             }
         }
-
-        if (do_send) {
-            qmp_send_response(qmp_mon, qdict);
-        }
+        qmp_send_response(qmp_mon, qdict);
     }
 }


Let me know if this is okay for you!

Paolo